Diagnostic value of high affinity anti-double-stranded DNA antibody in systemic lupus erythematosus

ObjectiveTo investigate the distribution of high affinity anti-double-stranded DNA(dsDNA) antibodies in patients with systemic lupus erythematosus(SLE), and its correlation with sex, age and lupus nephritis.

MethodsA total of 155 serum samples with anti-dsDNA antibody positive in Guangdong Provincial Hospital of Traditional Chinese Medicine from August 2017 to April 2018 were collected, which were divided the SLE group(116 cases) and non-SLE group(39 cases).The levels of total anti-dsDNA antibody and high affinity anti-dsDNA antibody were determined using the enzyme-linked immunosorbent assay(ELISA) and indirect immunofluorescence(IIF).The Kappa analysis was used to investigate the consistency of results among different detection methods.Spearman correlation coefficient was used to analyze the correlation between high affinity dsDNA antibody, and gender, age and other clinical indicators.

ResultsThe total anti-dsDNA antibody measured by ELISA(dsDNA-ELISA) was not specific for SLE.The overall compliance rate between dsDNA-IIF and dsDNA-ELISA was 58.7%(91/155), the Kappa was 0.172(< 0.4), and the consistency between two methods was low(P < 0.01).The overall compliance rate between dsDNA-IIF and high affinity dsDNA-ELISA was 61.9%(96/155), the Kappa was 0.514(0.4 < Kappa < 7.5), and the consistency between two methods was moderate(P < 0.01).The high affinity anti-dsDNA level was positively correlated with dsDNA-IIF and dsDNA-ELISA(P < 0.01), and was not related to the gender, age and lupus nephritis(P>0.05).The sensitivity and specificity of combined diagnosis of dsDNA-IIF and high affinity anti-dsDNA were 90.5%(105/116) and 100%(39/39), respectively.

ConclusionsThe combined diagnosis of dsDNA-IIF and high affinity antibody levels is more conducive to the diagnosis of SLE.High affinity anti-dsDNA antibodies are not associated with age, gender and lupus nephritis.