Secretor Status and Taste Perception of Phenylthiocarbamide (PTC) are Risk Factors for Pulmonary Tuberculosis

Aim: To examine whether or not non-secretion of ABH substances and non-tasting of PTC are risk factors exhibiting positive interactions for tuberculosis. Methodology: A total of 210 individuals comprising 110 tuberculosis patients (test group) and 100 apparently healthy subjects (control group) participated in this study. Secretors and non-secretors were determined among the study participants by haemagglutination inhibition test and Tasters and non-tasters were determined using phenylthiocarbamide (PTC) taste strips (0.0143 mg/strip). Results: Of the 110 tuberculosis patients, 65 (59.1%) and 45 (40.9%) were secretors and non- secretors respectively while 49 (44.5%) were tasters and 61 (55.5%) were non-tasters. Of the 100 control subjects, 78% and 22% were secretors and non-secretors respectively while 67% and 33% were tasters and non-tasters respectively. Non-secretors of ABH substances were significantly more associated with test patients than controls (X2 = 8.62, df = 1, p = 0.002). Non-tasters of PTC were significantly more associated with test patients than controls (X2=10.68, df=1, p=0.001). When combined, secretors and tasters were significantly lower in the test group than in the control group (X2=13.44, df=1, p<0.001) while non-secretors and non-tasters were significantly higher in the test group than in the control group (X2=9.77, df=1, p=0.002). Individuals who were both non-secretors and non-tasters were significantly associated with tuberculosis compared to those who were not (OR 3.5; 95% C.I 1.59-7.51). Conclusion: This study shows that there is a remarkable increased incidence of tuberculosis in individuals who are both unable to secrete ABH substances and taste PTC. Also in this study, we found that tuberculosis patients were more likely to be non-tasters than those without tuberculosis.