ANCA-associated vasculitis (GPA + MPA + EGPA)

What changes during this transition

ANCA-associated vasculitis arrives in the peptide-curiosity space along three predictable vectors: 'inflammation' framing (BPC-157, LL-37), 'vascular repair' framing (TB-500), and 'immune modulation / aging' framing (thymosin alpha-1, NMN). None of these map onto what AAV actually is, and that mismatch is the load-bearing editorial point. AAV is not generic inflammation. It is a specific autoimmune disease in which ANCA antibodies — anti-PR3 in c-ANCA-positive GPA, anti-MPO in p-ANCA-positive MPA and a subset of EGPA — activate primed neutrophils against vascular endothelium. The result is small-vessel destruction in glomeruli (crescentic glomerulonephritis), pulmonary capillaries (alveolar hemorrhage), upper respiratory mucosa (sinus and tracheal disease in GPA), and peripheral nerves (mononeuritis multiplex). EGPA adds an eosinophilic and asthmatic axis, distinguishing it from GPA and MPA mechanistically and therapeutically. The modern treatment paradigm reflects four decades of trial work. Rituximab established non-inferiority to cyclophosphamide for induction in the RAVE trial (NEJM 2010) and superiority over azathioprine for maintenance in MAINRITSAN (2014) and MAINRITSAN 2 (2018), and is FDA-approved for GPA and MPA. Avacopan, an oral C5a receptor antagonist that blocks the complement amplification loop driving neutrophil priming, became the first new mechanism approved for AAV in decades following the ADVOCATE Phase 3 trial (FDA October 2021) — a paradigm shift toward steroid-sparing induction. Mepolizumab (anti-IL-5) became the first FDA-approved EGPA-specific therapy in December 2017 via the MIRRA trial, and benralizumab (anti-IL-5Rα) was shown non-inferior to mepolizumab for EGPA in the MANDARA trial (2024). The PEXIVAS trial (NEJM 2020) reshaped two long-held practices simultaneously: plasma exchange showed no mortality or ESRD benefit (a dramatic negative result against decades of pulmonary-renal syndrome practice), and reduced-dose glucocorticoid regimens proved non-inferior to standard-dose with fewer serious infections. KDIGO 2024 published updated ANCA-vasculitis kidney involvement guidelines integrating PEXIVAS and ADVOCATE data. EULAR 2023 published parallel updated recommendations. The Vasculitis Foundation serves as the primary US patient organization. Mortality has dropped from roughly 90% at two years in the pre-cyclophosphamide era to under 20% at five years modern era — a transformation driven by sequential trial evidence and disciplined immunosuppression management. What AAV remains, despite this progress, is a chronic relapsing autoimmune disease with 30-50% five-year relapse rates, substantial treatment-related morbidity (cumulative glucocorticoid exposure, hypogammaglobulinemia from sequential B-cell depletion, opportunistic infection risk on prolonged immunosuppression), and a heavy daily-life burden during induction and the first two years of maintenance. The temptation to add peptides as 'adjuncts for healing' or 'immune rebalancing' is understandable. It is also not supported by any peptide-specific trial in AAV, and several peptides commonly raised by users — LL-37 most directly (NET-autoimmunity literature places it close to AAV disease biology), but also BPC-157 with its angiogenic profile and thymosin alpha-1 with its immune-enhancing framing — interact with disease-relevant biology in ways that are theoretically the wrong direction. The editorial posture: peptides do not have a role in AAV management, and the most useful framing this library can offer is a clear-eyed account of why the standard-of-care regimen looks the way it does, what the trial evidence actually supports, and where the load-bearing clinical conversations need to happen — with the rheumatologist or nephrologist managing the immunosuppression regimen, not with a peptide clinician.