Factors Reducing the Diagnostic Efficiency of Rapid Tuberculosis Tests Based on Immunochromatographic Assay

The objective: to study factors that reduce the diagnostic efficiency of rapid testing for tuberculosis based on the detection of antibodies to PstS1 and PstS3 antigens of M. tuberculosis and highly purified lipoglycan of the M. tuberculosis cell wall. Subjects and Methods. Clinical and laboratory data of 290 tuberculosis patients were analyzed. Logistic regression analysis and ROC analysis were used to identify factors associated with a negative result of rapid tuberculosis testing. Results. 45/290 (16%) patients had a positive result of the rapid test for PstS1, PstS3 antigens and 154/290 (53%) patients responded positively to lipoglycan antigen. The number of people who tested positive was 164/290 (57%). However, in HIV negative patients these values were higher and amounted to 41/196 (21%), 137/196 (70%) and 144/196 (73%), respectively. The following factors were found to be positively associated with a negative result of rapid testing: positive HIV status (OR=7.803; 95% CI 3.845-15.834; p <0.001) and male gender (OR=2.040; 95% CI 1.117-3.725; p =0.020). The combination of these two factors had a more significant predictive value (AUC 0.787; p <0.0001) of a negative rapid test result. In case of HIV infection, the lipoglycan antigen showed a greater degree of immunogenicity versus the PstS1, PstS3 antigens (18% positive results for lipoglycan versus 4% positive results for the PstS1, PstS3 antigens), OR = 4.968; 95% CI 1.603-15.392; p =0.003).