Primarily due to recent advances of detection techniques, microchimerism (the proportion of minor variant population is below 1%) has recently gained increasing attention in the field of transplantation. Availability of polymorphic markers, such as deletion insertion or single nucleotide polymorphisms along with a vast array of high sensitivity detection techniques, allow the accurate detection of small quantities of donor- or recipient-related materials. This diagnostic information can improve monitoring of allograft injuries in solid organ transplantations (SOT) as well as facilitate early detection of relapse in allogeneic hematopoietic stem cell transplantation (allo-HSCT). In the present review, genetic marker and detection platform options applicable for microchimerism detection are discussed. Furthermore, current results of relevant clinical studies in the context of microchimerism and SOT or allo-HSCT respectively are also summarized.

Introduction: Chronic graft-versus-host disease (chronic GVHD) is a leading cause of late death and contributes significantly to morbidity following hematopoietic stem cell transplantation. This study aims to provide a systematic literature review on incidence, mortality and relapse of chronic GVHD patients. Areas covered: The authors searched for English-language articles published between 2007 and 2017 using PubMed. Studies that applied the 2005 or 2015 NIH Consensus Criteria for the diagnosis and staging of chronic GVHD, and had a cohort size of at least 100 patients were included. Expert opinion: The authors found a wide variation of incidence rates, which can be explained by heterogeneity in the characteristics of study samples and applied transplantation protocols. Chronic GVHD was associated with higher non-relapse mortality (NRM), superior overall survival (OS) and lower risk of relapse. Studies indicated an increased risk for NRM and worse OS in the presence of more severe disease. Future therapies should focus to reach a delicate balance between controlling disease severity among patients diagnosed with chronic GVHD and preserving the graft versus tumor effect which goes along with chronic GVHD and results in improved OS and decreased relapse rate. Nonetheless, factors predicting disease severity still need to be further understood.

The spread of COVID-19 depends on a lot of social and economic factors. The aim: to study the influence of country’s gross domestic product, population prevalence of overweight/ obesity, NCD mortality, and vaccination on COVID-19 morbidity and mortality rates. A cross-sectional study with two phases: correlation-regression interrelations in 1) all world countries; 2) all world non-island countries. The study includes the following data from 218 world countries: COVID-19 morbidity/mortality rates, GDP per capita, the prevalence of overweight/ obesity, NCD mortality among adults (both sexes), people fully vaccinated against COVID-19. An average percentage of the prevalence of overweight among adults in world countries by 2019 was 47.31 ± 15.99%, obesity 18.34 ± 9.64%, while the prevalence by 2016 were 39% and 13%, respectively. Overweight and obesity among adults during three years grew by 21.2% and 40.8%, respectively. Data from the world countries provide significant correlations (p < 0.0001) between COVID-19 morbidity, and: GDP (r = 0.517), overweight (r = 0.54), obesity (r = 0.528), NCD mortality (r = 0.537); COVID-19 mortality, and: GDP (r = 0.344), overweight (r = 0.514), obesity (r = 0.489), NCD mortality (r = 0.611); GDP, and: overweight (r = 0.507), obesity (r = 0.523), NCD mortality (r = 0.35), fully vaccinated people (r = 0.754). An increase in fully vaccinated people, from 3% to 30% of world population, decreases new confirmed COVID-19 cases, although the dependence was not significant (p = 0.07). Data from non-island world countries provides more highly significant correlations (p < 0.0001) between COVID-19 morbidity, and: GDP (r = 0.616), overweight (r = 0.581), obesity (r = 0.583); COVID-19 mortality, and: GDP (r = 0.43), overweight (r = 0.556), obesity (r = 0.539); GDP, and: overweight (r = 0.601), obesity (r = 0.633). The differences of correlation coefficients between data of 176 world countries and data of 143 world non-island countries were not significant (Z-scores 0.05). The study provides evidence of a significant impact of overweight/obesity prevalence on the increase in COVID-19 morbidity/mortality. Countries with higher GDP have a high overweight/obesity prevalence and possibility to get vaccinated.

Introduction Plasma harvested from convalescent COVID-19 patients (CCP) has been applied as first-line therapy in the early phase of the SARS-CoV2 pandemic through clinical studies using various protocols. Methods We present data from a cohort of 267 hospitalized severe COVID-19 patients who received CCP. No transfusion-related complications were reported, indicating the overall safety of CCP therapy. Results Patients who eventually died from COVID-19 received CCP significantly later (3.95 versus 5.22 days after hospital admission) and had higher interleukin 6 (IL-6) levels (28.9 pg/ml versus 102.5 pg/ml) than those who survived. In addition, CCP transfusion caused a significant reduction in the overall inflammatory status of the patients regardless of the severity of disease or outcome, as evidenced by decreasing C-reactive protein, IL6 and ferritin levels. Conclusion We conclude that CCP transfusion is a safe and effective supplementary treatment modality for hospitalized COVID-19 patients characterized by better expected outcome if applied as early as possible. We also observed that IL-6 may be a suitable laboratory parameter for patient selection and monitoring of CCP therapy effectiveness.