FIG. 2.

Sera from healthy blood donors or C. trachomatis-infected patients tested in immunoassays have different patterns of reactivity with synthetic peptides or recombinant antigens. MOMP antigens are synthetic peptides derived from species-specific epitopes in the variable domain IV of the MOMP of C. trachomatis and are not homologous to C. pneumoniae MOMP (Labsystems Research Laboratory). LPS is an exclusively Chlamydia-specific recombinant fragment of the total LPS (3-deoxy-d-manno-2-octulopyranosonic acid) (Medac GmbH). hsp70, hsp60, MIP, pgp3, and hsp10 are native purified recombinant antigens prepared in our laboratory. Two mild detergents were used to purify MIP, which otherwise was prepared under the same conditions as the other recombinant proteins (cf., Materials and Methods). Black boxes, high reactivity (≥cutoff value with OD 1.0); gray boxes, lower reactivity (≥cutoff value with OD < 1.0); white boxes, reactivity below the cutoff values. The number of positive IgG responses obtained for each sample tested in the seven immunoassays is compared with the number of IgG responses to LGV2 antigens observed in immunoblots.