Risk of infection in postmenopausal women with rheumatoid arthritis and osteoporosis taking denosumab and bDMARDS

Background: There is no clear consensus regarding the potential of denosumab for increasing the risk of infection in patients who concurrently receive biologic disease-modifying anti-rheumatic drugs (bDMARDs). In this study, we compared the rate of infection in postmenopausal women with rheumatoid arthritis who received concurrent bDMARDs and denosumab with those who received bDMARDs alone.    Methods: In a case-control study, postmenopausal patients with a confirmed diagnosis of rheumatoid arthritis who received concurrent bDMARDs and denosumab for at least one year were identified and included as the case group (n=40). A total of 44 age-matched postmenopausal rheumatoid arthritis women who received bDMARDs alone were included as the control group of the study. Using a chi-squared test, the incidence of bacterial or viral infections was extracted from the patients’ profiles and compared between the two study groups. Statistical analyses were performed by SPSS for Windows, version 16 (Chicago, Illinois, USA). A p-value of fewer than 0.05 was regarded as significant.    Results: The clinical and demographic characteristics of the patients of the two study groups were not significantly different. In total, four infections were recorded in the present series, two infections in each group. Accordingly, the rate of infection was 4.5% in the bDMARDs alone group and 5% in bDMARDs + denosumab group. This difference was not statistically significant (p=0.655, 95% CI: 0.121-6.742). Three out of four infections were herpes zoster infection. The other one was osteomyelitis of the first metatarsal bone, which occurred in the bDMARDs+denosumab group. None of the infections needed a hospitalization of IV antibiotics.    Conclusion: The risk of infection is comparable between postmenopausal osteoporotic women with rheumatoid arthritis who receive bDMARDS alone and those who receive bDMARDS in combination with denosumab.