Puttick A H, Briggs D C, Welsh K I, Williamson E A, Jacoby R K, Jones V E
Postgraduate Medical School, University of Exeter, United Kingdom.
Ann Rheum Dis. 1990 Apr;49(4):225-8. doi: 10.1136/ard.49.4.225.
Associations were sought between major histocompatibility complex (MHC) genes on chromosome 6 and the complement component C3 and immunoglobulin genes located on other chromosomes which might contribute to susceptibility to mild inflammatory arthritis (IA) or definite rheumatoid arthritis (RA). Frequencies of the complement C3F allele were raised in patients with IA but were normal in patients with RA and controls. When associations between C3F and MHC genes were sought frequencies of some MHC genes were greater in patients with C3F than in those without--for example, HLA-B8 and DR3 in patients with RA and DR2 in patients with IA. Conversely, DR4 frequency was lower in patients with IA with C3F than in those without. Thus the C3F allele may act independently or exert an epistatic effect on MHC genes to increase susceptibility or protect against disease. The frequency of the immunoglobulin heavy chain allotype Glm(2) on chromosome 14 was increased in patients with RA but only in those with the phenotype Gm1,2,3,17;21,5; no significant associations were found between MHC genes and Gm phenotypes. Further, no associations of MHC, C3F, and immunoglobulin genes were shared by patients with RA and those with IA, indicating a different genetic basis for the two clinical entities.
研究了位于6号染色体上的主要组织相容性复合体（MHC）基因与位于其他染色体上的补体成分C3和免疫球蛋白基因之间的关联，这些基因可能与轻度炎症性关节炎（IA）或明确的类风湿性关节炎（RA）的易感性有关。IA患者中补体C3F等位基因的频率升高，但RA患者和对照组中的频率正常。当研究C3F与MHC基因之间的关联时，C3F患者中某些MHC基因的频率高于无C3F的患者，例如，RA患者中的HLA - B8和DR3以及IA患者中的DR2。相反，有C3F的IA患者中DR4频率低于无C3F的患者。因此，C3F等位基因可能独立起作用或对MHC基因发挥上位效应，以增加易感性或预防疾病。14号染色体上免疫球蛋白重链同种异型G1m(2)的频率在RA患者中升高，但仅在具有Gm1,2,3,17;21,5表型的患者中升高；未发现MHC基因与Gm表型之间存在显著关联。此外，RA患者和IA患者之间未共享MHC、C3F和免疫球蛋白基因的关联，表明这两种临床实体具有不同的遗传基础。
