Nephrology emergency · KIMS Secunderabad
ANCA Vasculitis — When Blood Vessel Inflammation Attacks the Kidneys
ANCA-associated vasculitis is a group of autoimmune conditions in which the body's immune system produces antibodies — antineutrophil cytoplasmic antibodies (ANCA) — that attack small blood vessels throughout the body. When these vessels are in the kidneys, the result is rapidly progressive glomerulonephritis (RPGN) — one of the most urgent nephrology emergencies. A patient whose creatinine doubles in two to three weeks, who has blood and protein in the urine, and who feels acutely unwell may have ANCA vasculitis attacking the kidneys. Without treatment within days, this can progress to dialysis-dependent kidney failure — sometimes irreversibly.
ANCA vasculitis encompasses three main conditions: Granulomatosis with Polyangiitis (GPA — formerly Wegener's granulomatosis), Microscopic Polyangiitis (MPA), and Eosinophilic Granulomatosis with Polyangiitis (EGPA — formerly Churg-Strauss syndrome). All three cause small vessel inflammation and can involve the kidneys, lungs, sinuses, skin, and nervous system. GPA and MPA most commonly cause significant kidney disease. At KIMS, ANCA vasculitis with kidney involvement is managed by the glomerular disease team — Dr. Aswini Dutt T — with the full biopsy, plasma exchange, and immunosuppression capabilities required.
What ANCA is and how it damages the kidneys
ANCA are autoantibodies directed against proteins within the granules of neutrophils — primarily proteinase-3 (PR3-ANCA, predominantly in GPA) and myeloperoxidase (MPO-ANCA, predominantly in MPA and EGPA). When circulating ANCA encounter neutrophils that have been primed by infection or inflammation, they activate these neutrophils — triggering the release of toxic oxygen species and proteases that damage the endothelium of small blood vessels.
In the kidneys, this small vessel damage produces pauci-immune necrotising glomerulonephritis — inflammation and necrosis of the glomerular capillary tufts with cellular crescent formation. Crescents are a pathological marker of severe glomerular injury — they form when the Bowman's space fills with proliferating cells following rupture of the glomerular capillary wall. The proportion of glomeruli showing crescents on kidney biopsy correlates with the severity of kidney injury and the likelihood of recovery. This is why prompt kidney biopsy — to determine the extent of crescentic injury — is essential in suspected ANCA vasculitis.
Symptoms — kidney and systemic involvement
ANCA vasculitis is a multi-system disease. The kidney presentation is the most critical for immediate prognosis, but the systemic features below — particularly when several appear together — should prompt urgent ANCA testing and nephrology review.
Organ-system features that should trigger ANCA evaluation
Any one of the following — and especially several together — warrants urgent ANCA serology, urine microscopy, and kidney function testing:
Kidneys (most critical) — Rapidly rising creatinine over days to weeks · Haematuria (often macroscopic — visible blood in urine) · Heavy proteinuria · Oliguria (reduced urine output) · Fluid retention and hypertension.
Upper respiratory tract (GPA) — Chronic sinusitis not responding to antibiotics · Nasal crusting and bleeding · Saddle-nose deformity (cartilage destruction) · Otitis media · Subglottic stenosis (throat narrowing causing stridor).
Lungs — Pulmonary haemorrhage — coughing blood, breathlessness — a life-threatening emergency. Pulmonary infiltrates on chest X-ray. Haemoptysis in GPA and MPA.
Skin — Palpable purpura — small raised purple-red spots on legs and trunk · Skin ulcers.
Peripheral nervous system — Mononeuritis multiplex — painful asymmetric peripheral nerve involvement · Foot drop or wrist drop.
Constitutional — Fever · Weight loss · Fatigue · Night sweats — the non-specific features that can delay diagnosis for months.
If a patient has rapidly rising creatinine (doubling in 2 weeks), haematuria, and any of the above systemic features — particularly lung haemorrhage — this is a nephrology emergency. Call KIMS on 040-4488-5000 immediately. Pulmonary-renal syndrome (simultaneous lung haemorrhage and glomerulonephritis) is life-threatening and requires same-day hospital admission.
Diagnosis at KIMS
ANCA serology
PR3-ANCA (c-ANCA pattern on immunofluorescence) and MPO-ANCA (p-ANCA pattern) are the primary diagnostic tests. Sensitivity for active renal ANCA vasculitis exceeds 85 to 90% when both assays are used together. A negative ANCA does not exclude the diagnosis — up to 10 to 15% of ANCA vasculitis cases are ANCA-negative. Anti-GBM antibody is simultaneously measured to exclude Goodpasture syndrome (see the KIMS Goodpasture page) — the two conditions can occur together (double-positive ANCA and anti-GBM).
Kidney biopsy — the definitive diagnostic test
Ultrasound-guided kidney biopsy at KIMS followed by full three-component pathological analysis — light microscopy (LM), immunofluorescence (IF), and electron microscopy (EM) — in the KIMS NABL-accredited laboratory. The LM findings in ANCA vasculitis show necrotising glomerulonephritis with cellular crescents. The IF result is characteristically pauci-immune — little or no immunoglobulin deposition — distinguishing ANCA vasculitis from immune-complex GN (IgA, lupus, MPGN). The proportion of crescentic glomeruli on biopsy guides prognosis and treatment intensity.
Chest CT and pulmonary function
CT of the thorax assesses pulmonary infiltrates, nodules, and cavitation (GPA) or ground-glass shadowing (pulmonary haemorrhage). Pulmonary function testing including gas transfer (DLCO) can detect subclinical pulmonary haemorrhage before it becomes clinically apparent.
Additional tests
ENT assessment for sinonasal disease (GPA) · Urine red cell casts on microscopy (pathognomonic of glomerulonephritis) · Full blood count (anaemia, elevated ESR, CRP) · Complement levels (normal or elevated in ANCA vasculitis — unlike lupus and MPGN where complement is consumed).
Treatment — induction and maintenance
ANCA vasculitis treatment is divided into two phases: induction (rapidly suppressing the acute attack to prevent further organ damage) and maintenance (preventing relapse over months to years). Plasma exchange and renal replacement therapy are added in severe presentations.
Induction — Glucocorticoids
High-dose methylprednisolone pulses (500mg to 1g IV for 3 days) followed by oral prednisolone (1mg/kg/day, tapering over 3 to 6 months). Corticosteroids suppress the acute inflammatory response rapidly and are the backbone of all induction regimens.
Induction — Rituximab (preferred at KIMS)
Anti-CD20 monoclonal antibody that depletes B-lymphocytes (the source of ANCA production). RAVE and RITUXVAS trials established rituximab as equivalent to cyclophosphamide for induction in GPA and MPA — with a better side-effect profile, particularly for younger patients and women of reproductive age (cyclophosphamide causes gonadal toxicity and bladder toxicity). Rituximab is the preferred induction agent at KIMS for most ANCA vasculitis patients.
Induction — Cyclophosphamide
The established alternative to rituximab — pulse IV cyclophosphamide monthly or daily oral cyclophosphamide. Used where rituximab is not available, not tolerated, or where the patient has concomitant conditions where cyclophosphamide is preferred.
Induction — Plasma exchange (plasmapheresis)
Removes ANCA and other inflammatory mediators from the circulation. Used additionally in patients with severe kidney failure at presentation (creatinine above 500 µmol/L or dialysis-dependent) or pulmonary haemorrhage. At KIMS, plasma exchange is available for ANCA vasculitis management. The PEXIVAS trial (2020) found that plasma exchange did not significantly reduce the risk of death or end-stage renal disease at 12 months compared to standard immunosuppression — but it did accelerate kidney recovery in severely affected patients. The KIMS team selects plasma exchange for individual patients based on clinical severity.
Maintenance — preventing relapse
After induction, maintenance immunosuppression continues for 24 months or longer to prevent relapse — which occurs in 30 to 50% of GPA patients and 20 to 30% of MPA patients. Maintenance options: rituximab (every 6 months) or azathioprine (combined with low-dose prednisolone). ANCA titre monitoring and clinical vigilance guide the duration of maintenance therapy.
When CRRT is required
Patients presenting with dialysis-dependent kidney failure from ANCA vasculitis — creatinine above 600 to 700 µmol/L, anuria, or severe fluid overload — require urgent renal replacement therapy. At KIMS, CRRT (continuous renal replacement therapy) is available 24/7 in the ICU for patients with haemodynamic instability. Intermittent haemodialysis is used for stable patients. Immunosuppression and plasma exchange proceed concurrently with dialysis support. Recovery of kidney function sufficient to come off dialysis occurs in approximately 40 to 60% of patients with ANCA vasculitis who present on dialysis — particularly those with fewer than 50% crescents on biopsy and those treated promptly.
ANCA vasculitis has a high relapse rate. Every KIMS patient with ANCA vasculitis is followed long-term by the glomerular disease team — monitoring ANCA titres, creatinine, urinalysis, and chest imaging at defined intervals. Relapses that are caught early by rising ANCA titre before clinical symptoms can be treated with intensified immunosuppression before kidney function deteriorates again.
Book an Urgent Nephrology Consultation at KIMS
Frequently Asked Questions — ANCA Vasculitis
ANCA positive means that antineutrophil cytoplasmic antibodies have been detected in the blood — antibodies that attack neutrophil granule proteins (PR3 or MPO). A positive ANCA result, in the clinical context of rapidly worsening kidney function, haematuria, proteinuria, and systemic symptoms (sinusitis, lung problems, skin rash, joint pain), strongly suggests ANCA-associated vasculitis. A positive ANCA without these clinical features has a much lower predictive value — ANCA can be positive in a range of inflammatory conditions and infections. The ANCA result must always be interpreted alongside the clinical picture and kidney biopsy findings.
ANCA vasculitis is a relapsing-remitting condition rather than a curable disease in most patients. Induction immunosuppression (rituximab or cyclophosphamide with steroids) achieves remission — no active vasculitis — in 85 to 90% of patients. However, relapse occurs in 30 to 50% of GPA patients and 20 to 30% of MPA patients, often months to years after initial remission. Long-term maintenance immunosuppression and careful monitoring are required to detect and treat relapses before irreversible kidney damage accumulates. The goal is sustained remission with the minimum effective immunosuppression — minimising both vasculitis damage and immunosuppression-related side effects.
Not necessarily — even patients who are dialysis-dependent at presentation can recover sufficient kidney function to come off dialysis after immunosuppression. Recovery is more likely when: treatment is started promptly (within days of presentation), the kidney biopsy shows fewer crescentic glomeruli (below 50%), and the biopsy also shows viable glomeruli that can recover. Patients with extensive irreversible fibrosis (more than 50% globally sclerosed glomeruli) on biopsy are less likely to recover. At KIMS, kidney biopsy findings are used to guide realistic expectations about recovery — and dialysis is supported concurrently with immunosuppression during the recovery period.
GPA (Granulomatosis with Polyangiitis) and MPA (Microscopic Polyangiitis) are both ANCA-associated vasculitides with similar kidney pathology but different clinical profiles. GPA is characterised by upper respiratory tract involvement (chronic sinusitis, nasal destruction, saddle-nose deformity), pulmonary granulomas and cavitation, and is predominantly associated with PR3-ANCA. MPA typically lacks upper respiratory granulomatous disease, causes pulmonary haemorrhage (rather than granulomas), and is predominantly associated with MPO-ANCA. The kidney pathology in both is indistinguishable — pauci-immune necrotising crescentic GN. The treatment protocols are similar, but the natural history and relapse pattern differ — GPA has a higher relapse rate than MPA.
Extremely urgent. Rapidly progressive glomerulonephritis from ANCA vasculitis can reduce kidney function from near-normal to dialysis-dependence within 2 to 4 weeks. Every day of delay in starting immunosuppression allows further crescent formation and more irreversible glomerular scarring. The combination of rapidly rising creatinine, haematuria, and any systemic vasculitis symptoms is a nephrology emergency requiring same-day evaluation, urgent kidney biopsy within 24 to 48 hours, and immunosuppression initiated within 48 to 72 hours of diagnosis. Call KIMS on 040-4488-5000 immediately.
Yes — pulmonary involvement is a major feature of ANCA vasculitis and the most life-threatening non-renal manifestation. In GPA, lung granulomas appear as nodules or masses on CT that may cavitate — they can be mistaken for lung cancer or tuberculosis. In MPA, pulmonary haemorrhage (alveolar capillaritis) causes coughing of blood, breathlessness, and haemoptysis — a medical emergency. Simultaneous lung and kidney involvement is called pulmonary-renal syndrome and requires immediate hospitalisation. Any patient with haemoptysis and abnormal kidney function must be evaluated urgently for ANCA vasculitis and anti-GBM disease simultaneously.
Long-term monitoring at KIMS after ANCA vasculitis treatment includes: serum creatinine and urine ACR at every visit (to detect kidney relapse), ANCA titres every 3 to 6 months (rising titre may precede clinical relapse), chest X-ray or CT if respiratory symptoms develop, and surveillance for immunosuppression side effects (infection, bone density, glucose, blood pressure). Rituximab maintenance is given every 6 months for at least 24 months after remission. The frequency of clinic visits decreases as remission is maintained — from monthly in year 1 to every 3 to 6 months in year 3 and beyond.
KIMS Secunderabad — Dr. Aswini Dutt T (glomerular disease subspecialty), NABL-accredited kidney biopsy with LM + IF + EM in-house, plasma exchange available, CRRT 24/7, rituximab induction protocol, long-term glomerular disease follow-up. NABH and NABL accredited. Emergency nephrology available 24/7 — call 040-4488-5000.