A plain-language guide

granulomatosis with polyangiitis

What's known, what's still uncertain, and what's actively debated, written plainly, and built only from published medical research.

Growing map · 27 sourced statements Every statement names its source Updated 2026-08-04
Please read this first. This guide is a companion to your medical team, not a replacement, and it is not medical advice. Everything here is tied to published research. If something you expected is not here, it almost always means we have not mapped a source for it yet, not that it is unknown to medicine. granulomatosis with polyangiitis is an early, growing map, so it will look incomplete on purpose: we would rather show less and have every line be something you can check than fill the page with claims we cannot stand behind. For anything about your own situation, your clinicians hold the full picture. How this guide is built and why.

What's granulomatosis with polyangiitis?

Granulomatosis with polyangiitis (GPA) is a rare disease in which the immune system inflames and damages small to medium-sized blood vessels. Because those vessels run throughout the body, GPA can affect several organs at once, most often the sinuses and airways, the lungs, and the kidneys.

Also indexed asORPHA:900, MONDO:0012105
Features mapped15
Treatments mapped3
Published sources9
Last reviewed2026-08-04

Signs and symptoms

Vasculitis

Granulomatosis with polyangiitis is characterised by vasculitis, meaning inflammation of small and medium-sized blood vessels. This inflammation is what damages the organs the disease affects.

Limited evidenceSource: PMID:30264013
Evidence ratingweak
Study designontology_import
Confidence (0-1)0.7
Replicationunreplicated
Supporting sourcesORPHA:900
Notesplain_language confirmed from PMID:30264013 via curation 2026-06-25 [claude-draft]. | regrounded primary ORPHA:900 -> PMID:30264013 on 2026-06-26 [Carrie Schluter, BCPA]
Last reviewed2026-06-26

Pulmonary nodule

GPA can produce nodules (rounded spots) in the lungs, sometimes with a hollow center, which is why a chest scan is often part of the work-up.

Limited evidenceCurated reference: ORPHA:900
Evidence ratingweak
Study designontology_import
Confidence (0-1)0.7
Replicationunreplicated
Supporting sourcesPMID:42158786
Notesplain_language confirmed from PMID:42158786 via curation 2026-06-12.
Last reviewed2026-06-12

Subglottic stenosis

GPA can scar and narrow the windpipe just below the vocal cords (subglottic stenosis). This narrowing can cause a hoarse voice, noisy breathing, and shortness of breath, and sometimes needs procedures to keep the airway open.

Limited evidenceSource: PMID:22430874
Evidence ratingweak
Study designontology_import
Confidence (0-1)0.7
Replicationunreplicated
Supporting sourcesPMID:41622276, ORPHA:900
Notesplain_language confirmed from PMID:41622276 via curation 2026-06-18 [carrie (curation)]. | regrounded primary ORPHA:900 -> PMID:22430874 on 2026-06-26 [Carrie Schluter, BCPA]
Last reviewed2026-06-26

Hemoptysis

Coughing up blood (hemoptysis) can occur when GPA inflames the lungs' blood vessels. It is a symptom to report to a clinician promptly.

Limited evidenceCurated reference: ORPHA:900
Evidence ratingweak
Study designontology_import
Confidence (0-1)0.7
Replicationunreplicated
Supporting sourcesPMID:42158786
Notesplain_language confirmed from PMID:42158786 via curation 2026-06-12.
Last reviewed2026-06-12

Epistaxis

Nosebleeds, along with crusting and a blocked or runny nose, are common early signs of GPA as the lining of the nose becomes inflamed and ulcerated.

Limited evidenceSource: PMID:41622276
Evidence ratingweak
Study designontology_import
Confidence (0-1)0.7
Replicationunreplicated
Supporting sourcesORPHA:900
Notesplain_language confirmed from PMID:41622276 via curation 2026-06-18 [carrie (curation)]. | regrounded primary ORPHA:900 -> PMID:41622276 on 2026-06-26 [Carrie Schluter, BCPA]
Last reviewed2026-06-26

Granulomatosis

In granulomatosis with polyangiitis, the immune system forms granulomas, which are small clusters of inflammatory cells. In this condition they typically develop in the respiratory tract.

Limited evidenceSource: PMID:40123739
Evidence ratingweak
Study designontology_import
Confidence (0-1)0.7
Replicationunreplicated
Supporting sourcesPMID:30264013, ORPHA:900
Notesplain_language confirmed from PMID:30264013 via curation 2026-06-25 [claude-draft]. | regrounded primary ORPHA:900 -> PMID:40123739 on 2026-06-26 [Carrie Schluter, BCPA]
Last reviewed2026-06-26

Cytoplasmic antineutrophil antibody positivity

Most people with GPA carry a specific autoantibody in their blood, c-ANCA, which a lab test can detect. A positive result helps point to the diagnosis.

Limited evidenceSource: PMID:40699500
Evidence ratingweak
Study designontology_import
Confidence (0-1)0.7
Replicationunreplicated
Supporting sourcesPMID:42158786, ORPHA:900
Notesplain_language confirmed from PMID:42158786 via curation 2026-06-12. | regrounded primary ORPHA:900 -> PMID:40699500 on 2026-06-26 [Carrie Schluter, BCPA]
Last reviewed2026-06-26

Anti-proteinase 3 antibody positivity

The c-ANCA in GPA is usually aimed at a protein called proteinase-3 (PR3). A blood test showing anti-PR3 antibodies strengthens the case for GPA.

Limited evidenceSource: PMID:40699500
Evidence ratingweak
Study designontology_import
Confidence (0-1)0.7
Replicationunreplicated
Supporting sourcesPMID:42164191, ORPHA:900
Notesplain_language confirmed from PMID:42164191 via curation 2026-06-12. | regrounded primary ORPHA:900 -> PMID:40699500 on 2026-06-26 [Carrie Schluter, BCPA]
Last reviewed2026-06-26

Fever

Granulomatosis with polyangiitis can cause a prolonged fever as part of its general, whole-body symptoms, and it is an uncommon but recognised cause of fever without an obvious source.

Limited evidenceCurated reference: ORPHA:900
Evidence ratingweak
Study designontology_import
Confidence (0-1)0.7
Replicationunreplicated
Supporting sourcesPMID:42164191
Notesplain_language confirmed from PMID:42164191 via curation 2026-06-25 [claude-draft].
Last reviewed2026-06-25

Hematuria

Blood in the urine (hematuria), often together with protein, can be an early sign that GPA is affecting the kidneys, even before symptoms are obvious.

Limited evidenceCurated reference: ORPHA:900
Evidence ratingweak
Study designontology_import
Confidence (0-1)0.7
Replicationunreplicated
Supporting sourcesPMID:42113751
Notesplain_language confirmed from PMID:42113751 via curation 2026-06-12.
Last reviewed2026-06-12

Glomerulonephritis

GPA often inflames the kidney's tiny filters (glomerulonephritis), which can show up as blood or protein in the urine and, if unchecked, can reduce kidney function.

Limited evidenceSource: PMID:41622276
Evidence ratingweak
Study designontology_import
Confidence (0-1)0.7
Replicationunreplicated
Supporting sourcesPMID:42113751, ORPHA:900
Notesplain_language confirmed from PMID:42113751 via curation 2026-06-12. | regrounded primary ORPHA:900 -> PMID:41622276 on 2026-06-26 [Carrie Schluter, BCPA]
Last reviewed2026-06-26

Otitis media

GPA frequently affects the ears, causing fluid build-up behind the eardrum (otitis media with effusion). This can lead to ear fullness, pain, and hearing loss, and is sometimes the first symptom before other organs are involved.

Limited evidenceSource: PMID:41622276
Evidence ratingweak
Study designontology_import
Confidence (0-1)0.7
Replicationunreplicated
Supporting sourcesORPHA:900
Notesplain_language confirmed from PMID:41622276 via curation 2026-06-18 [carrie (curation)]. | regrounded primary ORPHA:900 -> PMID:41622276 on 2026-06-26 [Carrie Schluter, BCPA]
Last reviewed2026-06-26

Sinusitis

Persistent sinus inflammation is one of the most common early features of GPA and is often mistaken for ordinary chronic sinus infection, which can delay the diagnosis.

Limited evidenceSource: PMID:41622276
Evidence ratingweak
Study designontology_import
Confidence (0-1)0.7
Replicationunreplicated
Supporting sourcesORPHA:900
Notesplain_language confirmed from PMID:41622276 via curation 2026-06-18 [carrie (curation)]. | regrounded primary ORPHA:900 -> PMID:41622276 on 2026-06-26 [Carrie Schluter, BCPA]
Last reviewed2026-06-26

Abnormality of the nose

In granulomatosis with polyangiitis, the nose is one of the most commonly affected areas. Nasal crusting, nosebleeds, and damage to the nasal septum are among the most frequent findings.

Limited evidenceSource: PMID:41622276
Evidence ratingweak
Study designontology_import
Confidence (0-1)0.7
Replicationunreplicated
Supporting sourcesORPHA:900
Notesplain_language confirmed from PMID:41622276 via curation 2026-06-25 [claude-draft]. | regrounded primary ORPHA:900 -> PMID:41622276 on 2026-06-26 [Carrie Schluter, BCPA]
Last reviewed2026-06-26

Saddle-nose deformity

GPA inflammation can destroy the cartilage that supports the bridge of the nose, causing it to collapse into a saddle shape. This saddle-nose deformity is one of the more recognizable signs of long-standing or severe disease.

Limited evidenceSource: PMID:41622276
Evidence ratingweak
Study designsystematic_review
Confidence (0-1)0.7
Replicationunreplicated
Notesplain_language confirmed from PMID:41622276 via curation 2026-06-18 [carrie (curation)].
Last reviewed2026-06-18

How it is diagnosed

Granulomatosis with polyangiitis

Diagnosed using: ANCA testing and tissue biopsy.

Limited evidenceSource: PMID:41622276
The source text this rests on
“Early biopsy, ANCA testing, and multidisciplinary management improved diagnostic accuracy and prevented organ damage.”
An excerpt quoted verbatim from the source named above, shown as recorded. The full sentence is in the linked source.
Evidence ratingweak
Confidence (0-1)0.7
Replicationunreplicated
Notesconfirmed from PMID:41622276 via curation 2026-06-25
Last reviewed2026-06-25

Treatment and management

What the research describes, not a recommendation. Treatment decisions belong with your clinician.

This covers treatments that appear in the published research mapped here. Investigational and experimental therapies are not included, so their absence is a boundary of this map, not a sign they do not exist.

Cyclophosphamide

Cyclophosphamide is a long-established immune-suppressing medicine used to bring active GPA under control (remission induction). It is one of the standard options a specialist may use for serious disease.

Used to help with: Granulomatosis with polyangiitis.

Limited evidenceSource: PMID:42100069
The source text this rests on
“Cyclophosphamide remains a cornerstone of remission induction therapy in granulomatosis with polyangiitis…”
An excerpt quoted verbatim from the source named above, shown as recorded. The full sentence is in the linked source.
Evidence ratingweak
Confidence (0-1)0.7
Replicationunreplicated
Notesconfirmed from PMID:42100069 via curation 2026-06-12
Last reviewed2026-06-12

rituximab

Rituximab is a medicine that targets certain immune (B) cells. In granulomatosis with polyangiitis it is now a central option both for bringing active disease under control (remission induction) and for keeping it controlled afterwards (maintenance).

Used to help with: Granulomatosis with polyangiitis.

Limited evidenceSource: PMID:42130237
The source text this rests on
“Rituximab is now central to remission induction and maintenance, while avacopan in GPA (granulomatosis with polyangiitis) and MPA (microscopic polyangiitis) and interleukin (IL)-5 blockade in EGPA (eosinophilic granulomatosis with polyangiitis) further reduce glucocorticoid exposure and toxicity.”
An excerpt quoted verbatim from the source named above, shown as recorded. The full sentence is in the linked source.
Evidence ratingweak
Confidence (0-1)0.7
Replicationunreplicated
Notesconfirmed from PMID:42130237 via curation 2026-06-25
Last reviewed2026-06-25

glucocorticoids

Glucocorticoids (steroids) are an established part of treatment for granulomatosis with polyangiitis. Newer treatment approaches aim to use them in lower amounts to reduce their side effects.

Used to help with: Granulomatosis with polyangiitis.

Limited evidenceSource: PMID:42130237
The source text this rests on
“Rituximab is now central to remission induction and maintenance, while avacopan in GPA (granulomatosis with polyangiitis) and MPA (microscopic polyangiitis) and interleukin (IL)-5 blockade in EGPA (eosinophilic granulomatosis with polyangiitis) further reduce glucocorticoid exposure and toxicity.”
An excerpt quoted verbatim from the source named above, shown as recorded. The full sentence is in the linked source.
Evidence ratingweak
Confidence (0-1)0.7
Replicationunreplicated
Notesconfirmed from PMID:42130237 via curation 2026-06-25
Last reviewed2026-06-25

What changes how it shows up

The diagnosis is not the whole story. The factors and open questions below are described in the research mapped here as shaping whether, or how strongly, the condition shows up, or as points the field has not yet settled. They are not, on their own, its cause or its cure.

PR3-ANCA positivity

Most people with granulomatosis with polyangiitis test positive for PR3-ANCA, a specific type of ANCA antibody. Across studies, the great majority of cases are PR3-ANCA positive.

Described as modulating: Granulomatosis with polyangiitis.

Limited evidenceSource: PMID:41622276
The source text this rests on
“PR3-ANCA positivity ranged from 21 to 100%, with most studies reporting rates above 85%.”
An excerpt quoted verbatim from the source named above, shown as recorded. The full sentence is in the linked source.
Evidence ratingweak
Confidence (0-1)0.7
Replicationunreplicated
Notesconfirmed from PMID:41622276 via curation 2026-06-25
Last reviewed2026-06-25

How to read the evidence labels

Widely acceptedSpecialists broadly agree on this.
Strong evidenceBacked by solid, repeated research.
Moderate evidenceReasonable evidence, still being confirmed.
Limited evidenceSome evidence, but not yet convincing.
Early evidenceAn early finding that needs more study.
Experts disagreeResearchers actively disagree about this.
No longer supportedLater, stronger evidence or guidance overturned this.

Where this comes from

This guide is built from 9 published source(s). Every claim above links back to one of them. Click any source ID to read the original on PubMed.

ORPHA:900 · Orphanet/HPO annotations for Granulomatosis with polyangiitis
PMID:22430874 · Vasculitis of the upper airways.
PMID:30264013 · Granulomatosis with polyangiitis causing subglottic stenosis-two cases and their management.
PMID:40123739 · Pediatric Presentations of Granulomatosis With Polyangiitis: A Double Case Study.
PMID:40699500 · Seasonal variation in incidence and relapse of granulomatosis with polyangiitis: A retrospective cohort study from Central Anatolia.
PMID:41622276 · Otolaryngologic manifestations in granulomatosis with Polyangitis: A systematic review of clinical presentations and renal correlation.
PMID:42100069 · Predictors of Cyclophosphamide Resistance in Granulomatosis with Polyangiitis: A Retrospective Cohort Study.
PMID:42130237 · ANCA vasculitis: what is in the pipeline.
PMID:42253887 · PR3-ANCA-associated vasculitis (granulomatosis with polyangiitis / Wegener's)

Take it further

Printed, source-linked documents built from this condition's graph — ready to bring to an appointment or attach to a coverage request. Every claim carries its published source, the same as this guide.