Dasatinib, a selective tyrosine kinase inhibitor, prevents joint destruction in rheumatoid arthritis animal model

AIM

We aimed to evaluate the preventive role of the tyrosine kinase inhibitor dasatinib in an animal model of rheumatoid arthritis (RA).

METHODS

DBA/1J mice were injected with bovine type II collagen to induce arthritis (collagen-induced arthritis [CIA]). There were four experimental groups of mice, namely negative control (non-CIA), vehicle-treated CIA, dasatinib-pretreated CIA, and dasatinib-treated CIA. After collagen immunization, arthritis progression in the mice was clinically scored twice weekly for 5 weeks. Flow cytometry was used to evaluate in vitro CD4⁺ T-cell differentiation and ex vivo mast cell/CD4⁺ T-cell differentiation. Osteoclast formation was evaluated using tartrate-resistant acid phosphatase (TRAP) staining and by estimating the resorption pit area.

RESULTS

We found that the clinical arthritis histological scores were lower in the dasatinib pretreatment group than in the vehicle and dasatinib post-treatment groups. Flow cytometry showed that FcεR1⁺ cells were downregulated and regulatory T cells were upregulated in splenocytes of the dasatinib pretreatment group compared with those in the vehicle group. Additionally, there was a decline in IL-17⁺  CD4⁺ T-cell differentiation and an increase in CD4⁺  CD24^high  Foxp3⁺ T-cell differentiation with in vitro dasatinib treatment of human CD4⁺ T cells. The number of TRAP⁺ osteoclasts and the area of the resorption were decreased in the bone marrow cells derived from dasatinib-pretreated mice compared with those derived from vehicle group.

CONCLUSION

Dasatinib protected against arthritis in an animal model of RA by regulating the differentiation of regulatory T cells and IL-17⁺  CD4⁺ T cells and inhibiting osteoclastogenesis, indicating the therapeutic potential of dasatinib in the treatment of early RA.

Associations of Neutrophil-to-Lymphocyte Ratio, Platelet-to-Lymphocyte Ratio and Monocyte-to-Lymphocyte Ratio with Osteoporosis and Incident Vertebral Fracture in Postmenopausal Women with Rheumatoid Arthritis: A Single-Center Retrospective Cohort Study

Background and Objectives: We investigated whether nutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphoycte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR) are associated with the presence of osteoporosis (OP) and vertebral fractures in patients with rheumatoid arthritis (RA). Materials and Methods: This retrospective cohort study included 413 postmenopausal patients with RA and 200 healthy controls who underwent dual-energy X-ray absorptiometry (DEXA) between January 2005 and December 2017. DEXA examination data were defined as the index date, and all laboratory values were measured within one month from the index date. OP was defined as a T-score < −2.5, and incident vertebral fractures were defined as the first occurrence of non-traumatic fractures after the index date. NLR, PLR, and MLR measures were dichotomized by a median split (low vs. high). Results: The median NLR, PLR, and MLR in RA patients were significantly higher than those in controls. The frequencies of OP of the lumbar spine, hip, and either site in postmenopausal patients with RA were 24.7%, 15.5%, and 32%, respectively, and were significantly higher than those in controls. After adjusting for confounding factors, a high baseline NLR was significantly associated with OP at either site (OR = 1.61, p = 0.041). In addition, high baseline NLR (OR = 2.11, p = 0.025) and PLR (OR = 2.3, p = 0.011) were related with the presence OP at hip. During the follow-up period, 53 (12.8%) patients with RA developed vertebral fractures incidentally. In multivariable Cox regression models, a high baseline NLR (HR = 4.72, p < 0.001), PLR (HR = 1.96, p = 0.024), and MLR (HR = 2.64, p = 0.002) were independently associated with a higher risk of incidental vertebral fractures. Conclusions: Our data suggest that NLR, PLR, and MLR can be used as potential markers of systemic bone loss among individuals with RA.

Comparison of healthcare resource utilization and medical costs between patients with seropositive and seronegative rheumatoid arthritis

Objectives:

To compare healthcare utilization and medical costs between patients with seronegative (SN) and seropositive (SP) rheumatoid arthritis (RA).

Methods:

We conducted a nationwide population study using the Korean health insurance claims database in 2016. We divided patients with RA into SN and SP groups and compared healthcare utilization including medications, medical utilization, and direct medical costs for 1 year between the groups in a cross-sectional analysis. Differences in costs between patients with SPRA and SNRA were assessed using the quantile regression model. We performed longitudinal analysis using data from 2012 and 2016 to examine changes over time.

Results:

A total of 103,815 SPRA and 75,809 SNRA patients were included in the analyses. The SPRA group used significantly more methotrexate (73.2% versus 30.3%) and biologic agents (7.9% versus 2.9%) than the SNRA group. The number of RA-related outpatient visits [6.0 ± 3.7 versus 4.4 ± 4.0 times/year, standardized difference (SD) = 0.41] and annual medical costs per patient ($1027 versus $450/year, SD = 0.25) were higher in the SPRA group than the SNRA group. Quantile regression results indicated that the incremental cost of seropositivity on total medical costs of RA patients gradually increased as medical costs approached the upper quantile. The annual direct medical costs for each patient between 2012 and 2016 increased in both groups: by 25.1% in the SPRA group and 37.6% in the SNRA group.

Conclusion:

Annual RA-related direct medical costs and RA-related healthcare utilization per patient are higher in patients with SPRA than those with SNRA.