AIM:To investigate the expression and potential role of complement 5a receptor (C5aR) in chro-nic graft-versus-host disease (cGVHD).METHODS:The expression of C5aR on lymphocytes and the frequency of CD4+CD25+ Foxp3+ regulatory T cells (Tregs) in 20 cGVHD patients and 9 healthy donors was detected by flow cytometry.The correlation between the expression of C5aR and the percentage of Tregs in the cGVHD patients was analyzed.In addition, the splenocytes from the mice were cultured in vitro, and stimulated these splenocytes with recombinant mouse C5a protein (rmC5a).The peripheral blood mononuclear cells (PBMCs) from cGVHD patients were cultured in vitro, which was inhibited by C5aR antagonist (C5aRA).The frequency of Tregs in these splenocytes and the PBMCs were evaluated by flow cytometry.RESULTS:The expression of C5aR on the lymphocytes was significantly increased in the cGVHD patients compared with the healthy donors, while the percentage of Tregs was markedly lower in the cGVHD patients.The expression of C5aR was negatively correlated with the percentage of Tregs.Furthermore, the development of Tregs was suppressed by rmC5a stimulation, but was promoted by C5aRA in vitro.CONCLUSION:C5aR elevation is associated with Treg reduction in cGVHD, indicating that C5aR may play a potential role in suppressing Tregs, resulting in the incidence of cGVHD.

Objective:To compare the numerical rating scales (NRS) and Oswestry disability index (ODI) of denosumab in Chinese postmenopausal osteoporosis patients after 3 months, and analyze the early adverse reactions to provide reference for clinical diagnosis and treatment.Methods:Using a prospective study method, 260 patients with postmenopausal osteoporosis who were outpatients and inpatients in the Second Affiliated Hospital of Soochow University from September 2020 to October 2021 were selected, and general information, including age, height, weight, bone mineral density, history of fragility fractures, and use of anti-osteoporosis drugs. All subjects received denosumab 60 mg subcutaneously, and were given calcium and vitamin D at the same time. Pain was scored by NRS before treatment and 3 months after treatment, and functional improvement was assessed by ODI.Results:After 3 months of denosumab treatment in postmenopausal women with osteoporosis, among patients with different age groups, different degrees of osteoporosis, history of fragility fractures, and history of use of anti-osteoporosis drugs, NRS score and ODI score were lower than those before treatment, and the difference was statistically significant ( P<0.05). In addition, in patients with a history of fragility fractures (mainly vertebral fractures), the NRS scores and the ODI score decreased more significantly, and the difference was statistically significant ( P<0.05); the NRS score and ODI score decreased more significantly in patients with severe osteoporosis than in patients with osteoporosis, and the difference was statistically significant ( P<0.05); the BMD value of lumbar spine was negatively correlated with the reduction of NRS score before and after treatment ( P=0.042). In this study, 260 patients had musculoskeletal pain in 6 (2.3%), fatigue in 5 (1.9%), rash in 4 (1.5%), urinary tract infection in 2 (0.7%), and dizziness in 2 (0.7%), 2 case of fever (0.7%), 1 case of hypocalcemia (0.4%), a total of 22 cases of adverse reactions were reported, and the overall adverse reaction rate was 8.5%. Conclusion:Denosumab can improve pain symptoms and functional disability early in the clinical application of Chinese postmenopausal women with osteoporosis, and the incidence of adverse reactions is low. Especially for postmenopausal female osteoporosis patients with severe osteoporosis, low lumbar spine bone density, and a history of fragility fractures (mainly vertebral fractures), the application effect is more significant.