PLA2R1 and focal segmental glomerulosclerosis: This case represents the first report of PLA2R-positive adult MCD complicated by active pulmonary tuberculosis (TB) and systemic osteoarthropathy, highlighting the potential for chronic infection to induce PLA2R antibodies through inflammatory activation or molecular mimicry.<h4>Patient concerns</h4>A 73-year-old male with 7-year steroid-dependent nephrotic syndrome developed pulmonary TB and systemic osteoarthropathy during immunosuppressive therapy.<h4>Diagnoses</h4>Serial renal biopsies confirmed MCD/focal segmental glomerulosclerosis (FSGS) without membranous nephropathy features.