Poststreptococcal Crescentic Glomerulonephritis in a Kidney Transplant Recipient (KTR)

Introduction: Postinfectious glomerulonephritis(PIGN) is rarely reported among KTRs. When it occurs, allograft loss may occur in up to 60% of cases. Case Description: A28-year-old man with IgA nephropathy received a living related kidney transplant & presented 11 months after with right leg group A beta-hemolytic streptococci cellulitis. He was treated with cephalexin and had stable allograft function at the time (baseline sCr 1.8-2mg/dL). Four weeks later, he presented with hypertension, nausea, vomiting, tea-colored urine, & oliguria. sCr was 3.82mg/dL & increased to 5.57mg/dL after 3 days. Urinalysis revealed RBC >20/hpf, protein 3+, with a urine protein/creatinine ratio 6.2 g/g. Blood cultures were negative. ASO & antiDNAse B titers were elevated (541 IU/mL & 3180 U/mL), with low C3(39 mg/dL) & normal C4. Kidney biopsy showed cellular crescents involving 50% of glomeruli, fibrinoid necrosis, & endocapillary neutrophilic infiltration. IF revealed granular glomerular capillary wall & mesangial staining for IgG (2-3+), C3 (4+), and C4D (2-3+), with no staining for IgA. He needed 2 sessions of hemodialysis, methylprednisolone pulse followed by a prednisone taper over 12 weeks, & an extended antibiotic course for 8 weeks. Kidney function returned to baseline & C3 levels normalized after 4 weeks. Discussion: KTRs are at increased risk for infections but reports of PIGN remain low & to our knowledge, only 2 other cases of Streptococcus related PIGN in KTRs have been reported. Antibiotics are the mainstay of therapy & there is no data supporting steroids use. Our patient had a RPGN with crescents involving 50% of the glomeruli which prompted steroid therapy. Despite an initial need for dialysis, he eventually recovered kidney function, which highlights the importance of early histological diagnosis & aggressive management, including steroids, when crescents are present, & infection is controlled.