Cost-Effectiveness Rivaroxaban versus Enoxaparin for Prevention of Venous Thromboembolism after Knee Replacement Surgery in Iran.

Background: The highest risk of developing venous thromboembolism (VTE) is seen in patients who have undergone orthopedic surgery. One of the most common methods to reduce the risk of thromboembolism in these patients is anticoagulant prophylaxis. Rivaroxaban is one of the anticoagulants that has a lower cost than other anticoagulants and has a significant effect on people's quality of life as it is edible. The study aimed to determine the cost-effectiveness of rivaroxaban as compared with enoxaparin for venous thromboembolism prophylaxis in knee replacement patients in Iran. Methods: It was a quantitative and economic evaluation study with a cost-effectiveness approach and an applied study because its results could be used directly for policy-making and decision-making in the health system. The study was conducted in 2019 and 2020. This study considered the health system perspective. The study population included all knee replacement patients. The sample included 203 patients referred to Shafa Yahyaeian Hospital and 300 patients referred to Rasoul Hospital in Tehran. The study was conducted in two steps. A systematic review of studies was conducted in the first step. The CHEERS checklist was used to evaluate the quality of the studies in the systematic review. The EQ-5D questionnaire was used in the second step to calculate the QALY, and the cost collection form was used to calculate the direct medical cost. The data were analyzed through a decision tree, and Stata and Tree age pro softwares were the analysis tools. Also, according to the per capita GDP index for Iran in 2018, the incremental cost-effectiveness threshold was considered to be $10,000. Results: The results of this study showed that during the prophylaxis period, rivaroxaban was one and a half times less costly than enoxaparin. Quality of life in uncomplicated conditions were 0.85 QALY for rivaroxaban and 0.69 QALY for enoxaparin. Based on the results of this study, the cost of rivaroxaban during the prophylaxis was $ 160.97 and the quality of life was 0.85 QALY and the cost of enoxaparin was $ 276.07 and the quality of life was 0.69 QALY. The cost difference between the two interventions was $ 115.09 and the outcome difference was 0.16 QALY. The incremental cost-effectiveness ratio was $ 189.40 for rivaroxaban and $ 416.28 for enoxaparin. According to the results of this study, rivaroxaban reduced the duration of hospitalization by an average of 2 days in asymptomatic patients (prophylaxis period) compared to enoxaparin. Conclusion: Rivaroxaban, an oral medication, reduced costs and increased the quality of life in people undergoing knee replacement surgery compared with an enoxaparin injection vial. This drug was less costly for the patient and health systems and its use was cost-effective as a thromboprophylaxis drug following knee replacement surgery.

Both T and B cells are indispensable for the development of a PBMC transfer-induced humanized mouse model for SSc.

BACKGROUND: Recently, a novel humanized mouse model for systemic sclerosis (SSc) was established by transferring peripheral blood mononuclear cells (PBMC) from patients with SSc to Rag2-/-Il2rg-/- immunodeficient mice. Here, we aimed to investigate the role of T and B cells in this humanized mouse model. METHODS: T and B cells were depleted in vitro from freshly isolated PBMC using anti-CD3 and anti-CD19 magnetic microbeads, respectively. Subsequently, PBMC and T or B cell-depleted PBMC were transferred into Rag2-/-/Il2rg-/- mice via intraperitoneal injection. Twelve weeks after the transfer, mice were sacrificed and evaluated. RESULTS: Mice transferred with whole PBMC from SSc patients developed systemic inflammation in the lungs, kidneys, and liver, and 6 out of 11 mice died or had to be sacrificed during the experiment. By contrast, such inflammation and death were not observed in mice transferred with corresponding T or B cell-depleted PBMC. In line with this finding, transfer with whole PBMC restored the splenic white pulp composing of human T, B, and plasma cells and led to the production of a considerable amount of human autoantibodies in recipient mice, while those immunological features were rarely observed in mice that received T or B cell-depleted PBMC. In contrast to our previous findings demonstrating a transfer of the protective effect of a B cell therapy into the mouse, treatment of SSc patients with chemical immunosuppressive drugs did not affect the pathogenicity of PBMC. CONCLUSIONS: This study demonstrates that both T and B cells are indispensable for the pathogenesis of the PBMC transfer-induced mouse model for SSc.

Transfer of PBMC From SSc Patients Induces Autoantibodies and Systemic Inflammation in Rag2-/-/IL2rg-/- Mice.

Objective: The contribution of sustained autologous autoantibody production by B cells to the pathogenesis of systemic sclerosis (SSc) and granulomatosis with polyangiitis (GPA) is not fully understood. To investigate this, a humanized mouse model was generated by transferring patient-derived peripheral blood mononuclear cells (PBMC) into immunocompromised mice. Methods: PBMC derived from patients with SSc and GPA as well as healthy controls (HD) were isolated, characterized by flow cytometry, and infused into Rag2-/-/IL2rg-/- mice. In addition, PBMC from SSc patients treated with rituximab were transferred into mice. Twelve weeks later, human autoantibodies were determined in blood of the recipient mice and affected tissues were analyzed for pathological changes by histology and immunohistochemistry. Results: Mice engrafted with PBMC derived from SSc patients developed autoantibodies such as antinuclear antibodies (ANA) mimicking the pattern of the respective donors. Moreover, cellular infiltrates dominated by B cells were observed in lung, kidney and muscles of the recipient mice. By contrast, PBMC derived from HD or GPA patients survived in recipient mice after transfer, but neither human autoantibodies nor inflammatory infiltrates in tissues were detected. Furthermore, these pathological changes were absent in mice transferred with PBMC from rituximab-treated SSc patients. Conclusion: This humanized mouse model is indicative for cross-reactivity of human lymphocytes to murine autoantigens and argues for a pivotal role of B cells as well as of sustained autoimmunity in the pathogenesis of SSc. It provides a powerful tool to study interstitial lung disease and so far, under-recognized disease manifestations such as myositis and interstitial nephritis.

Medical student and patient perspectives on bedside teaching.

OBJECTIVE: To evaluate the perspectives of medical students and patients on bedside teaching (BST). METHODS: A cross-sectional study was undertaken to elicit patients and learners opinions on BST in Hazrat Rasool Hospital, a university teaching hospital in Tehran, Iran. From June 2008 to September 2008, 100 fourth-year medical students and 100 adult patients admitted to the general medical service of a teaching hospital were chosen randomly. Patients who stayed for a minimum of 48 hours and had at least 2 case presentations in 2 consecutive mornings were included in the study. Patients under 18 years of age, non-Persian speakers, and cognitively impaired were excluded from the study. Their perspectives on BST were assessed with 2 separate questionnaires. RESULTS: The mean age of medical students was 25.2 +/- 2.2 (22-36) years and 35% were male. The mean age of patients was 46.3 +/- 18.7 (17-85) years and 50% were male. Most of medical students believed that BST is an effective way for learning principle of history taking, physical examination, practical skills, data registry, communicating skills, evidence based medicine, and interpretation of para-clinical findings. Fifty-three percent of them believed that the time of BST is not enough, while 40% thought BST is the most effective way of learning clinical skills. Sixty percent of patients were comfortable with BST and 80% of them preferred that case presentation be performed in front of them. CONCLUSION: Our study suggests that teaching in the presence of patients provides unique and valuable opportunities to integrate the knowledge and skills of medicine for the direct benefit of the patient.