Elisa kit evaluation for IGG and IGM antibodies to A-60 tubercular protein antigen.

AIMS: The purpose of this study is to evaluate the A-60 antigen-based enzyme-linked immuno sorbent assay (ELISA) test for its sensitivity, specificity, and other related statistical parameters. SETTINGS AND DESIGN: Sera from 114 healthy volunteers, 105 bacteriologically confirmed cases of pulmonary tuberculosis (PTB), 59 sera from family contacts of PTB, and 40 sera from cases of lung infections other than tuberculosis collected from September to December 2003 were used for the kit evaluation. METHODS AND MATERIALS: Enzyme-linked immuno sorbent assay test using tuberculosis A-60 antigen-based kit manufactured by Anda Biologicals, France was used for the evaluation. STATISTICAL ANALYSIS: Differences in the optical density (OD) values for immunoglobulins G (IgG), and immunoglobulins M (IgM) antibodies in various groups were studied using t-test. RESULTS: On the basis of the findings the threshold value was setup as 400 U for IgG and mean OD for sera from healthy volunteers +2SD as the threshold for IgM. The sensitivity was 80% and specificity 95.8% for the IgG antibody test. The efficiency and predictive values were also high. The sensitivity for IgM was low (28.5%) but the specificity was high (95.7%). None of the 40 nontubercular lung infection cases were positive for the IgG and IgM antibody test for A-60, whereas five and three cases of 59 family contacts of PTB were positive for IgG and IgM antibody test. The test reproducibility was good for both IgG and IgM. CONCLUSION: IgG antibody test using A-60 antigen has good sensitivity and specificity, whereas IgM antibody test had high specificity but low sensitivity. Multicentric trials suggested evaluation of the diagnostic utility of the test for the extra-PTB.

Drug resistance among tubercle bacilli from pulmonary tuberculosis cases in central India.

An estimate of drug resistance is extremely important in the epidemiology and control of tuberculosis. Data on drug resistance among mycobacterial isolates from sputum samples analysed at Microbiology dept. of Choithram Hospital and Research Centre, Indore, M.P. is presented here. Drug sensitivity testing was carried out on 1426 Mycobacterial isolates by the method of proportion using critical concentration in Lowenstein Jensen medium. Resistance for Isoniazid, streptomycin, and pyrazinamide was found to be high (54.2%, 41.5% and 50% respectively) and was followed by resistance to rifampin (25%) and ethambutol (22%). Resistance for kanamycin, p-aminosalicylic acid, thiacetazone and ciprofloxacin was much lower (18%, 13%, 6.5% and 3.6% respectively). Only 12% of the isolates were sensitive to all the anti-TB drugs while resistance to two, three, and four or more drugs was in the range of 20-25%. Pattern wise, simultaneous resistance to INF and Rifampin with or without resistance to other drugs was observed in 8.1% while resistance for Isoniazid + pyrazinamide and Isoniazid + streptomycin was 11.9 and 11.5% respectively. Resistance for Isoniazid + ethambutol was the lowest (5.1%). Growing multiple drug resistance among tubercle bacilli warrant urgent attention in tuberculosis control programme.

Low level nitrogen laser therapy in pulmonary tuberculosis.

We report a technique for treatment of pulmonary tuberculosis that has become resistant to traditional antibiotics. We introduce a needle into the lung that carries the N2 laser to the affected chest cavity. It is irradiated for 10 min and usually only one sitting is required. Clinical improvement occurred in 90% of the patients; 60% of the patients showed improvement on their X-rays. This technique is recommended as an adjuvant to traditional tuberculosis therapy.