Reliability of Mycolic Acid IgG Antibodies in the Diagnosis of Pulmonary Tuberclosis

Abstract

This study aimed to test the reliability of mycolic acid IgG antibodies compared to PCR among patients suspected to have pulmonary tuberculosis in Khartoum State. Sputum and blood specimens were collected from patients attended to Alsha'ab Teaching Hospital, Tuberculosis Reference Laboratory, Ibrahim Malik Hospital and Abu Anga Hospital. All patients were priorly informed. Smear from direct sputum specimens (90) showed that 17 (18.9%) were ZN positive, while 73 (81.1%) were negative. The 90 sputum specimens were cultivated on LJ medium and incubated at 37°C, 15 (16%) showed typical characteristics of M. tuberculosis, the morphological features were dry, tough and pale color colonies, while 75 (84%) showed no obvious growth or contaminated. The biochemical tests showed sensitivity for para nitro benzoic acid test, negative for thiophin-2- carboxylic acid hydrazide, positive for nitrates oxidation and negative for catalase test at 68°C. The ninety sputum specimens were subjected to PCR to ampilify IS6110 segment. The result showed that 79 (87.8%) were positive for IS6110 while 11 (12.2%) were negative. Eighty Serum samples were analysed by ELISA, 16 (20%) gave positive result for antimycolic acid IgG while 64 (80%) were negative. This study suggested that detection of antimycolic acid antibodies is a promising rapid and reliable technique in the diagnosis of pulmonary tuberculosis.