Kidney damage in patients with multiple myeloma associated with light chain deposition disease and C3 glomerulopathy

Background. Kidney dysfunction is a common manifestation of multiple myeloma (MM). Kidney damage in MM is most often associated with cast nephropathy; however, rarer forms such as light chain deposition disease (LCDD) and C3 glomerulopathy (C3 GP) also occur. According to several studies, patients with these forms of kidney damage more frequently develop end-stage renal disease and have a worse prognosis for kidney function recovery.

Aim. To evaluate the efficacy of induction therapy with targeted drugs followed by consolidation with high-dose melphalan and autologous hematopoietic stem cell transplantation (auto-HSCT) in patients with multiple myeloma and nephropathy associated with LCDD and C3 GP.

Materials and methods. Medical data from 3 patients with MM and nephropathy caused by LCDD (2 cases) and C3 GP (1 case) who received induction therapy courses followed by auto-HSCT were retrospectively analyzed.

Results. At disease onset, impaired kidney function with reduced glomerular filtration rate was detected in all 3 patients; 1 case presented with anuria. All patients received renal replacement therapy (RRT). After induction, complete hematologic response (CR) was achieved in 2 patients and very good partial response in 1 patient with MM and C3 GP. RRT sessions were discontinued in 2 out of 3 cases. On the 100th day after auto-HSCT, hematologic CR persisted in 2 patients with LCDD; in the C3 GP case, the response deepened to stringent CR. All patients achieved renal response, with no need for RRT. During long-term follow-up (23-82 months), 1 patient maintained the achieved response, while 2 patients relapsed at 2,5 and 2 years post-auto-HSCT, respectively.

Conclusion. MM patients with LCDD- or C3 GP-associated nephropathy exhibit severe kidney dysfunction, often requiring RRT, necessitating thorough evaluation in the absence of typical cast nephropathy features. Comprehensive therapy including auto-HSCT in young, fit MM patients with LCDD- or C3 GP-associated nephropathy enables deep hematologic response and improves renal function.