The hidden impact of different Blastocystis genotypes on C-3 and IgE serum levels: a matter of debate in asthmatic Egyptian children

Abstract

Blastocystis hominis is highly prevalent with respiratory allergies among Egyptian children. Yet, little is known about the possible immunological relationship. Aims of this study were to measure complement-3 (C-3), total and specific IgE to intestinal allergens in patients' serum regarding the identified B. hominis genotypes. In a cross-sectional study, three hundred children (150 asthmatics and 150 non asthmatics) participated in the study from both sexes, mean age 7.5 ± SD (3-4) years after a questionnaire administration. PCR-based genotyping of B. hominis selective in vitro cultivation was performed. C-3, total and specific IgE were all measured in patients' serum utilizing ELISA. Blastocystosis was detected in 100 out of 300 children, 65 (43.3%) out of 150 asthmatics and 35 (23.3%) out of 150 non-asthmatics. Vacuolar forms were the most prevalent in both direct wet mount and stool cultures. Forty (61.5%) out 65 asthmatics and 5 (14.2%) out of 35 non-asthmatics were C 5 organisms/HPF. Sex and irritable bowel disease were statistically insignificant (p value \ 0.05). Urticaria was coincided in 15.4% of asthmatics and 8.6% of non-asthmatics. Of 100 cases of blastocystosis, eighty-four were genotype-3 and sixteen were genotype-4. Out of these, 55 cases of genotype-3 and 6 cases of genotype-4 were asthmatics. Positive C-3 serum levels were in 46 (54.81%) of genotype-3 and 2 (12.5%) of genotype-4. High total IgE levels in 30 (35.7%) out of 84 cases of genotype-3 and 4 (25%) out of 16 cases of genotype-4. Positive specific IgE was in 25 (29.8%) of genotype-3 and 3 (18.75%) of genotype-4. Genotype-3 was of higher infection intensity (p value = 0.0001). In conclusion, B. hominis possess a hidden allergy triggering impact that can be obscured by simultaneous high (total and specific) IgE levels towards specific common intestinal allergens. Blastocystosis induces allergy by increasing C-3 serum levels in a genotype-dependent manner being higher in genotype-3. Virulence of genotype-3 seems to stand beyond increased parasite intensity and wide absorption of intestinal allergens that indirectly elevate IgE serum levels.

Epidemiology of Blastocystis infection from 1990 to 2019 in China

“…Clinical manifestations of Blastocystis are very diverse, including acute or chronic diarrhea, abdominal pain, nausea, anorexia, bloating, fatigue and flatulence [ 11 , 12 ], along with allergy [ 13 ]. The prevalence of Blastocystis is high.…”

“…Blastocystis ST1 is regarded as a pathogenic subtype and associated with irritable bowel syndrome diarrhoea (IBS-D) [ 17 ]. Blastocystis ST3 is considered to be virulent, which not only increases the pathogenicity of this parasite, but also increases the level of IgE in the serum, thereby causing allergies [ 13 ]. Jimenez et al [ 3 ] proposed that the pathogenicity of Blastocystis is still controversial for many reasons, for example, the high proportion of asymptomatic carriers, host susceptibility, differences in intestinal microbiota and different pathogenic potentials of different Blastocystis subtypes.…”

Epidemiology of Blastocystis sp. infection from 1990 to 2019 in China

“…Clinical manifestations of Blastocystis are very diverse, including acute or chronic diarrhea, abdominal pain, nausea, anorexia, bloating, fatigue and atulence [11,12], along with allergy [13]. The prevalence of Blastocystis is high.…”

“…Blastocystis ST1 is regarded as a pathogenic subtype and associated with irritable bowel syndrome diarrhoea (IBS-D) [17]. Blastocystis ST3 is considered to be virulent, which not only increases the pathogenicity of this parasite, but also increases the level of IgE in the serum, thereby causing allergies [13]. Jimenez et al [3] proposed that the pathogenicity of Blastocystis is still controversial for many reasons, for example, the high proportion of asymptomatic carriers, host susceptibility, differences in intestinal microbiota and different pathogenic potentials of different Blastocystis subtypes.…”

Literature Analysis of Blastocystis sp. from 1990 to 2019 in China

“…Clinical manifestations of Blastocystis are very diverse, including acute or chronic diarrhea, abdominal pain, nausea, anorexia, bloating, fatigue and flatulence [11,12], along with allergy [13]. The prevalence of Blastocystis is high.…”