Table 3.

HLA compatibility of mother–son pairs when the son (SLE or healthy) carries genes encoding HLA molecules associated with SLE risk (HLA–DR2 or DR3)^*

Locus/compatibility	Patients	Controls	OR (95% CI)	P
DRB11†
Bidirectional	7 (39)	3 (8)	7.2 (1.6–32.8)	0.011
Mother from son’s perspective	2 (11)	5 (14)	0.8 (0.1–4.6)	0.80
Son from mother’s perspective	1 (6)	3 (8)	0.7 (0.1–6.9)	0.73
DRB12‡
Bidirectional	5 (29)	1 (3)	15.0 (1.6–142)	0.018
Mother from son’s perspective	2 (12)	3 (8)	1.5 (0.2–10)	0.67
Son from mother’s perspective	1 (6)	3 (8)	0.7 (0.1–7.4)	0.77
DQA1
Bidirectional	9 (50)	5 (14)	6.4 (1.7–24)	0.006
Mother from son’s perspective	2 (11)	4 (11)	1.0 (0.2–6.2)	0.97
Son from mother’s perspective	1 (6)	7 (19)	0.3 (0.1–2.2)	0.22
DQB1
Bidirectional	6 (33)	3 (8)	5.7 (1.2–26.3)	0.027
Mother from son’s perspective	2 (11)	3 (8)	1.4 (0.2–9.3)	0.72
Son from mother’s perspective	1 (6)	3 (8)	0.7 (0.1–6.9)	0.73

^*Values are the number (%) of subjects. The analyses were not adjusted for age or ethnicity. For DRB1₁, n = 18 patients and 37 controls; for DRB1₂, n = 17 patients and 37 controls; for DQA1, n = 18 patients and 37 controls; for DQB1, n = 18 patients and 37 controls. See Table 1 for descriptions of compatibility. SLE = systemic lupus erythematosus; OR = odds ratio; 95% CI = 95% confidence interval.

^†Basic DRB1 groups DRB1*01 through DRB1*14 sharing sequence similarities but not necessarily identical throughout the entire DRβ1 chain.

^‡Specific alleles within DRB1 groups.