Serodiagnosis of extrapulmonary tuberculosis by enzyme-linked immunosorbent assay (ELISA).

Antibodies against Mycobacterium tuberculosis antigenic glycolipids were determined by enzyme-linked immunosorbent assay (ELISA). The 720 sera were collected from adult patients under investigation, suspected with extrapulmonary tuberculosis. The test performance was estimated according to definitive diagnosis in terms of specificity, sensitivity, positive predictive value and negative predictive value. These parameters calculated on 142 sera from patients with extrapulmonary tuberculosis and on 578 sera from patients with different nontuberculosis diseases were 92%, 81.6%, 70.9% and 95.1%, respectively. The specificity decreased to 85% when tuberculosis was associated with cancer or hepatic cirrhosis. In reactivated tuberculosis the sensitivity and the positive predictive value were 86.9% and 83.3%, respectively. Our results showed that ELISA was conclusive for patients with active tuberculosis, before the initiation of the treatment. The sensitivity decreased to 30% in inactive forms. It was demonstrated that ELISA was positive in cases with negative microscopy genitourinary tuberculosis. ELISA could be used as a supporting test in the laboratory diagnosis of active extrapulmonary tuberculosis in adults, disregarding the site involved.

Application of ELISA with antigenic glycolipids in early diagnosis of pulmonary tuberculosis.

Antibodies against M. tuberculosis antigenic glycolipids were determined by enzyme-linked immunosorbent assay (ELISA) in 80 sera from patients suspected of pulmonary tuberculosis, with suggestive clinical signs and radiological abnormalities, but smears negative. The test was also performed on 68 control sera from patients with bacteriologically confirmed pulmonary tuberculosis, in different stages of disease. We obtained the test sensitivity of 89.5% for the confirmed tuberculosis patient sera. Low levels of specific antibodies and the sensitivity of 75% were found when using ELISA in smears negative patients at the onset of clinical tuberculosis. The experimental results showed that ELISA could be used as a supporting test in early diagnosis of pulmonary tuberculosis.

Serodiagnosis of tuberculous meningitis by enzyme-linked immunosorbent assay (ELISA).

IgG antibodies against glycolipids and proteins isolated from M. tuberculosis and BCG suspension were determined by ELISA in sera, in CSFs and in serum and CSF paired samples, from patients with tuberculous meningitis and from healthy control subjects. With specificities between 90 and 94% for the antigens used, we obtained senitivities of 75% for Pr-ELISA, 60% for G1-ELISA and 35% for BCG-ELISA. As specific antibodies were detected in serum and CSFs, only one sample is enough to perform the test. We concluded that Pr-ELISA and G1-ELISA could be used as a supporting test in TBM diagnosis, especially when repeated bacteriological methods failed to prove the presence of tubercle bacilli and in cases without evidence of pulmonary tuberculosis.

Clinical usefulness of rapid serodiagnosis in pulmonary tuberculosis by ELISA with glycolipidic antigens extracted from Mycobacterium tuberculosis and with whole BCG suspension.

Antibodies against Mycobacterium tuberculosis glycolipids and whole BCG suspension were determined by ELISA on 58 sera from hospitalized patients with presumptive pulmonary tuberculosis and on 127 sera from control subjects. The experimental results demonstrated that the glycolipids are more adequate to be used as antigens than whole BCG suspension, as high sensitivity of the test was obtained. By using only one antigen, ELISA becomes more efficient in rapid diagnosis. ELISA with glycolipidic antigens should be used as a supporting test for direct smear examination in the diagnosis of pulmonary tuberculosis, especially in cases when repeated bacterial methods failed to prove the presence of M. tuberculosis.

Humoral immune response in human pulmonary tuberculosis: antibodies against Mycobacterium tuberculosis polysaccharide, protein and glycolipid antigens.

Sera from 67 tuberculosis patients and 30 healthy subjects have been analyzed for the presence of specific antibodies against polysaccharide, protein and glycolipid antigens from H37Rv strain of Mycobacterium tuberculosis. The results proved the advantages of using the glycolipid antigens in diagnosing tuberculosis as well as the relationship between the antibodies level and the extension of the pulmonary tuberculous lesions.

Interleukin 2 enhances the efficiency of immunotoxins in the treatment of mice with ascitic tumors.

Two multivalent immunotoxins (ITs) with cytotoxic potential against Thy 1.2-expressing tumor cells were used in association with mouse interleukin 2 (IL2) for treatment of mice bearing ascitic EL4 lymphomas. The combined treatment, ITs + IL2, induced an enhanced antitumor effect revealed by a significant prolongation of the survival time of mice as compared to the simple treatment with ITs or IL2 alone. According to the survival of mice treated by combined therapy, the proportion of killed tumor cells rose up to 94% as resulted from the dose-dependent curve of the survival of nontreated mice versus the number of tumor cells inoculated.

Specific antibodies and mycobacterial antigens in pulmonary tuberculosis patients sera. Note I.

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.

Specific antibodies and mycobacterial antigens in patient sera with pulmonary tuberculous and nontuberculous diseases. Note II.

"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".

Treatment of murine EL4 leukemia in ascitic form with anti-Thy 1.2 specific immunotoxins.

C57BL/6 mice with EL4 leukemia cells in ascitic form were intraperitoneally treated with ricin A chain-multivalent antibody immunotoxins. The immunotoxins containing rabbit IgG anti-Thy 1.2 antibodies complemented by protein A of Staphylococcus aureus were able to interact specifically with the target cells and to induce an antitumor effect as revealed by an increase in survival time of the mice. No apparent secondary effects consecutive to a cytotoxic action on the normal Thy 1.2 antigen bearing cells were observed with the immunotoxin doses used.