Blastocystis ST1: Protein Profile and Specific Serum Immunoglobulin in Irritable Bowel Syndrome (IBS) Patients.

Abstract

Purpose: Blastocystis sp. is a common enteric human parasite, which recently has been linked to gastrointestinal disorders i.e. Irritable Bowel Syndrome (IBS) and symptomatic patients (non IBS). Analyzing antibodies level in these patients could help in differential diagnosis. The current study aimed to identify the protein profile of the Blastocystis ST1 (Syrian strain: OR537347) lysates and to investigate the differences in IgG serum immunoglobulin between patients with IBS and non IBS.

Methods: Twenty two IBS (Rome III) and nineteen patients suffering from different gastrointestinal disorders (non IBS), positive for Blastocystis were enrolled in this study. SDS-PAGE was used to identify the protein profile of the Blastocystis ST1 lysates and immunoblotting using sera from patients was used for reactivity compared to known Blastocystis protein targets.

Results: The crude protein profile of Blastocystis ST1 showed 24 protein bands ranged between 10 and 130 kDa. Western blot demonstrated that the proteins (27-29);32;(39-42);(50-51) kDa had similar immunogenicity characteristic in IBS and non IBS patients while the proteins (60-95 kDa) only interacted with IBS patients' sera.

Conclusions: Our results highlighted the importance of Blastocystis proteins 60-95 kDa (probably a metalloproteases) in IBS patients compared to non IBS, suggesting that these metalloproteases may be important Blastocystis antigens and can be used as a serologic test tool or as a biomarker for differential diagnosis.