International cohort study of 73 anti-Ku-positive patients: association of p70/p80 anti-Ku antibodies with joint/bone features and differentiation of disease populations by using principal-components analysis

Table 1 Prevalence of anti-Ku p70/p80 in patient groups as detected with immunoblot analysis

Diagnosis	Number of patients	Ku p70	Ku p80	Ku p70 only	Ku p80 only	Ku p70 and Ku p80	Ku pXX None
PM/DM	6	4 (67%)	3 (50%)	2 (33%)	1 (17%)	2 (33%)	1 (17%)
RA	8	7 (88%)	6 (75%)	2 (25%)	1 (13%)	5 (63%)	0 (0)
SLE	13	10 (77%)	11 (84%)	1 (8%)	2 (15%)	9 (69%)	1 (8%)
SS	2	2 (100%)	2 (100%)	0 (0)	0 (0)	2 (100%)	0 (0)
SSc	21	17 (81%)	11(52%)	8 (38%)	2 (10%)	9 (43%)	2 (10%)
UCTD	22	20 (91%)	15 (68%)	6 (27%)	1 (5%)	14 (64%)	1 (5%)
Total	72	60 (83%)	48 (67%)	19 (26%)	7 (10%)	41 (57%)	5 (7%)

Numbers of patients in each group are indicated, followed by the percentage. Ku pXX.none, neither anti-Ku p70 nor anti-Ku p80 present; PM/DM, polymyositis/dermatomyositis; RA, rheumatoid arthritis; SLE, systemic lupus erythematosus; SS, Sjögren syndrome; SSc, systemic sclerosis; UCTD, undifferentiated connective tissue disease.

ISSN: 1478-6362