Dr JOCELYN SHAN1,2, Dr ZAKARIYA KANAAN2, A/Prof MUHAMMAD M JAVAID1,3,4
1South West Healthcare, Warrnambool, Australia, 2St Vincent’s Hospital, Melbourne, Australia, 3Monash University, , Australia, 4Deakin University, , Australia
Background
Immunoglobulin A Nephropathy (IgAN) is generally a slowly progressive disease, with less than 10% of patients presenting with rapidly progressive glomerulonephritis (RPGN). We report a rare case of severe crescentic IgAN with positive circulating anti-neutrophil cytoplasmic autoantibodies (ANCA).
Case Report
A sixty-four-year-old female presented with acute kidney injury (AKI) and peripheral oedema on a background of type 2 diabetes mellitus, hypertension, sarcoidosis, monoclonal gammopathy of undetermined significance (MGUS), and stage 3B chronic kidney disease (CKD).
Serum creatinine peaked at 404μmol/L with an eGFR of 10ml/min/1.73m2 during admission. Urine albumin/creatinine ratio (ACR) was 380mg/mmol, with significant microhaematuria (660 x106/L erythrocytes).
Nephrotoxic agents were withheld, and furosemide was commenced to manage fluid overload. Intravenous methylprednisolone pulse was given for suspected primary glomerular pathology.
Renal biopsy showed sixteen glomeruli, six with fibrocellular crescents. Immunofluorescence showed mesangial and capillary granular staining with IgA and C3. The diagnosis of IgAN was subsequently made.
She was commenced on prednisolone 80 mg daily and discharged. Subsequently, ANCA returned as positive with elevated anti-myeloperoxidase (MPO) titre of 7.8 AI. Autoimmune and viral screen was otherwise unremarkable.
Four weeks later, creatinine remained elevated at 416μmol/L, with urine ACR 398mg/mmol. Based on poor steroid response, crescents on biopsy, and ANCA positivity, she was treated with intravenous cyclophosphamide for six months. Renal function improved rapidly and at six months creatinine was 211μmol/L, urine ACR 79mg/mmol, and ANCA was negative. She was maintained on low dose azathioprine and prednisolone.
Conclusions
ANCA-positive IgAN is a rare, severe disease phenotype which has greater response to immunosuppression than ANCA-negative IgAN. Clinicians should consider measurement of ANCA in IgAN patients with RPGN, as immunosuppression therapy in this patient cohort could vastly improve outcomes.
Biography:
Dr. Jocelyn Shan is a current General Medicine Advanced Trainee at St Vincent’s Hospital Melbourne, who will be commencing Nephrology Advanced Training next year. She intends to dual train, and particularly has a special interest in transplant medicine and renal bone disease.