European Cytokine Network

, Volume 28, Issue 1, pp 36–40 | Cite as

Interferon Gamma Release Assay in response to PE35/PPE68 proteins: a promising diagnostic method for diagnosis of latent tuberculosis

  • Shima Mahmoudi
  • Babak Pourakbari
  • Setareh Mamishi
Research Article


Tuberculosis control relies on the identification and preventive treatment of people who are latently infected with Mycobacterium tuberculosis (Mtb). PE/PPE proteins have been reported to elicit CD4 and/or CD8 responses either in the form of whole recombinant proteins or as individual peptides. Very few of the PE and PPE proteins have been previously tested for responses in patients with TB and healthy donors. This is the first study to evaluate the Interferon Gamma Release Assay (IGRA) after stimulation with PE35 and PPE68. The antigenspecific levels of IFN-γ following stimulation with QuantiFERON-TB gold in-tube (QFT-G-IT) antigens, and PE35 and PPE68 recombinant proteins were evaluated in 79 children and 102 adults, respectively. Using QFT-G-IT kit, latent tuberculosis infection (LTBI) was detected in 26 children (33%) and 41 adults (40%); IGRA following stimulation with PE35 and PPE68 recombinant proteins, was positive, respectively, in 36 (46%) and 32 (40.5%) children, respectively. In addition, 53 adults (52%) had positive results following stimulation with these two proteins. The sensitivity and specificity ofIGRAfollowing stimulation with recombinant PE35 in children were76%and 80%, and following stimulation with recombinant PPE68 in this group, it was 73% and 75%, respectively. Meanwhile, there is no gold standard test for LTBI. Our designed tests using PE35 and PPE68 PE/PPE proteins, two PE/PPE proteins not present in BCG vaccins, which elicit CD4 and/or CD8 responses, might be helpful for rapid diagnosis of TB and improve the detection of LTBI. However, further validation studies to determine the advantage of IGRAs using these proteins, alone or combined, are highly recommended.

Key words

Interferon Gamma Release Assay diagnostic method PE35 PPE68 


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Copyright information

© John Libbey Eurotext 2017

Authors and Affiliations

  • Shima Mahmoudi
    • 1
  • Babak Pourakbari
    • 1
  • Setareh Mamishi
    • 1
    • 2
  1. 1.Pediatric Infectious Disease Research CenterTehran University of Medical SciencesTehranIran
  2. 2.Department of Infectious Diseases, Pediatrics Center of Excellence, Children’s Medical CenterTehran University of Medical SciencesTehranIran

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