肺炎支原体感染与强直性脊柱炎活动性的研究

目的 研究成人强直性脊柱炎(AS)患者肺炎支原体(MP)感染与疾病活动性的关系.方法 选取我院门诊AS患者66例;对照组选取类风湿关节炎(RA)31例,骨关节炎(OA)25例,健康人群(NC)36名.根据抗肺炎支原体抗体(anti-MP IgM)将AS患者分成MP感染组和非MP感染组,比较和分析4周以内上呼吸道感染史、白细胞、疾病活动指数(BASDAI)、红细胞沉降率(ESR)、C反应蛋白(CRP)、免疫球蛋白以及骶髂关节损害程度、脊柱活动度(Schober测量和胸廓活动度).结果 66例AS患者抗MP抗体检测发现,阳性检出率为52%(34/66),与RA(6%)、OA(4%)、NC(11%)比较,差异有统计学意义(P＜0.01).MP感染组的疾病活动也显著高于非MP感染组,其中BASDAI(4.0±1.1对3.0±1.9,P=0.017),ESR[(44±32)mm/1 h对(28±23)mm/1 h,P=0.029],CRP[(40±38)mg/L对(22±21)mg/L,P=0.025],血清总IgG水平[(18±3)g/L对(16±5)g/L,P=0.027],但与总IgA和IgM无关.两组的骶髂关节分级、Schober测量和胸廓扩张度差异无统计学意义.抗MP抗体阳性的AS患者中只有44%出现呼吸道症状,但有呼吸道症状的AS患者中,71%的患者抗MP抗体阳性,与无呼吸道症状组比较,差异具有统计学意义(P=0.027).结论 AS患者的MP感染与疾病的活动性密切相关,可能是AS发病的主要诱发因素.

Relationship between Mycoplasma pneumoniae infection and disease activity of ankylosing spondylitis

Objective To investigate the association of Mycoplasma pneumoniae(MP) infection with disease activity of ankylosing spondylitis. Methods A total of 158 subjects in our hospital were enrolled in this study, including patients with ankylosing spondylitis(AS, n=66), rheumatoid arthritis (RA, n=31),osteoarthritis(OA, n=25) and normal controls(NC, n=36). MP infection was defined as anti-MP IgM antibody positive. Anti-MP IgM antibodies were determined by a mycoplasma pneumoniae(Mac strain)membrane-based agglutination test. AS patients were divided into two groups: MP infection group and non-MP infection group. T-test was used for statistical analysis of age, blood white cells, ESR, CRP, immunoglobulin, BASDAI index, global assessment on VAS scale, Schober test and chest expansion reflecting spinal mobility.χ2-test was used to compare the positive rate of MP infection in different groups. Gender difference and prevalence of clinical infection in past four weeks between MP infection and MP-free group in AS patients was also compared. Ridit analysis was used to analyze the association of MP infection with degree of sacroiliac damage on CT. Results The prevalence of MP infection in AS (52%, 34/66) was much higher than that in rheumatoid arthritis (RA, 6%, P＜0.01 ), osteoarthritis(OA, 4%, P＜0.01 ) and normal controls (NC, 11%, P＜0.01) . Compared with the non-MP infection group, the MP infection group had more active disease in term of BASDAI(4.0±1.1 vs 3.0±1.9, P=0.017), ESR[(44±32) mm/1h vs (28±23) mm/1h, P=0.029], CRP [(40±38) mg/L vs (22±21) mg/L, P=0.025] serum total IgG level [(18±3) g/L vs (16±5) g/L, P=0.027],but not in serum total IgA and IgM. Regarding to the sacroiliac joint and spinal mobility, MP infection group did not exhibit any association with the sacroiliac grading on CT, Schober test and expansion. In AS patients with MP infection, only 44.1%(15/34) was complicated by clinical manifestations of upper respiratory tract in the past 4 weeks. However, a higher prevalence of MP infection was found in AS patients with clinical manifestation of upper respiratory tract, compared with those with negative clinical manifestation(71% vs 42%,P=0.027). Conclusion Mycoplasma pneumoniae is the most common reported pathogen in ankylosing spondylitis and relates to the disease activity of AS. MP infection is probably a principal triggering factor in the pathogenesis of AS.