Dr I. Benhsaien
Clinical Immunology Unit, Hospital A. Harouchi, Casablanca, Morocco
Translated by L. Jeddane

Background: The Chediak-Higashi syndrome (CHS) is characterized by partial oculocutaneous albinism, immunodeficiency and bleeding tendency. These signs result from functional anomalies of polymorphonuclears containing characteristics large lysosomal inclusions and a functional defect of NK cells (Natural Killer). Transmission is autosomal recessive. CHS gene was localized on the long arm of chromosome 1, 1q42.1-q42.2. Once suspected, the diagnosis is based on the presence of granules in the white blood cells on the blood smear.

The management of the disease requires control of hemophagocytic lymphohistiocytosis whose diagnosis criteria (fever, splenomegaly, bicytopenia, ferritin, hypertriglyceridemia or hypofibrinemia, high level of soluble CD25 fraction, decreased NK activity, hemophagocytosis in bone marrow) should not be all gathered to start the treatment that proves an emergency.

Curative treatment is based on the bone marrow transplant as soon as possible because there is always the risk of recurrence of hemophagocytic lymphohistiocytosis and this is also the treatment of immunodeficiency. Platelet transfusion if bleeding is important, vision correction and physical reeducation can be required.

The prognosis is very severe in the absence of hematopoietic stem cell transplantation, approximately 85% of affected children develop hemophagocytic lymphohistiocytosis, lymphoproliferative infiltration of the bone marrow and reticulo-endothelial system. The evolution is marked by neurological deterioration despite a bone marrow transplant.

Case: We present the case of a ten months-old boy from 1^st degree cousins, who presented with a prolonged fever for 1 month accompanied by chronic diarrhea.

At clinical examination: The patient had failure to thrive, hypopigmented clear skin, gray hair, a maculopapular rash, splenomegaly (4 cm) without hepatomegaly and bilateral otitis.
The explorations revealed anemia (7.6 g / dl) without anomaly on the white or platelet lineage. The blood smear objectified the presence of granulation within polymorphonuclear neutrophils, and the hair study showed granules forming a pigment aggregation. The study of lymphocyte subpopulations revealed no abnormality; also the levels of serum immunoglobulins was normal for his age.

The child received a ceftazidime-based antibiotic for the treatment of otitis with good evolution. After a week, the infant presented with persistent fever and splenomegaly. Laboratory tests noted elevated serum ferritin and high triglycerides levels. An HLH was diagnosed and the patient treated with steroids bolus and ciclosporin. Unfortunately, there was no possibility of a bone marrow transplant and the child is lost-to-follow up since its release three months ago.