Eastmond C J
City Hospital, Aberdeen, UK.
Baillieres Clin Rheumatol. 1994 May;8(2):263-76. doi: 10.1016/s0950-3579(94)80018-9.
There is convincing evidence of a genetic basis for both psoriasis and psoriatic arthritis (PsA). Part of this genetic predisposition is due to genes within the major histocompatibility complex (MHC). In psoriasis, the primary association is with HLA-Cw6. Further work on specific nucleotide frequencies, especially those in the alpha 1 domain helix of the HLA-C molecule, will be of interest in determining whether a specific nucleotide frequency is present in all patients. The situation in PsA is considerably more complex. It is now established that there is an association between HLA-B27 and PsA, both in its peripheral arthropathy and in spinal disease in which radiological sacroiliitis is present. Spinal disease without radiological sacroiliitis is probably not associated with HLA-B27. There is some suggestion that HLA-B16 or its splits, HLA-B38 and HLA-B39, may also be associated with PsA, but there is considerable heterogeneity between the series, which prevents a firm conclusion being made. It is possible, but again not conclusive, that there is an association between HLA-DR4 and the symmetrical seronegative pattern of peripheral PsA. It is also likely that genes outwith the MHC predispose to psoriasis and PsA. It is further likely that a role will be found for environmental factors in both psoriasis and PsA. There is a tantalizing possibility of a complex interplay between a variety of environmental factors and genetic factors, both within and outwith the MHC, determining not only susceptibility but also the individual clinical pattern of disease. Further clarification of these possibilities is likely to depend primarily on understanding the role of genes within the MHC in predisposing to comparatively more homogeneous diseases, such as psoriasis and ankylosing spondylitis, before the mechanisms operating in PsA can be analysed and better understood.
有令人信服的证据表明，银屑病和银屑病关节炎（PsA）都有遗传基础。这种遗传易感性部分归因于主要组织相容性复合体（MHC）中的基因。在银屑病中，主要关联基因是HLA - Cw6。进一步研究特定核苷酸频率，特别是HLA - C分子α1结构域螺旋中的核苷酸频率，对于确定所有患者是否存在特定核苷酸频率将是有意义的。PsA的情况要复杂得多。现已确定，HLA - B27与PsA在外周关节病以及存在放射学骶髂关节炎的脊柱疾病中均有关联。无放射学骶髂关节炎的脊柱疾病可能与HLA - B27无关。有一些迹象表明，HLA - B16或其亚型HLA - B38和HLA - B39也可能与PsA相关，但各研究系列之间存在相当大的异质性，这使得无法得出确凿结论。HLA - DR4与外周PsA的对称性血清阴性模式之间有可能存在关联，但同样也不具有决定性。MHC之外的基因也可能导致银屑病和PsA。环境因素在银屑病和PsA中发挥作用的可能性也很大。各种环境因素与MHC内外的遗传因素之间可能存在复杂的相互作用，这不仅决定易感性，还决定疾病的个体临床模式，这种可能性很诱人。对这些可能性的进一步阐明可能主要取决于先了解MHC中的基因在导致相对更具同质性的疾病（如银屑病和强直性脊柱炎）易感性方面的作用，然后才能分析和更好地理解PsA中起作用的机制。
