Table 2.

Medians and interquatile ranges (IQRs) of IgG1 and IgG3 antibody levels (μg/mL) against six different antigens in the SpA group

Antigen	Median (IQR)
	2006		2010
	IgG1	IgG3	IgG1	IgG3
Human HSP60	2.046 (1.896-2.345)	2.689 (2.476-4.827)	2.131 (1.936-2.503)	2.583 (2.455-3.475)
Salmonella enterica Enteritidis HSP60	2.635 (2.109-4.300)	2.514 (2.443-2.799)	2.660 (2.240-3.681)	2.534 (2.452-3.142)
Chlamydia trachomatis HSP60	2.123 (1.939-2.694)	2.522 (2.453-2.726)	2.096 (1.957-2.747)	2.631 (2.472-2.960)
Campylobacter jejuni HSP60	2.459 (2.347-2.640)	2.447 (2.403-2.628)	2.496 (2.395-2.622)	2.462 (2.409-2.684)
Chlamydia pneumoniae	7.965 (2.807-24.56)	2.397 (2.397-2.730)	8.953 (2.839-21.75)	2.450 (2.397-2.777)
Chlamydia trachomatis	2.082 (2.052-2.174)	2.416 (2.406-2.473)	2.103 (2.065-2.216)	2.421 (2.410-2.491)