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ORPHA:727

Microscopic polyangiitis

medium confidenceDisorder

Also known as: MPA · Micropolyangiitis · Microscopic polyarteritis

Publications

7,353

94.1th percentile

Trials

34

Interventional, condition-specific

Researchers

1,232

Distinct authors in sample

Gene link

—

Readiness

4/6

Stages with a signal

Clinical definition (Orphanet)

A rare inflammatory, necrotizing, systemic vasculitis that affects predominantly small vessels (i.e. small arteries, arterioles, capillaries, venules) in multiple organs, including the kidney, the lungs, the skin and the peripheral nerves.

How rare: 1-9 / 100 000 — about one to nine people per hundred thousand.

Orphanet entry

Cross-references

Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.

Additional Mondo synonyms (1)

microscopic polyarteritis

Research stages

Trial readiness signals

Where this condition sits on an open-data research pipeline — not how close a treatment is, and not medical advice. Empty stages often mean “not in these databases under this Mondo ID,” not “impossible.”

4/6 stages with a signal

An interventional trial matched this condition name on ClinicalTrials.gov — see trials below.

  1. Gene identifiedNot found

    No GenCC disease–gene assertion in this build

  2. LiteraturePresent

    7,353 matched papers (4,395 in last 10 years) Source

  3. Phenotype characterisedPresent

    55 HPO annotations (e.g. Glomerulonephritis; Hematuria; Skin rash) Source

  4. Animal modelNot found

    No Alliance genotype “model of” associations via Monarch for these Mondo IDs

  5. Orphan designationPresent

    2 FDA designations (1 FDA orphan-indication approval) — e.g. avacopan Source

  6. Interventional trialPresent

    34 matched on ClinicalTrials.gov (4 recruiting in sample)

Biology

Genes and phenotypes

Gene–disease validity from GenCC, plus phenotypes and animal models joined from Monarch Initiative via Mondo ID — not a clinical diagnosis aid.

Do we know what causes it?

Not yet — the cause hasn't been pinned down in GenCC.

No strong gene–disease assertion joined for this Orphanet entity.

Phenotypes (Monarch / HPO)

55

Associated phenotypes · MONDO:0019124

  • Glomerulonephritis
  • Hematuria
  • Skin rash
  • Glomerulopathy
  • Anemia

Showing 5 of 55 — open Monarch for the full list.

Animal models (Monarch / Alliance)

None returned for this Mondo ID. Empty here is not proof that no model organism work exists under another name or gene.

Monarch fetch 2026-07-29

Therapies

Designations, candidates, and chemicals

FDA OOPD and EMA orphan designations, Open Targets clinical candidates, and CTD chemical associations via MyDisease.info. These never change the interventional-trial headline.

Orphan designation (FDA · EMA)

2

Designations · 1 with FDA orphan-indication approval

  • FDA avacopanChurg-Strauss Syndrome Vasculitides Microscopic Polyangiitis Granulomatosis with polyangiitis Wegener Granulomatosis · 2014-06-02 · Not FDA Approved for Orphan Indication
  • FDA rituximab (Rituxan)Churg-Strauss Syndrome Microscopic Polyangiitis Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis Wegener's Granulomatosis · 2006-02-14

Sources: FDA OOPD · EMA orphan designations

Open Targets candidates

21

Drugs / clinical candidates · MONDO_0019124

CTD chemicals (MyDisease.info)

10 associated chemicals. Therapeutic evidence is listed first when present — not a treatment recommendation.

  • Adrenal Cortex Hormones · therapeutic
  • Azathioprine · therapeutic
  • Cyclophosphamide · therapeutic
  • Glucocorticoids · therapeutic
  • Leflunomide · therapeutic
  • Methotrexate · therapeutic
  • Mycophenolic Acid · therapeutic
  • Prednisolone · therapeutic
  • Methimazole · marker/mechanism
  • Propylthiouracil · marker/mechanism

MyDisease.info · MONDO:0019124

Literature

Is anyone studying this?

7,353

7,353 papers — among the better-studied rare conditions, though still a fraction of common-disease literature (breast cancer: over 700,000). Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=3967) is 59.

7,353 papers since the earliest indexed year in this search — median last-10-year count for a rare disease in this dataset is 59 (publications denominator n=3967).

4,395 in the last 10 years · medium confidence · 94.1th percentile (publications denominator)

Phrase hits: 7,353 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

1,232

Distinct author names in 200 sampled papers — named people below.

Who's working on it?

People publishing on this condition (sampled Europe PMC records). Affiliation is the most recent found in that sample.

  1. 01
    Takeuchi T10 papers · 2026

    Department of Internal Medicine (IV), Osaka Medical and Pharmaceutical University, Takatsuki, Japan.

    Papers in Europe PMC
  2. 02
    Lee SW9 papers · 2026

    Division of Rheumatology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul 03722, Republic of Korea.

    Papers in Europe PMC
  3. 03
    Park YB9 papers · 2026

    Division of Rheumatology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul 03722, Republic of Korea.

    Papers in Europe PMC
  4. 04
    Ito-Ihara T8 papers · 2026

    The Clinical and Translational Research Center, University Hospital, Kyoto Prefectural University of Medicine, Kyoto, Japan.

    Papers in Europe PMC
  5. 05
    Kawaguchi T8 papers · 2026

    Department of Clinical Assessment, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan.

    Papers in Europe PMC
  6. 06
    Kawahito Y8 papers · 2026

    Inflammation and Immunology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.

    Papers in Europe PMC
  7. 07
    Kida T8 papers · 2026

    Inflammation and Immunology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.

    Papers in Europe PMC
  8. 08
    Nakagomi D8 papers · 2026

    Department of Rheumatology, University of Yamanashi Hospital, Chuo, Yamanashi, Japan.

    Papers in Europe PMC
  9. 09
    Omura S8 papers · 2026

    Inflammation and Immunology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.

    Papers in Europe PMC
  10. 10
    Takatani A8 papers · 2026

    Department of Rheumatology, Sasebo Chuo Hospital, Sasebo, Japan.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

34

interventional trials for this specific condition

34 interventional trials matched this specific condition name; 4 currently recruiting in our sample.

Data as of 11 September 2026

34 interventional trials — more than 77.2% of diseases in the trials denominator have none at all (5501 of 7126; this disease is at the 96.3th percentile).

medium confidence · 96.3th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

34 interventional trials matched after quoted-phrase search and title/condition post-filter.

Observational and natural-history studies

23 observational studies match this condition. These do not test a treatment and are not counted in the interventional-trial headline, but they are genuine research: natural-history work often defines the endpoints needed for a future rare-disease trial, and families may be able to enroll.

Recruiting or not-yet-recruiting

Open the complete matched search on ClinicalTrials.gov

Other registries (secondary)

Broader net from EU CTIS, ISRCTN, and ICTRP when available — deduped against ClinicalTrials.gov IDs already counted above. Dual-model LLM relevance gates what we keep. These rows are not added to the interventional headline.

raw 14 · after dedupe 14 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 14 · dropped 0 · fetched 2026-07-29

Source notes: ictrp: Error: ICTRP public search unavailable (WHO portal is SPA-only; SOAP needs partnership). Tried: https://apps.who.int/tri

No secondary-registry studies passed dual-model relevance for this condition name (after dedupe).

Uncertain / not reviewed (14)

Where to find support

Condition-specific patient organisations, when Orphanet lists them, are on the disease’s Orphanet page. We also link umbrella groups that support undiagnosed and ultra-rare families.

Orphanet entry for Microscopic polyangiitis — check Associations / patient organisations on that page.

India — NPRD

Last verified 2026-07-26

This ORPHAcode is not on our curated NPRD list (direct or Mondo-parent match). That does not decide clinical eligibility; families in India should ask a notified Centre of Excellence about current coverage.

Hand-curated for this project. ORPHAcode mappings are best-effort and may be incomplete or imprecise for umbrella categories. Parent (Mondo) matches mean the policy lists a broader category — confirm eligibility with a Centre of Excellence. Financial entitlements summarised from public policy statements and may change. This is not official government guidance.

How we counted this

Europe PMC query (preferred label + any corrected label + Orphanet and Mondo exact synonyms, stoplisted; unioned with resolved MeSH labels when available). UMLS / OMIM / NCIT cross-references are stored on the overview but are not added to the query string.

"Microscopic polyangiitis" OR "Micropolyangiitis" OR "Microscopic polyarteritis"

Run this search on Europe PMC

ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):

"Microscopic polyangiitis" OR "Micropolyangiitis" OR "Microscopic polyarteritis"

Interventional trials matched via: phrase (mesh = registered under a MeSH descriptor no name phrase would catch; recall-expansion = gene / selected parent terms used only for trials).

Study-type breakdown: 34 interventional · 23 observational · 0 expanded access. Only interventional studies enter the trial headline.

Query health: ok — strategies attempted: phrase; with hits: phrase

Run this search on ClinicalTrials.gov

Synonyms dropped by stoplist: MPA

Confidence reasoning

  • Preferred label is multi-word and distinctive
  • 1 synonym(s) dropped by stoplist (may under-count)
  • No label/synonym collisions with other diseases in this corpus

Ingested 2026-07-26T15:04:16.388Z