Identification of a SmD3 epitope with a single symmetrical dimethylation of an arginine residue as a specific target of a subpopulation of anti-Sm antibodies

Table 1 Results of ELISA using SmD3 peptide with systemic lupus erythematosus and various control sera

Sera (n)	Number (%) of anti-SMP positive sera	Mean value (U/ml)	Top value (U/ml)
SLE (176)	28 (15.9)	43.0	1190.0
Rheumatic diseases (181)	1 (0.6)	2.2	24.6
RA (86)	1 (1.2)	1.6	24.6
pSS (24)	0	1.9	3.9
MCTD (26)	0	3.1	12.8
SSc (26)	0	2.4	4.3
PM/DM (13)	0	2.8	9.6
Overlap syndromes (8)	0	2.1	3.6
Infectious diseases (77)	0	0.67	3.3
HCV (30)	0	0.42	1.1
CMV (22)	0	0.8	3.2
EBV (25)	0	0.78	3.3
Healthy individuals (192)	0	2.21	11.5

CMV, cytomegalovirus; EBV, Epstein – Barr virus; HCV, hepatitis C virus; MCTD, mixed connective tissue disease; PM/DM, polymyositis/dermatomyositis; pSS, primary Sjögren's syndrome; RA, rheumatoid arthritis; SLE, systemic lupus erythematosus; SMP, SmD3 peptide; SSc, systemic sclerosis.

ISSN: 1478-6362