肿瘤患者血清中SARS-CoV抗体阳性原因分析

探讨SARS冠状病毒(SARS—CoV)抗体在SARS病原学诊断中的特异性及其在肿瘤患血清中的假阳性问题。应用ELISA和荧光定量RT-PCR技术检测了111例正常对照和40例肿瘤患血清中SARS—CoV抗体的阳性率。在111例正常对照中，IgM抗体均阴性，IgG抗体的阳性率为3．6％(4／111)；IgG抗体诊断SARS的特异性为96．4％，两种抗体同时阳性诊断SARS的特异性为100％。40例肿瘤患中，IgM抗体均阴性，IgG抗体阳性率17．5％(7／40)。经RT—PCR检测，上述肿瘤患阳性病例均为阴性。结果表明，同时测定SARS—CoV的两种抗体可降低诊断的假阳性率，提高诊断的特异性。用非纯化SARS—CoV抗原制备的ELISA试剂盒测定肿瘤患的SARS—CoV抗体，可能出现假阳性。在肿瘤患中出现假阳性的原因可能与包被的抗原有关。

Analysis of false-positive associated with antibody tests for SARS-CoV in cancer patients

To investigate the specificity of serological diagnostic testing for coronavirus antibody in patients with SARS and to discuss the fasle-positive of SARS-associated coronavirus(SARS-CoV)antibody in patients with cancer.SARS-CoV IgG and IgM antibody was detected in serum specimens from40cancer patients with non-SARS and111healthy controls without SARS-CoV infection by ELISA,and SARS-CoV RNA was also detected in serum spec-imens from the patients with SARS-CoV antibody positive by RT-PCR.Of 111sera from healthy controls,4(3.6%)were positive of SARS-CoV-IgG antibody and111(100%)were all negative of SARS-CoV-IgM antibody;the speci-ficity of SARS-CoV-IgG antibody for SARS patients was96.4%,but the specificity of both SARS-CoV-IgG and IgM antibody for SARS patients was100%.In40cases with cancer,positive rate of SARS-CoV-IgG antibody was17.5%(7/40),and40(100%)were all negative of SARS-CoV-IgM antibody.Of all samples with positive SARS-CoV-IgG antibody for cancer patients,SARS-CoV-specific RNA were all negative by RT-PCR.This results suggested that the ELISA kit coated by non-purification SARS-CoV antigen may lead to the false-positive of SARS-CoV antibody in patients with cancer,ELISA tests for SARS-CoV antibodies was specific.SARS-CoV-IgG and IgM antibody tests had low fasle-positive rates,the false-posotive with SARS-CoV-IgG antibody may be related to coated antigens with SARS-CoV and Vero-E6cells in patients with cancer.