Oen Kiem, Robinson David B, Nickerson Peter, Katz Steven J, Cheang Mary, Peschken Christine A, Canvin Janice M G, Hitchon Carol A, Schroeder Marial-Louise, El-Gabalawy Hani S
Department of Paediatrics and Child health; and the School of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada.
J Rheumatol. 2005 Jun;32(6):983-91.
A number of North American native (NAN) populations have high prevalence rates of both rheumatoid arthritis (RA) and the shared epitope (SE). We examined the phenotype and familial incidence of RA in a NAN population, and investigated how the SE and cytokine genes may affect disease risk within affected families.
NAN patients with seropositive RA or polyarthritis rheumatoid factor (RF) positive juvenile idiopathic arthritis (JIA) were identified from clinical databases. Patients were recruited consecutively as they presented for clinic visits. Family pedigrees were constructed and consenting relatives were interviewed and examined. The risk of RA within families was calculated by multiple logistic regression. Input variables were the SE and cytokine genotypes. Probands and affected relatives were entered as the affected group, and unaffected relatives within families as the unaffected group. Results were confirmed among unrelated subjects, i.e., unrelated patients and unaffected relatives of other probands.
The familial prevalence of RA was 0.50 (95% confidence intervals 0.30, 0.70) among 28 families studied. The interleukin 10 (IL-10) promoter -1082 G/A genotype decreased the odds of RA relative to the A/A genotype in affected families (OR 0.247, 95% CI 0.081, 0.751; p = 0.014) and among unrelated subjects (OR 0.203, 95% CI 0.064, 0.640; p = 0.006). The G/G genotype yielded an OR of 0.093 (95% 0.013, 0.676; p = 0.019) among unrelated subjects. The SE had no effect in these calculations.
There was a high familial prevalence of RA in this NAN cohort. In susceptible NAN families, the risk of RA was reduced by IL-10 genotypes, whereas the SE did not affect risk. Study of healthy NAN controls is required to determine if these conclusions apply to this NAN population as a whole.
一些北美原住民（NAN）人群中类风湿关节炎（RA）和共享表位（SE）的患病率都很高。我们研究了一个NAN人群中RA的表型和家族发病率，并调查了SE和细胞因子基因如何影响受影响家庭中的疾病风险。
从临床数据库中识别出血清阳性RA或类风湿因子（RF）阳性的多关节炎型幼年特发性关节炎（JIA）的NAN患者。患者在就诊时被连续招募。构建家系图谱，并对同意参与的亲属进行访谈和检查。通过多元逻辑回归计算家庭中RA的风险。输入变量为SE和细胞因子基因型。先证者和受影响的亲属作为受影响组，家庭中未受影响的亲属作为未受影响组。在无关个体中，即无关患者和其他先证者的未受影响亲属中对结果进行了确认。
在研究的28个家庭中，RA的家族患病率为0.50（95%置信区间0.30，0.70）。在受影响的家庭中，白细胞介素10（IL-10）启动子-1082 G/A基因型相对于A/A基因型降低了RA的发病几率（比值比0.247，95%置信区间0.081，0.751；p = 0.01），在无关个体中也是如此（比值比0.203，95%置信区间0.064，0.640；p = 0.006）。在无关个体中，G/G基因型的比值比为0.093（95% 0.013，0.676；p = 0.019）。在这些计算中，SE没有影响。
在这个NAN队列中，RA的家族患病率很高。在易感的NAN家庭中，IL-10基因型降低了RA的风险，而SE不影响风险。需要对健康的NAN对照进行研究，以确定这些结论是否适用于整个NAN人群。
