Strength and nature of the evidence Only one RCT exists, an underpowered single-center trial of just 17 patients comparing PLEX plus immunosuppression versus immunosuppression alone; KDIGO rates the overall quality of evidence as low. [1] Observational/historical-control data drive the recommendation: early mortality fell from ~47% (untreated) to ~8.5% with PLEX plus immunosuppression, and 5-year patient survival now exceeds 90%. [1] Kidney survival improvement: 5-year kidney survival rose from ~25% to ~50% since 2007, attributed to earlier diagnosis and higher proportion treated with PLEX. [1] KDIGO 2021 recommendation (1C) Initiate cyclophosphamide + glucocorticoids + plasmapheresis in all patients with anti-GBM GN, except those who are simultaneously (1) dialysis-dependent at presentation, (2) have 100% crescents or >50% global glomerulosclerosis on adequate biopsy, and (3) lack pulmonary hemorrhage. Patients with alveolar hemorrhage should receive PLEX regardless of renal status, as it is life-saving there. [1-2] Start empirically without delay (within 24 hours) when anti-GBM disease is suspected, before biopsy confirmation. [1][4] Practical protocol Frequency/duration: Daily (or near-daily) single-volume exchanges, typically for 2–3 weeks, continued until anti-GBM antibodies are no longer detectable. [1-2] Replacement fluid: Albumin is generally sufficient, but use fresh frozen plasma (or albumin followed by FFP at the end) in patients with alveolar hemorrhage or recent kidney biopsy to reduce bleeding risk. [1][4] Continuation: Extend if alveolar hemorrhage persists or antibody titers fail to fall or rebound after withdrawal. [2] Prognostic caveats Presenting creatinine drives renal outcome: SCr <5.7 mg/dl → ~95% and ~91% kidney survival at 1 and 5 years; SCr >5.7 mg/dl (non-dialysis) → 82% and 50%; dialysis-dependence at presentation portends poor renal recovery. PLEX is most clearly beneficial in patients with independent kidney function at presentation. [1-3] Selected severe cases may still recover: Case reports describe early, intensive/frequent plasmapheresis continued to complete antibody clearance rescuing kidney function even in anuric patients with high crescent burden, suggesting individualized aggressive treatment can occasionally be worthwhile despite poor-prognosis features. [5] Double-positive (anti-GBM + ANCA) patients should receive PLEX and, unlike classic anti-GBM disease, warrant maintenance immunosuppression given higher relapse risk. [1][3] Emerging therapy: Imlifidase (IgG-degrading enzyme of S. pyogenes) rapidly cleaves circulating IgG including anti-GBM antibodies and is under investigation, though evidence for renal recovery in dialysis-dependent disease remains unestablished; rituximab as an alternative to cyclophosphamide is not yet supported by evidence.