Incidence of Parasitic Diarrhea in Patients with Common Variable Immune Deficiency

Parasites might cause atypical and severe infections in immunocompromised hosts. The prevalence of diarrhea among common variable immune deficiency (CVID) syndrome patients varies between 20% and 94%, which indicates that diarrhea and gastrointestinal system (GIS) complaints could be the second leading cause of morbidity in CVID patients after respiratory tract infections. This study aimed to assess the prevalence of intestinal parasites in CVID patients with GIS complaints and diarrhea.

In this study, all cases followed up in the Immunology and Allergy Clinic of Ege University School of Medicine from July 2008 to August 2015 with the diagnosis of CVID were reviewed retrospectively. The stool samples of patients with diarrhea were identified using direct microscopy of native (0.09% NaCl) and Lugol's iodine preparations followed by formol-ethyl acetate concentration to apply modified Kinyoun, trichrome, acid-fast trichrome, and modified trichrome stains for the presence of intestinal parasites.

Overall, 26 of 37 CVID patients had diarrhea; white and red blood cells (WBCs and RBCs, respectively) were identified in 11 and 10 of these 26 samples, respectively. Intestinal parasites were found to be present in 7 of the 11 patients with WBCs and 3 of the 10 patients with RBCs. With the addition of patients who neither had WBCs nor RBCs in their stool, a parasitic agent was detected in 13 (50%) of the 26 patients with diarrhea. There was no significant difference between the diarrheic patients with or without intestinal parasites with respect to cramps, fever, nausea and vomiting, tenesmus, bloody feces, and presence of mucus in the stool. Only one patient had malabsorption, which was not associated with intestinal parasites. The most common parasites detected in this study were Cryptosporidium spp. (n=9; 69.2%), Giardia spp. (n=7; 53.8%), and Blastocystis spp. (n=3; 23.1%). We also identified that parasitic diarrhea in CVID patients tended to last longer (M (mean): 16.2 days) than other causes of infectious diarrhea; this is in accordance with previous studies.

Cryptosporidium spp. was found be the major cause of parasitic intestinal infection in this patient population. It was concluded that parasitic infections may cause chronic diarrhea, which are major causes of morbidity in CVID patients. Therefore, special attention is necessary for the identification of intestinal parasites in CVID patients with diarrhea.