Transfusion transmitted infections in thalassaemics: need for reappraisal of blood screening strategy in India

Current challenges of blood transfusions in patients with thalassemia in India and future perspectives

The introduction of regular red blood cell transfusions transformed thalassemia major from a fatal childhood disease into a chronic disorder. Thalassemia is highly prevalent in South Asia, including the Indian subcontinent, and blood transfusion remains the cornerstone of management for these patients. But safe blood transfusions still remain a major problem in India. Difficulties in maintaining adequate blood inventory, a lack of a national blood act, and fragmented blood transfusion services are some of the major contributing factors for the delay in blood supply. In most of the blood centers, alloantibody detection facilities and extended red cell antigen typing are unavailable. Awareness is the key to reducing alloimmunization, which limits the effectiveness of transfusions and the potential availability of blood. Patients with thalassemia are also at high risk of transfusion-transmitted infections unless appropriate blood screening is in place. Hence, many patients remain under-transfused, resulting in decreased health and quality-of-life outcomes. Facilities such as leucoreduction and immunohematological monitoring following a blood transfusion are often lacking in India, especially at the sub-district level. Continuous efforts to raise community awareness, regular training of health-care workers, and proper utilization of available resources are essential to ensuring safe blood transfusions for patients with thalassemia. Access to the new treatments at an affordable cost may reduce the blood transfusion burden for thalassemia patients in India.

Hepatitis B infection among β-thalassemia major patients in Bushehr province of southern Iran

This study was performed to determine the prevalence, genotype distribution and risk factors of hepatitis B virus (HBV) infection among β-thalassemia patients. ELISA was used to detect HBsAg and HBcAb. Molecular evaluation of HBV infection was performed by nested PCR, targeting S, X and pre-C regions of the genome, and sequencing. Of 126 thalassemia patients, 4 cases (3.17%) were positive for HBsAg, 23 cases (18.25%) were positive for HBcAb, and 6 cases (4.76%) had HBV viremia with genotype D, sub-genotype D3 and subtype ayw2. HBV prevalence among thalassemia patients was not statistically associated with gender distribution, place of residency, marital status and frequency of blood transfusion. HBsAg seroprevalence was significantly higher in Afghan immigrants and patients with ALT levels of 41-80 IU/L. The prevalence of HBV viremia was significantly higher among thalassemia patients aged >20 years compared to the patients aged <20 years. Moreover, 1.59% of thalassemia patients had seropositive occult HBV infection, which was positive for HBV-DNA and HBcAb but negative for HBsAg. Considering the relatively high prevalence of occult HBV infection among thalassemia patients, there is a possibility of their contamination through donated blood. Therefore, screening of donated blood based on detection of HBsAg cannot abolish HBV transmission through blood transfusion.

Prevalence and Molecular Evaluation of Hepatitis C Virus Infection among Multi-transfused Thalassemia Patients in South of Iran

OBJECTIVES

Information regarding the magnitude of hepatitis C virus (HCV) infection among thalassemia patients is of great importance for health care providers to assess blood safety and improve the quality of screening systems. Therefore, this study evaluated the prevalence, risk factors, and genotypic pattern of HCV infection among β-thalassemia patients in South Iran.

METHODS

This descriptive-analytical cross-sectional study was conducted from March to June 2019. All patients with β-thalassemia major from Borazjan, Bushehr, Delvar, Kangan, and Ahram cities participated in the study and attended the transfusion center of the Bushehr University of Medical Sciences located in southern Iran. Serum samples were tested for the presence of anti-HCV antibodies by an enzyme-linked immunosorbent assay. The seropositive serum samples were tested for detection of HCV viremia and genotypes by semi-nested reverse transcriptase-polymerase chain reaction and sequencing.

RESULTS

Of 125 thalassemia patients, 22 (17.6%) were positive for anti-HCV antibodies and two (1.6%) had HCV viremia with genotype 3a. HCV seroprevalence increased with age, so anti-HCV seropositive thalassemia patients had significantly higher mean age than anti-HCV seronegative patients. HCV seroprevalence was higher among female patients, residents of Kangan, patients with blood transfusion every two weeks, Fars patients, and thalassemia patients with alanine aminotransferase levels of < 20 IU/L and aspartate aminotransferase levels of > 80 IU/L. Nevertheless, anti-HCV seroprevalence among thalassemia patients was not statistically associated with these variables.

CONCLUSIONS

These results indicate ongoing HCV incidence among the thalassemia population in this region. Transfusion of HCV-seronegative viremic blood units donated during the infectious window period contributes to HCV infection in thalassemia patients. These findings highlight the need to include sensitive molecular assays in the screening process of donated blood for HCV infection in Iran.

Thalassemia Patients from Baluchistan in Pakistan Are Infected with Multiple Hepatitis B or C Virus Strains

There are an estimated 2,000 children with β-thalassemia in the province Baluchistan of Pakistan. These children are at high risk of acquiring transfusion-transmitted infections (TTIs) due to their need of regular blood transfusions for survival. Therefore, we investigated the frequencies of TTIs among these multi-transfused patients in a region where the WHO guidelines for blood safety are not always followed. Sera from 400 children (mean age 7.7 ± 4.70 years) treated at two thalassemia centers in Baluchistan were investigated for TTIs. Eleven (2.8%) were hepatitis B surface antigen positive, and 72 (18.3%) had anti-hepatitis C virus (HCV), two of which were infected with both viruses. Only 22% of the children had been reached by the program for universal hepatitis B virus (HBV) vaccination which started in 2004. Half (51%) of the HCV infected had also been HBV infected. The HBV- and HCV-infected patients were older and had received more blood transfusions than the uninfected patients (P < 0.001). Molecular characterization of the viral strains revealed the presence of several genetically different strains in at least three HBV- and seven HCV-infected children. This is the first study to demonstrate infections with multiple HBV or HCV strains simultaneously infecting thalassemia patients. These may become the source for new emerging recombinant viruses of unknown virulence. The high prevalence of anti-HCV-positive children, and the presence of HBV infections among children who should have been vaccinated, highlights an urgent need for improvements of blood safety in this region of Pakistan.

Erythropoiesis In Vitro-A Research and Therapeutic Tool in Thalassemia

Thalassemia (thal) is a hereditary chronic hemolytic anemia due to a partial or complete deficiency in the production of globin chains, in most cases, α or β, which compose, together with the iron-containing porphyrins (hemes), the hemoglobin molecules in red blood cells (RBC). The major clinical symptom of β-thal is severe chronic anemia—a decrease in RBC number and their hemoglobin content. In spite of the improvement in therapy, thal still severely affects the quality of life of the patients and their families and imposes a substantial financial burden on the community. These considerations position β-thal, among other hemoglobinopathies, as a major health and social problem that deserves increased efforts in research and its clinical application. These efforts are based on clinical studies, experiments in animal models and the use of erythroid cells grown in culture. The latter include immortal cell lines and cultures initiated by erythroid progenitor and stem cells derived from the blood and RBC producing (erythropoietic) sites of normal and thal donors, embryonic stem cells, and recently, "induced pluripotent stem cells" generated by manipulation of differentiated somatic cells. The present review summarizes the use of erythroid cultures, their technological aspects and their contribution to the research and its clinical application in thal. The former includes deciphering of the normal and pathological biology of the erythroid cell development, and the latter—their role in developing innovative therapeutics—drugs and methods of gene therapy, as well as providing an alternative source of RBC that may complement or substitute blood transfusions.

Challenges of blood transfusions in β-thalassemia

Patients with β-thalassemia major (BTM) require regular blood transfusions, supported by appropriate iron chelation therapy (ICT), throughout their life. β-thalassemia is a global disease that is most highly prevalent in Southeast Asia, Africa, and Mediterranean countries. However, the global distribution of patients with β-thalassemia is changing due to population migration, and Northern European countries now have significant thalassemia populations. Globally, many patients with BTM have limited access to regular and safe blood transfusions. A lack of voluntary nonremunerated blood donors, poor awareness of thalassemia, a lack of national blood policies, and fragmented blood services contribute to a significant gap between the timely supply of, and demand for, safe blood. In many centers, there is inadequate provision of antigen testing, even for common red cell antigens such as CcEe and Kell. Policies to raise awareness and increase the use of red blood cell antigen testing and requesting of compatible blood in transfusion centers are needed to reduce alloimmunization (the development of antibodies to red blood cell antigens), which limits the effectiveness of transfusions and the potential availability of blood. Patients with BTM are also at risk of transfusion-transmitted infections unless appropriate blood screening and safety practices are in place. Hence, many patients are not transfused or are undertransfused, resulting in decreased health and quality-of-life outcomes. Hemovigilance, leukoreduction, and the ability to thoroughly investigate transfusion reactions are often lacking, especially in resource-poor countries. ICT is essential to prevent cardiac failure and other complications due to iron accumulation. Despite the availability of potentially inexpensive oral ICT, a high proportion of patients suffer complications of iron overload and die each year due to a lack of, or inadequate, ICT. Increased awareness, training, and resources are required to improve and standardize adequate blood transfusion services and ICT among the worldwide population of patients with BTM. ICT needs to be available, affordable, and correctly prescribed. Effective, safe, and affordable new treatments that reduce the blood transfusion burden in patients with β-thalassemia remain an unmet need.