What Could Lead to the Production of Anti-Rheumatoid Antibodies in Patients with Brucellosis Spondylodiscitis: Possible Causes.

Background: High titers of specific antibodies to cyclic citrulline peptide (ACCP) are often present in the serum of patients with rheumatoid arthritis (RA) and, together with rheumatoid factor (RF), are a diagnostic marker of RA. Brucellosis is a zoonotic infection in which osteoarticular involvement occurs in 10-85% of patients. RF in brucellosis patients is significantly higher than in healthy people. Methods: We presented 2 cases of brucellosis spondylodiscitis with positive results for RF and ACCP, which aroused great interest among the rheumatologists of our center. Results: Both patients described were men (27 and 60 years old) with arthritis, back pain, and high levels of rheumatoid arthritis-specific antibodies. These patients were suspected of having tuberculous spondylitis, but the tuberculous process was excluded using specific tests. During antibacterial therapy, there is a dynamic decrease in antirheumatoid antibodies. X-rays of the hand joints revealed no signs of erosive arthritis. Conclusion: All cases of arthritis, spondylitis, and spondylodiscitis in endemic areas require careful analysis and comparison of patients' clinical and laboratory-instrumental data to prevent misdiagnosis. With brucellosis infection, against the background of adequate antibacterial therapy, inflammation of the joints and spine is reversible.