[Recent findings in the field of humoral immunology in syphilis].

Investigations on 404742 sera by the Automated Micro-Haemagglutination Assay with Treponema pallidum Antigen (AMHA-TP) and the VDRL-test for screening revealed 9848 (2,43%) reactive results in one of the two or in both methods. All reactive samples were checked by the FTA-ABS-test. A reactivity in both, the AMHA-TP and the FTA-ABS indicates a former infection with Treponema pallidum. The VDRL failed to point out reactivity in 4226 of 7474 sera (56,5%) deriving from syphilitic donors. The agglutination in the AMHA-TP can be inhibited by a protein of low molecular weight which occurs appearently in extraordinarily rare cases and was found in one sample only until now. The margin of error of the screening procedure by using the AMHA-TP and the VDRL amounts to 0,04%-0,38% of all samples examined.