Table 5.

Numbers of rheumatoid arthritis (RA) patients with an isolated or combined deficiency of IgG subclasses

Patient group	IgG1 alone	IgG2 alone	IgG3 alone	IgG4 alone	IgG 2 + 3	IgG 2 + 4	IgG 1 + 2	IgG 1 + 2 + 3	IgG 2 + 3 + 4
Controls	0	4	2	0	1	0	0	0	0
Gold	1	8	6	4	2	2	1	1	1

Deficiency defined as IgG1 = 3·2 g/l, IgG2 = 1·2 g/l, IgG3 = 0·2 g/l, IgG4 = 0·1 g/l.