Infusion of autologous bone marrow mononuclear cells leads to transient reduction in proteinuria in treatment refractory patients with Idiopathic membranous nephropathy

BACKGROUND: The current treatment options for idiopathic membranous nephropathy (IMN) carry significant toxicity. In this prospective, observational pilot study, we used single time infusion of bone marrow derived autologous mononuclear cells (MNCs) in adult patients with treatment refractory IMN. METHODS: Twelve patients of biopsy proven IMN who had failed a cyclical 6-month regimen of steroid and cyclophosphamide were enrolled in the study. Bone-marrow was harvested from the iliac crest and underwent processing to isolate MNCs. Cells were counted and subjected to viability testing before being infused through a peripheral vein on the same day. After the infusion, subjects were followed up monthly for the next six months. Supportive treatment including angiotensin antagonists and statins was continued throughout the study period. RESULT: The proteinuria, serum albumin and creatinine values at entry were 2.97 ± 0.6 gm/1.73 m(2)/d, 2.27 ± 1.1 gm/l and 0.9 ± 0.8 mg/dl respectively. There was a reduction in proteinuria (p < 0.0001), and increase in serum albumin (p = 0.001) at 1 month, with 64% of the subjects showing >50% reduction in proteinuria. However, the response was ill sustained. At 6 months, only 2 patients had >50% reduction. Serum creatinine remained stable throughout the study period. No infusion related side effects were noted. CONCLUSION: Autologous mononuclear cell infusion leads to transitory reduction in proteinuria and improvement in serum albumin in treatment refractory IMN. This effect, however, is transient. Whether this can be overcome by repeated infusion of cultured mesenchymal cells needs to be investigated.