Subtyping of Blastocystis in Urticarial Patients in Turkey

Aim: This study aims to investigate Blastocystis’ etiologic role and association with gastrointestinal symptomatology in acute and chronic urticaria patients and to identify Blastocystis subtypes responsible for urticaria. Method: The study included urticaria patients and healthy individuals referred to the Erzincan University Mengücek Gazi Training and Research Hospital Dermatology Polyclinic between June 2015 and May 2017. Participants were divided into Group I (133 patients), subdivided into acute (70) and chronic urticaria patients (63), and Group II (123 control individuals). Blastocystis presence was investigated by native-lugol examination, trichrome staining, PCR using STS primers, and DNA sequencing analysis. Sequences were aligned using CLUSTALW, and phylogenetic tree was constructed using MEGA version 7.0. Participants completed a questionnaire inquiring age, gender, urticaria existence, drinking-water source, animal raising, itching and gastrointestinal complaints. Results: The native-lugol and trichome staining methods revealed sixteen of 133 patients (12%) had Blastocystis positive stool samples. Seven positive samples (7/70; 10%) belonged to acute and nine (9/63; 14.3%) to chronic urticaria patients. Concerning Blastocystis subtypes, of the acute urticaria patients, three had ST1, one had ST2, and three had ST3. Of the chronic urticaria patients, one had ST1 and eight had ST3. Blastocystis positivity was detected in two control individuals (1.6%), both being ST3. All subtypes identified by PCR were confirmed by sequence analysis. The acute and chronic urticaria groups showed no statistically significant differences for Blastocystis positivity and subtype distribution (p = 0.595, p = 0.149). A statistically significant difference was found between urticaria patients and the control group for Blastocystis positivity but not for subtype distribution (p = 0.001, p = 0.658) or for Blastocystis presence and gender, drinkingwater source, animal raising, gastrointestinal complaints, itching. Conclusion: This is the first study on Blastocystis subtype distribution among Turkish urticaria patients and the results consistent with data from urticaria patient studies.