This study systematically evaluates the concordance among different anti-dsDNA antibody detection methods and reveals their complex relationship with HEp-2 cell immunofluorescence results, emphasizing the importance of combined multi-method testing in the diagnosis of systemic lupus erythematosus.
Literature Overview
The article titled 'Evaluation of Anti-dsDNA Antibodies in Laboratory Practice: Management of Different Analytical Methods and Correlation with HEp-2 Immunofluorescence Patterns,' published in the journal Antibodies, reviews and summarizes the laboratory practices for detecting anti-double-stranded DNA (anti-dsDNA) antibodies in clinical settings, with a focus on analyzing result consistency across different detection methods and their association with HEp-2 cell indirect immunofluorescence (IIF) patterns. The study included 138 anti-dsDNA-positive patients and assessed the performance of various detection techniques, including fluorescent enzyme immunoassay (FEIA), immunoblotting (IB), and Crithidia luciliae indirect immunofluorescence (CLIFT), while also exploring the relationship between antibody levels and HEp-2 IIF titers. The results showed that a substantial proportion of anti-dsDNA-positive patients tested negative by HEp-2 IIF, and FEIA demonstrated high concordance with immunoblotting, suggesting that a multi-step testing strategy should be adopted to improve diagnostic accuracy. This study provides important guidance for laboratory practices in the serological diagnosis of systemic lupus erythematosus (SLE). Ultimately, it emphasizes the necessity of integrating multiple testing methods for comprehensive evaluation in the absence of a unified standard.Background Knowledge
Systemic lupus erythematosus (SLE) is a complex autoimmune disease whose diagnosis relies on the integrated analysis of multiple immunological markers. Anti-nuclear antibodies (ANA) are a key serological marker for SLE, and anti-dsDNA antibodies, due to their high disease specificity, are included in the classification criteria for SLE. However, the detection of anti-dsDNA antibodies faces numerous challenges: first, the immune response is highly heterogeneous, with different assays recognizing distinct antigenic epitopes, leading to variable results; second, although traditional indirect immunofluorescence (IIF) on HEp-2 cells is a common screening method for ANA, its sensitivity for anti-dsDNA is limited, potentially resulting in false-negative outcomes. Current commonly used detection methods include radiolabeled antigen binding assays (Farr assay), CLIFT, ELISA, chemiluminescence assays (CLIA), and fluorescent enzyme immunoassays (FEIA). Among these, FEIA, which uses a liquid-phase reaction system, better preserves the natural conformation of DNA and offers high sensitivity and specificity. However, differences in affinity, antigen sources, and detection principles across methods lead to inconsistent results. Moreover, anti-dsDNA antibodies are not only present in SLE patients but may also appear in other autoimmune diseases or infections, making specific confirmation crucial. CLIFT, which uses the kinetoplast of Crithidia luciliae—rich in dsDNA—as a substrate—is considered highly specific and is often used as a confirmatory test, although it suffers from lower sensitivity. Balancing high sensitivity and high specificity and establishing standardized testing protocols remain key challenges in current serological diagnosis of SLE. This study systematically compares the performance of multiple detection methods to provide more reliable testing strategies for clinical laboratories.
Research Methods and Experiments
This study was a single-center retrospective analysis that included 3,090 patients who underwent anti-dsDNA antibody testing, of whom 138 were positive by fluorescent enzyme immunoassay (FEIA) (≥15 IU/mL), and 29 negative patients were included as a control group. All patients underwent indirect immunofluorescence (IIF) testing on HEp-2 cells to evaluate fluorescence patterns and titers. Anti-dsDNA-positive patients were further divided into low (15–25 IU/mL), medium (26–49 IU/mL), and high (>50 IU/mL) groups based on antibody levels. In a subgroup of 30 positive patients, immunoblotting (IB) and Crithidia luciliae indirect immunofluorescence (CLIFT) were performed to assess concordance among different methods. Data analysis was conducted using R and SPSS software; continuous variables were expressed as mean ± standard deviation, group comparisons were performed using ANOVA and chi-square tests, and agreement was analyzed using percentage concordance.Key Conclusions and Perspectives
Research Significance and Prospects
This study reveals significant differences among anti-dsDNA detection methods and highlights that relying solely on HEp-2 IIF may lead to missed diagnosis of anti-dsDNA-positive patients. FEIA, due to its high sensitivity, can effectively detect low-affinity or epitope-specific antibodies, while immunoblotting, as an orthogonal method, helps confirm specificity. Although CLIFT has high specificity, its limited sensitivity may cause it to miss some positive cases. Therefore, clinical laboratories should consider combining FEIA with immunoblotting to improve the accuracy of SLE diagnosis.
Future studies should expand sample sizes and incorporate more clinical information, such as disease activity, organ involvement, and treatment history, to further validate the value of these detection methods in disease monitoring and prognosis assessment. Additionally, exploring novel detection platforms, such as microarray-based or multiparametric flow cytometry techniques, may help more comprehensively characterize the heterogeneity of anti-dsDNA antibodies. Standardizing testing protocols and establishing internationally harmonized reference materials remain critical directions for advancing serological diagnosis in SLE. This study provides important evidence for optimizing anti-dsDNA antibody testing strategies, helping to reduce misdiagnosis and missed diagnosis and improving early recognition and management of SLE.
Conclusion
This study systematically evaluated the performance of anti-dsDNA antibody testing in clinical practice and its concordance with HEp-2 cell immunofluorescence results. It was found that although high antibody levels are generally associated with high IIF titers, a significant proportion of anti-dsDNA-positive patients test negative by HEp-2 IIF—reaching 19% in the high-antibody group. This indicates that FEIA has higher sensitivity than traditional IIF and can detect antibodies that are difficult to identify by IIF. Further comparison of FEIA, immunoblotting, and CLIFT revealed high concordance between FEIA and immunoblotting, while CLIFT showed low concordance with the other two methods, suggesting differences in the antigenic epitopes recognized. Therefore, the study supports a multi-step testing strategy: using FEIA as a screening tool and confirming positive results with immunoblotting to enhance reliability. The study emphasizes that serological diagnosis of SLE should not rely solely on HEp-2 IIF results, but should integrate multiple methods for comprehensive assessment. Ultimately, establishing a standardized, multi-method testing workflow will improve diagnostic accuracy in SLE, reduce false-negative results, and provide stronger support for clinical decision-making.
