关键词: 抗核抗体, 抗SS-A/Ro60 抗体, 间接免疫荧光法, 结缔组织病

Abstract:

Objective To investigate the influence of different antinuclear antibody（ANA） statuses on the diagnosis of connective tissue diseases（CTD） in anti-SS-A/Ro60 antibody positivity patients. Methods A total of 88 588 patients who underwent ANA screening（ANA screening group） and 3 499 healthy subjects（healthy control group） at Renji Hospital of Shanghai Jiao Tong University School of Medicine from January to December 2023 were enrolled. Based on the results from indirect immunofluorescence assay（IFA） for ANA and line immunoassay（LIA） for anti-SS-A/Ro60 antibodies，the 88 588 patients were classified into 4 serological patterns，ANA-/Ro60+（419 cases），ANA+/Ro60+（11 005 cases），ANA-/Ro60-（53 295 cases） and ANA+/Ro60-（23 869 cases）. Pearson correlation analysis was used to evaluate the relationship between the LIA gray scale values of anti-SS-A/Ro60 antibodies and quantitative enzyme-linked immunosorbent assay（ELISA） results. Odds ratios（OR） and their 95% confidence intervals（CI） were calculated by four-fold table to assess the association between different ANA/anti-SS-A/Ro60 antibody serological patterns and CTD，other disease occurrence. Receiver operating characteristic（ROC） curves were used to evaluate the diagnostic performance of anti-SS-A/Ro60 antibodies for CTD under different ANA statuses. Results The gray scale values and proportion of strong positivity（+++） for anti-SS-A/Ro60 antibodies in ANA screening group were higher than those in healthy control group（P<0.001）. In the ANA+/Ro60+ group，the gray scale values，the proportion of strong positivity（+++） and the rate of concurrent determination of other anti-extractable nuclear antigen（ENA） antibodies were higher than those in the ANA-/Ro60+ group（P<0.05）. Among the 47 ANA-/Ro60+ samples，the concordance rate between LIA and ELISA for determining anti-SS-A/Ro60 antibodies was 91.5%（43/47），and a positive correlation was observed between LIA gray scale values and ELISA quantitative results （r=0.690，P<0.000 1）. The CTD confirmation rate in the ANA+/Ro60+ group（60.34%）was higher than that in the ANA-/Ro60+ group（16.7%）（P<0.001）. The ANA+/Ro60+ pattern showed a positive association with CTD（OR=7.46，95%CI 5.760-9.651），whereas the ANA-/Ro60+ pattern showed a negative association（OR=0.13，95%CI 0.104-0.174）. When ANA was positive，the area under curve（AUC） for diagnosing CTD with positive anti-SS-A/Ro60 antibodies was 0.928. When ANA was negative，the AUC was 0.516. Conclusions Positive anti-SS-A/Ro60 antibodies represent a strong risk signal for CTD when ANA is positive，but have low specificity when ANA is negative. Combined determination of ANA and anti-SS-A/Ro60 antibodies improves the accuracy of CTD diagnosis.

Key words: Antinuclear antibody, Anti-SS-A/Ro60 antibody, Indirect immunofluorescence assay, Connective tissue disease