Recurrence of membranoproliferative glomerulonephritis post transplant - Is this mere recurrence of pattern or recurrence of disease?

Recurrence of membranoproliferative glomerulonephritis (MPGN) is seen in 1965% cases of postrenal transplant resulting in graft loss in up to 35-50% of cases. A 31-year-old female, after 1% years on maintenance hemodialysis, underwent ABO compatible deceased donor kidney transplantation with basiliximab induction. During the immediate posttransplant period, the patient had delayed graft function, but achieved nadir creatinine of 0.9 mg/dL by 10 days. Nine months posttransplant, the patient developed fever, anasarca, and decrease in urine output with albuminuria 3+, active sediments in urine, serum creatinine 3.5 mg/dL, 24-h urine protein 7.5 g, and low C3. The patient underwent graft biopsy. Subsequently, the patient received pulse steroid for three days and five sessions of plasmapheresis. Renal biopsy report was suggestive of MPGN with focal crescents and acute tubular necrosis. Immunofluorescence showed Ig G3+, C3 3+, к 3+, and negative for λ or other immunoglobulins or complements. As her native kidney disease was immune-complex-mediated MPGN with no light chain restriction, paraffin tissue of the native kidney was reexamined for light chain restrictions by immunoperoxidase method, but did not show light chain restriction. The patient underwent extensive workup for paraproteinemias, but results were negative. Subsequently, she received four doses of bortezomib. The patient's serum creatinine got reduced to 0.8 mg/dL and proteinuria reduced to 800 mg/day. Our case is unique as we were not able to demonstrate monoclonal deposits in native kidney sample although there was recurrence of MPGN with monoclonal light chain deposits post transplant. Our findings emphasize the need for thorough evaluation of paraproteinemias in patients with idiopathic MPGN even in the absence of light chain deposition in biopsy.