The Level of IgA Antibodies to CD74 in Patients with Spondyloarthritis and Degenerative-Dystrophic Diseases of the Spine

Abstract

Background. According to the scientific literature, anti-CD74 IgA antibodies (IgA anti-CD74) are considered as a possible marker for the diagnosis of axial spondyloarthritis (SpA). The level of IgA anti-CD74 in patients with back pain due to degenerative spine disease has not been studied. Therefore, it could be interesting to compare the serum levels of IgA anti-CD74 in patients with chronic back pain in various diseases. Aim: to compare the levels of IgA anti-CD74 in patients with SpA and degenerative spine diseases. Material and methods. A total of 87 SpA patients (55 male, mean age 41 [29; 49] years) fulfilling the Assessment of Spondyloarthritis International Society (2009) criteria for Axial SpA, and 39 patients (25 male, mean age 45 [34; 53] years) with neurologist-verified degenerative spine diseases (ICD 10 codes — M 51.1 and M 54.4) were enrolled to the study. The serum levels of IgA anti-CD74 were analyzed by enzyme-linked immunosorbent assay (ELISA) in all patients. Results. The median levels of IgA anti-CD74 in patients with SpA were 11.3 [5.4; 19.4] U/ml, in patients with degenerative spine disease — 6.9 [4.5; 13.7] U/ml (p=0.024). IgA anti-CD74 serum levels were above the cut-off value in 58 (66.7 %) patients with SpA and only in 11 (28.2 %) patients with degenerative spine disease (p<0,001). The elevated serum levels of IgA anti-CD74 were detected in 10 (40 %) of 25 male patients and in 1 (7.1 %) of 14 female patients (p = 0.029, χ2 = 4.785) with degenerative spine disease. Conclusion. Serum levels of I gA anti-CD74 were increased in two-thirds of patients with SpA. IgA anti-CD74 was significantly higher in SpA patients compared to patients with degenerative spine disease. >< 0,001). The elevated serum levels of IgA anti-CD74 were detected in 10 (40 %) of 25 male patients and in 1 (7.1 %) of 14 female patients (p = 0.029, χ2 = 4.785) with degenerative spine disease. Conclusion. Serum levels of I gA anti-CD74 were increased in two-thirds of patients with SpA. IgA anti-CD74 was significantly higher in SpA patients compared to patients with degenerative spine disease.