Impact of Ultra-fast Genetic Diagnosis of Familial Lymphohistiocytosis on the Time to Bone Marrow Transplantation and Overall Survival

NCT07741747 · tracked via the Priya Life Science France tracker

Sponsor

Assistance Publique Hopitaux De Marseille

Phase

Not applicable

Started

2026-10

Last updated

2026-08-03

Condition(s) studied

Familial LymphohistiocytosisLymphohistiocytosis

Investigational drug(s) / intervention(s)

Third-generation sequencing

Third-generation sequencing: Blood sample will be collected in order to perform the third-generation sequencing testing which sould give results in a 5 day delay, instead of 6-8 weeks (standard testing)

Study summary

Familial lymphohistiocytosis (FHL) is a group of rare genetic diseases (around fifteen cases per year in France). The defect in T lymphocyte cytotoxicity resulting from this disease is responsible for hemophagocytic lymphohistiocytosis (HLH). Promptly treatment of HLH is essential for prognosis. These diseases are fatal without a bone marrow transplant, with an overall 5-year survival rate of no more than 80% for FHL. The genetic or acquired nature of HLH is not easy to determine. An infectious trigger can be confounding when it occurs in an FHL. But above all, functional biological tests demonstrating a T lymphocyte cytotoxicity defects are difficult to interpret. Genetic diagnosis is therefore essential for confirming the primary nature of HLH, and for initiating targeted treatments (first stage: putting HLH into remission with chemotherapy or immunotherapy; second stage: bone marrow transplant). Genetic diagnosis of FHL is therefore a matter of emergency, and is currently based on targeted gene panel exploration (fragmentation sequencing) requiring 6 to 8 weeks. Recently, the development of third-generation sequencing (TGS) has revolutionized genomic medicine, enabling unitary sequencing in real time. As a result of this innovation, certain private molecular diagnostic specialties can now access this new emergency genomic medicine.

Aim: the main aim of this study is to demonstrate the feasibility of a national circuit for ultra-rapid genetic diagnosis of pediatric HLH revealing familial lymphohistiocytosis. The secondary objective is to evaluate the impact of this early genetic diagnosis on the delay to remission of HLH and the delay to transplantation.

Methods: This prospective, multicenter study measures the time required for genetic diagnosis of FHL in pediatric HLH, using innovative TGS sequencing technology.

Perspectives: Fast genomic diagnosis of FHL will considerably shorten the time to confirm the diagnosis, to obtain HLH remission and, finally, to reach transplantation faster.

Eligibility

Sex

ALL

Min age

—

Max age

18 Years

Healthy volunteers

Inclusion Criteria: * Children under 18 years old * Confirmed or suspected diagnosis of FHL or a related genetic syndrome predisposing to HLH (e.g. Griscelli Syndrome, Chédiak-Higashi Syndrome, XLP1, XLP2) or a family history of lymphohistiocytic activation syndrome * Presence of at least 5 of the 8 following criteria (diagnostic criteria according to the definition of the "Histiocyte Society" (1)): 1. Fever 2. Splenomegaly 3. Hypertriglyceridemia ≥ 3 mmol/l and/or hypofibrinogenemia≤ 1.5g/l 4. Hemophagocytosis found in a histological sample 5. Decreased or absent NK function (\<10% of the laboratory normal) 6. Ferritin ≥ 500μg/l 7. Soluble CD25 ≥ 2,400U/ml or presence of activated T cells in phenotyping 8. Cytopenia (affecting at least two blood cell lines): Haemoglobin \< 9.0 g/dl, Platelets \<100 G/L, Neutrophils \<1,0 G/L * Patient benefiting from social security coverage * The legal guardian(s) who have signed the informed consent form Exclusion Criteria: * Age ≥ 18 years * Solid tumor, leukemia, lymphoma * Subjects covered by articles L1121-5 to 1121-8 of the public health code (patients under guardianship or curatorship, patient deprived of liberty, pregnant or breadtfeeding woman) * Persons who do not understand the French language * Patient in the exclusion period of another research protocol at the time of signing the consent form

Primary outcome measure(s)

Time (in days) from clinical suspicion to hematopoietic stem cell transplantation — From enrollment until 24 months post transplantation

Trial sites (1)

Facility	City	Region	Status
Assistance Publique - Hôpitaux de Marseille	Marseille	France

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Official registry record

This page summarises publicly available registry data for informational purposes — not medical advice. Eligibility is determined by each study team; patients should discuss participation with their clinician.

View NCT07741747 on ClinicalTrials.gov ↗ ← All trials in France