A common anti-DNA idiotype in sera of patients with active pulmonary tuberculosis.

The sera of 57 patients with active, untreated pulmonary tuberculosis were examined for the presence of a common anti-DNA idiotype, 16/6. Thirty-four of the 57 sera (60%) had an increased level of the idiotype, as measured by enzyme-linked immunosorbent assay using a specific rabbit anti-16/6 serum. Of 28 matched control sera, only 1 (4%) was found to be positive for the idiotype. The sera of patients with tuberculosis also showed increased activity against a variety of antigens with which lupus autoantibodies are known to crossreact (e.g., single-stranded DNA, double-stranded DNA, polynucleotides, and cardiolipin). A correlation was observed between serum IgG and IgM levels and the 16/6 idiotype levels.