Frequency of serological markers of rheumatoid arthritis in patients with IgA anti-ß2 glycoprotein I antibodies.

ABSTRACT

AIM: To determine the frequency of serological markers of RA in patients with anti-ß2 glycoprotein I antibodies (aß2GPI) of IgA isotype. MATERIAL AND METHODS: A retrospective study was conducted on 67 patients with aß2GPI-IgA. Ninety healthy blood donors (HBD) were used as a control group. IgG anti-cyclic citrullinated peptides antibodies (CCP-Ab) and rheumatoid factors (RF) IgG, IgA, and IgM were detected by enzyme-linked immunosorbent assay (ELISA). RESULTS: Seventeen patients and eight HBD had CCP-Ab and/or RF (25.4% vs. 8.9%, p = 0.005, CI 95% [14.95; 35.79], odds ratio = 3.5). The frequency of CCP-Ab was significantly higher in patients than in healthy subjects (14.9% vs. 3.3%, p = 0.009). IgA isotype of RF was significantly higher in patients than in controls (7.5% vs. 0%, p = 0.02). In male patients, CCP-Ab and/or RF were more frequent than in healthy male subjects (37.5% vs. 11.8%, p = 0.02). In patients, no correlation was found between the levels of aß2GPI-IgA and CCP-Ab (r = 0.082, p = 0.51). There was no correlation between the level aß2GPI-IgA and the level of the isotypes of RF (IgG, IgA, and IgM) in patients (r = 0.1, p = 0.37; r = 0.17, p = 0.17 and r = 0.07, p = 0.59 respectively). CONCLUSION: Frequencies of CCP-Ab and RF are high in patients with aß2GPI-IgA suggesting that these patients are susceptible to developing RA.