Serological levels of cytokines in irritable bowel syndrome (IBS) patients and non-IBS subjects with and without Blastocystis spp. infection.

The objectives of the present study were to investigate the prevalence of Blastocystis spp. and to determine the levels of some pro-and anti-inflammatory cytokines in patients with irritable bowel syndrome (IBS) and without Blastocystis infection in comparison with non-IBS control individuals. Stool samples were collected from 250 IBS patients and 100 samples from controls, examined for the presence of Blastocystis and the percentage of infection was recorded. After that each group subdivided into two groups: non-IBS subjects not infected with Blastocystis (group 1), non-IBS subjects infected with Blastocystis (group 2), IBS patients not infected with Blastocystis (group 3), and IBS patients infected with Blastocystis (group 4). After that, blood samples were collected from 10 participant from each group and sera were separated and used for measuring the levels of the selected pro- and anti-inflammatory cytokines using ELISA method. The results revealed that about 60% of IBS patients were found infected with Blastocystis while 22% of the subjects in the control group were found infected with this parasite and the difference between the two groups was highly significant (P=0.0001). In addition, the results revealed that IBS patients with Blastocystis showed significantly higher In addition, the results revealed that IBS patients with Blastocystis showed significantly higher serum IL-6 (P=0.0004), IL-10 (P=<0.0001), IL-18 (P=0.0001), IFN-γ (P=<0.0001), and TNF-α (P=<0.0001) when compared with the subjects in the control group. Similarly, the non-IBS subjects infected with Blastocystis showed significantly higher serum IL-6 (P=0.0032), IL-10 (P=0.0001), IL-18 (P=0.0002), IFN-γ (P=0.0001), and TNF-α (P=0.0001) in comparison with the subjects in the control group. In conclusion, the infection with Blastocystis has a significant impact on the levels of all the selected cytokines.