The role of monocytes and SLC11A1 polymorphisms in the pathogenesis of Chlamydia-induced reactive arthritis

Objectives: To investigate the role that monocytes and solute carrier family 11 member A1 (SLC11A1) gene polymorphisms play in the pathogenesis of reactive arthritis (ReA). Methods: SLC11A1 274C/T and 823C/T polymorphisms were determined by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). The phagocytic activity of monocytes was analysed by flow cytometry after they were co-cultured with Chlamydia trachomatis. The inclusions in the monocytes were demonstrated by immunohistochemistry staining. Bactericidal activity was determined by immunofluorescence staining with the recovered inclusions. Results: There was no significant difference in the phagocytic activity of monocytes between the ReA patients and healthy controls. The bactericidal activity of monocytes from the healthy controls was more efficient than that from the ReA patients. The patients with SLC11A1 823T tended to have a higher bactericidal activity of monocytes than those with SLC11A1 823 C/C. Moreover, the bactericidal activity of monocytes in the patients with SLC11A1 274T seemed to decrease in comparison with that in the patients with SLC11A1 274C/C. Conclusions: The bactericidal activity of monocytes in patients with ReA is lower than that in healthy controls. The SLC11A1 274C/T and 823C/T polymorphisms may be associated with the decreased bactericidal activity of the monocytes.