Rare Histiocytic Disorders (RHDs)IRHDRNCT02285582
International Rare Histiocytic Disorders Registry (IRHDR)
An observational study of Rare Histiocytic Disorders (RHDs) and Erdheim-Chester Disease (ECD), run by The Hospital for Sick Children at 15 sites in 9 countries.
Trial summary
The rare histiocytic disorders (RHDs) are characterized by the infiltration of one or more organs by non-LCH histiocytes. They can range from localized disease that resolves spontaneously, to progressive disseminated forms that can be sometimes life-threatening. Read more about this study
- Who is it for?
- Any age
- Conditions the study is for
- Rare Histiocytic Disorders (RHDs), Erdheim-Chester Disease (ECD), Rosai-Dorfman Disease (RDD)
- What is being tested?
- Registry study
- How many people
- 400 participants
- Where
- 15 sitesin 9 countries
- Study dates
- Oct 2014to Sep 2028
- How long will I take part?
- 10 Years
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Any age
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Study population: Rare Histiocytic Disorders: 1. Xanthogranuloma Family (XG) * Cutaneous * Benign cephalic histiocytosis (BCH) * Generalized eruptive histiocytosis (GEH) * Progressive nodular histiocytosis (PNH) * Xanthoma disseminatum (XD) * Giant XG * Reticulohistiocytoma * Ocular * Systemic 2. Erdheim-Chester Disease (ECD) 3. Rosai-Dorfman disease (RDD) * Single system * Nodal * Extranodal * Skin * CNS * Bone * Orbit * Other * Multisystemic 4. Indeterminate Dendritic Cell Histiocytosis 5. Malignant Histiocytic Neoplasm (MHN) * Histiocytic * Langerhans cell * Interdigitating dendritic cell * Indeterminate dendritic cell * Primary MHN * Secondary to: * ALL * Follicular lymphoma * Other B-cell lymphoma * Other hematologic malignancy * Histiocytosis 6. ALK-positive Histiocytosis 7. Mixed Histiocytosis (MXH) * ECD/LCH * RDD/LCH * RDD/ECD * LCH/JXG * Other 8. Other * Multicentric reticulohistiocytoma (MRH) * Necrobiotic xanthogranuloma (NX) * Not otherwise specified (NOS)
Who may be able to join
- Any age at diagnosis.
- Diagnosis of a rare histiocytic disorder, established before or after the opening of the registry.
- Cases diagnosed from January - 01- 1995 until the present time and prospectively.
- Signed informed consent by a patient, or parent/legal guardian.
- Cognitively impaired patients can be included after consent by legal guardian/parent.
- Deceased patients can be included if they are contacted at least 6 months after the death of their child and not on their child's birthday or anniversary of death.
Who cannot join
- Informed consent has not been signed.
- Diagnosis other than RHD.
- Cases diagnosed before the year 1995.
Trial locations and contacts
15 sites in 9 countries. Contact the study team or a site near you to ask about taking part.
15 sites in 9 countries
United States6 sites, 6 recruiting
- Recruiting
The University of Alabama at Birmingham
Birmingham, Alabama
Gaurav Goyal, MD, ggoyal@uabmc.edu
Gaurav Goyal
- Recruiting
Dana-Farber Cancer Institute
Boston, Massachusetts, 02215
Barbara Degar, MD, barbara_degar@dfci.harvard.edu
Barbara Degar, MD
- Recruiting
Children's Hospital of Los Angeles
Los Angeles, California, 90027
Rima Jubran, MD, 323-361-4624, rjubran@chla.usc.edu
Rima Jubran, MD
- Recruiting
Valley Children's Hospital
Madera, California, 93636
Faisal Razzaqi, MD, 559-353-3000, frazzaqi@valleychildrens.org
Faizal Razzaqi, MD
- Recruiting
Memorial Sloan Kettering Cancer Center
New York, New York, 10022
Eli Diamond, MD, 212-610-0188, diamone1@mskcc.org
Eli Diamond, MD
- Recruiting
University of Pittsburgh Medical Center
Pittsburgh, Pennsylvania, 15219
Steven Allen, MD, steven.allen@chp.edu
Steven Allen, MD
Canada2 sites, 1 recruiting
- Active, not recruiting
Centre hospitalier universitaire Sainte-Justine
Montreal, Quebec, H3T 1C5
- Recruiting
The Hospital for Sick Children
Toronto, Ontario, M5G 1X8
Oussama Abla, MD, 416-813-7879, oussama.abla@sickkids.ca
Arnelle Lardizabal, HBSc, 416-813-6431 ext. 406431, arnelle.lardizabal@sickkids.ca
Argentina1 site, 1 recruiting
- Recruiting
Hospital Nacional de Pediatria Garrahan
Buenos Aires
Guido Felizzia, MD, 5411 41226254, guidofelizzia@gmail.com
Guido Felizzia, MD
Czechia1 site, 1 recruiting
- Recruiting
University Hospital Brno
Brno
Zdenka Křenová, MD, Krenova.Z@seznam.cz
Zdenka Křenová, MD
Germany1 site, 1 recruiting
- Recruiting
Rostock University Medical Hospital
Rostock
Carl Friedrich Classen, MD, carl-friedrich.classen@med.uni-rostock.de
Carl Friedrich Classen, MD
Italy1 site, 1 recruiting
- Recruiting
Azienda Ospedaliero-Universitaria Meyer
Florence
Elena Sieni, MD, elena.sieni@meyer.it
Elena Sieni, MD
Netherlands1 site, 1 recruiting
- Recruiting
Prinses Maxima Center
Utrecht, CS, 3584
Leonie Naeije, MD, l.naeije-3@prinsesmaximacentrum.nl
Leonie Naeije, MD
Poland1 site, 1 recruiting
- Recruiting
Children's Memorial Health Institute
Warsaw
Olga Gryniewicz-Kwiatkowska, MD, O.Gryniewicz@IPCZD.PL
Olga Gryniewicz-Kwiatkowska, MD
Spain1 site, 1 recruiting
- Recruiting
Hospital Universitario Cruces
Barakaldo
Itziar Astigarraga, MD, 34 946006000
Itziar Astigarraga, MD
About this study
The rare histiocytic disorders (RHDs) are characterized by the infiltration of one or more organs by non-LCH histiocytes. They can range from localized disease that resolves spontaneously, to progressive disseminated forms that can be sometimes life-threatening. Since they are extremely rare, there is limited understanding of their causes and best treatment options. Physicians, patients and parents of children with RHDs frequently consult members of the Histiocyte Society regarding the best management of these disorders. Very often, no specific recommendation can be made due to the lack of prospective outcome data, or even large retrospective case series. The creation of an international rare histiocytic disorders registry (IRHDR) could facilitate a uniform diagnosis of the RHDs, as well as the collection and analysis of the clinical, epidemiological, treatment and survival data of patients with RHD. The registry may also lead to future therapeutic recommendations, provide a framework for future clinical trials and create excellent research opportunities.
Read the detailed description
Histiocytoses are rare diseases caused by an excess of cells called Histiocytes, which can infiltrate the skin, bones, lungs, liver, spleen and the central nervous system. These disorders can range from localized involvement that resolves spontaneously, to progressive disseminated forms that can be debilitating and sometimes life-threatening. The rare histiocytic disorders (RHD), or non-Langerhans cell disorders, are a diverse group of disorders defined by the accumulation of histiocytes that do not meet the criteria for Langerhans cell histiocytosis (LCH) or hemophagocytic lymphohistiocytosis (HLH). They include: Juvenile xanthogranuloma family, Erdheim-Chester disease, Multifocal Reticulohistiocytosis, Rosai-Dorfman disease and the Malignant Histiocytoses. Since they are so rare, there is limited understanding of their causes and treatments. Physicians, patients and parents of children with rare histiocytoses frequently consult members of the Histiocyte Society on the management of these disorders. Very often, no specific recommendation about treatment can be made due to the lack of prospective outcome data for these rare entities. The creation of an International Rare Histiocytic Disorders Registry (IRHDR) will facilitate a uniform diagnosis of the RHD's, as well as the collection and analysis of the clinical, epidemiological, treatment and survival data of patients with RHD. The registry will also provide expert pathology reviews and may lead to future therapeutic recommendations. Furthermore, the IRHDR can provide a framework for future clinical trials, thus, creating excellent research opportunities. Lastly, a de-identified link between clinical data and companion biology studies can potentially be accomplished in the future through the IRHDR. This may further help in understanding the etiology of these rare diseases, as well as identifying potential therapeutic targets.
- Conditions
- Rare Histiocytic Disorders (RHDs), Erdheim-Chester Disease (ECD), Rosai-Dorfman Disease (RDD), Xanthogranuloma Family (XG), Indeterminate Dendritic Cell Histiocytosis, Malignant Histiocytic Neoplasm (MHN)
- Being tested
- Registry study
- Medical subject headings
- Erdheim-Chester Disease, Histiocytosis, Sinus, Necrobiotic Xanthogranuloma
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Registry studyOther
No intervention.
What is being measured
The primary outcome is the main question the study is designed to answer.
Collecting data on disease presentation, treatments used and treatment outcomes over time for patients diagnosed with RHD to better understand the diseases and optimize the treatments.
Collecting data on disease presentation, treatments used and treatment outcomes over time for patients diagnosed with RHD to better understand the diseases and optimize the treatments. Data will be analysed on average yearly, the registry will be ongoing for 10 years.
Measured: Data will be analysed on average yearly, the registry will be ongoing for 10 years.
Secondary outcomes (1)
Develop treatment guidelines for the RHD based on solid clinical trial data.
Develop treatment guidelines for the RHD based on solid clinical trial data. Data will be analysed on average yearly, the registry will be ongoing for 10 years.
Measured: Data will be analysed on average yearly, the registry will be ongoing for 10 years.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Nov 2014 (estimated)
- Study startOct 2014
- Primary completionSep 2028 (estimated)
- Study completionSep 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Rare Histiocytic Disorders (RHDs)Studies of the same condition, open and under way.
- More trials run by The Hospital for Sick ChildrenThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case only
- Time perspective
- Other
- Enrolment
- 400 participants (estimated)
- Target duration
- 10 Years
Sponsor and investigators
- Lead sponsor
- The Hospital for Sick Children
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Oussama Abla, The Hospital for Sick Children
- Investigators
- Oussama Abla, MD, Principal investigator, The Hospital for Sick Children
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02285582
- Sponsor's protocol ID
- 1000045224
- Acronym
- IRHDR
- Status last verified
- Jun 2025
- First submitted
- 3 Nov 2014
- Last updated
- 24 Jun 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Weitzman S, Jaffe R. Uncommon histiocytic disorders: the non-Langerhans cell histiocytoses. Pediatr Blood Cancer. 2005 Sep;45(3):256-64. doi: 10.1002/pbc.20246.
PubMed 15547923
Study at a glance
From the registry record, last updated by the sponsor on 24 Jun 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- International Rare Histiocytic Disorders Registry (IRHDR)
- ClinicalTrials.gov ID
- NCT02285582
- Acronym / sponsor ID
- IRHDR / 1000045224
- Conditions
- Rare Histiocytic Disorders (RHDs), Erdheim-Chester Disease (ECD), Rosai-Dorfman Disease (RDD), Xanthogranuloma Family (XG), Indeterminate Dendritic Cell Histiocytosis, Malignant Histiocytic Neoplasm (MHN)
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 400 participants (estimated)
- Lead sponsor
- The Hospital for Sick ChildrenUniversity, hospital or other
- Study start
- Oct 2014
- Primary completion
- Sep 2028 (estimated)
- Study completion
- Sep 2028 (estimated)
- First posted
- 7 Nov 2014 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The rare histiocytic disorders (RHDs) are characterized by the infiltration of one or more organs by non-LCH histiocytes. They can range from localized disease that resolves spontaneously, to progressive disseminated forms that can be sometimes life-threatening. Since they are extremely rare, there is limited understanding of their causes and best treatment options. Physicians, patients and parents of children with RHDs frequently consult members of the Histiocyte Society regarding the best management of these disorders. Very often, no specific recommendation can be made due to the lack of prospective outcome data, or even large retrospective case series. The creation of an international rare histiocytic disorders registry (IRHDR) could facilitate a uniform diagnosis of the RHDs, as well as the collection and analysis of the clinical, epidemiological, treatment and survival data of patients with RHD. The registry may also lead to future therapeutic recommendations, provide a framework for future clinical trials and create excellent research opportunities.
Detailed description
Histiocytoses are rare diseases caused by an excess of cells called Histiocytes, which can infiltrate the skin, bones, lungs, liver, spleen and the central nervous system. These disorders can range from localized involvement that resolves spontaneously, to progressive disseminated forms that can be debilitating and sometimes life-threatening. The rare histiocytic disorders (RHD), or non-Langerhans cell disorders, are a diverse group of disorders defined by the accumulation of histiocytes that do not meet the criteria for Langerhans cell histiocytosis (LCH) or hemophagocytic lymphohistiocytosis (HLH). They include: Juvenile xanthogranuloma family, Erdheim-Chester disease, Multifocal Reticulohistiocytosis, Rosai-Dorfman disease and the Malignant Histiocytoses. Since they are so rare, there is limited understanding of their causes and treatments. Physicians, patients and parents of children with rare histiocytoses frequently consult members of the Histiocyte Society on the management of these disorders. Very often, no specific recommendation about treatment can be made due to the lack of prospective outcome data for these rare entities. The creation of an International Rare Histiocytic Disorders Registry (IRHDR) will facilitate a uniform diagnosis of the RHD's, as well as the collection and analysis of the clinical, epidemiological, treatment and survival data of patients with RHD. The registry will also provide expert pathology reviews and may lead to future therapeutic recommendations. Furthermore, the IRHDR can provide a framework for future clinical trials, thus, creating excellent research opportunities. Lastly, a de-identified link between clinical data and companion biology studies can potentially be accomplished in the future through the IRHDR. This may further help in understanding the etiology of these rare diseases, as well as identifying potential therapeutic targets.
Study design
- Observational model
- Case only
- Time perspective
- Other
- Target follow-up
- 10 Years
Who may qualify
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
- Study population
- Rare Histiocytic Disorders: 1. Xanthogranuloma Family (XG) * Cutaneous * Benign cephalic histiocytosis (BCH) * Generalized eruptive histiocytosis (GEH) * Progressive nodular histiocytosis (PNH) * Xanthoma disseminatum (XD) * Giant XG * Reticulohistiocytoma * Ocular * Systemic 2. Erdheim-Chester Disease (ECD) 3. Rosai-Dorfman disease (RDD) * Single system * Nodal * Extranodal * Skin * CNS * Bone * Orbit * Other * Multisystemic 4. Indeterminate Dendritic Cell Histiocytosis 5. Malignant Histiocytic Neoplasm (MHN) * Histiocytic * Langerhans cell * Interdigitating dendritic cell * Indeterminate dendritic cell * Primary MHN * Secondary to: * ALL * Follicular lymphoma * Other B-cell lymphoma * Other hematologic malignancy * Histiocytosis 6. ALK-positive Histiocytosis 7. Mixed Histiocytosis (MXH) * ECD/LCH * RDD/LCH * RDD/ECD * LCH/JXG * Other 8. Other * Multicentric reticulohistiocytoma (MRH) * Necrobiotic xanthogranuloma (NX) * Not otherwise specified (NOS)
Key inclusion criteria (6 listed)
- Any age at diagnosis.
- Diagnosis of a rare histiocytic disorder, established before or after the opening of the registry.
- Cases diagnosed from January - 01- 1995 until the present time and prospectively.
- Signed informed consent by a patient, or parent/legal guardian.
- Cognitively impaired patients can be included after consent by legal guardian/parent.
Key exclusion criteria (3 listed)
- Informed consent has not been signed.
- Diagnosis other than RHD.
- Cases diagnosed before the year 1995.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Registry studyNo intervention. | Other | – |
Primary outcome
Collecting data on disease presentation, treatments used and treatment outcomes over time for patients diagnosed with RHD to better understand the diseases and optimize the treatments.
Time frame: Data will be analysed on average yearly, the registry will be ongoing for 10 years.
Collecting data on disease presentation, treatments used and treatment outcomes over time for patients diagnosed with RHD to better understand the diseases and optimize the treatments. Data will be analysed on average yearly, the registry will be ongoing for 10 years.
1 secondary outcome
Develop treatment guidelines for the RHD based on solid clinical trial data.
Time frame: Data will be analysed on average yearly, the registry will be ongoing for 10 years.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 24 Jun 2025.
- Background: PubMed 15547923Weitzman S, Jaffe R. Uncommon histiocytic disorders: the non-Langerhans cell histiocytoses. Pediatr Blood Cancer. 2005 Sep;45(3):256-64. doi: 10.1002/pbc.20246.
- Individual participant dataSharing planned: No
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Oussama Abla, MD principal investigator
The Hospital for Sick Children
15 sites in 9 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Rare Histiocytic Disorders (RHDs) and Erdheim-Chester Disease (ECD), run by The Hospital for Sick Children at 15 sites in 9 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 24 Jun 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 15 sites in United States, Canada, Argentina, Czechia, Germany and 4 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Oussama Abla, MD (416-813-7879 ext. 407879, oussama.abla@sickkids.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Collecting data on disease presentation, treatments used and treatment outcomes over time for patients diagnosed with RHD to better understand the diseases and optimize the treatments. (time frame: Data will be analysed on average yearly, the registry will be ongoing for 10 years.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT02285582, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 24 Jun 2025; AzTrials last refreshed its copy on 7 Nov 2026.