HIV and Tip-Variant FSGS

Introduction: HIV-associated nephropathy (HIVAN) is classically characterized by collapsing focal segmental glomerulosclerosis (FSGS). The case below demonstrates a case of tip-variant FSGS in the setting of HIV infection that improved with glucocorticoid therapy. Case Description: A 44-year-old man with a history of eosinophilic esophagitis presented with worsening edema in lower extremities (LE), abdomen, and face. On exam, HR 70 bpm, BP 154/91, RR 18, T 36.1C, with periorbital edema and 3+ bilateral LE edema. Work up revealed WBC 5,100 cells/uL, Hg 10.8 g/dL, Plt 291 thou/uL, Cr 2.8 mg/dL (baseline ~0.7 mg/dL ), sodium 127 mEq/L , potassium 5.2 mEq/L, CO2 20 mEq/L, albumin 1.6g/dL. Urinalysis and sediment revealed non-dysmorphic RBCs, and granular and renal tubular epithelial cell casts. Urine protein/creatinine ratio was 9.57g/g and albumin/urine creatinine ratio >4476mg/g. Serologic work up yielded a positive HIV-1 antibody, HIV RNA 55325 copies/mL and a CD4 count 386 cells/uL. Normal/negative C3, C4, ANA, anti-GBM, ANCA, PLA2R, HCV, HBV, kappa/lambda, SPEP and serum immunofixation. Patient underwent renal biopsy and discharged on diuretics and antiretroviral therapy (ART). Losartan initiated, however, limited by worsening AKI with peak creatinine of 3.6mg/dL. Renal biopsy subsequently revealed FSGS with tip lesions, no collapsing lesions. Follow up 17 days after ART initiation revealed worsening proteinuria, and patient was initiated on prednisone 60mg daily with resolution of AKI, albumin >3.0 g/dL and constant downtrend of UPCR (2.25g/g most recently). Patient currently on taper. Discussion: HIV associated kidney disease is classically described as collapsing FSGS in patients with high viral load. However, with the introduction of ART, the incidence of non-collapsing variants has increased. KDIGO describes it as FSGS-not otherwise specified (NOS) and causality is established when no other cause is identified. In a cohort of 47 biopsies, 27 had FSGS, 16 were collapsing and only 1 was tip-variant. Only two other case reports of tip-variant FSGS & HIV are reported, one showed steroid responsiveness while on ART with undetectable viral load.