Table 1.

Age division and ratio of anti‐measles (IgG)‐seronegative samples in systemic autoimmune disease groups

SAD	No. of sera	Mean age (rounded years)	No. of anti‐measles IgG seronegative sera	Ratio (%)
SSc	157	56	13	8·28
SLE	92	44	13	14·13
RA	73	59	3	4·10
Other*	52	53	4	7·69
Total	374	52	33	8·82

^*Other = myositis, non‐differentiated collagen disease, arthritis psoriatica, mixed connective tissue disease, morphea, primary Raynaud syndrome, secondry Raynaud syndrome, Sjögren’s syndrome.

Ig = immunoglobulin; SAD = systemic autoimmune diseases; SLE = systemic lupus erythematosus; SSc = systemic sclerosis; RA = rheumatoid arthritis.