ABSTRACT
206 sera collected from different groups of subjects were analyzed by immunoenzymatic methods regarding the content of Mycobacterium tuberculosis specific antibodies and mycobacterial antigens. The results underlined that two assays offered improved serologic diagnosis of tuberculosis over a single antibody test. BCG vaccination interferes with serologic tests for tuberculosis when polyspecific antibodies or mixture of common and specific antigens are used as immunologic reagents. A mycobacterial antigens circadian variation in correlation with vesperal fever in tuberculous patients was not revealed. The mycobacterial antigens seem to become undetectable, in sera, after 6 months of efficient treatment.
Subject(s)
Antibodies, Bacterial/blood , Antibody Specificity , Mycobacterium tuberculosis/immunology , Tuberculosis, Pulmonary/diagnosis , Adult , Child , Enzyme-Linked Immunosorbent Assay/methods , Female , Humans , Male , Middle Aged , Sensitivity and Specificity , Serologic Tests/methodsABSTRACT
"Two-assay" tests (TAT), immunoenzymatic determination of both specific antibodies and mycobacterial antigens in sera of tuberculous and non-tuberculous subjects, was undertaken in our territorial conditions, where BCG vaccination is systematically applied and the prevalence of tuberculous infection is relatively high. The sensitivity of the method, calculated on 42 patients with active pulmonary tuberculosis and on 39 patients with post-tuberculosis syndromes is high, i.e. 0.952. The specificity of the method separately calculated for 44 young subjects (under 21 years old), for 78 healthy adults and for 201 lung diseased patients, bacteriologically not ascertained as tuberculosis at the moment of sera prelevation, varied between 0.830 and 0.489. "TAT", performed with crude immunologic reagents, produces false-positive reactions in early BCG vaccinated subjects. Method specificity low values in pulmonary non-tuberculous patients group may be partially explained by the difficulty in establishing the real relationships, in time, between host and mycobacteria, by the bacteriological method imperfections or sample prelevating methods. Our results certainly underestimate the diagnosis value of "TAT".
