Anti-Carbamylated Protein Antibodies as Biomarkers in RA, SLE, and Primary Sjögren's Syndrome: Clinical Relevance and Diagnostic Utility

Background: Anti-carbamylated protein antibodies (Anti-CarPA) have been discovered to be useful as biomarkers for diagnosing systemic rheumatic disorders (RDs) and monitoring of disease activity. Nonetheless, they lack complete profiles on their occurrence, their value in the diagnosis, and clinical correlations in rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and primary Sjögren syndrome (pSS).Objective: In this study, the prevalence, diagnostic abilities, and clinical correlates of anti-CarPA in rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and primary Sjögren syndrome (pSS) patients were investigated and determined as opposed to healthy controls (HC).Methods: One hundred and thirty-one cases were employed in this retrospective study (40 with RA, 40 with SLE, 11 patients with pSS, and 40 healthy people were also used, and were matched with age and sex). The current international classification criteria were used in the diagnosis of all the patients (ACR/EULAR in RA and SLICC in SLE). The enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of serum anti-CarPA. The performance of the diagnosis was evaluated through sensitivity and specificity analysis. Connections with clinical and laboratory indicators of the disease activity were established.Results: There was elevated serum Anti-CarPA concentration in RA (30.3 ± 22.9 ng/mL; p < 0.001), SLE (18.1 ± 11.1 ng/mL; p = 0.005), and pSS (14.6 ± 5.6 ng/mL; p = 0.005) when set alongside healthy control (3.2 ± 0.6 ng/mL). In RA, the Anti-CarPA positivity was correlated significantly with increased DAS28 scores (p = 0.041), rheumatoid factor detection (p = 0.003), and the volume of white blood cells (p = 0.045). The Anti-CarPA positivity was linked with a higher ESR (p = 0.002) and SLEDAI-2K (p = 0.025) in SLE. While in pSS patients, the anti-CarPA levels were also found to be significantly linked to elevated platelet counts (p = 0.001). Anti-CarPA sensitivity were 74.2 and 75.8 % in RA, 72.0 and 88.5 % in SLE, and 71.9 and 75.0 % in pSS, respectively.Conclusion: Anti-CarPA antibodies are important in the diagnosis as well as in clinical evaluation of RA, SLE, and pSS. It is indicated by their close bonds to disease-related activity parameters and good diagnostic selectivity that they could be used as supporting biomarkers in the early detection of systemic rheumatic illnesses, their administration, and patient stratification.