Cryptosporidium infection in patients with primary immunodeficiencies

Background: Cryptosporidium species infection is usually self-limited in immunocompetent populations, but can be severe and life-threatening among immunocompromised individuals, particularly in patients with AIDS and in these patients with primary immumodeficiencies (PIDs). Patients and Methods: A group of 5 patients with genetically confirmed hyper-IgM syndrome type I (XHIM) and one patient with primary CD4 lymphopenia were enrolled in the study. At least 2 stool samples and a bile sample in one patient were examined for Cryptosporidium oocysts by a modified Ziehl-Neelsen technique, by immunofluorescence assay using a commercial kit, as well as by molecular analysis followed by genotyping. Immunological status at the time of PID diagnosis and the complex picture of disease are presented. Results: Chronic cryptosporidiosis was confirmed in 3 patients with XHIM and in one patient with primary CD4 lymphopenia. Molecular diagnosis showed the presence of C parvum, C hominis, and C meleagridis in analyzed specimens. Conclusions: Cryptosporidium infection with serious clinical symptoms observed in patients with hyper-IgM syndrome calls for regular, repeated screening in this group of patients. JPGN 45:458-464, 2007.