Wilson J G, Wong W W, Murphy E E, Schur P H, Fearon D T
J Immunol. 1987 Apr 15;138(8):2708-10.
The role of genetic factors in controlling CR1 quantitative expression on erythrocytes (E) of patients with systemic lupus erythematosus (SLE) was reexamined by determining the temporal stability of CR1 numbers and the frequency of a CR1 genomic restriction fragment length polymorphism (RFLP). The mean number of binding sites/(E) for Yz-1 monoclonal anti-CR1 correlated with the number of sites for polyclonal anti-CR1 that had been determined 2 to 4 yr previously in 18 normal persons (p less than 0.001), 18 patients (p less than 0.001), and 28 relatives (p less than 0.001), indicating that CR1 sites/E was a stable characteristic in all three groups. The mean number of Yz-1 sites/E was 281 +/- 34 (+/- SEM) in 28 probands with SLE and 457 +/- 21 in 93 relatives, both determinations being less than that for 100 normal persons, 553 +/- 21 (p less than 0.002). Thirty-six patients and 51 normal individuals were also assessed for the presence of the 7.4 kb and 6.9 kb HindIII CR1 allelic restriction fragments that correlate with high and low expression, respectively, of CR1 on E. The distribution of patients differed from normal (p less than 0.05), with a smaller proportion being homozygous for the 7.4 kb allele. In addition, the mean numbers of Yz-1 sites/E for patients and relatives who were homozygous (p less than 0.02) and heterozygous (p less than 0.05) for the 7.4 kb allele were significantly lower than those for normal persons matched for the HindIII RFLP, suggesting the existence of additional heritable factors that decrease CR1 expression. The stability over time of the CR1 deficiency among patients, the finding of decreased CR1 number among an expanded group of relatives, the altered frequency among patients of CR1 alleles defined by the HindIII RFLP, and the decreased expression of CR1 on E among patients and relatives compared with normal individuals having the same HindIII RFLP indicate a role for genetic factors in CR1 deficiency in SLE.
通过测定补体受体1（CR1）数量的时间稳定性以及CR1基因组限制性片段长度多态性（RFLP）的频率，重新审视了遗传因素在控制系统性红斑狼疮（SLE）患者红细胞（E）上CR1定量表达中的作用。Yz-1单克隆抗CR1的结合位点/（E）平均数与2至4年前在18名正常人（p<0.001）、18名患者（p<0.001）和28名亲属（p<0.001）中测定的多克隆抗CR1位点数量相关，表明CR1位点/ E在所有三组中都是一个稳定的特征。28名SLE先证者的Yz-1位点/ E平均数为281±34（±SEM），93名亲属为457±21，两者均低于100名正常人的553±21（p<0.002）。还对36名患者和51名正常个体进行了评估，以确定分别与E上CR1高表达和低表达相关的7.4 kb和6.9 kb HindIII CR1等位基因限制性片段的存在情况。患者的分布与正常情况不同（p<0.05），纯合7.4 kb等位基因的比例较小。此外，7.4 kb等位基因纯合（p<0.02）和杂合（p<0.05）的患者及亲属的Yz-1位点/ E平均数显著低于与HindIII RFLP匹配的正常人，提示存在其他可降低CR1表达的遗传因素。患者中CR1缺乏随时间的稳定性、在扩大的亲属组中发现CR1数量减少、患者中由HindIII RFLP定义的CR1等位基因频率改变以及与具有相同HindIII RFLP的正常个体相比患者及亲属中E上CR1表达降低，表明遗传因素在SLE患者CR1缺乏中起作用。
