Table 1 Anti‐GPI Abs and DRB1 genotype in patients with RA, SLE, and in healthy subjects.

Subject	huGPI	raGPI	DRB1 genotype	IFNγ+ T cells	IL4+ T cells
RAI	1.32	2087	0405 0901	4	9
RA2	2.73	3.02	0409 0803	0	0
RA3	1.33	1.15	0405 1501	190	12
RA4	2.43	2.55	0101 0803	0	0
RA5	1.79	3.14	0405 0401	6	3
RA6	1.65	2.67	0802 0901	15	3
RA7	1.88	1.15	1402 0901	55	10
RA8	2.60	3.47	0405 0901	0	0
RA9	2.46	1.70	1502 0405	8	1
RA10	1.93	2.65	0405 0803	16	24
RA11	1.72	0.95	0405 0803	49	3
RA12	1.40	1.61	0405 1502	7	0
RA13	1.49	0.94	0405 0803	0	0
RA14	1.39	0.99	0405 1502	0	0
RA15	2.48	3.32	0901 0901	20	2
SLE1	3.68	1.86	0803 1404	0	0
SLE2	1.32	1.38	0427 0427	0	0
SLE3	1.91	2.41	0101 0428	2	0
SLE4	2.89	2.97	0803 0803	0	0
Control1	3.75	3.54	1501 1403	2	0
Control2	3.05	3.19	1302 0803	9	4
Control3	2.19	3.28	1501 0803	3	0
Control4	2.51	2.59	1329 1406	1	1

The cut off optical density was calculated from an ELISA of 145 healthy subjects, the mean value + two standard deviation was 1.32 to human recombinant GPI, and 0.94 to rabbit native GPI. Double positive populations were considered anti‐GPI Ab positive. For MACS cytokine secretion assay, positive cell numbers were determined after subtracting control cells, either reacted on thrombin or spontaneously secreting cytokines, from GPI reactive IFNγ+ and IL4+ T cells. The cut off cell numbers were calculated from the reaction of four patients with SLE and four control subjects who were all anti‐GPI Ab positive. The mean value + two standard deviation was 7.6 to IFNγ, and 3.6 to IL4. Bold numbers indicate a positive reaction to GPI.

Abs, antibodies; RA, rheumatoid arthritis; SLE, systemic lupus erythematosus; IFN, interferon; IL, interleukin.