TABLE 2 .

Correlation of C. trachomatis and C. pneumoniae peptide reactivities with species-specific MIF titers

Peptide seta	Chlamydia species specificity	Source proteins	Antibody isotype	Correlation tob:
				C. trachomatis MIF titer		C. pneumoniae MIF titer		Peptide set 1
				P	R	P	R	P	R
1 (peptides 1–11)	C. trachomatis	OmpA, TarP, CT143, PmpD. IncE, CT529, CT442, CT618	IgG1	10−4	0.56	0.91	–	–	–
2 (peptides 12–22)	C. trachomatis	CT813, LcrE, CT226, IncE, IncG, CT223, CT618, CT795, PmpC	IgG1	10−3	0.47	0.20	–	<10−6	0.81
3 (peptides 23–34)	C. trachomatis	OmpA, variable domains (VD) 1, 2, 3, 4	IgG1	0.02	0.33	0.32	–	10−5	0.65
3 (peptides 23–34)	C. trachomatis	OmpA (VD1 to VD4)	IgG3	0.01	0.36	0.12	–	10−5	0.60
4 (peptides 35–38)	C. trachomatis	Hsp60, pGP3	IgG1	0.42	–	0.92	–	0.002	0.44
5 (peptides 39–50)	C. pneumoniae	IncA, PmpD, PmpG/I, CT618, PmpG, Cpn0525, YscC	IgG1	0.66	–	0.39	–	0.003	0.42

^aPeptide sets and peptide numbers are identical to those of the peptides shown in Fig. 6.

^bPearson’s correlation coefficient (R) and P values were calculated in linear regression analyses. The correlations are based on the mean reactivity of a peptide set with each of 48 individual sera (Fig. 6). –, absence of significant correlation or self-comparison.