[Treponemal hemagglutination test (TPHA). Validity of the micromethod using dilutions of sera 1/20-1/40].

The Authors studied the possibility to use, for the carrying out of the TPHA micromethod, higher serum dilutions, as preliminary investigations had pointed out an insufficient sensitivity of the reaction performed at the 1:80 - 1:160 dilutions, particularly in the primary-secondary phase of the luetic infection. The Authors controlled, preliminarily, that at the dilutions studied, no unacceptable increase of spontaneous hemagglutinations and false positive reactions took place in the test sera. The investigation stressed the acceptability of the methodological modification set forth.