Table 2.

Percentages of lines reactive to PPD, tetanus toxoid (TT), and Chlamydia trachomatis (Ct) produced from cultures stimulated with either antigen or mitogen, from a total of 14 patients

Stimulus used during culture	Number of PPD-reactive lines produced	Number of TT-reactive lines produced	Number of Ct-reactive lines produced	Number of lines unresponsive to antigens tested
PHA	20	9	6	38
PPD	7	7	1	28
TT	4	6	4	8
Ct	2	2	8	28

The number of patients producing at least one line specific for PPD was 13, for TT was eight and for Ct was 10. Lines capable of responding to more than one antigen were also observed. PHA, Phytohaemagglutinin.