Role of HLA typing and chimerism analysis in post-liver transplantation GVHD in pediatrics: A systematic review.

BACKGROUND: GVHD is a well-documented complication after liver transplantation. GVHD occurs when donor immune cells mount a destructive immune response against host cells. The rarity of the GVHD complication and the nonspecific presentation of symptoms and histopathological features provide a diagnostic challenge. Therefore, diagnosis and initiation of treatment are often delayed. AIM: In this systematic review, we assessed relevant literature to better understand the utilization of HLA typing and chimerism analysis in liver transplantation. We mainly focused on their importance in diagnosing GVHD incidence after liver transplantation. RESULTS: A total of 18 articles reported 21 cases of GVHD after liver transplantation in pediatrics. Generally, there is a consensus on the advantage of HLA typing and chimerism analysis in confirming the diagnosis of GVHD after liver transplantation. However, there is an inconsistency in the timing and the application of the accurate HLA typing and chimerism analysis. CONCLUSION: Further studies are required to assess the incidence of GVHD post-LT and to determine the impact of HLA typing and chimerism analysis in assessing the risk, early determination of GVHD incidence, and improving outcomes. This systematic review highlights the gap in the field of liver transplantation and calls for revisiting the guidelines to consider HLA typing and chimerism analysis in predicting GVHD before transplantation and diagnosing GVHD incidence after liver transplantation.

Factors related to COVID-19 vaccine hesitancy in Saudi Arabia.

Objectives: To assess the amount of vaccine hesitancy and its determinants in relation to various demographic, social, and personal characteristics among the Saudi population. Study design: Cross-sectional study. Methods: we utilized a structured questionnaire on a five point-Likert scale that included immunization process awareness, perception towards immunization and factors leading to vaccine refusal. Results: The study included 5965 participants characterized according to various demographical factors. The participant's knowledge, perception, and the factors affecting the decision of taking the vaccine were calculated. About 40.7% had enough information about COVID-19 vaccines and were willing to take it. The participant's perception towards COVID-19 vaccines is proportional to their knowledge and varied with the personal characteristics. Factors influencing vaccine use varied also with personal characteristics. Intent to be vaccinated was higher among older age groups, advanced education, retirees, and higher income persons (P < 0.001). Moreover, the influence of heterogeneity in personal perception towards COVID-19 vaccines has been discussed. Vaccine barriers scores were significantly higher among lower educational and income levels (P = 0.004). The leader's influence on vaccine decision was high (p < 0.001). The side effects of COVID-19 vaccine is the most important barrier to vaccine acceptance. Knowledge and perception score were consistently and significantly higher among the group who received their information from official websites, followed by those who had used both websites and social media (p < 0.001). Conclusion: Additional approaches will be needed to effectively meet the needs of the hesitant population, particularly the safety and efficacy concerns, the speed of vaccine development, and the distrust in government and health organizations.