A SUCCESSFUL TREATMENT OF IMMUNOTACTOID GLOMERULOPATHY IN A PATITNT WITH MULTIPLE MYELOMA

Abstract

ITG (immunotactoid glomerulopathy) cases in patients with multiple myeloma (MM) are extremely rare. We present a clinical case of a patient with MM Gκ who developed nephrotic syndrome, macrohematuria and acute kidney injury. Kidney biopsy revealed microtubules in glomerular basement membrane 19 nm in diameter, organized in bundles. The patient was treated with bortezomib, cyclophosphamide and  dexamethasone (BorCyDex) and  achived complete remission after  6 cycles of therapy with a complete renal  function recovery. Repeated renal  biopsy has  revealed a complete resorption of the deposits. Later the patient has  received autologous hematopoietic stem cells  transplantation (auto-HSCT). After 2 years, an immunochemical relapse of MM has  developed. Nephropathy signs have appeared 4 years after  auto-HSCT, ITG was diagnosed again on kidney biopsy during MM relapse with microtubules 11-12 nm in diameter. A special characteristic of our case was excessive glomerular infiltration by the lymphoid cells  with capillary lumen  obstruction. We consider the build-up of lymphoid cells  in the glomerulal capillaries lumen  as a special variant  of renal  tumor lesion  in MM. Lymphoid cells  had  signs of plasmatization. Bundles of microtubules, similar to the deposits in kidneys, were revealed in some of lymphoid cells. The data obtained confirm that microtubules are formed in plasma cells that situated in the lumen  of glomerular capillary vessels and later migrate into renal structures.