The role of phenotypic factors in predicting the effectiveness of chemoprophylaxis in children

Abstract

Background. The purpose was to study the prognostic role of some phenotypic factors in the effectiveness of tuberculosis chemoprophylaxis in children at present stage. Materials and methods. To study the role of phenotypic factors in predic­ting the effectiveness of tuberculosis chemoprophylaxis, an analysis was performed of dermatoglyphic indicators, gender, and the inactivation phenotype of isonicotinic acid hydrazide (IAH) in 76 children with tuberculin skin test conversion who underwent a 3-month course of preventive therapy with isoniazid. Dermatoglyphics of fingers and palms was determined according to the standard method [5]. The dynamics of skin sensitivity to tuberculin PPD-L according to the Mantoux test with 2 tuberculin units was used as a criterion for the effectiveness of chemoprophylaxis. According to the latter, the examinees were divided into two groups: the first one consisted of 52 children in whom the size of a wheal decreased by 4 mm or more after the end of a course (effective chemoprevention); the second one included 24 patients in whom skin sensitivity to tuberculin increased or remained at the previous level or decreased by a wheal size for 3 mm or less (ineffective chemoprevention). Results. The conducted statistical analysis revealed a significant difference in 7 indicators between the groups (p < 0.05). Determination of their prognostic informativeness made it possible to rank the prognostic significance of phenotypic signs, namely: the size of the atd angle on the left palm (J = 1.7), the number of ulnar loops on the right hand (J = 1.4), the type of IAH inactivation (J = 1.3), the number of whorls on the right hand (J = 1.2), the total number of whorls (J = 1.1), the atd angle on the right palm (J = 0.7), the number of whorls on the left hand (J = 0.5). The correlation analysis between the dermatoglyphic indicators and the type of IAH inactivation showed that there are reliable connections between them (p < 0.05), but their number differs significantly in groups. In patients with ineffective chemoprophylaxis, the number of correlations (n = 13) exceeded that of the alternative group (n = 2) by more than 6 times, which indicates significant structural phenotypic differences. Conclusions. There were significant correlations between the type of IAH inactivation and dermatoglyphic indicators, but the number of such connections was 6 times higher in children with ineffective chemoprophylaxis than in the alternative group. This indicates that a more pronounced integration of dermatoglyphic genes and the ability to neutralize IAH is a favorable moment in general, but negative in relation to the effectiveness of tuberculosis prevention.