MSY NG1,2, L FRANCIS3, E PILLAI4, AJ MALLETT1,2
1Kidney Health Service, Royal Brisbane and Women’s Hospital, Brisbane, Queensland; 2Faculty of Medicine, The University of Queensland, Brisbane, Queensland; 3Department of Anatomical Pathology, Pathology Queensland, Royal Brisbane and Women’s Hospital, Brisbane, Queensland; 4Haematology and Bone Marrow Transplantation Service, Royal Brisbane and Women’s Hospital, Brisbane, Queensland
Background: Paraneoplastic glomerulonephritis is rare in haematological malignancies with the majority rare and tends to manifest as minimal change disease, membranous glomerulonephritis or membranoproliferative glomerulonephritis. We present the first report of immunoglobulin A nephropathy (IgAN) and associated focal segmental glomerulosclerosis in a patient with asymptomatic low grade B-cell lymphoma.
Case Report: A 53 year old gentleman presented with nephrotic range proteinuria (urine protein creatinine ratio 662g/mol creatinine) on a background of type 2 diabetes mellitus (glycosylated haemoglobin: <6%) , hypertension, obesity (body mass index: 47.6) and degenerative spine disease. Physical examination demonstrated bipedal oedema up to the bottom third of his shins, but his jugular venous pressure was not elevated and his chest was clear to auscultation. Full blood count, electrolytes and creatinine were within normal range. Serum albumin was 32g/L. Repeated serum electrophoreses over three months showed persistent κ and λ immunoglobulin G bands in trace amounts consistent with an inflammatory or reactive pattern in the absence of inflammation. This prompted bone marrow biopsy which diagnosed a low grade B-cell lymphoma. Renal biopsy demonstrated mesangial reactivity for immunoglobulin A consistent with IgAN. Lymphoma treatment with six cycles of cyclophosphamide/ rituximab/ prednisolone led to near normalisation of urinary protein excretion (urine protein creatinine ratio: 18g/mol creatinine at 22 months post-chemotherapy).
Conclusion: Paraneoplastic IgAN can occur with a broad range of haematological malignancies regardless of stage. This case illustrates the importance of meticulous haematological system work-up for patients presenting with IgAN. Recognition of paraneoplastic IgAN and early diagnosis of associated malignancy can be life-saving.