Predictive Value of Laboratory Assays Toward Autoimmune Diseases.

OBJECTIVE: With an increasing number of unmet medical needs for autoimmune diseases (AD) in the United States, it is important to assess the value of laboratory assays in diagnosis. Healthcare providers must understand general and specific laboratory results that can lead to an efficient diagnosis. METHODS: A nonexperimental study using a retrospective design and data collected between 2018 and 2021 was completed to explore whether the presence of positive anti-ENA and anti-dsDNA antibodies in individuals with an autoimmune disorder (anti-ENA, N = 1495; anti-dsDNA, N = 1261) can be predicted by their demographics and selected general laboratory test results. RESULTS: For predicting anti-ENA, multiple logistic regression analysis χ2(1) = 237.62, p < 0.001 indicated antinuclear antibody (ANA), complement C3, globulin, monocyte-to-lymphocyte ratio (MLR), and blood urea nitrogen (BUN) were statistically associated with the probability of a positive anti-ENA result. The regression analysis had a sensitivity of 98.6% and a specificity measure of 16.1%. Regarding anti-dsDNA, multiple logistic regression analysis χ2(1) = 388.04, p < 0.001, indicated that complement C3, complement C4, pH, urine protein, and neutrophil-to-lymphocyte ratio (NLR) were statistically associated with the probability of a positive anti-dsDNA result. The regression analysis had a sensitivity of 77.7% and a specificity measure of 64.5%. CONCLUSION: In diagnosing an AD, ANA, complement C3, globulin, MLR, and BUN are important factors in patients with a positive anti-ENA. In determining Systemic Lupus Erythematosus diagnosis, complement C3, complement C4, pH, urine protein, and NLR are important factors in patients with a positive anti-dsDNA.