Transfusion in Haemoglobinopathies: Review and recommendations for local blood banks and transfusion services in Oman

Seroprevalence and trends of hepatitis B virus, hepatitis C virus and human immunodeficiency virus in Syrian blood donors at Damascus University Blood Center between 2004 and 2021

Introduction

Seroprevalence of transfusion-transmitted viral infections (TTVIs) is a valuable indicator for assessing blood safety, population health and health system performance in the times of peace and conflicts. Only scarce information is available on the impact of the decade-long violent conflict on the prevalence of TTVIs in Syria. Moreover, hepatitis B vaccine was introduced to the national vaccination program in 1993; however, no data is available on the vaccine effectiveness.

Methods

In this retrospective cross-sectional study, we compiled the screening results for major TTVIs, namely hepatitis B virus (HBV), hepatitis C virus (HCV), and human immuno-deficiency virus (HIV), of volunteer donors at Damascus University Blood Center from May 2004 to October 2021. Prevalence was expressed in percentages for the entire study group and subgroups. Chi-square test and linear regression were used to examine the differences and describe trends in prevalence, respectively, based on demographic characteristics (i.e., age and gender) and time. P-value of <0.005 was considered statistically significant.

Results

Of the total 307,774 donors (82.27% males, median age 27 years), 5,929 (1.93%) had serological evidence of at least one TTVI, and 26 (0.0085%) had multiple infections. The lowest prevalence (1.09%) was detected in donors aged 18-25 years old, and a higher prevalence (2.05%) was evident in males in comparison with females (1.38%). The seroprevalence of HBV, HCV, and HIV was 1.18, 0.52, and 0.23%, respectively. Trend analyses revealed a significant regression in HBV and HIV prevalence from 2011 to 2021. HBV seropositivity depicted a temporal decline by ~80%, from 0.79% in 2011 to 0.16% in 2021 in those born in 1993 and thereafter.

Discussion

The seroprevalence of HBV, HIV, and to a lesser extent HCV dropped over the study 18-year period. Possible explanations may include implementation of the HBV vaccine, robust national health system, conservative sociocultural values, and isolation.

State of the field: cellular and exosomal therapeutic approaches in vascular regeneration

Pathologies of the vasculature including the microvasculature are often complex in nature, leading to loss of physiological homeostatic regulation of patency and adequate perfusion to match tissue metabolic demands. Microvascular dysfunction is a key underlying element in the majority of pathologies of failing organs and tissues. Contributing pathological factors to this dysfunction include oxidative stress, mitochondrial dysfunction, endoplasmic reticular (ER) stress, endothelial dysfunction, loss of angiogenic potential and vascular density, and greater senescence and apoptosis. In many clinical settings, current pharmacologic strategies use a single or narrow targeted approach to address symptoms of pathology rather than a comprehensive and multifaceted approach to address their root cause. To address this, efforts have been heavily focused on cellular therapies and cell-free therapies (e.g., exosomes) that can tackle the multifaceted etiology of vascular and microvascular dysfunction. In this review, we discuss 1) the state of the field in terms of common therapeutic cell population isolation techniques, their unique characteristics, and their advantages and disadvantages, 2) common molecular mechanisms of cell therapies to restore vascularization and/or vascular function, 3) arguments for and against allogeneic versus autologous applications of cell therapies, 4) emerging strategies to optimize and enhance cell therapies through priming and preconditioning, and, finally, 5) emerging strategies to bolster therapeutic effect. Relevant and recent clinical and animal studies using cellular therapies to restore vascular function or pathologic tissue health by way of improved vascularization are highlighted throughout these sections.

Iron Overload in Patients With Heavily Transfused Sickle Cell Disease-Correlation of Serum Ferritin With Cardiac T2* MRI (CMRTools), Liver T2* MRI, and R2-MRI (Ferriscan®)

The treatment of sickle cell disease (SCD) is mainly supportive, except for a minority, who receive bone marrow transplantation (BMT). Serum ferritin (SF) is routinely available but is notoriously unreliable as a tool for iron-overload assessment since it is an acute-phase reactant. Although blood transfusion is one of the most effective ways to deal with specific acute and chronic complications of SCD, this strategy is often associated with alloimmunization, iron overload, and hemolytic reactions. This study, thus, aims to evaluate iron overload in patients with SCD on chronic blood transfusions and specifically, correlate SF with the current standard of care of iron-overload assessment using MRI-based imaging techniques. Amongst a historic cohort of 58 chronically transfused patients with SCD, we were able to evaluate 44 patients who are currently alive and had multiple follow-up testing. Their mean age (±SD) was 35 (9) years and comprised of 68.2% of women. The studied iron-overload parameters included cardiac T2^* MRI, liver iron concentration (LIC) by Liver T2^* MRI, and serial SF levels. Additionally, in a smaller cohort, we also studied LIC by FerriScan^© R2-MRI. Chronic blood transfusions were necessary for severe vaso-occlusive crisis (VOC) (38.6%), severe symptomatic anemia (38.6%), past history of stroke (15.9%), and recurrent acute chest syndrome (6.9%). About 14 (24%) patients among the original cohort died following SCD-related complications. Among the patients currently receiving chelation, 26 (96%) are on Deferasirox (DFX) [Jadenu® (24) or Exjade® (2)], with good compliance and tolerance. However, one patient is still receiving IV deferoxamine (DFO), in view of the significantly high systemic iron burden. In this evaluable cohort of 44 patients, the mean SF (±SD) reduced marginally from 4,311 to 4,230 ng/ml, mean Liver T2^* MRI dropped from 12 to 10.3 mg/gm dry weight, while the mean cardiac T2^*MRI improved from 36.8 to 39.5 ms. There was a mild to moderate correlation between the baseline and final values of SF ng/ml, r = 0.33, p = 0.01; Cardiac T2^* MRI ms, r = 0.3, p = 0.02 and Liver T2^* MRI mg/kg dry weight, r = 0.6, p < 0.001. Overall, there was a positive correlation between SF and Liver T2^* MRI (Pearson's r = 0.78, p < 0.001). Cardiac T2^*MRI increased with the decreasing SF concentration, showing a negative correlation which was statistically significant (Pearson's r = -0.6, p < 0.001). Furthermore, there was an excellent correlation between SF ng/ml and LIC by FerriScan^© R2-MRI mg/g or mmol/kg (Spearmen's rho = -0.723, p < 0.008) in a small subset of patients (n = 14) who underwent the procedure. In conclusion, our study demonstrated a good correlation between serial SF and LIC by either Liver MRI T2^* or by FerriScan^© R2-MRI, even though SF is an acute-phase reactant. It also confirms the cardiac sparing effect in patients with SCD, even with the significant transfusion-related iron burden. About 14 (24%) patients of the original cohort died over the past 15 years, indicative of a negative impact of iron overload on disease morbidity and mortality.

A systematic review of quality of life in sickle cell disease and thalassemia after stem cell transplant or gene therapy

Patients with sickle cell disease (SCD) and thalassemia experience several complications across their lifespan that lead to impairment in different health-related quality of life (HRQOL) domains. There is increasing interest in curative therapies for patients with SCD and thalassemia, including hematopoietic stem cell transplant (HSCT) and gene therapy; however, the effect of these therapies on various HRQOL domains remains unclear. Our objective was to systematically evaluate the most recent evidence for the effect of HSCT and gene therapy on HRQOL in patients with SCD and thalassemia. A systematic search of medical literature databases was conducted. A total of 16 studies (thalassemia, n = 9; SCD, n = 6; both, n = 1) involving 517 participants met inclusion criteria (thalassemia, n = 416; SCD, n = 101). HSCT was associated with a small to large positive effects in most HRQOL domains (Cohen's d; mean = 0.47; median = 0.37; range, 0.27-2.05). In thalassemia, HSCT was frequently associated with large positive effects in physical and emotional HRQOL domains (median d = 0.79 and d = 0.57, respectively). In SCD, HSCT was associated with large positive effects in all HRQOL domains. Emerging data suggest improvement in HRQOL outcomes across different domains following gene therapy in thalassemia and SCD. The quality of evidence was moderate in 13 studies (81%). HSCT has a positive impact on several HRQOL domains in patients with SCD and thalassemia; however, more longitudinal studies are warranted to assess the sustainability of these effects. Reporting HRQOL outcomes from ongoing gene therapy or gene-editing trials in SCD and thalassemia is key to better understand the benefits of such therapies.

Prevalence of Hepatitis B, Hepatitis C, and HIV in Multiply Transfused Sickle Cell Disease Patients from Oman

Background

In Oman, the prevalence of hepatitis B (HBV) infection is 5.8%, with 2.8–7.1% HBV carriers. Hepatitis C (HCV) prevalence among Omanis is 0.41%. A total of 2917 human immunodeficiency virus (HIV) infections were notified among Omanis by 2017. This study was performed as there was no data on the prevalence of HIV, HBV and HCV in sickle cell disease (SCD) patients from Oman.

Study Design and Methods

In this retrospective, cross-sectional study, medical records of all SCD patients who attended our hospital between 2011 to 2017 were retrieved from the hospital information system. Following approval by the local medical research and ethics committee, data on HIV, HBV, and HCV exposure were recorded to estimate the prevalence.

Results

Among a total of 1000 SCD patients (491 males and 509 females), twenty-three (2.3%) patients showed positive serology for hepatitis B surface antigen (HbsAg), of whom sixteen (1.6%) were HBV DNA positive. 126 (12.6%) had anti-HCV antibodies (anti-HCV), of whom fifty-two (5.2%) were HCV RNA positive. None of the patients had positive serology for HIV. A normal liver was observed on abdominal ultrasound in 788 (78.8%) patients, whereas 208 (20.8%) had hepatomegaly, and 4 (0.4%) had liver cirrhosis. Thirty-six (3.6%) patients died, but in only two patients, the mortality was due to cirrhosis of liver.

Conclusions

This study provides the first comprehensive data on the prevalence of HBV and HCV infections among Omani SCD patients exposed to blood transfusions. Reassuringly, no case with HIV was observed.

International Comparison of Thalassemia Registries: Challenges and Opportunities

Background:

Patient registries use standardized methods to systematically gather uniform data for specific groups of patients managed in clinical practice to evaluate specified outcomes.

Aim:

The objective of this study was to identify and describe structures of the identified thalassemia registries in worldwide and summarize their key characteristics.

Methods:

We reviewed the literature on thalassemia registries. A search of PubMed, Scopus, ProQuest, and Science Direct databases was conducted in September 2018. We also reviewed the existing thalassemia registry websites in different countries. The keywords used to our search were as follows: Thalassemia, Hemoglobinopathy, Registry, Database, and Registration System. Some features such as the name of registry, funding source, objectives of the registry, minimum data set, and methods of data collection were determined.

Results:

We identified 16 thalassemia registries operating on a multinational, national, or regional level between1984 and 2016. Most of these aimed to improve the diagnosis and management of control programs. Government funding was the most common funding source for registries. Furthermore, the most common method of data submission was Web-based data entry. The data were entered by a member of the clinical team or a nominated data manager.

Conclusion:

Registries provide a positive return on investment; their establishment and maintenance require ongoing support by government, policy makers, research funding bodies, clinicians, thalassemia patients and their caregivers. However, the results of research suggest the establishment of an international network for coordination and collaboration between thalassemia registries.