A CASE OF IGA-DOMINANT INFECTION-RELATED GLOMERULONEPHRITIS (IRGN)
Jolene Zhuo Lin Ng1, Andrea Huang1, William James1, Sanjeev Baweja1, Victoria Sasongko1, Jessica Reagh1, Venkat Manickavasagam1 1Lismore Base Hospital, Northern New South Wales Local Health District, NSW, Australia
Abstract
Background
Immunoglobulin A (IgA) dominant infection-related glomerulonephritis (IRGN) is an immune complex mediated glomerulonephritis typically presenting with rapidly progressive renal failure. It is associated with skin or bacterial infections, in particular staphylococcus infections. It has been postulated that bacterial superantigens could induce overactivation of the immune system with downstream activation of T and B cells with expression of IgA.
Case Report
A 50-year-old man with a history of Klinefelter’s Syndrome and chronic lower limb lymphoedema presented with worsening right ankle cellulitis, fevers and significant myalgias despite oral antimicrobial therapy. Initial biochemistry revealed an acute kidney injury with haemoproteinuria (3+ protein). He developed worsening generalized anasarca and renal injury with a peak serum creatinine of 216mmol/L, eGFR 30mL/min and serum albumin of 15g/L. 24-hour urine protein collection revealed nephrotic range proteinuria of 7.37g/day. Serial microbiology cultures and autoimmune screen were negative. Renal biopsy revealed 42 glomeruli with 18 glomeruli (42%) showing active lesions, including 16 glomeruli with cellular crescents and 8 glomeruli with fibrinoid necrosis. Areas of tubular rupture with florid acute inflammation were seen. Plentiful neutrophils and lymphocytes were seen occluding capillary lumens. Immunofluorescence revealed dominant 2+ IgA staining with 1+ C3, Kappa and Lambda staining. Electron microscopy showed marked proliferative changes, mesangial expansion and large electron dense deposits, favouring an immune complex mediated post infectious glomerulonephritis with a mesangiocapillary pattern. He was initially commenced on corticosteroid therapy which was rapidly weaned. His renal function and proteinuria improved 5 months post discharge with serum creatinine of 110mmol/L, eGFR 67mL/min and urine albumin/creatinine ratio of 65.5mg/mmol.
Conclusions
IgA-dominant IRGN is an increasingly recognized entity with its mainstay of treatment remains eradication of underlying infection.
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.