老年患者梅毒螺旋体特异性抗体生物学假阳性结果分析

摘要

目的 分析我院老年患者梅毒螺旋体特异性抗体筛查情况,同时探讨其生物学假阳性的原因及临床意义.方法选取2016年1月至2016年12月我院8741例60岁以上老年患者,利用化学发光微粒子免疫检测法(CMIA)检测梅毒螺旋体特异性抗体,梅毒甲苯胺红不加热血清试验(TRUST)检测梅毒螺旋体非特异性抗体,同时采用免疫印迹法(Western Blot)进行梅毒确证.根据老年患者年龄将其分为60～69岁、70～79岁和80岁以上三个年龄组进行统计学分析.结果8741例60岁以上老年患者中有354例患者梅毒螺旋体特异性抗体阳性,60～69岁、70～79岁和80岁以上三个年龄组的梅毒螺旋体特异性抗体阳性率分别为3.42%、6.30%和6.02%,差异具有统计学意义(x2=31.236,P<0.001);同时,60~69岁与70~79岁年龄组比较,差异具有统计学意义(x2=28.932,P<0.001).240例老年患者CMIA筛查梅毒抗体阳性标本经TRUST和Western Blot检测都为阴性,且无临床症状和体征、无相关病史,结果判为假阳性.老年患者梅毒抗体假阳性人群主要分布在60~69岁.但随着老年患者年龄的增加,梅毒螺旋体抗体假阳性率也呈上升趋势,60~69岁、70~79岁和80岁以上三个年龄组的梅毒抗体假阳性率分别64.81%、71.43%和87.50%.老年患者梅毒螺旋体抗体生物学假阳性伴有的其他临床症状及指标异常主要包括癌症(55.36%)、溶栓剂或抗凝剂治疗(35.71%)、糖尿病(28.57%)、肝硬化(25.00%)、严重感染(25.00%)、肾病(17.86%)、自身抗体阳性(16.07%)、手术(14.29%)、肝炎(12.50%)和代谢紊乱(8.93%),各类原因相互影响,梅毒抗体检测假阳性S/CO值最高可达10.29.而梅毒螺旋体特异性抗体真阳性老年患者伴有的其他临床症状及指标异常百分比情况明显低于生物学假阳性患者.结论 对于CMIA梅毒筛查阳性而TRUST检测阴性的老年患者,需进行Western Blot检测并结合临床症状、体征和病史,作出最后诊断.老年患者随着年龄的增高,梅毒抗体的假阳性率也呈上升趋势,需注意癌症、自身免疫病、严重感染、代谢紊乱等可能会导致老年患者梅毒抗体检测生物学假阳性的因素,有助于临床医生分析检测结果并向患者作出合理解释.%Objective To analyze the screening results of Treponema pallidum specific antibody in elderly patients in our hospital, and to explore the causes and clinical significance of biological false positive.Methods From January 2016 to December 2016, 8741 cases of patients over the age of 60 were adopted in our hospital.By using chemiluminescent microparticle immunoassay (CMIA), we detected Treponema pallidum antibody, and using syphilis toluidine red unheated serum test (TRUST) to detect Treponema pallidum non specific antibody.At the same time, Western Blot (WB) was conducted to confirm syphilis.According to the age of the elderly patients, the patients were divided into three groups: 60~69 years old, 70-79 years old and over 80 years old.Results There were 354 cases of patients with Treponema pallidum specific antibody positive in 8741 cases of patients over the age of 60 patients.The positive rates of Treponema pallidum specific antibody in 60-69 years old group, 70-79 years old group and over 80 years old group were 3.42%, 6.30% and 6.02%, respectively.The difference was statistically significant among the three age groups (x2=31.236, P<0.001).At the same time, the two age groups of 60-69 years old and 70-79 years old also had a significant difference (x2=28.932, P<0.001).240 cases of elderly patients with CMIA screening syphilis antibody positive specimens were detected negatively by TRUST and Western Blot, which were found to be false positive with no clinical symptoms and signs and no history.Elderly patients with syphilis antibody false positive crowd were mainly distributed in 60-69 years old.However, with the increase of the age in elderly patients, the false positive rate of Treponema pallidum antibody showed an upward trend.The false positive rates of Treponema pallidum specific antibody in 60-69 years old group, 70-79 years old group and over 80 years old group were 64.81%, 71.43% and 87.50%, respectively.The false positive of Treponema pallidum antibody in elderly patients were associated with other clinical symptoms and abnormalities mainly including cancer (55.36%), thrombolytic or anticoagulant therapy (35.71%), diabetes (28.57%), hepatocirrhosis (25%), severe infection (25%), kidney (17.86%), positive autoantibodies (16.07%), surgery(14.29%), hepatitis (12.50%) and metabolic disturbance (8.93%).With all kinds of factors interacted with each other, and the false positive value of S/CO was up to 10.29.However, the specific clinical symptoms and abnormal percentage of the elderly patients with positive Treponema pallidum specific antibody were significantly lower than those of the patients with false positive.Conclusion For CMIA syphilis screening positive and TRUST detection negative in elderly patients, they need to carry out Western Blot testing, and combined with clinical symptoms, signs and history, to have a final diagnosis by doctors.With the increase of age, the false positive rate of syphilis antibody also increased.We need to pay more attentions to the biological factors, such as cancer, autoimmune disease, seriously infect, metabolic disturbance and so on, which might lead to false positive syphilis antibody in elderly patients.By doing so would help clinicians analyze the results and give a reasonable explanation to patients.