Anti-Double-Stranded DNA Isotypes and Anti-C1q Antibody Improve the Diagnostic Specificity of Systemic Lupus Erythematosus

Table 1

Clinical features and laboratory findings in 96 SLE patients.

Clinical characteristics
Sex (M/F)	12/84
Disease duration median (range) in months	20 (0–216)
SLEDAI score median (range)	10 (0–30)
Organ involvement	Number	%
Central nervous system involvement	5	5.2
Skin rashes	35	36.5
Arthritis	8	8.3
Serositis	39	40.6
Vasculitis	15	15.6
Anemia	39	40.6
Leukopenia	28	29.2
Thrombocytopenia	27	28.1
Autoantibody profile
ANA positivity	96	100
Anti-Sm	34	35.4
Anti-U1RNP	38	39.6
Anti-SSA	57	69.8
Anti-SSB	17	17.7
IgG anti-dsDNA	68	70.8
IgM anti-dsDNA	43	44.8
IgA anti-dsDNA	32	33.3
Anti-C1q	28	29.2
Complement levels
Low C3	43/89	48.3
Low C4	44/89	49.4

M: male; F: female; SLEDAI: SLE disease activity index; ANA: antinuclear antibodies; anti-Sm: anti-Smith; anti-dsDNA: anti-double-stranded DNA.