Table 2

Linear mixed model estimates for the clinical SELENA-SLEDAI and PGA in relation to laboratory measures

Marker	Outcome	Study group	Subject/visit, n	Intercept (SE)	Slope estimate (SE)	P values	Marginal R² (%)
EC4d (log net MFI)	Clinical SELENA-SLEDAI	1	37/384	2.52±1.55	0.94±0.46	0.042	2.0
		2	64/126	1.81±1.05	1.36±0.40	0.001	10.3
		3	23/102	0.09±0.57	0.74±0.25	0.005	10.7
		1–3	124/612	1.49±0.76	1.17±0.27*	<0.001	5.7
	PGA	1	37/385	0.77±0.20	0.12±0.06	0.047	2.2
		2	64/128	0.75±0.15	0.18±0.06	0.002	8.7
		3	23/106	0.50±0.24	0.10±0.11	0.363	1.4
		1–3	124/619	0.64±0.11	0.17±0.04	<0.001	5.6
Low complement C3/C4	Clinical SELENA-SLEDAI	1	37/383	4.32±0.73	1.72±0.61	0.005	2.7
		2	64/127	4.65±0.46	1.46±0.74	0.052	3.6
		3	23/103	1.47±0.28	0.71±0.48	0.148	2.8
		1–3	124/613	3.80±0.35	1.68±0.42†	<0.001	3.7
	PGA	1	37/384	0.99±0.08	0.26±0.08	0.002	4.0
		2	64/127	1.11±0.06	0.27±0.10	0.010	5.7
		3	23/107	0.58±0.11	0.47±0.17	0.007	9.1
		1–3	124/618	0.95±0.05	0.31±0.06	<0.001	5.9
Anti-dsDNA (log net MFI)	Clinical SELENA-SLEDAI	1	37/379	−1.11±1.43	1.27±0.26	<0.001	17.4
		2	64/126	2.03±1.03	0.97±0.30	0.002	9.7
		3	23/102	−0.94±1.44	1.01±0.55	0.070	4.6
		1–3	124/607	0.44±0.65	1.08±0.15	<0.001	18.2
	PGA	1	37/380	0.69±0.17	0.09±0.03	0.005	5.9
		2	64/128	0.83±0.15	0.11±0.04	0.009	6.3
		3	23/106	−0.52±0.52	0.47±0.20	0.019	7.6
		1–3	124/614	0.68±0.09	0.10±0.02	<0.001	8.3
Anti-C1q (log net MFI)	Clinical SELENA-SLEDAI	1	37/383	1.50±1.18	1.27±0.32	<0.001	6.6
		2	64/126	2.38±0.98	1.28±0.42	0.003	8.3
		3	23/102	1.08±0.57	0.34±0.30	0.265	2.1
		1–3	124/611	1.55±0.60	1.24±0.22	<0.001	9.9
	PGA	1	37/384	0.62±0.14	0.17±0.04	<0.001	8.5
		2	64/128	0.91±0.14	0.13±0.06	0.029	4.3
		3	23/106	0.76±0.24	−0.04±0.12	0.765	0.2
		1–3	124/618	0.70±0.09	0.15±0.03	<0.001	7.5

Intercept, slope estimates, p values and marginal R² are given.
*One log EC4d levels were associated with a 1.2-point in clinical SELENA-SLEDAI.
†Low C3/C4 status was associated with a 1.7-point clinical SELENA-SLEDAI.
dsDNA, double-stranded DNA; EC4d, erythrocyte-bound C4d; MFI, mean fluorescence intensity; PGA, Physicians Global Assessment; SELENA-SLEDAI, Safety of Estrogens in Lupus Erythematosus National Assessment—SLE Disease Activity Index.