Table 2

Rates of incident proteinuria by compliment and autoantibodies

Subgroup	Observed number of new cases of proteinuria	Person-years of follow-up	Rate of events per 1000 person-years	Rate ratios	p Value
C3 (mg/dL) at previous cohort visit
117+	10	1996	5.0	1.0 (Ref)
79–116	14	2007	7.0	1.5 (0.7 to 3.5)	0.34
70–78	5	268	18.7	3.5 (1.2 to 10.4)	0.026
≤69	27	277	97.4	16.1 (7.5 to 34.6)	<0.0001
Ever low C3 during cohort
No	13	2763	4.7	1.0 (Ref)
Yes	44	1906	23.1	5.6 (2.9 to 10.6)	<0.0001
C4 (mg/dL) at previous cohort visit
22+	11	2024	5.4	1.0 (Ref)
12–21	14	2038	6.9	1.4 (0.6 to 3.1)	0.46
10–11	8	223	35.8	5.9 (2.3 to 15.1)	0.0002
≤9	23	261	88.0	16.3 (7.7 to 34.6)	<0.0001
Ever low C4 during cohort
No	18	3086	5.8	1.0 (Ref)
Yes	39	1583	24.6	4.8 (2.7 to 8.5)	<0.0001
Anti-dsDNA (titer) at previous visit
0	17	3707	4.6	1.0 (Ref)
1–80	13	476	27.3	4.9 (2.4 to 10.2)	<0.0001
81+	26	363	71.6	10.8 (5.7 to 20.3)	<0.0001
Ever positive for anti-dsDNA
No	7	1034	6.8	1.0 (Ref)
Yes	50	3635	13.8	2.8 (1.2 to 6.1)	0.013
Previous lupus anticoagulant
No	41	3337	12.3	1.0 (Ref)
Yes	16	1332	12.0	1.0 (0.5 to 1.7)	0.94
Recent lupus anticoagulant (RVVT<45)
No	6	398	15.1	1.0 (Ref)
Yes	51	4271	11.9	0.8 (0.3 to 1.8)	0.59
Anti-Sm
No	35	3846	9.1	1.0 (Ref)
Yes	22	806	27.3	3.0 (1.8 to 5.1)	<0.0001
Anti-Ro
No	29	3188	9.1	1.0 (Ref)
Yes	27	1466	18.4	2.0 (1.2 to 3.4)	0.0083
Anti-La
No	43	3983	10.8	1.0 (Ref)
Yes	13	669	19.4	1.8 (1.0 to 3.4)	0.063
Anti-RNP
No	34	3580	9.5	1.0 (Ref)
Yes	22	1079	20.4	2.2 (1.3 to 3.7)	0.0052
Anticardiolipin
No	17	1756	9.7	1.0 (Ref)
Yes	40	2910	13.7	1.45 (0.8 to 2.6)	0.22