ORPHA:158061
Macrophage activation syndrome
Publications
8,196
Trials
12
Interventional, condition-specific
Researchers
1,285
Distinct authors in sample
Gene link
—
Readiness
2/6
Stages with a signal
Clinical definition (Orphanet)
A rare hemophagocytic syndrome characterized by excessive activation and proliferation of macrophages and T cells occurring in the context of a variety of diseases, including infections, neoplasms, rheumatic disorders, and leading to sudden onset of persistent fever, lymphadenopathy, and . Complications include profound depression of one or more blood cell lines with coagulopathy and pancytopenia, and impaired liver and renal function. Bone marrow examination reveals numerous well differentiated macrophages actively phagocytosing hematopoietic elements.
How rare: How common this is has not been clearly measured.
Cross-references
Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.
- MONDO:0015545
- MeSH:D055501
- UMLS:C1096155
- NCIT:C114471
Additional Mondo synonyms (2)
MAS · reactive hemophagocytic lymphohistiocytosis
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.”
2/6 stages with a signal
An interventional trial matched this condition name on ClinicalTrials.gov — see trials below.
- Gene identifiedNot found
No GenCC disease–gene assertion in this build
- LiteraturePresent
8,196 matched papers (6,968 in last 10 years) Source
- Phenotype characterisedNot checked
Not yet enriched from Monarch / HPO
- Animal modelNot checked
Not yet enriched from Monarch / Alliance
- Orphan designationNot checked
FDA/EMA orphan-drug designation not enriched yet
- Interventional trialPresent
12 matched on ClinicalTrials.gov (1 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)
Not enriched in this build — Monarch phenotype joins were not run for this record.
Animal models (Monarch / Alliance)
Not enriched in this build.
Literature
Is anyone studying this?
8,196
8,196 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=5449) is 41.
8,196 papers since the earliest indexed year in this search — median last-10-year count for a rare disease in this dataset is 41 (publications denominator n=5449).
6,968 in the last 10 years · low confidence
Phrase hits: 8,196 · MeSH hits: 206
Who's working on it?
1,285
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.
- 01De Benedetti F6 papers · 2026
Division of Rheumatology, ERN-RITA Center, IRCCS Ospedale Pediatrico Bambino Gesù, Roma, Italy.
Papers in Europe PMC - 02Wang X6 papers · 2026
Department of Gastroenterology, Hepatology and Nutrition, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China.
Papers in Europe PMC - 03Zhang Y6 papers · 2026
Department of Rheumatology and Immunology, The Second Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.
Papers in Europe PMC - 04Bracaglia C5 papers · 2026
Division of Rheumatology, ERN-RITA Center, IRCCS Ospedale Pediatrico Bambino Gesù, Roma, Italy.
Papers in Europe PMC - 05Ozen S5 papers · 2026
Department of Pediatrics, Division of Rheumatology, Faculty of Medicine, Hacettepe University, Ankara, Türkiye.
Papers in Europe PMC - 06Bilginer Y4 papers · 2026
Department of Pediatrics, Division of Rheumatology, Faculty of Medicine, Hacettepe University, Ankara, Türkiye.
Papers in Europe PMC - 07Bindoli S4 papers · 2026
Rheumatology Unit, Department of Medicine, University of Padova, Via Giustiniani, 2, 35128, Padua, Italy.
Papers in Europe PMC - 08De Matteis A4 papers · 2026
Division of Rheumatology, ERN-RITA center, IRCCS Ospedale Pediatrico Bambino Gesù, Roma, Italy.
Papers in Europe PMC - 09Simonini G4 papers · 2026
Rheumatology Unit, IRCCS Anna Meyer, ERN ReCONNET Center, NEUROFARBA Department, University of Florence, Firenze, Italy.
Papers in Europe PMC - 10Su Y4 papers · 2026
Department of Rheumatology and Immunology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Papers in Europe PMC
Clinical research
Is a treatment being tested?
12
interventional trials for this specific condition
12 interventional trials matched this specific condition name; 1 currently recruiting in our sample.
Data as of 27 July 2026
12 interventional trials — more than 73% of diseases in the trials denominator have none at all (5114 of 7003; this disease is at the 92.5th percentile).
low confidence · 92.5th percentile (trials denominator)
Recruiting interventional trials
From the matched ClinicalTrials.gov set
12 interventional trials matched after quoted-phrase search and title/condition post-filter.
- NCT07208058·RECRUITING·A Phase III Clinical Study to Evaluate the Efficacy, Safety, and Tolerability of Plonmarlimab in Subjects With Relapsed/Refractory Rheumatic and Immunologic Disease-associated Haemophagocytic Lymphohistiocytosis (Also Known as Macrophage Activation Syndrome [MAS])
Conditions: Relapsed/Refractory Rheumatic and Immunologic Disease-associated Haemophagocytic Lymphohistiocytosis·Matched via name + MeSH
Observational and natural-history studies
7 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
- NCT07491926·NOT YET RECRUITING·MASKd: a Study on Kawasaki Disease (KD) Complicated by Macrophage Activation Syndrome (MAS)
Conditions: Kawasaki Disease · Macrophage Activation Syndrome (MAS)·Matched via name + MeSH
- NCT06339177·RECRUITING·Hemophagocytic Lymphohistiocytosis (HLH) Evaluation and Research of Clinical, ImmUnoLogic and TranscriptomE Study
Conditions: Lymphohistiocytosis, Hemophagocytic · Secondary Hemophagocytic Lymphohistiocytosis · Macrophage Activation Syndrome · Hyperinflammatory Syndromes·Matched via name + MeSH
Where to find support
We do not yet link condition-specific patient organisations. These umbrella groups support undiagnosed and ultra-rare families:
India — NPRD
Last verified 2026-07-26This 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.
"Macrophage activation syndrome" OR "reactive hemophagocytic lymphohistiocytosis"
MeSH descriptor terms unioned into the query: Macrophage Activation Syndrome
ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"Macrophage activation syndrome" OR "reactive hemophagocytic lymphohistiocytosis"
Interventional trials matched via: both (mesh = registered under a MeSH descriptor no name phrase would catch; recall-expansion = gene / selected parent terms used only for trials).
Study-type breakdown: 12 interventional · 7 observational · 0 expanded access. Only interventional studies enter the trial headline.
Query health: ok — strategies attempted: phrase, mesh; with hits: phrase, mesh
Run this search on ClinicalTrials.gov
Synonyms dropped by stoplist: MAS
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
- Publication count (8196) is extremely high with unknown/missing prevalence — treat as possible over-matching, not proven research intensity
Ingested 2026-07-27T08:06:36.840Z