ORPHA:169147
Immunodeficiency due to a classical component pathway complement deficiency
Also known as: Immunodeficiency due to C1, C4, or C2 component complement deficiency · Immunodeficiency due to an early component of complement deficiency
Publications
2
13.3th percentile
Trials
0
Interventional, condition-specific
Researchers
29
Distinct authors in sample
Gene link
—
Readiness
3/6
Stages with a signal
Clinical definition (Orphanet)
A rare primary immunodeficiency due to a deficiency in either complement components C1q, C1r, C1s, C2 or C4 characterized by increased susceptibility to bacterial infections, particularly with encapsulated bacteria, and increased risk for autoimmune disease. Most commonly, these include systemic lupus erythematosus (SLE), SLE-like disease, Henoch-Schonlein purpura, polymyositis and arthralgia. Disease severity is variable and dependent on the complement affected.
Cross-references
Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.
- MONDO:0015699
- UMLS:C0398750
Additional Mondo synonyms (3)
immunodeficiency due to C1, C4, or C2 component complement deficiency · immunodeficiency due to a C1, C4, or C2 component complement deficiency · immunodeficiency due to an early component of complement deficiency
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.”
3/6 stages with a signal
No specific-condition interventional trial, but broader-category trials exist — discuss eligibility with a clinician.
- Gene identifiedNot found
No GenCC disease–gene assertion in this build
- LiteraturePresent
2 matched papers (2 in last 10 years) Source
- Phenotype characterisedPresent
62 HPO annotations (e.g. Atelectasis; Anemia; Elevated erythrocyte sedimentation rate) Source
- Animal modelNot found
No Alliance genotype “model of” associations via Monarch for these Mondo IDs
- Orphan designationNot found
No FDA or EMA orphan-drug designation matched this disease via UMLS or preferred name Source
- Interventional trialPartial
None under the specific name; 1 for broader category complement deficiency
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)
62
Associated phenotypes · MONDO:0015699
- Atelectasis
- Anemia
- Elevated erythrocyte sedimentation rate
- Persistent fever
- Extractable nuclear antigen positivity
Showing 5 of 62 — 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)
No designation matched this disease via UMLS or preferred name on the FDA OOPD mirror or EMA orphan register. Absence here is not proof that none exists under another wording.
Open Targets candidates
No drugs or clinical candidates returned for this Mondo ID on Open Targets.
CTD chemicals (MyDisease.info)
No CTD chemical associations returned for this Mondo ID.
Literature
Is anyone studying this?
2
2 papers have ever been indexed under this name. For scale, breast cancer has over 700,000. Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=3967) is 59.
2 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).
2 in the last 10 years · high confidence · 13.3th percentile (publications denominator)
Phrase hits: 2 · MeSH hits: 0
Who's working on it?
29
Distinct author names in 2 sampled papers — named people below.
Who's working on it?
No interventional trial matched this name; these authors publish on it in the sampled literature — a practical starting point for contact.
- 01Barrett J1 paper · 2019
Open Targets, Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SD, UK.
Papers in Europe PMC - 02Carmona M1 paper · 2019
European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SD, UK.
Papers in Europe PMC - 03Carvalho-Silva D1 paper · 2019
European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SD, UK.
Papers in Europe PMC - 04Chen J1 paper · 2022
Department of Ophthalmology, Jincheng People's Hospital, Jincheng, China.
Papers in Europe PMC - 05Chen X1 paper · 2022
Department of Vitreoretinal and Ocular Trauma, Tianjin Medical University Eye Hospital, Eye Institute and School of Optometry, Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin International Joint Research Center of Ophthalmology and Visual Science, Tianjin, China.
Papers in Europe PMC - 06Cui L1 paper · 2022
Department of Nephrology, Jincheng People's Hospital, Jincheng, China.
Papers in Europe PMC - 07Dunham I1 paper · 2019
European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SD, UK.
Papers in Europe PMC - 08Fan X1 paper · 2022
Department of Ophthalmology, Jincheng People's Hospital, Jincheng, China.
Papers in Europe PMC - 09Fan Y1 paper · 2022
Department of Ophthalmology, Jincheng People's Hospital, Jincheng, China.
Papers in Europe PMC - 10Faulconbridge A1 paper · 2019
European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SD, UK.
Papers in Europe PMC
Clinical research
Is a treatment being tested?
0
interventional trials for this specific condition
No interventional trial testing a treatment matched this specific condition name on ClinicalTrials.gov (observational studies and pan-disease registries are listed separately when present). 1 trial are registered for complement deficiency, the broader category — shown separately because they may or may not enrol this specific subtype.
Data as of 11 September 2026 · last trial check 11 September 2026
No matched interventional trials. This is true for 77.2% of diseases in the trials denominator (5501 of 7126). Here are the researchers publishing on it.
high confidence · 38.6th percentile (trials denominator)
Recruiting interventional trials
From the matched ClinicalTrials.gov set
No interventional trial testing a treatment was found for this specific condition name on ClinicalTrials.gov.
1 interventional trial matched complement deficiency, the broader category — listed below. Those studies are not counted in the condition-specific total.
Broader category: complement deficiency
1
Interventional trials for the parent category, exclusive of NCT IDs already counted above. Eligibility for this subtype is not guaranteed.
Worth raising with a clinician. How we count trials.
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 41 · after dedupe 41 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 41 · dropped 0 · fetched 2026-07-30
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 (41)
- ctis·2024-519985-35-00·Authorised·Obinutuzumab for systemic lupus erythematosus pure membranous nephropathy: a phase II trial
(OBLUMEN)
skipped — LLM skipped (--skip-llm)
- ctis·2025-523654-13-00·Authorised·A multicentre, randomized, double-blind, placebo-controlled phase II/III trial investigating the efficacy of anti-FcRn targeting with efgartigimod as a first-line add-on therapy to IVMP in moderate-to-severe attacks of demyelinating diseases of the central nervous system
skipped — LLM skipped (--skip-llm)
- ctis·2025-524181-26-00·Authorised·A Phase 2, Open-Label, Single-Arm, Multicenter Study to Evaluate the Efficacy of Cemsidomide + Dexamethasone in Subjects With Relapsed/Refractory Multiple Myeloma (r/r MM)
skipped — LLM skipped (--skip-llm)
- ctis·2025-521891-78-00·Authorised·IMMUNOTIME « EVALUATION OF THE EFFECT OF TIME OF ADMINISTRATION ON THE ACTIVITY ON FIRST LINE OF PEMBROLIZUMAB IN ASSOCIATION WITH CARBOPLATIN PEMETREXED IN METASTATIC NON-SQUAMOUS LUNG CANCER. A RANDOMISED MULTICENTER PHASE III TRIAL»
skipped — LLM skipped (--skip-llm)
- ctis·2025-523868-20-00·Authorised·Efficacy and safety of a novel dual pH-dependent delayed-release ColeseveLam for the trEatment of bile Acid diarrhoea: a Randomized, double-blind, parallel-group, placebo-controlled clinical trial - CLEAR
skipped — LLM skipped (--skip-llm)
- ctis·2024-519941-32-00·Authorised·A SINGLE-ARM, OPEN-LABEL, PHASE II STUDY TO DETERMINE THE SAFETY AND EFFICACY OF OBECABTAGENE AUTOLEUCEL (OBE-CEL) IN PARTICIPANTS WITH SEVERE, REFRACTORY SYSTEMIC LUPUS ERYTHEMATOSUS WITH ACTIVE LUPUS NEPHRITIS
skipped — LLM skipped (--skip-llm)
- ctis·2025-520918-64-00·Authorised, recruiting·A Phase II Open-Label Pilot Trial Assessing the Safety of Anifrolumab in Adult Patients with Primary Antiphospholipid Syndrome (APS). The AnifAPS trial.
skipped — LLM skipped (--skip-llm)
- ctis·2024-518824-56-00·Authorised, recruiting·Pregabalin or Baclofen in Spastic Motor Behavior Treatment After SCI (PoBSCI), Prospective, Double-Blind, Randomised Drug Study
skipped — LLM skipped (--skip-llm)
- ctis·2023-508930-33-00·Authorised, ongoing·CRYOBI study - A multicenter phase 2 single-arm proof-of-concept trial assessing the efficacy and safety of Obinutuzumab in the treatment of non-infectious active cryoglobulinemia vasculitis refractory or intolerant to Rituximab
skipped — LLM skipped (--skip-llm)
- ctis·2024-519930-22-00·Authorised, ongoing·A Phase II Open-Label Study to Evaluate the Efficacy, Safety, and Pharmacokinetics of Mosunetuzumab in Patients with Systemic Lupus Erythematosus with or without Active Lupus Nephritis
skipped — LLM skipped (--skip-llm)
- ctis·2025-521856-47-00·Authorised, ongoing·Treatment of Bile Acid Diarrhoea with Atorvastatin (BASTA)
skipped — LLM skipped (--skip-llm)
- ctis·2024-514440-86-00·Authorised, ongoing·Response-adaptive to Epcoritamab In FIrst Relapse: A Phase II, response-adaptive, Open-Label, Multicenter Study to Evaluate the Efficacy of Eptoritamab in Patients with Relapse/Refractory Large B Cell Lymphoma
skipped — LLM skipped (--skip-llm)
- ctis·2024-512643-23-00·Expired·A phase I/IIa clinical trial to assess feasibility, safety and antitumor activity of autologous SLAMF7 CAR-T cells in multiple myeloma
skipped — LLM skipped (--skip-llm)
- ctis·2024-515039-31-00·Cancelled·Isatuximab in type I cryoglobulinemia: A prospective pilot study / ICE STUDY
skipped — LLM skipped (--skip-llm)
- ctis·2024-516237-12-00·Authorised, ongoing·TRIBECA - Multicenter randomized double-blind study comparing the efficacy and safety of belimumab in the treatment of non-infectious active cryoglobulinemia vasculitis compared to placebo
TRIBECA STUDY (Treatment after RItuximab with BElimumab in mixed Cryoglobulinemia Associated vasculitis)
skipped — LLM skipped (--skip-llm)
- ctis·2024-516773-69-00·Cancelled·Evaluation of the safety and efficacy of Berubicin in the treatment of central nervous system lymphomas- BERUBICIN
skipped — LLM skipped (--skip-llm)
- ctis·2024-516466-11-00·Authorised, ongoing·A Phase II Multicentric Study of Olaparib in PALB2-related Advanced Pancreatic Cancer (PALBOLA)
skipped — LLM skipped (--skip-llm)
- ctis·2024-516770-29-00·Cancelled·ANISE-II; ANIfrolumab treatment for 24 weeks in patients with primary Sjögren’s syndrome – Efficacy and safety assessment in a randomized, double-blind, placebo-controlled phase-IIa proof-of-concept trial
skipped — LLM skipped (--skip-llm)
- ctis·2024-517083-32-00·Expired·A phase 2 clinical trial assessing the efficacy and safety of adding cladribine for treatment modifying course of seropositive myasthenia gravis
skipped — LLM skipped (--skip-llm)
- ctis·2023-507613-10-01·Authorised, ongoing·A Phase 1/2 Open-Label Study to Evaluate the Safety and Efficacy of Autologous CD19-specific Chimeric Antigen Receptor T cells (CABA-201) in Subjects with Active Systemic Lupus Erythematosus
skipped — LLM skipped (--skip-llm)
- ctis·2024-516739-29-00·Authorised, recruiting·P2-IMU-838-MS - Randomized, double-blind, placebo-controlled, multicenter Phase 2 trial assessing the effect of IMU-838 on disease activity, as measured by magnetic resonance imaging (MRI), as well as safety and tolerability in patients with relapsingremitting multiple sclerosis (RRMS) (EMPhASIS)
skipped — LLM skipped (--skip-llm)
- ctis·2024-512232-30-00·Expired·A Double-blind, Randomized, Placebo-Controlled Study and Open-label Long Term Extension to Evaluate the Efficacy and Safety of Elafibranor 80 mg in Patients with Primary Biliary Cholangitis with Inadequate Response or Intolerance to Ursodeoxycholic Acid
skipped — LLM skipped (--skip-llm)
- ctis·2023-505825-15-00·Authorised, ongoing·A Phase II, Randomized, Double-Blind, Placebo-Controlled, Multicenter Study to Evaluate the Efficacy, Safety, and Pharmacokinetics of Obinutuzumab in Adolescent Patients with Active Class III or IV Lupus Nephritis, Including an Evaluation of Open Label Safety and PK in a Cohort of Pediatric Patients (Aged 5 To < 12)
skipped — LLM skipped (--skip-llm)
- ctis·2024-516819-24-00·Authorised, ongoing·CAR-T cells in systemic B cell mediated autoimmune disease - CASTLE
skipped — LLM skipped (--skip-llm)
- ctis·2024-513584-77-00·Cancelled·A Phase 2a, Double-Blind, Randomized, Active Controlled, Parallel Group Study Evaluating the Efficacy, Safety, and Tolerability of Bezafibrate Administered in Combination with Obeticholic Acid in Subjects with Primary Biliary Cholangitis
skipped — LLM skipped (--skip-llm)
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 Immunodeficiency due to a classical component pathway complement deficiency — check Associations / patient organisations on that page.
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.
"Immunodeficiency due to a classical component pathway complement deficiency" OR "Immunodeficiency due to C1, C4, or C2 component complement deficiency" OR "Immunodeficiency due to an early component of complement deficiency" OR "Immunodeficiency due to an early component of the complement deficiency" OR "immunodeficiency due to a C1, C4, or C2 component complement deficiency"
ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"Immunodeficiency due to a classical component pathway complement deficiency" OR "Immunodeficiency due to C1, C4, or C2 component complement deficiency" OR "Immunodeficiency due to an early component of complement deficiency" OR "Immunodeficiency due to an early component of the complement deficiency" OR "immunodeficiency due to a C1, C4, or C2 component complement deficiency"
Study-type breakdown: 0 interventional · 0 observational · 0 expanded access. Only interventional studies enter the trial headline.
Parent-category trials query:
"complement deficiency"
Query health: ok — strategies attempted: phrase; with hits: phrase
Run this search on ClinicalTrials.gov
Confidence reasoning
- Preferred label is multi-word and distinctive
- No synonyms dropped by stoplist
- No label/synonym collisions with other diseases in this corpus
Ingested 2026-07-27T08:36:02.053Z