Secretor Status and Phenylthiocarbamide (PTC) Taste Perception 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 (χ2 = 8.62, df = 1, p = 0.002). Non-tasters of PTC were significantly more associated with test patients than controls (χ2=10.68, df=1, p=0.001). When combined, secretors and tasters were significantly lower in the test group than in the control group (χ2=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 (χ2=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.