Severe Combined Immunodeficiency (SCID) is a rare congenital syndrome, characterized by cellular and humoral immunodeficiency which is fatal in the first two years of life. X-SCID is a variant, caused by a hemizigous mutation in IL-2 receptor γ-chain (IL2RG) gene. The R222C mutation, leads to atypical X-SCID, associates with classical clinical SCID picture despite normal NK and T-cell numbers. Delayed diagnosis leads to failure to thrive, absent tonsils/lymph nodes, chronic diarrhea, candidiasis and severe infections. Bone marrow transplantation (BMT) is a single curative therapy for this life threatening disease.
Described here a unique case of a child with the R222C mutation who presented with rash, loss of weight and significant liver impairment several months after BMT. Using lung bronchoscopy, liver and skin biopsies he was diagnosed with Langerhans cells histiocytosis (LCH), a rare disease with extremely variable clinical manifestations, characterized mainly with dysregulated proliferation of histiocytic cells.
This patient was successfully treated with high-dose steroids and Cytarabine. Currently M. is 4 years old, 1.5 years after completion of this therapeutic regimen. On last follow-up, he was in a good general condition, without any complaints and off any therapy.
However, this is the first report of LCH occurrence among post-BMT patients, inasmuch amongst post-BMT, SCID-infant. We want to discuss a possible correlation between LCH and SCID/post BMT immune dysregulation.
