TRIPLE THREAT, DOUBLE THE TROUBLE? MARGINAL ZONE LYMPHOMA WITH CONCURRENT ANCA AND ANTI-GBM POSITIVITY
Jolene Zhuo Lin Ng1, Yong Sul Kim1, William James1, Manickavasagam Venkat1, Sanjeev Baweja1, Jagadeesh Kurtkoti2, Dakshina Murthy Divi2, Victoria Sasongko1 1Lismore Base Hospital, Northern New South Wales Local Health District, NSW, Australia2Gold Coast University Hospital, Gold Coast Hospital and Health Service, NSW, Australia
Abstract
Background
Paraneoplastic ANCA-associated vasculitis (AAV) is an uncommon presentation of haematological malignancies. It has been postulated that AAV is triggered by misdirected immune responses and overall immune dysregulation from the breakdown of usual surveillance mechanisms.
Case Report
A 58-year-old Caucasian female being investigated for subacute myalgias was found to be in acute renal failure (serum creatinine of 499mmol/L). Initial workup revealed P-ANCA positivity with a serum MPO titre of >222 IU/mL and elevated serum anti-GBM antibody titre of 80.3 CU. Serum electrophoresis also demonstrated an elevated total immunoglobulin M of 8.04g/L with a monoclonal IgM Lambda predominance, kappa/lambda free light chains ratio of 0.05 (2110mg/L to 101mg/L). Renal biopsy showed pauci-immune glomerulonephritis and marked interstitial inflammation composed of monotonous population of small lymphocytes and scattered plasma cells (predominantly CD20+ B cells) suspicious for a low-grade B cell lymphoma. There were active crescents in 3/5 viable glomeruli (and 8 obsolete glomeruli). There was equivocal IgG linear staining to the glomerular basement membrane (1+). She was initially treated with IV Methylprednisolone and plasma exchange given concurrent anti-GBM positivity. A subsequent bone marrow biopsy demonstrated CD20 staining on approximately 70% of cells consistent with a B-cell lymphoproliferative disorder, most likely Marginal Zone Lymphoma. Her eventual treatment is R-CD (Rituximab-Cyclophosphamide-Dexamethasone), resulting in marginal improvement in her light chain ratio and MPO antibody. She remains dialysis-independent 8 months later with serum creatinine of 467umol/L. It has been postulated that B-cell clonal proliferation from her lymphoma is the driver of the development of MPO and anti-GBM antibodies.
Conclusion
Renal-limited AAV can occur during the course or prior to malignancies and continues to pose a complex diagnostic and therapeutic challenge.
Biography
Dr Jolene Zhuo Lin Ng is a final year Renal Advanced Trainee currently working at Liverpool Hospital, New South Wales, Australia. She has special interests in area of obstetric medicine, glomerulonephritis and hypertension.