ORPHA:687733
Pulmonary Langerhans cell histiocytosis
Also known as: Single-system pulmonary Langerhans cell histiocytosis · Single-system pulmonary histiocytosis X · PLCH · Single-system Langerhans cell granulomatosis
Clinical definition (Orphanet)
A form of Langerhans cell histiocytosis characterized by interstitial changes in the lung tissue, manifesting as a variable combination of cellular inflammation, cystic, and fibrotic lesions. Patients can have symptoms like dyspnea, cough and fever but most of them are asymptomatic, and they may undergo spontaneous remission. It is predominantly observed in young smokers or ex-smokers.
Is anyone studying this?
1,140
1,140 papers have been published on this condition. That is a real research literature — still far smaller than common diseases (breast cancer: over 700,000 papers). Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=183) is 38.
1,140 papers since the earliest indexed year in this search — median last-10-year count for a rare disease in this dataset is 38 (publications denominator n=183).
673 in the last 10 years · low confidence
Is a treatment being tested?
1
trials for this specific condition
1 interventional trial matched this specific condition name; none in our sample are currently recruiting.
Data as of 26 July 2026
1 interventional trial — more than 59.2% of diseases in the trials denominator have none at all (151 of 255; this disease is at the 65.3th percentile).
low confidence · 65.3th percentile (trials denominator)
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.
Who's working on it?
1,069
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.
- 01Tazi A13 papers · 2026
Hôpital Saint-Louis, Centre National de Référence des Histiocytoses, Service de Pneumologie, Assistance Publique-Hôpitaux de Paris, Paris, France. abdellatif.tazi@aphp.fr.
Papers in Europe PMC - 02Benattia A9 papers · 2026
Hôpital Saint-Louis, Centre National de Référence des Histiocytoses, Service de Pneumologie, Assistance Publique-Hôpitaux de Paris, Paris, France.
Papers in Europe PMC - 03Lorillon G6 papers · 2026
Hôpital Saint-Louis, Centre National de Référence des Histiocytoses, Service de Pneumologie, Assistance Publique-Hôpitaux de Paris, Paris, France.
Papers in Europe PMC - 04Wang L5 papers · 2026
Department of Respiratory and Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
Papers in Europe PMC - 05Harari S4 papers · 2026
Department of Medicine, Division of Internal Medicine, Ospedale San Giuseppe MultiMedica IRCCS, University of Milan, 20133 Milan, Italy.
Papers in Europe PMC - 06Liu Y4 papers · 2026
Department of Pulmonary and Critical Care Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China.
Papers in Europe PMC - 07Wang J4 papers · 2026
Department of Pulmonary and Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
Papers in Europe PMC - 08de Margerie-Mellon C3 papers · 2026
Université de Paris, INSERM UMR-1149, Paris, France.
Papers in Europe PMC - 09Ding Y3 papers · 2025
Center of Community-Based Health Research, Department of Pulmonary and Critical Care Medicine, Shanghai Fifth People's Hospital, Fudan University, Shanghai, China.
Papers in Europe PMC - 10Donadieu J3 papers · 2024
National Reference Centre for Histiocytoses, Paediatric Haemato-Oncology Department, Hôpital Trousseau, Assistance Publique - Hopitaux de Paris, Paris, Île-de-France, France.
Papers in Europe PMC
Recruiting interventional trials
Trials testing a treatment from the matched ClinicalTrials.gov set
1 interventional trials matched after quoted-phrase search and title/condition post-filter.
No currently recruiting studies in the matched set. Open the same search on ClinicalTrials.gov.
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
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 below but are not added to the query string.
"Pulmonary Langerhans cell histiocytosis" OR "Single-system pulmonary Langerhans cell histiocytosis" OR "Single-system pulmonary histiocytosis X" OR "Single-system Langerhans cell granulomatosis"
ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"Pulmonary Langerhans cell histiocytosis" OR "Single-system pulmonary Langerhans cell histiocytosis" OR "Single-system pulmonary histiocytosis X" OR "Single-system Langerhans cell granulomatosis"
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: 1 interventional · 7 observational · 0 expanded access. Only interventional studies enter the trial headline.
0Query health: ok — strategies attempted: phrase; with hits: phrase
Run this search on ClinicalTrials.gov
Synonyms dropped by stoplist: PLCH
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 (1140) is extremely high with unknown/missing prevalence — treat as possible over-matching, not proven research intensity