Abstract

VDRL (Venereal disease research laboratory) and TPHA(Treponema pallidum hemagglutination) tests were carried out to evaluate the BFP (biological false positives) for non-treponemalantigen tests in leprosy patients admitted in Sorok National Leprosarium. The results were obtained as follows: 1. VDRL qualitative tests: Of 167 leprosy patients, 26 patients (15.6%) gave the positive VDRL reactions, which were graded as weakly reactive in 19 patients(11.4% ), and reactive in 7 patients (4.2%). 2. VDRL quantitative tests: Of the 26 leper's sera which gave the positive VDRL quantitative tests, the titer was 1 : 1 in 18 sera (69.2 4 in 2 sera (7.7%), and 1 : 8 in 2 sere (7.7%). 3. TPHA tests : Of the VDRL-reactive 26 lepers, 12 patients (46.2%) showed positive reactions and the other 14 lepers (53.8%) gave the negative reactions in TPHA tests. TPHA-negative reactions were observed in the patients giving the positive VDRL quantitative reactions in 1 : 1, and 1 : 2. But all of those giving reactivity in 1 : 4 or above gave the positive TPHA tests. TPHA tests revealed that the 53. 8% of VDRL-reactive lepers in qualitative rests gave the positive reactions possibly due to BFP and these BFP might be excluded by concomittant VDRL quantitative tests.