Introduction: IEI comprise a group of heterogeneous and complex diseases in which infectious manifestations are prominent. To facilitate the understanding of the immunological defect involved, the identification of the microorganism and the mechanisms to eliminate it must be clarified. The purpose of this case report is to detail the unpublished story of a child with IEI.
Case report: TSS, girl, 3 years old, consanguineous parents, from Bahia. History of omphalitis and mastoiditis in the 1st year of life. From the age of two, severe anemia with robust monocytosis, massive hepatosplenomegaly and weight loss. The diagnosis of juvenile myelomonocytic leukemia was ruled out and diagnosis of type 1 leukocyte adhesion defect (LAD1) with variant in ITGB2: c.433-436del in homozygosity was made at 2 years and 2 months. After diagnosis presented macrophage activation syndrome (MAS) several times, with little response to corticosteroid and intravenous immunoglobulin G replacement therapy. Hepatomegaly is not part of the LAD picture as well as MAS. During clinical evolution she was presented with hypoalbuminemia and hepatic involvement (endothelitis) and underwent a liver biopsy. A diagnosis of infection by Crithidia fasciculata, a recently discovered protozoan with a phylogeny like Leishmania and Trypanosoma cruzi, was made. The patient received amphotericin B, glucantime and miltefosine, but had several relapses, leading to death.
Discussion: The IEI forms a group of surprising diseases, mainly in our country with different tropical diseases many times unprecedented. The view of Brazilian immunologist must go beyond the international literature and form connections with national expertise’s for a better understanding and care of these patients. To our knowledge, this is the 1st case of infection by Crithidia fasciculata in humans.