What has zinc transporter 8 autoimmunity taught us about type 1 diabetes?


Zinc transporter 8 (ZnT8), a protein highly specific to pancreatic insulin-producing beta cells, is vital for the biosynthesis and secretion of insulin. ZnT8 autoantibodies (ZnT8A) are among the most recently discovered and least-characterised islet autoantibodies. In combination with autoantibodies to several other islet antigens, including insulin, ZnT8A help predict risk of future type 1 diabetes. Often, ZnT8A appear later in the pathogenic process leading to type 1 diabetes, suggesting that the antigen is recognised as part of the spreading, rather than the initial, autoimmune response. The development of autoantibodies to different forms of ZnT8 depends on the genotype of an individual for a polymorphic ZnT8 residue. This genetic variant is associated with susceptibility to type 2 but not type 1 diabetes. Levels of ZnT8A often fall rapidly after diagnosis while other islet autoantibodies can persist for many years. In this review, we consider the contribution made by ZnT8 to our understanding of type 1 diabetes over the past decade and what remains to be investigated in future research.


Islet autoantibodies develop before the clinical onset of type 1 diabetes and are currently the principal biomarkers for identifying individuals at risk of the disease. Detection of multiple autoantibody positivity in childhood implies an 80% risk of developing diabetes within 15 years, although the rate of progressions varies from a few months to decades [1]. In 2007, zinc transporter 8 (ZnT8) autoantibodies (ZnT8A) were characterised [2] and have since been recognised [1, 3] as one of the four major islet autoantibodies, together with GAD65 autoantibodies (GADA) [4], islet antigen-2 autoantibodies (IA-2A) [5] and insulin autoantibodies (IAA) [6].

ZnT8 is encoded by SLC30A8 and the first genome-wide association study (GWAS) linking a polymorphism in this gene, on chromosome 8q24.11, with type 2 diabetes was published in 2007 [7]. The common single nucleotide polymorphism (SNP) in SLC30A8, rs13266634 (C/T), causes a non-synonymous R325W modification in the protein sequence [7, 8]. The SLC30A8 genotype appears to impact insulin production [9] and rare protective loss-of-function mutations in this gene can increase insulin secretory capacity and reduce type 2 diabetes risk considerably [10, 11]. Numerous studies and a meta-analysis have shown that the rs13266634 SNP is not associated with overall type 1 diabetes risk in childhood [12]. However, data from the German prospective cohort studies BABYDIAB and BABYDIET suggested that SLC30A8 may influence age at onset of diabetes and rate of progression within predisposed individuals, perhaps by its effect on insulin production [13, 14]. In this review, we consider questions concerning the autoimmune response to ZnT8 in type 1 diabetes that remain to be answered (summarised in Table 1).

Table 1 A summary of important unanswered questions about the immune response to ZnT8 in type 1 diabetes

The structure and function of ZnT8

A member of the zinc transporter family, ZnT8 is highly expressed in the pancreatic beta cells, where it is the most abundantly expressed zinc transporter [15]. Like other major autoantigens in type 1 diabetes, ZnT8 has high beta cell specificity and is localised to insulin secretory granules (Fig. 1a). ZnT8 is important for beta cell function, through its role in supplying zinc ions (Zn2+) for insulin storage and biosynthesis [16]. ZnT8 is a 369-amino acid polytopic transmembrane protein with cytoplasmic N- and C- terminal tails (Fig. 1b) [11, 17].

Fig. 1

(a) Schematic diagram of the pancreatic islet beta cell illustrating the locations of the major antigens that autoantibodies recognise: GAD65, islet antigen-2 (IA-2), insulin and the zinc transporter ZnT8. IA-2, insulin and ZnT8 are found within insulin secretory granules but GAD65 is found within synaptic-like microvesicles within the beta cell. (b) The structure of the transmembrane protein ZnT8, which is embedded within insulin secretory granule membranes. The C- and N-terminals are cytosolic but the transmembrane domains (numbered 1–6) include three luminal regions, which are expressed extracellularly during insulin granule exocytosis. Adapted from [2]. Copyright 2007 National Academy of Sciences. (c) The codons for the major allele and the SNPs in SLC30A8, which encodes ZnT8. These SNPs determine protein sequence at amino acid (aa)325 in the C-terminal of ZnT8. The major allele (encoding R325) is associated with increased risk of type 2 diabetes; however, in type 1 diabetes, this SNP influences autoantibody specificity to ZnT8 and can aid risk stratification of disease progression. MAF, minor allele frequency. This figure is available as part of a downloadable slideset

The development of the ZnT8A immune response

The structure of ZnT8 suggests that less than half of the protein is accessible to immune surveillance and this may explain why ZnT8 is a target of autoimmune attack in type 1 diabetes. The whole protein or fragmented peptides are most likely to be accessible to the immune system upon beta cell death, although following granule exocytosis, during insulin secretion, the luminal transmembrane domains are exposed extracellularly [18].

Initiation of ZnT8 autoimmunity

At diagnosis, IAA, IA-2A and GADA are associated with specific HLA class II alleles contained within type 1 diabetes risk genotypes [19, 20]. In contrast, ZnT8A have not shown consistent HLA class II associations [21], except with DQ6.4 in individuals with type 1 diabetes [22]. They are, however, associated with high diabetes risk (i.e. DR3/DR4) in first-degree relatives. Epitope scanning identified more putative ZnT8 epitopes for HLA-DQ2 than for -DQ8 or -DQ6.4 [23]. An intermediate binding epitope for HLA-DQ2 was predicted to bind W325 but not R325, suggesting that this may contribute to differences in central tolerance for ZnT8. However, regardless of DQ type, people with diabetes had a higher frequency of proinflammatory ZnT8-specific CD4+ T cells than age- and HLA-matched non-diabetic individuals [24].

The predisposing HLA class I A*24 allele was negatively associated with presence of ZnT8A at and before diagnosis when age at onset was accounted for [25, 26]. Studies of ZnT8 epitopes for CD8+ T cells have focused on the better-characterised HLA-A*2. There is evidence that CD8+ T cells recognise a range of ZnT8 peptides across the transmembrane/loop and C-terminal regions in individuals with diabetes [27,28,29]. This could suggest previous epitope spreading but may also reflect the technical challenge of detecting and characterising antigen-specific T cell responses ex vivo. The number and phenotype of ZnT8-specific T cells identified in people with and without diabetes appear to be similar but functional differences have been identified, such as greater ZnT8-stimulated IFN-γ secretion by isolated CD8+ T cells from people with diabetes [30]. In the pancreases of people who had type 1 diabetes, compared with type 2 diabetes or no diabetes, more ZnT8-specific CD8+ T cells were present, suggesting that ZnT8-specific lymphocytes home to the pancreas.

ZnT8 as an autoantigen

Humoral islet autoimmunity can develop in children as young as 6 months of age with a peak incidence of seroconversion at 2–3 years and a probable second peak in puberty [1]. The first autoantibodies to develop in young children are typically IAA and/or GADA and, therefore, insulin and GAD65 are often regarded as primary targets of autoimmunity. In contrast, IA-2A and ZnT8A are rarely the only islet autoantibodies identified at primary seroconversion; data for ZnT8A are, however, more limited [2, 14]. Although ZnT8A can be detected close to initiation of autoimmunity, ZnT8A and IA-2A typically arise later in prediabetes and are more common in adolescents at diagnosis. Similarly, in mice, transfer of ZnT8 C-terminal-specific CD4+ T cells only caused diabetes if insulitis was present. Additionally, ZnT8-specific CD4+ T cells were only found in pancreas and lymph nodes of mice in advanced disease [31], supporting the observation that antigen spreading to ZnT8 is characteristic of the developing autoimmune response.

Most of the mature ZnT8A responses recognise the C-terminal of the protein and only 10% recognise the N-terminal [3]. Within the C-terminal, ZnT8A can be specific to amino acid 325 of ZnT8 (Fig. 1c) and this specificity is defined by the SLC30A8 polymorphism rs13266634 [32]. Hence, individuals with the CC genotype (R325) rarely develop ZnT8 tryptophan-specific autoantibodies (ZnT8WA) and individuals with the TT genotype (W325) rarely develop ZnT8 arginine-specific autoantibodies (ZnT8RA). Competitive displacement experiments show that ZnT8A are truly specific for R325 or W325 [33]. Thus, individuals respond to endogenous ZnT8 protein determined by their own genome. This has not been as easy to demonstrate for the other islet antigens because they lack an amino acid polymorphism with such an obvious influence on the autoantibody response. In several populations, ZnT8A appear to cross-react with a viral protein from Mycobacterium avium subsp. paratuberculosis (e.g. [34]) and around 50% of ZnT8A-positive individuals have antibodies recognising epitopes independent of amino acid 325 [32]. Therefore, molecular mimicry could be a contributing factor in the initial response to ZnT8 but more work is needed to evaluate this.

For other islet autoantibodies, epitope spreading has been demonstrated to occur during progression, and identification of epitopes indicative of later stages of disease has improved the specificity of these markers [35, 36]. Investigations into ZnT8 epitope autoantibody responses have focused on samples taken close to disease onset. In addition to the well-characterised amino acid 325R/W polymorphism, a second SNP, rs16889462 (G/A) which encodes Q325, has also been identified but is present in <1% of Europeans. A conformational ZnT8A epitope (dependent on R332, E333, K336 and K340 but independent of R325) [37] was characterised by comparing human and mouse chimeric ZnT8 proteins. The importance of conformational epitopes to ZnT8A responses is also supported by the observation that linear 15 amino acid ZnT8 peptides were insufficient to displace ZnT8A [38]. If epitopes of ZnT8A associated with higher risk of diabetes could be identified, these would aid prediction but the pattern of epitope-specific responses before diagnosis has not so far proved useful for risk stratification.

Predicting diabetes using ZnT8A

Wenzlau et al first described ZnT8A in 2007; analysis of 43 individuals at high genetic risk followed prospectively showed that ZnT8A could stratify risk in those positive for IAA, GADA or IA-2A alone [2]. Subsequently, the prospective birth-cohort study BABYDIAB also showed that ZnT8A aid prediction of disease in the presence or absence of other islet autoantibodies [14]. The much larger TrialNet dataset confirmed these findings and concluded that screening for ZnT8A should be included in prediction and prevention studies [39]. Several studies have shown that combined testing for IA-2A and ZnT8A identifies relatives who progress rapidly to disease in the most cost-effective way [40,41,42]. The contribution of ZnT8A in predicting risk is likely age-dependent; as the benefit of adding ZnT8A in single-islet-autoantibody-positive individuals in the Diabetes Autoimmunity Study in the Young (DAISY) was found when onset was after age 6 years [2]. In preselected relatives who were positive for other islet autoantibodies, ZnT8A only added to risk prediction in relatives who were older or who were at genetically lower risk [43]. Within those who progress slowly to disease, ZnT8A are frequently detected [44]. Most studies of risk stratification for type 1 diabetes have been conducted in relatives or individuals with high HLA class II risk. The added predictive value of ZnT8A in the general population has not been fully assessed but is ongoing (e.g. in the German Fr1da study [45]). Despite contradictions, current evidence suggests that screening for ZnT8A will provide additional information about risk, especially in older individuals in whom early autoimmune responses to insulin are waning.

Lessons learnt from ZnT8A measured at diagnosis

When ZnT8A were originally characterised, these autoantibodies increased the number of people identified as single- or multiple-antibody positive at diabetes onset. Of 133 individuals negative for IAA, GADA and IA-2A at diagnosis, 26% were positive for ZnT8A and 47% of 51 people positive for a single antibody (IAA, GADA or IA-2A) became multiple-antibody positive when ZnT8A were considered [2]. Overall, several international studies have shown that around two-thirds of children are ZnT8A positive at diagnosis [32, 46]; depending on the age group considered, the prevalence is similar to IA-2A.

The importance of ZnT8A as a biomarker in adult disease has not been fully assessed. One study from Belgium suggested that only half of those diagnosed over the age of 20 years are positive for ZnT8A [40]. This frequency is less than for GADA (65%) but comparable with IA-2A (45%) [47, 48]. The contribution of ZnT8A in populations defined as LADA is difficult to determine because the characteristics of the participants vary between studies. There is, however, evidence that screening for ZnT8A reduces the cost of discriminating monogenic diabetes [49].

ZnT8A also contributed to our observation that the natural history of humoral autoimmunity may be changing. In our UK-based study, carried out between 1985 and 2002 in individuals at disease onset, the prevalence of IA-2A and ZnT8A increased while that of GADA and IAA remained stable over time [46]. This could indicate a shift towards a more aggressive form of disease, as IA-2A and ZnT8A tend to develop later in pathogenesis. During the same time period, the incidence of diabetes in younger children has increased and the proportion of probands with high genetic risk has reduced, suggesting an increase in environmental risk [50, 51]. Lower genetic risk alleles, such as DQ6.4, could therefore have become more common in people with diabetes and contributed to increased ZnT8A. A Danish study, covering a shorter time span, found no difference in prevalence of IA-2A or GADA in individuals at the time of diagnosis (1997–2005) but ZnT8A were not measured [52].

ZnT8A as a biomarker of insulin secretory capacity post diagnosis

Another suggestion from the initial 2007 paper was that ZnT8A may be correlated with loss of insulin secretion because of ZnT8’s beta cell specificity and co-localisation with insulin [2]. Following initially successful pancreas transplant, ZnT8A have been associated with rapid onset of hyperglycaemia and eventual loss of graft function, making them a potentially important biomarker for predicting beta cell loss [53]. Ongoing beta cell death is likely to drive levels of ZnT8A [2, 54], although low-level expression in non-functional beta cells or neighbouring alpha cells may also contribute. After diagnosis ZnT8A are lost more rapidly than GADA or IA-2A [2], while T cell responses, particularly to the transmembrane domain, are also lost within a few years post diagnosis [28]. This is important because if ZnT8A, which are easier to measure than T cells, reflect insulin secretory capacity and autoreactivity, they may be useful biomarkers for assessing/monitoring the efficacy of clinical trials. In 2013, Ingemansson et al showed that in a group of 15–34 year olds with diabetes (71% type 1), high C-peptide (indicative of endogenous insulin secretion) at diagnosis correlated with prospective preservation of ZnT8A 5 years after diagnosis [55]. However, another study in individuals with younger onset showed that high positivity for ZnT8A at diagnosis was associated with lower C-peptide levels and increased insulin dose within the first 2 years after diagnosis, despite similar levels at disease onset [56]. In a minority of individuals where ZnT8A persist for decades after diagnosis, cross-sectional studies have also failed to reach a consensus about the relationship between ZnT8A and C-peptide [57,58,59]. These contrasting findings could be explained if age at diagnosis influences this association. The hypothesis that ZnT8A could be used as a biomarker for therapeutic effect is attractive but is not strongly supported by current literature.

What benefits could new assays for ZnT8A offer for prediction?

Currently, the gold standard method for measuring circulating islet autoantibodies, including ZnT8A, is RIA. Internationally, RIAs for GADA and IA-2A have been harmonised but work to standardise measurement of ZnT8A and IAA is ongoing [60]. These assays have proved highly specific and sensitive in differentiating healthy individuals from diabetic individuals and have been used to investigate C-terminal epitopes recognised by ZnT8A [2, 32]. However, this method is disadvantaged by the use of costly radioisotopes, which are tightly regulated and have limited shelf lives. The main assay development has been to create dimers (Fig. 2a) of the amino acid 268–369 sequence connected by a linking sequence to allow for the simultaneous measurement of antibodies to the most common R325 and W325 variants using RIA (Fig. 2b). In one Finnish study, addition of a Q325 probe further increased RIA sensitivity by reducing the number of antibody-negative children and adolescents [61].

Fig. 2

(a) Dimeric C-terminal probes enable measurement of ZnT8RA and ZnT8WA in a single assay [65]. Monomeric probes can also be used. (be) Multiple assay formats have been employed to measure ZnT8A. (b) The gold standard RIA, C-terminal ZnT8A assay, uses 35S-methionine and Protein A Sepharose (PAS) to immunoprecipitate ZnT8A in serum. (c) LIPS employs antigen-conjugated N-luciferase (N-Luc) and the substrate furimazine to produce a detectable luminescence signal. LIPS has a similar assay format to gold standard RIAs and provides an alternative to radioisotope use. (d) The routinely used commercial ZnT8 bridge ELISA (developed by RSR) employs plates coated in C-terminal ZnT8 and detects ZnT8A by means of a biotin–streptavidin–peroxidase system, where the peroxidase acts as a substrate to 3,3′, 5,5′-tetramethylbenzidine (TMB) to create a colourogenic reaction proportionate to the level of ZnT8A [66]. (e) A method for measuring ZnT8A responses outside of the C-terminal, through a three-dimensional format, has been proposed, creating scope for elucidating conformational epitopes. This method uses full-length ZnT8 and proteoliposomes immobilised on pGOLD platform plates. Detection of ZnT8A is through binding of anti-human IgG Fc secondary antibodies conjugated to a fluorophore. (e) Adapted from [54]. a indicates that the exact ZnT8 sequences for these assays are still being optimised (c) or are proprietary (d). aa, amino acid. This figure is available as part of a downloadable slideset

Alternative assays, such as the luciferase immunoprecipitation system (LIPS) (Fig. 2c) and ELISAs (Fig. 2d), have begun matching or even exceeding the specificity and sensitivity of RIAs for GADA and IA-2A [62, 63]. While ELISAs eliminate the requirement for radioisotopes, sample volume requirements greatly exceed those of RIAs (increased from 4 μl per test to 50 μl); LIPS assays offer similar performance to RIAs with potentially even lower sample volume requirements [64]. This would facilitate the use of small volume samples such as capillary bleeds for screening young infants and the general population.

There are assays in development that may maintain the conformational structure of ZnT8. In 2017 Wan et al developed a novel assay using full-length ZnT8 (R325) in combination with proteoliposomes (Fig. 2e) [54]. This assay has the potential to detect ZnT8A that recognise epitopes outside the C-terminal but the need to use the pGOLD platform restricts routine application of this assay due to costs. Future assay adaptations to investigate other epitopes, including post-translational protein modification, and that are validated on ‘at-risk’ individuals before disease onset may improve disease prediction and should continue to be investigated.


Measurement of ZnT8A is a cost-effective method by which to identify multiple-islet-autoantibody-positive individuals at increased risk of diabetes. This marker may be particularly useful in assigning risk from adolescence onwards. The study of ZnT8A has also given us vital evidence of a true autoimmune response and strengthens observations that the pathogenesis of the disease may change over generations. In the future, the influence of variants in SLC30A8 on the rate of progression to clinical type 1 diabetes should be clarified, especially in those with age of onset above 15 years. Why autoimmunity spreads to target ZnT8 later in the pathogenesis of the disease, why this response is lost rapidly after diagnosis and whether these changes are related to beta cell function are just some of the questions that still require clarification. Analysis of ZnT8A and T cell epitopes before diagnosis will improve our understanding of disease pathogenesis and provide better biomarkers of disease.



GAD65 autoantibodies


Insulin autoantibodies


Islet antigen-2 autoantibodies


Luciferase immunoprecipitation system


Zinc transporter 8


ZnT8 autoantibodies


ZnT8 arginine-specific autoantibodies


ZnT8 tryptophan-specific autoantibodies


  1. 1.

    Ziegler AG, Rewers M, Simell O et al (2013) Seroconversion to multiple islet autoantibodies and risk of progression to diabetes in children. JAMA 309(23):2473–2479. https://doi.org/10.1001/jama.2013.6285

    CAS  Article  PubMed Central  PubMed  Google Scholar 

  2. 2.

    Wenzlau JM, Juhl K, Yu L et al (2007) The cation efflux transporter ZnT8 (Slc30A8) is a major autoantigen in human type 1 diabetes. Proc Natl Acad Sci U S A 104(43):17040–17045. https://doi.org/10.1073/pnas.0705894104

    Article  PubMed Central  PubMed  Google Scholar 

  3. 3.

    Lampasona V, Liberati D (2016) Islet autoantibodies. Curr Diab Rep 16(6):53. https://doi.org/10.1007/s11892-016-0738-2

    CAS  Article  Google Scholar 

  4. 4.

    Baekkeskov S, Aanstoot HJ, Christgau S et al (1990) Identification of the 64K autoantigen in insulin-dependent diabetes as the GABA-synthesizing enzyme glutamic acid decarboxylase. Nature 347(6289):151–156. https://doi.org/10.1038/347151a0

    CAS  Article  Google Scholar 

  5. 5.

    Rabin DU, Pleasic SM, Palmer-Crocker R, Shapiro JA (1992) Cloning and expression of IDDM-specific human autoantigens. Diabetes 41(2):183–186. https://doi.org/10.2337/diab.41.2.183

    CAS  Article  Google Scholar 

  6. 6.

    Palmer JP, Asplin CM, Clemons P et al (1983) Insulin antibodies in insulin-dependent diabetics before insulin treatment. Science 222(4630):1337–1339. https://doi.org/10.1126/science.6362005

    CAS  Article  Google Scholar 

  7. 7.

    Sladek R, Rocheleau G, Rung J et al (2007) A genome-wide association study identifies novel risk loci for type 2 diabetes. Nature 445(7130):881–885. https://doi.org/10.1038/nature05616

    CAS  Article  Google Scholar 

  8. 8.

    Wenzlau J, Frisch L, Gardner T, Sarkar S, Hutton JC, Davidson H (2009) Novel antigens in type 1 diabetes: the importance of ZnT8. Curr Diab Rep 9(2):105–112. https://doi.org/10.1007/s11892-009-0019-4

    CAS  Article  Google Scholar 

  9. 9.

    Kirchhoff K, Machicao F, Haupt A et al (2008) Polymorphisms in the TCF7L2, CDKAL1 and SLC30A8 genes are associated with impaired proinsulin conversion. Diabetologia 51(4):597–601. https://doi.org/10.1007/s00125-008-0926-y

    CAS  Article  Google Scholar 

  10. 10.

    Flannick J, Thorleifsson G, Beer NL et al (2014) Loss-of-function mutations in SLC30A8 protect against type 2 diabetes. Nat Genet 46(4):357–363. https://doi.org/10.1038/ng.2915

    CAS  Article  PubMed Central  PubMed  Google Scholar 

  11. 11.

    Xu K, Zha M, Wu X et al (2011) Association between rs13266634 C/T polymorphisms of solute carrier family 30 member 8 (SLC30A8) and type 2 diabetes, impaired glucose tolerance, type 1 diabetes: a meta-analysis. Diabetes Res Clin Pract 91(2):195–202. https://doi.org/10.1016/j.diabres.2010.11.012

    CAS  Article  Google Scholar 

  12. 12.

    Brorsson C, Bergholdt R, Sjogren M et al (2008) A non-synonymous variant in SLC30A8 is not associated with type 1 diabetes in the Danish population. Mol Genet Metab 94(3):386–388. https://doi.org/10.1016/j.ymgme.2008.02.011

    CAS  Article  Google Scholar 

  13. 13.

    Gohlke H, Ferrari U, Koczwara K, Bonifacio E, Illig T, Ziegler AG (2008) SLC30A8 (ZnT8) polymorphism is associated with young age at type 1 diabetes onset. Rev Diabet Stud 5(1):25–27. https://doi.org/10.1900/RDS.2008.5.25

    Article  PubMed Central  PubMed  Google Scholar 

  14. 14.

    Achenbach P, Lampasona V, Landherr U et al (2009) Autoantibodies to zinc transporter 8 and SLC30A8 genotype stratify type 1 diabetes risk. Diabetologia 52(9):1881–1888. https://doi.org/10.1007/s00125-009-1438-0

    CAS  Article  Google Scholar 

  15. 15.

    Chimienti F, Devergnas S, Pattou F et al (2006) In vivo expression and functional characterization of the zinc transporter ZnT8 in glucose-induced insulin secretion. J Cell Sci 119(20):4199–4206. https://doi.org/10.1242/jcs.03164

    CAS  Article  Google Scholar 

  16. 16.

    Rutter GA, Chimienti F (2015) SLC30A8 mutations in type 2 diabetes. Diabetologia 58(1):31–36. https://doi.org/10.1007/s00125-014-3405-7

    CAS  Article  Google Scholar 

  17. 17.

    Wenzlau JM, Hutton JC (2013) Novel diabetes autoantibodies and prediction of type 1 diabetes. Curr Diab Rep 13(5):608–615. https://doi.org/10.1007/s11892-013-0405-9

    CAS  Article  Google Scholar 

  18. 18.

    Huang Q, Merriman C, Zhang H, Fu D (2017) Coupling of insulin secretion and display of a granule-resident zinc transporter ZnT8 on the surface of pancreatic beta cells. J Biol Chem 292(10):4034–4043. https://doi.org/10.1074/jbc.M116.772152

    CAS  Article  PubMed Central  PubMed  Google Scholar 

  19. 19.

    Genovese S, Bonfanti R, Bazzigaluppi E et al (1996) Association of IA-2 autoantibodies with HLA DR4 phenotypes in IDDM. Diabetologia 39(10):1223–1226. https://doi.org/10.1007/BF02658510

    CAS  Article  Google Scholar 

  20. 20.

    Hermann R, Laine AP, Veijola R et al (2005) The effect of HLA class II, insulin and CTLA4 gene regions on the development of humoral beta cell autoimmunity. Diabetologia 48(9):1766–1775. https://doi.org/10.1007/s00125-005-1844-x

    CAS  Article  Google Scholar 

  21. 21.

    Howson JM, Krause S, Stevens H et al (2012) Genetic association of zinc transporter 8 (ZnT8) autoantibodies in type 1 diabetes cases. Diabetologia 55(7):1978–1984. https://doi.org/10.1007/s00125-012-2540-2

    CAS  Article  PubMed Central  PubMed  Google Scholar 

  22. 22.

    Andersson C, Vaziri-Sani F, Delli A et al (2013) Triple specificity of ZnT8 autoantibodies in relation to HLA and other islet autoantibodies in childhood and adolescent type 1 diabetes. Pediatr Diabetes 14(2):97–105. https://doi.org/10.1111/j.1399-5448.2012.00916.x

    CAS  Article  Google Scholar 

  23. 23.

    Delli AJ, Vaziri-Sani F, Lindblad B et al (2012) Zinc transporter 8 autoantibodies and their association with SLC30A8 and HLA-DQ genes differ between immigrant and Swedish patients with newly diagnosed type 1 diabetes in the Better Diabetes Diagnosis study. Diabetes 61(10):2556–2564. https://doi.org/10.2337/db11-1659

    CAS  Article  PubMed Central  PubMed  Google Scholar 

  24. 24.

    Dang M, Rockell J, Wagner R et al (2011) Human type 1 diabetes is associated with T cell autoimmunity to zinc transporter 8. J Immunol 186(10):6056–6063. https://doi.org/10.4049/jimmunol.1003815

    CAS  Article  PubMed Central  PubMed  Google Scholar 

  25. 25.

    Long AE, Gillespie KM, Aitken RJ, Goode JC, Bingley PJ, Williams AJ (2013) Humoral responses to islet antigen-2 and zinc transporter 8 are attenuated in patients carrying HLA-A*24 alleles at the onset of type 1 diabetes. Diabetes 62(6):2067–2071. https://doi.org/10.2337/db12-1468

    CAS  Article  PubMed Central  PubMed  Google Scholar 

  26. 26.

    Ye J, Long AE, Pearson JA et al (2015) Attenuated humoral responses in HLA-A*24-positive individuals at risk of type 1 diabetes. Diabetologia 58(10):2284–2287. https://doi.org/10.1007/s00125-015-3702-9

    CAS  Article  Google Scholar 

  27. 27.

    Enee E, Kratzer R, Arnoux JB et al (2012) ZnT8 is a major CD8+ T cell-recognized autoantigen in pediatric type 1 diabetes. Diabetes 61(7):1779–1784. https://doi.org/10.2337/db12-0071

    CAS  Article  PubMed Central  PubMed  Google Scholar 

  28. 28.

    Xu X, Gu Y, Bian L et al (2016) Characterization of immune response to novel HLA-A2-restricted epitopes from zinc transporter 8 in type 1 diabetes. Vaccine 34(6):854–862. https://doi.org/10.1016/j.vaccine.2015.10.108

    CAS  Article  Google Scholar 

  29. 29.

    Scotto M, Afonso G, Larger E et al (2012) Zinc transporter (ZnT)8(186-194) is an immunodominant CD8+ T cell epitope in HLA-A2+ type 1 diabetic patients. Diabetologia 55(7):2026–2031. https://doi.org/10.1007/s00125-012-2543-z

    CAS  Article  PubMed Central  PubMed  Google Scholar 

  30. 30.

    Culina S, Lalanne AI, Afonso G et al (2018) Islet-reactive CD8+ T cell frequencies in the pancreas, but not in blood, distinguish type 1 diabetic patients from healthy donors. Sci Immunol 3:eaao4013

    Article  PubMed  Google Scholar 

  31. 31.

    Nayak DK, Calderon B, Vomund AN, Unanue ER (2014) ZnT8-reactive T cells are weakly pathogenic in NOD mice but can participate in diabetes under inflammatory conditions. Diabetes 63(10):3438–3448. https://doi.org/10.2337/db13-1882

    CAS  Article  PubMed Central  PubMed  Google Scholar 

  32. 32.

    Wenzlau JM, Liu Y, Yu L et al (2008) A common nonsynonymous single nucleotide polymorphism in the SLC30A8 gene determines ZnT8 autoantibody specificity in type 1 diabetes. Diabetes 57(10):2693–2697. https://doi.org/10.2337/db08-0522

    CAS  Article  PubMed Central  PubMed  Google Scholar 

  33. 33.

    Skarstrand H, Krupinska E, Haataja TJ, Vaziri-Sani F, Lagerstedt JO, Lernmark A (2015) Zinc transporter 8 (ZnT8) autoantibody epitope specificity and affinity examined with recombinant ZnT8 variant proteins in specific ZnT8R and ZnT8W autoantibody-positive type 1 diabetes patients. Clin Exp Immunol 179(2):220–229. https://doi.org/10.1111/cei.12448

    CAS  Article  PubMed Central  PubMed  Google Scholar 

  34. 34.

    Niegowska M, Rapini N, Piccinini S et al (2016) Type 1 diabetes at-risk children highly recognize Mycobacterium avium subspecies paratuberculosis epitopes homologous to human Znt8 and proinsulin. Sci Rep 6(1):22266. https://doi.org/10.1038/srep22266

    CAS  Article  PubMed Central  PubMed  Google Scholar 

  35. 35.

    Naserke HE, Ziegler AG, Lampasona V, Bonifacio E (1998) Early development and spreading of autoantibodies to epitopes of IA-2 and their association with progression to type 1 diabetes. J Immunol 161:6963–6969

    CAS  Google Scholar 

  36. 36.

    Williams AJ, Lampasona V, Wyatt R et al (2015) Reactivity to N-terminally truncated GAD65(96-585) identifies GAD autoantibodies that are more closely associated with diabetes progression in relatives of patients with type 1 diabetes. Diabetes 64(9):3247–3252. https://doi.org/10.2337/db14-1694

    CAS  Article  Google Scholar 

  37. 37.

    Wenzlau JM, Frisch LM, Hutton JC, Davidson HW (2011) Mapping of conformational autoantibody epitopes in ZNT8. Diabetes Metab Res Rev 27(8):883–886. https://doi.org/10.1002/dmrr.1266

    CAS  Article  PubMed Central  PubMed  Google Scholar 

  38. 38.

    Skarstrand H, Lernmark A, Vaziri-Sani F (2013) Antigenicity and epitope specificity of ZnT8 autoantibodies in type 1 diabetes. Scand J Immunol 77(1):21–29. https://doi.org/10.1111/sji.12008

    CAS  Article  Google Scholar 

  39. 39.

    Yu L, Boulware DC, Beam CA et al (2012) Zinc transporter-8 autoantibodies improve prediction of type 1 diabetes in relatives positive for the standard biochemical autoantibodies. Diabetes Care 35(6):1213–1218. https://doi.org/10.2337/dc11-2081

    CAS  Article  PubMed Central  PubMed  Google Scholar 

  40. 40.

    Vermeulen I, Weets I, Asanghanwa M et al (2011) Contribution of antibodies against IA-2β and zinc transporter 8 to classification of diabetes diagnosed under 40 years of age. Diabetes Care 34(8):1760–1765. https://doi.org/10.2337/dc10-2268

    Article  PubMed Central  PubMed  Google Scholar 

  41. 41.

    Gorus FK, Balti EV, Vermeulen I et al (2013) Screening for insulinoma antigen 2 and zinc transporter 8 autoantibodies: a cost-effective and age-independent strategy to identify rapid progressors to clinical onset among relatives of type 1 diabetic patients. Clin Exp Immunol 171(1):82–90. https://doi.org/10.1111/j.1365-2249.2012.04675.x

    CAS  Article  Google Scholar 

  42. 42.

    De Grijse J, Asanghanwa M, Nouthe B et al (2010) Predictive power of screening for antibodies against insulinoma-associated protein 2 beta (IA-2β) and zinc transporter-8 to select first-degree relatives of type 1 diabetic patients with risk of rapid progression to clinical onset of the disease: implications for prevention trials. Diabetologia 53:517–524

    Article  Google Scholar 

  43. 43.

    Long AE, Gooneratne AT, Rokni S, Williams AJ, Bingley PJ (2012) The role of autoantibodies to zinc transporter 8 in prediction of type 1 diabetes in relatives: lessons from the European Nicotinamide Diabetes Intervention Trial (ENDIT) cohort. J Clin Endocrinol Metab 97(2):632–637. https://doi.org/10.1210/jc.2011-1952

    CAS  Article  Google Scholar 

  44. 44.

    Long AE, Wilson IV, Becker DJ et al (2018) Characteristics of slow progression to diabetes in multiple islet autoantibody-positive individuals from five longitudinal cohorts: the SNAIL study. Diabetologia 61(6):1484–1490. https://doi.org/10.1007/s00125-018-4591-5

    CAS  Article  PubMed Central  PubMed  Google Scholar 

  45. 45.

    Puff R, Haupt F, Winkler C, Assfalg R, Achenbach P, Ziegler AG (2016) Early diagnosis, early care: “Fr1da” screening of children for type 1 diabetes. MMW Fortschr Med 158:65–66 [article in German]

    Article  Google Scholar 

  46. 46.

    Long AE, Gillespie KM, Rokni S, Bingley PJ, Williams AJ (2012) Rising incidence of type 1 diabetes is associated with altered immunophenotype at diagnosis. Diabetes 61(3):683–686. https://doi.org/10.2337/db11-0962

    CAS  Article  PubMed Central  PubMed  Google Scholar 

  47. 47.

    Gorus FK, Goubert P, Semakula C et al (1997) IA-2-autoantibodies complement GAD65-autoantibodies in new-onset IDDM patients and help predict impending diabetes in their siblings. The Belgian Diabetes Registry. Diabetologia 40(1):95–99

    CAS  Article  Google Scholar 

  48. 48.

    Vandewalle CL, Falorni A, Svanholm S, Lernmark A, Pipeleers DG, Gorus FK (1995) High diagnostic sensitivity of glutamate decarboxylase autoantibodies in insulin-dependent diabetes mellitus with clinical onset between age 20 and 40 years. The Belgian Diabetes Registry. J Clin Endocrinol Metab 80:846–851

    CAS  Google Scholar 

  49. 49.

    Patel KA, Weedon MN, Shields BM et al (2018) Zinc transporter 8 autoantibodies (ZnT8A) and a type 1 diabetes genetic risk score can exclude individuals with type 1 diabetes from inappropriate genetic testing for monogenic diabetes. Diabetes Care 42:e16–e17

    Article  PubMed  Google Scholar 

  50. 50.

    Gardner SG, Bingley PJ, Sawtell PA, Weeks S, Gale EA (1997) Rising incidence of insulin dependent diabetes in children aged under 5 years in the Oxford region: time trend analysis. The Bartʼs-Oxford Study Group. BMJ 315:713–717

    CAS  Article  PubMed  Google Scholar 

  51. 51.

    Gillespie KM, Bain SC, Barnett AH et al (2004) The rising incidence of childhood type 1 diabetes and reduced contribution of high-risk HLA haplotypes. Lancet 364(9446):1699–1700. https://doi.org/10.1016/S0140-6736(04)17357-1

    Article  Google Scholar 

  52. 52.

    Thorsen SU, Pipper CB, Mortensen HB, Pociot F, Johannesen J, Svensson J (2016) No contribution of GAD-65 and IA-2 autoantibodies around time of diagnosis to the increasing incidence of juvenile type 1 diabetes: a 9-year nationwide Danish study. Int J Endocrinol 2016:8350158

    Article  PubMed  Google Scholar 

  53. 53.

    Burke GW 3rd, Chen LJ, Ciancio G, Pugliese A (2016) Biomarkers in pancreas transplant. Curr Opin Organ Transplant 21(4):412–418. https://doi.org/10.1097/MOT.0000000000000333

    CAS  Article  PubMed Central  PubMed  Google Scholar 

  54. 54.

    Wan H, Merriman C, Atkinson MA et al (2017) Proteoliposome-based full-length ZnT8 self-antigen for type 1 diabetes diagnosis on a plasmonic platform. Proc Natl Acad Sci U S A 114(38):10196–10201. https://doi.org/10.1073/pnas.1711169114

    CAS  Article  PubMed Central  PubMed  Google Scholar 

  55. 55.

    Ingemansson S, Vaziri-Sani F, Lindblad U, Gudbjornsdottir S, Torn C, Diss-Study G (2013) Long-term sustained autoimmune response to beta cell specific zinc transporter (ZnT8, W, R, Q) in young adult patients with preserved beta cell function at diagnosis of diabetes. Autoimmunity 46:50–61

    CAS  Article  Google Scholar 

  56. 56.

    Juusola M, Parkkola A, Harkonen T et al (2016) Positivity for zinc transporter 8 autoantibodies at diagnosis is subsequently associated with reduced β-cell function and higher exogenous insulin requirement in children and adolescents with type 1 diabetes. Diabetes Care 39(1):118–121. https://doi.org/10.2337/dc15-1027

    CAS  Article  Google Scholar 

  57. 57.

    Richardson CC, Dromey JA, McLaughlin KA et al (2013) High frequency of autoantibodies in patients with long duration type 1 diabetes. Diabetologia 56(11):2538–2540. https://doi.org/10.1007/s00125-013-3017-7

    Article  Google Scholar 

  58. 58.

    Wang L, Lovejoy NF, Faustman DL (2012) Persistence of prolonged C-peptide production in type 1 diabetes as measured with an ultrasensitive C-peptide assay. Diabetes Care 35(3):465–470. https://doi.org/10.2337/dc11-1236

    CAS  Article  PubMed Central  PubMed  Google Scholar 

  59. 59.

    Williams GM, Long AE, Wilson IV et al (2016) Beta cell function and ongoing autoimmunity in long-standing, childhood onset type 1 diabetes. Diabetologia 59(12):2722–2726. https://doi.org/10.1007/s00125-016-4087-0

    CAS  Article  PubMed Central  PubMed  Google Scholar 

  60. 60.

    Bonifacio E, Yu L, Williams AK et al (2010) Harmonization of glutamic acid decarboxylase and islet antigen-2 autoantibody assays for national institute of diabetes and digestive and kidney diseases consortia. J Clin Endocrinol Metab 95(7):3360–3367. https://doi.org/10.1210/jc.2010-0293

    CAS  Article  PubMed Central  PubMed  Google Scholar 

  61. 61.

    Andersson C, Larsson K, Vaziri-Sani F et al (2011) The three ZNT8 autoantibody variants together improve the diagnostic sensitivity of childhood and adolescent type 1 diabetes. Autoimmunity 44(5):394–405. https://doi.org/10.3109/08916934.2010.540604

    CAS  Article  Google Scholar 

  62. 62.

    Torn C, Mueller PW, Schlosser M, Bonifacio E, Bingley PJ (2008) Diabetes antibody standardization program: evaluation of assays for autoantibodies to glutamic acid decarboxylase and islet antigen-2. Diabetologia 51(5):846–852. https://doi.org/10.1007/s00125-008-0967-2

    CAS  Article  Google Scholar 

  63. 63.

    Marcus P, Yan X, Bartley B, Hagopian W (2011) LIPS islet autoantibody assays in high-throughput format for DASP 2010. Diabetes Metab Res Rev 27(8):891–894. https://doi.org/10.1002/dmrr.1268

    CAS  Article  Google Scholar 

  64. 64.

    Liberati D, Wyatt RC, Brigatti C et al (2018) A novel LIPS assay for insulin autoantibodies. Acta Diabetol 55(3):263–270. https://doi.org/10.1007/s00592-017-1082-y

    CAS  Article  Google Scholar 

  65. 65.

    Kawasaki E, Nakamura K, Kuriya G et al (2011) Differences in the humoral autoreactivity to zinc transporter 8 between childhood- and adult-onset type 1 diabetes in Japanese patients. Clin Immunol 138(2):146–153. https://doi.org/10.1016/j.clim.2010.10.007

    CAS  Article  Google Scholar 

  66. 66.

    Dunseath G, Ananieva-Jordanova R, Coles R et al (2015) Bridging-type enzyme-linked immunoassay for zinc transporter 8 autoantibody measurements in adult patients with diabetes mellitus. Clin Chim Acta 447:90–95. https://doi.org/10.1016/j.cca.2015.05.010

    CAS  Article  Google Scholar 

Download references


The authors would like to thank K. M. Gillespie and A. J. K. Williams (University of Bristol) for their encouragement, guidance and advice about this review.


Work in the authors’ laboratories is supported by Diabetes UK and JDRF. CLW was awarded a Diabetes UK studentship (16/0005556) and AEL was awarded a Diabetes UK and JDRF RD Lawrence fellowship (18/0005778 and 3-APF-2018-591-A-N).

Author information




Both authors were responsible for drafting the article and revising it critically for important intellectual content. Both authors approved the version to be published.

Corresponding author

Correspondence to Anna E. Long.

Ethics declarations

The authors declare that there is no duality of interest associated with this manuscript.

Additional information

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Electronic supplementary material


(PPTX 483 kb)

Rights and permissions

Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Williams, C.L., Long, A.E. What has zinc transporter 8 autoimmunity taught us about type 1 diabetes?. Diabetologia 62, 1969–1976 (2019). https://doi.org/10.1007/s00125-019-04975-x

Download citation


  • Autoimmunity
  • B and T cells
  • Biomarker
  • Epitope specificity
  • Method development
  • Pathogenesis
  • Prediction
  • Review
  • SLC30A8
  • Type 1 diabetes
  • ZnT8 autoantibodies