[Serological and immunochemical properties of carbohydrate-containing fraction from mycobacterium tuberculosis H37Rv]

Using affinity chromatography on concanavalin A (Con A) sepharose CL 6B, a carbohydrate-containing fraction was derived from Mycobacterium tuberculosis H37Rv sonicate. Surprisingly, the main component of Con A fraction was a protein having a molecular weight of a 30-kD range which is generally absent in the Con A-adsorbed fraction from the culture filtrate. ELISA by means of an antimycobacterial monoclonal antibody panel showed that the 30-kD range of Con A fraction contained antigen 85. It is suggested that the derived components antigen 85 are a glycosylated form of the proteins associated with the mycobacterial cell wall. The Con A fraction, antigen 85 (Department of Virology, Pasteur Institute, Brussels, Belgium), and PPD (Batch RT 45, Stattens Seruminstitute, Denmark) were used for ELISA determination of antimycobacterial antibody titers in the sera of 30 patients with pulmonary tuberculosis, 28 patients with nonspecific lung diseases (bronchitis and/or asthma, pneumonia), as well as in the sera of 12 healthy volunteers. The sensitivities were 46.42, 57.34, and 72.33% and the specificities were 36.97, 26.73, and 56.75% for Con A fraction, antigen 85, and PPD, respectively. The authors suggest that serodiagnostic properties of Con A fraction are extremely limited.