Table 4.

Concentrations (mean ± SEM, U/ml) of anti-dsDNA isotypes and anti-C1q antibody in active, inactive, LN, and non-LN SLE patients and active, inactive LN patients.

	Activity of SLE (N = 96)			SLE with renal involvement (N = 96)			Activity of LN (N = 50)
	Active SLE (U/ml)	Inactive SLE (U/ml)	p value	LN (U/ml)	Non-LN (U/ml)	P value	Active LN (U/ml)	Inactive LN (U/ml)	p value
Anti-dsDNA IgG	116.66 ± 10.63	62.21 ± 11.27	0.001	95.57 ± 11.29	95.60 ± 12.17	NS	98.60 ± 13.40	88.90 ± 22.06	NS
Anti-dsDNA IgM	36.49 ± 5.99	34.20 ± 8.71	NS	26.14 ± 5.72	45.80 ± 8.16	0.037	26.61 ± 6.28	25.23 ± 11.90	NS
Anti-dsDNA IgA	44.39 ± 8.03	17.89 ± 5.61	0.003	29.45 ± 6.90	38.17 ± 8.53	NS	32.04 ± 9.44	23.13 ± 8.47	NS
Anti-C1q	29.36 ± 4.17	11.44 ± 2.79	0.000	23.07 ± 4.00	21.02 ± 4.12	NS	26.38 ± 5.52	16.62 ± 4.63	NS

SLE: systemic lupus erythematosus; LN: lupus nephritis; NS: no significance; p < 0.05, Mann–Whitney U test.