Prevalence of Flare and Influence of Demographic and Serologic Factors on Flare Risk in Systemic Lupus Erythematosus: A Prospective Study

Article Figures & Data

Table 1.

Frequency of BILAG A, B, or A/B flares by organ system, per person-year.

Organ System	A	B	A or B	Two B Flares
Any organ	0.254	1.637	1.765	0.502
General	0.000	0.016	0.016
Mucocutaneous	0.059	0.370	0.429
Neurologic	0.023	0.016	0.040
Musculoskeletal	0.013	0.313	0.327
Cardiorespiratory	0.003	0.030	0.033
Vasculitis	0.030	0.046	0.076
Renal	0.102	0.469	0.571
Hematologic	0.033	0.868	0.901

Table 2.

Distribution summary of progression to A or B flares from previous BILAG score of E, D, C, or B. Each cell shows the number of patients.

Organ Systems	E→A	D→A	C→A	B→A	E→B	D→B	C→B
General	0	0	0	0	4	0	1
Mucocutaneous	2	1	1	7	28	19	17
Neurologic	4	2	0	1	5	0	0
Musculoskeletal	1	0	0	3	19	14	26
Cardiorespiratory	0	0	0	1	3	1	0
Vasculitis	1	0	1	2	5	1	2
Renal	4	2	6	10	26	10	38
Hematologic	0	0	0	8	13	17	37

Table 3.

Risk factors for later A or B flares based on organ system involvement.

Factor at Baseline	Organ System	No A or B Flare, %	Later A or B Flare, %	p	OR (95% CI)
Sex female	Hematologic	85	96	0.0100	3.85 (1.41, 10.6)
Sex female	Any flare	83	91	0.0394	2.13 (1.06, 4.29)
Ethnicity African American	Hematologic	34	52	0.0070	2.07 (1.23, 3.50)
Ethnicity African American	Any flare	25	47	0.0003	2.67 (1.57, 4.55)
Low C3	Mucocutaneous	20	36	0.0156	2.20 (1.18, 4.10)
	Renal	19	33	0.0217	2.02 (1.14, 3.57)
	Hematologic	17	39	< 0.0001	3.19 (1.80, 5.63)
	Any flare	17	27	0.0580	1.87 (1.01, 3.46)
Low C4	Mucocutaneous	18	41	0.0004	3.14 (1.69, 5.84)
	Renal	19	31	0.0217	1.98 (1.11, 3.51)
	Hematologic	17	36	0.0004	2.89 (1.63, 5.13)
	Any flare	15	27	0.0183	2.17 (1.15, 4.11)
Anti-dsDNA-positive	Hematologic	20	37	0.0033	2.33 (1.34, 4.04)
Anti-dsDNA-positive	Any flare	19	29	0.0651	1.80 (1.00, 3.26)
Low C3 AND anti-dsDNA-positive	Mucocutaneous	10	23	0.0095	2.71 (1.30, 5.67)
	Renal	8	23	0.0017	3.23 (1.60, 6.54)
	Hematologic	10	20	0.0209	2.40 (1.19, 4.84)
	Any flare	7	16	0.02770	2.61 (1.10, 6.18)
Low C4 AND anti-dsDNA-positive	Mucocutaneous	8	25	0.0009	3.91 (1.83, 8.33)
	Renal	8	18	0.0249	2.45 (1.18, 5.12)
	Hematologic	8	20	0.0026	3.13 (1.50, 6.54)
	Any flare	5	15	0.0110	3.47 (1.30, 9.30)
Low C3 AND low C4	Mucocutaneous	10	27	0.0024	3.18 (1.56, 6.48)
	Hematologic	9	25	0.0007	3.37 (1.70, 6.68)
	Any flare	7	18	0.0120	2.98 (1.27, 7.00)

Table 4.

Influence of demographic and serologic factors in BILAG A or 2B flare.

Factor at Baseline	No A or 2B, %	Later A or 2B, %	p	OR (95% CI)
African American	35	49	0.0397	1.77 (1.04, 3.01)
Low C3	18	36	0.0019	2.57 (1.45, 4.55)
Low C4	17	36	0.0009	2.75 (1.54, 4.90)
Anti-dsDNA-positive	21	37	0.0070	2.24 (1.28, 3.92)