Z THET1,2, T HAN1,2, C HAN1,D JAMA3, M WIN3
1Department of Nephrology, Central Queensland Hospital and Health Service, Rockhampton, Australia, 2University of Queensland, Rural Clinical School, Rockhampton, Australia, 3Department of Haematology, Central Queensland Hospital and Health Service, Rockhampton, Australia
Background: Extramedullary/extranodal manifestations of chronic lymphocytic leukemia(CLL) are rare and they can occur with or without the presence of systemic CLL. Renal biopsies are rarely performed in patients with CLL and little is known about the mechanisms causing renal pathology in CLL. There is no standard of care in such patients.
Case Report: A 78 year old female was diagnosed with Binet Stage B CLL with trisomy 21 and IgM paraproteinaemia more than a decade ago. She had been on watchful waiting without any treatment for her CLL. In 2016, her eGFR declined gradually to 26ml/min/1.73m2. Urine examination showed microscopic glomerular haematuria and proteinuria (8g/day). Renal ultrasound, complement results, screening tests for infections, autoimmune diseases and cryoglobulinemia were normal. Renal Biopsy showed acute membranoproliferative glomerulonephritis (MPGN) with mixed lymphocytic infiltrate of aberrant B cells and reactive lymphocytes with no cytological atypia. There is clumpy focal staining for IgG, IgM, C3, C1q and light chains (lambda>kappa) in the glomeruli. The RCVP (Rituximab, Cyclophosphamide, Vincristine, Prednisolone) chemotherapy regimen was given for 6 cycles with omission of Vincristine in the last 2 cycles. Restaging marrow post treatment showed good partial response. Subsequently, her renal function was normalised to baseline (eGFR 62ml/min/1.73m2) with resolution of proteinuria. Bone marrow examination repeated 2 months after her chemotherapy showed good partial response.
Conclusion: Deposition of monoclonal immunoglobulins especially IgM secreted by leukemia B cells may cause MPGN. Kidney biopsy can provide important information for diagnosis and therapeutic guidance. Renal dysfunction due to CLL can be reversed by treating the underlying CLL.
Dr Zaw Thet is a full time Nephrologist from Central QLD Renal Service. He is also a Director of Physician Education and a member of Central QLD Clinical Senate. He is a leading investigator of local and state research projects.