Remission of light chain proximal tubulopathy in IgG λ-type multiple myeloma by lenalidomide and dexamethasone therapy
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Light chain proximal tubulopathy is a rare manifestation of monoclonal gammopathy. A 73-year-old Japanese woman was noted to have urinary protein and hypertension on health examination and visited the regional clinic. She was noted to have IgG λ M protein and suspected of multiple myeloma. She was referred to us with massive proteinuria (7.5 g/g creatinine) and Bence Jones proteinuria without renal dysfunction. A renal biopsy revealed no glomerular abnormalities, but a tubular cast was observed partially in tubules without tubular atrophy or a crystalline structure. Direct Fast Scarlet staining was absent both in glomerulus and vascular wall. Immunofluorescence revealed λ light chain (LC) staining in the proximal tubules. Electron microscopy revealed nonspecific findings including increased lysosomes with irregular contours and mottled appearance. A bone marrow biopsy revealed plasma cell proliferation (35%) and multiple myeloma immunoglobulin G λ type. She showed progressive anemia and decrease of eGFR with elevated level of urinary β-2 microglobulin. She was treated with lenalidomide + dexamethasone (Ld). With Ld therapy, she achieved hematologic and nephrologic remission reducing the free LC, λ/κ ratio, urinary protein level, and urinary β-2 microglobulin level.
KeywordsLight chain proximal tubulopathy Multiple myeloma IgG lambda M protein Lenalidomide
We thank Takuya Okamura, department of pathology for immunostaining and Matsuo Jinnai, Collaborative Research Center for electron microscopy.
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Conflict of interest
All authors declare no competing interests.
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This article does not contain any studies with human participants performed by any of the authors.
Informed consent was obtained from participants included in the article.
- 3.Nasr SH, Valeri AM, Sethi S. Clinicopathologic correlations in multiple myeloma: a case series of 190 patients with kidney biopsies. 2012;5+:786–794.Google Scholar
- 5.Herrera GA. Proximal tubulopathies monoclonal light chain mediated (proximal light chain tubulopathy). In: Jennette JC, editor. Heptinstall’s pathology of the kidney, 7th ed. Philadelphia: Wolters Kluwer; 2015. pp. 959–63.Google Scholar
- 12.Aucounturier P, Bauwens M, Khamlichi AA, Denoroy L, Spinelli S, Touchard G, Preud’homme JL, Cogné M. Monoclonal Ig L chain and L chain V domain fragment crystallization in myeloma-associated Fanconi syndrome. J Immunol. 1993;150:3561–8.Google Scholar
- 18.Furukawa M, Ohkawara H, Ogawa K, Ikeda K, Ueda K, Nakamura AS, Ito M, Imai J, Yanagisawa Y, Honma R, Watanabe S, Waguri S, Ikezoe T, Takahashi H. Autocrine and paracrine interactions between multiple myeloma cells and bone marrow stromal cells by growth arrest-specific gene 6 cross-talk with interleukin-6. J Biol Chem. 2017;292:4280–92.CrossRefGoogle Scholar
- 19.Kimura S, Ohkawara H, Ogawa K, Tanaka M, Sano T, Shirado HK, Takahashi H, Ueda K, Nakamura AS, Matsumoto H, Kazama JJ, Hashimoto Y, Ikezoe T. Lenalidomide as a beneficial treatment option for renal impairment caused by light chain deposition disease: a case series. Intern Med Adv Publ. https://doi.org/10.2169/internalmedicine.1018-18.