类风湿关节炎患者血清中抗环瓜氨酸肽抗体不同亚型的临床意义

目的检测类风湿关节炎（RA）患者血清中不同亚型的抗环瓜氦酸肽（CCP）抗体，探讨其在RA中的相关临床意义。方法采用ELISA法检测135例RA患者、53例非RA的其他结缔组织病（CTD）患者和45例健康体检者血清中抗CCP抗体－IgA、IgG和IgM，并用比浊法检测类风湿因子（RF）－IgM。结果RA患者血清中的抗CCP抗体－IgA、IgG、IgM的检出率分别为57．8％、73．3％、30．4％，均高于CTD组和健康对照组，差异均有统计学意义（均P〈0．05）。RA患者的RF－IgM阳性者中的抗CCP抗体－IgA、IgG、IgM的阳性检出率均高于RF－IgM阴性者（P〈0．05）。抗CCP抗体一IgA、IgG亚型在≥24个月、7～23个月病程组中的阳性率高于≤6个月组（P〈005），但≥24个月与7～23个月阳性率的比较差异无统计学意义（P〉005）。抗CCP抗体一IgM在≥24个月的阳性率低于≤6个月组（P〈005），但7～23个月与≥24个月、≤6个月病程组间的阳性率比较差异均无统计学意义（均P〉0．05）。抗CCP抗体一IgA、IgM对RA的诊断敏感度均低于抗CCP抗体－IgG，差异均有统计学意义（均P〈0．05）；而抗CCP抗体－IgA、IgM的诊断特异度分别与抗CCP抗体－IgG的比较差异均无统计学意义（均P〉0．05）。结论RA患者血清中存在不同亚型的抗CCP抗体，抗CCP抗体－IgA、IgM在RA诊断中与IgG亚型有相似的诊断特异度。

Clinical significance of the different subtypes of anti-cyclic citrullinated peptide antibodies in patient with rheumatoid arthritis

Objective To investigate the subtypes of the anti-cyclic citrullinated peptide （CCP） antibodies in patients with rheumatoid arthritis（RA） and its clinical significance. Methods The subtypes of anti-CCP antibodies including IgA, IgG and IgM were detected by enzyme-linked immunosorbent assay （ELISA） in patients serum samples of 135 patients with RA, 53 patients with non-RA connective tissue diseases （CTD） and 45 healthy controls. Results IgA, IgG and IgM anti-CCP antibodies were present in 57.8%,73.3% and 30.4% of RA patients, and their diagnostic specificity was 96.9%,96.9% and 95.9%, respectively. The positive rate of IgA, IgG and IgM anti-CCP antibodies were significant higher than those in non-RA CTD and healthy controls （P〈0.05）. The positive rate of IgA, lgG and IgM anti-CCP antibodies were more frequently in RA patients with positive rheuma- toid factor （RF）-IgM than that in negative RF-IgM RA patients （P〈0.05）. The positive rate of IgA, IgG anti-CCP antibodies in RA patients with disease duration ≥24months and 6-24months groups were significant higher than those in ≤6 group. The positive rate of IgM anti-CCP antibodies in ≥24months group was significant lower than in ≤6 group. There was no statistically signifi- cant difference （P 〉0.05） between 6-24months group and ≥24months group or ≤6 group. Conclusion The subtypes of an- ti-CCP antibodies are common in patients with RA. IgA and IgM anti-CCP antibodies are similarly specific for RA as IgG an- ti-CCP antibodies.