Related Articles

Background:

Red blood cell (RBC) alloantibodies may be formed following exposure to RBC antigens. In most cases, the alloimmunization develops during pregnancy or from previous blood transfusions. The RBC antigens and their alloantibodies vary among different human populations and ethnic groups, and they do have a clinical significance for their adverse immunological reactions.

Aims:

This study aimed at studying the prevalence of RBC alloantibodies at the Blood Transfusion Unit of Hospital Raja Perempuan Zainab II in Kota Bharu, Malaysia.

Patients and Methods:

A cross-sectional study was performed utilizing data obtained in the years 2007 and 2008. Data of antibody screening tests from 5719 patients were examined.

Results and Discussion:

The overall prevalence of alloimmunization was 65 (1.13%). The majority of these had a single alloantibody (76.9%), whereas the remaining 23.1% had multiple antibodies. The anti-E antibody comprised the most common alloantibody (24.6%) followed by the anti-Lewis (a) antibodies (18.5%) and the anti-M antibody (13.8%). There were more female recipients than males.

Conclusions:

It was concluded that the findings of this work have been comparable with other published works, and that the main factors associated with alloantibody formation were multiple transfusions and pregnancies. The study also emphasizes the necessity for carrying out immunohematology studies prior to every blood transfusion especially in cases that require multiple transfusions for a long period of time such as in thalassemia patients.

Background

Several irregular red blood cell alloantibodies, produced by alloimmunization of antigens in transfusions or pregnancies, have clinical importance because they cause hemolysis in the fetus and newborn and in transfused patients.

Objective

a prospective analysis of patients treated by the surgical and clinical emergency services of Hospital de Clínicas of the Universidade Federal do Triângulo Mineiro (HC/UFTM), Brazil was performed to correlate alloimmunization to clinical and epidemiological data.

Methods

Blood samples of 143 patients with initial negative antibody screening were collected at intervals for up to 15 months after the transfusion of packed red blood cells. Samples were submitted to irregular antibody testing and, when positive, to the identification and serial titration of alloantibodies. The Fisher Exact test and Odds Ratio were employed to compare proportions.

Results

Fifteen (10.49%) patients produced antibodies within six months of transfusion. However, for 60% of these individuals, the titers decreased and disappeared by 15 months after transfusion. Anti-K antibodies and alloantibodies against antigens of the Rh system were the most common; the highest titer was 1:32 (anti-K). There was an evident correlation with the number of transfusions.

Conclusions

Given the high incidence of clinically important red blood cell alloantibodies in patients transfused in surgical and clinical emergency services, we suggest that phenotyping and pre-transfusion compatibilization for C, c, E, e (Rh system) and K (Kell system) antigens should be extended to all patients with programmed surgeries or acute clinical events that do not need emergency transfusions.

Introduction

The objective of this study was to explore the frequency of red cell alloantibodies and autoantibodies among β-thalassaemia patients who received regular transfusions.

Material and methods

This study included 501 patients with β-thalassaemia. This work planned to study the presence of alloantibodies and autoantibodies to different red cell antigens in multitransfused thalassaemia patients using the ID. Card micro typing system.

Results

Of a total of 501 β-thalassaemia patients included in the study, 11.3% of patients developed alloantibodies; 9.7% of these alloantibodies were clinically significant. The most common alloantibodies were anti-K, anti-E and anti-C. The rate of incidence of these alloantibodies was 3.9%, 3.3% and 1.7% respectively. Autoantibodies occurred in 28.8% of the patients and 22.1% of these antibodies were typed IgG. There was a significant association between splenectomy with alloimmunization and autoantibody formation (p = 0.03, p = 0.001 respectively). There was no significant association between alloantibody, autoantibody formation and number of transfused packed red cells.

Conclusions

Alloimmunization to minor erythrocyte antigens and erythrocyte autoantibodies of variable clinical significance are frequent findings in transfused β-thalassaemia patients. There is an association between absence of the spleen and the presence of alloimmunization and autoantibody formation.

The development of irregular serum antibodies (alloantibodies) following massive transfusion was studied in 144 patients who had undergone cardiac valve replacement. An overall incidence of alloimmunization of 8·3% was found. Of the 15 antibodies detected nine were Rhesus anti-E and four anti-Kell. The incidence of anti-E formation in Rhesus E-negative patients was 11·4%; the corresponding figure for anti-Kell was 3·2%. The results suggest that the risk of allo-immunization is directly related to the volume of blood transfused, and Rhesus E-negative persons appear to be at particular risk.

Australia (Au) antigen investigations were also carried out in 102 of these cases. Three patients were Au antigen positive, one of them developing acute hepatitis. In each case no Au antigen could be detected in the donor blood that was used.

It is suggested that tests for alloantibodies and for the Australia antigen should become part of the routine follow-up of any patient receiving massive transfusion.

Background:

Alloantibodies of clinical importance can cause transfusion reactions or hemolytic disease of the fetus and newborn (HDFN). The frequencies of these antibodies have not been reported in our locality.

Aims:

To determine the frequency of occurrence of alloantibodies among pregnant women in Port Harcourt, Nigeria.

Settings and Design:

This is a prospective study, which was carried out in the Braithwaite Memorial Specialist Hospital, Port Harcourt, Nigeria.

Materials and Methods:

Screening and identification of red blood cell alloantibodies was done on the sera of 500 pregnant women using the DiaMed, DiaCell, and DiaPanel reagents (Cressier, Switzerland). ABO and Rh blood groups were done using antisera bought from Biotec (Ipswich, UK).

Results:

Alloantibodies were identified in the serum of 17 of the 500 (3.4%) pregnant women. The specificity of the antibodies was as follows: anti-C 6 (1.2%), anti-E 3 (0.6%), anti-Jsb 3 (0.6%), and anti-K 5 (1.0%). No anti-D was identified despite 8.6% of the study population being Rhesus D (Rh D) negative. The distribution of the antibodies was found to be independent of the blood groups of the participants (χ2 = 4.050, P = 0.670). Blood group O constituted the highest percentage (48.0%).

Conclusion:

This study has identified the presence of non-Rh D antibodies to the proportion of 3.4%. Rh D antibody was absent in this population irrespective of the relatively high percentage of Rh D negative women. There is a need to determine the actual risk these antibodies may pose to the antenatal women and to include antibody screening and identification in routine antenatal care.

In this study, we report the first Korean case of an anti-Gerbich (Ge) alloantibody to a high-incidence antigen that belongs to the Ge blood group system. The alloantibody was detected in a middle-aged Korean woman who did not have a history of transfusion. Her blood type was B+, and findings from the antibody screening test revealed 1+ reactivity in all panels except the autocontrol. The cross-matching test showed incompatible results with all 5 packed red blood cells. Additional blood type antigen and antibody tests confirmed the anti-Ge alloantibody. While rare, cases of hemolytic transfusion reaction or hemolytic disease in newborns due to anti-Ge have been recently reported in the literature. Therefore, additional further studies on alloantibodies to high-incidence antigens, including anti-Ge, are necessary in the future.

Objective

The thalassemias are among the most common genetic disorders worldwide, occurring more frequently in the Mediterranean region. The aim of this study was to determined frequency of sensory-neural hearing loss in major ß- thalassemias transfusion dependent patients in south of Iran.

Methods

A cross sectional study on 308 cases of major beta-thalassemia patients referring to Thalassemia Center of Shiraz University of Medical Sciences between 2006–2007 years. The diagnosis of ß- thalassemia major was based on clinical history, complete blood count and hemoglobine electrophoresis. Clinical data such as serum ferritin level, deferoxamine (DFO) dose, mean daily doses of DFO (mg/kg) and audiometric variables was recorded.

Findings

Out of 308 cases, 283 (96.5%) had normal hearing and 10 (3.5%) sensorineural hearing loss. There was no statically significant difference between two groups regarding mean age, weight, age at the first blood transfusion, age at the first DFO infusion.

Conclusion

We found the lowest incidence of sensorineural hearing loss in a large population of patients suffered from major thalassemia who received DFO. We show that DFO is not ototoxic at a low dose. When considering all related literature, as a whole there has been much critical misrepresentation about DFO ototoxicity.

Beta-thalassemias are a group of hereditary blood disorders characterized by anomalies in the synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic individuals. The total annual incidence of symptomatic individuals is estimated at 1 in 100,000 throughout the world and 1 in 10,000 people in the European Union. Three main forms have been described: thalassemia major, thalassemia intermedia and thalassemia minor. Individuals with thalassemia major usually present within the first two years of life with severe anemia, requiring regular red blood cell (RBC) transfusions. Findings in untreated or poorly transfused individuals with thalassemia major, as seen in some developing countries, are growth retardation, pallor, jaundice, poor musculature, hepatosplenomegaly, leg ulcers, development of masses from extramedullary hematopoiesis, and skeletal changes that result from expansion of the bone marrow. Regular transfusion therapy leads to iron overload-related complications including endocrine complication (growth retardation, failure of sexual maturation, diabetes mellitus, and insufficiency of the parathyroid, thyroid, pituitary, and less commonly, adrenal glands), dilated myocardiopathy, liver fibrosis and cirrhosis). Patients with thalassemia intermedia present later in life with moderate anemia and do not require regular transfusions. Main clinical features in these patients are hypertrophy of erythroid marrow with medullary and extramedullary hematopoiesis and its complications (osteoporosis, masses of erythropoietic tissue that primarily affect the spleen, liver, lymph nodes, chest and spine, and bone deformities and typical facial changes), gallstones, painful leg ulcers and increased predisposition to thrombosis. Thalassemia minor is clinically asymptomatic but some subjects may have moderate anemia. Beta-thalassemias are caused by point mutations or, more rarely, deletions in the beta globin gene on chromosome 11, leading to reduced (beta+) or absent (beta0) synthesis of the beta chains of hemoglobin (Hb). Transmission is autosomal recessive; however, dominant mutations have also been reported. Diagnosis of thalassemia is based on hematologic and molecular genetic testing. Differential diagnosis is usually straightforward but may include genetic sideroblastic anemias, congenital dyserythropoietic anemias, and other conditions with high levels of HbF (such as juvenile myelomonocytic leukemia and aplastic anemia). Genetic counseling is recommended and prenatal diagnosis may be offered. Treatment of thalassemia major includes regular RBC transfusions, iron chelation and management of secondary complications of iron overload. In some circumstances, spleen removal may be required. Bone marrow transplantation remains the only definitive cure currently available. Individuals with thalassemia intermedia may require splenectomy, folic acid supplementation, treatment of extramedullary erythropoietic masses and leg ulcers, prevention and therapy of thromboembolic events. Prognosis for individuals with beta-thalassemia has improved substantially in the last 20 years following recent medical advances in transfusion, iron chelation and bone marrow transplantation therapy. However, cardiac disease remains the main cause of death in patients with iron overload.

Objectives:

Hepatitis C virus (HCV) is the major cause of post-transfusion hepatitis infection (PTH). Patients with thalassemia major are at high risk of hepatitis C due to the blood transfusion from donors infected by HCV. The aim of this study was to detect the prevalence of anti-HCV antibodies and risk factors in multitransfused thalassemic patients in Isfahan-Iran to establish more preventive strategies.

Methods:

This study was conducted to assess the patients with beta-thalassemia in Isfahan hospitals during 1996-2011 for HCV infection. A structured interview questionnaire was developed by the trained researcher to collect the demographic and risk factors. Statistical analysis was done by Chi-square test, Mann-Withney and multiple logistic regressions using SPSS software, version 15.

Results:

466 patients with major thalassemia participated in this study. The mean age of patients was 17.46 ± 8.3. Two hundred and seventy (58.3%) and 193 (41.7%) of participants were male and female, respectively. The prevalence of HCV was estimated 8% among thalassemia patients. History of surgery, history of dental procedure, number of units transfused per month, number of transfusion per month and duration of transfusion had significant association with HCV seropositivity in univariate analysis. There were no statistical significant risk factors for HCV seropositivity in multiple logistic regression models.

Conclusions:

Our findings revealed that blood transfusion was the main risk factors for HCV infection among beta-thalassemic patients. Therefore, more blood donor screening programs and effective screening techniques are needed to prevent transmission of HCV infection among beta-thalassemic patients.

Background

The aim of this study was to evaluate the frequency of red blood cell (RBC) alloantibodies in surgical patients.

Methods

Blood samples of 18,980 Chinese surgical patients were collected and tested between January 2009 and September 2010. For patients with RBC alloantibodies, sequences of antibodies were identified with the DiaMed Asia antibody screening system. Data regarding sex, age, transfusion history, pregnancy history, and alloantibody specificity were collected.

Results

39 alloantibodies were identified from 18,980 samples, yielding a prevalence of 0.21%. The most frequently identified alloantibodies were Rhesus system antibodies (28/39, 71.8%), including anti-E (17/39; 1 anti-E accompanied by anti-Fyb), anti-c (5/39), anti-cE (2/39), anti-Cw (1/39), anti-D (1/39), and anti-e (1/39). Other antibodies included anti-M (5/39), anti-Lea (2/39), anti-Leb (1/39), anti-K+S (1/39), anti-JKa (1/39), and anti-JSa (1/39). The frequency of alloantibodies was greater in females than in males (31 vs. 8).

Conclusion

The results show a higher prevalence of RBC alloantibodies in females than in males. Anti-E was the most common alloantibody identified in this Chinese surgical population and was also more frequent in females compared to males.

Background

Thalassemia is a blood disorder passed down through families (inherited) in which the body makes an abnormal form of hemoglobin. This disorder results in excessive destruction of red blood cells, and there is no effective treatment. Patients require lifelong blood transfusion, usually started within 6 to 12 months of birth of patient, which on other hand has its own complications. It is a chronic disease that manifests so early in life that it leads to psychological and social problems for parents . We focused on parents to assess the impact of their child’s disease.

Objective

To determine the psychosocial problems of parents of thalassemic children.

Methods

This cross sectional study was conducted among the parents of thalassemic children attending THALASSEMIA CENTRE, BAHAVAL VICTORIA HOSPITAL (BVH), BAHAWALPUR, PAKISTAN during the year 2011. A self designed questionnaire was used that contained questions regarding psychological and social aspects. Patient Health Questionnaire-9 (PHQ-9) was used to assess the depression of parents of thalassemic children.

Results

Of the 100 parents interviewed, the majority were mothers (71%) , with a mean age of 32 ± 8.07 years for both sexes. 29 percent of the parents had moderate to severe depression, 16 percent had sleep disturbances. 56 percent were downgraded by relatives. There was a significant relationship between respondent education and depression (p < 0.05).

Conclusion

A substantial number of parents have psychosocial problems due to the disease of their child. Parent counseling is needed on regular basis.

Background

Naturally occurring alloantibodies produced against A and B red cell antigens in cats can cause acute hemolytic transfusion reactions. Blood incompatibilities, unrelated to the AB blood group system, have also been suspected after blood transfusions through routine crossmatch testing or as a result of hemolytic transfusion reactions.

Hypothesis

Incompatible crossmatch results among AB compatible cats signify the presence of a naturally occurring alloantibody against a newly identified blood antigen in a group of previously never transfused blood donor cats. The associated alloantibody is clinically important based upon a hemolytic transfusion reaction after inadvertent transfusion of red cells expressing this red cell antigen in a feline renal transplant recipient that lacks this red cell antigen.

Methods

Blood donor and nonblood donor cats were evaluated for the presence of auto- and alloantibodies using direct antiglobulin and crossmatch tests, respectively, and were blood typed for AB blood group status. Both standard tube and novel gel column techniques were used.

Results

Plasma from 3 of 65 cats and 1 feline renal transplant recipient caused incompatible crossmatch test results with AB compatible erythrocytes indicating these cats formed an alloantibody against a red cell antigen they lack, termed Mik. The 3 donors and the renal transplant recipient were crossmatch-compatible with one another. Tube and gel column crossmatch test results were similar.

Conclusions and Clinical Importance

The absence of this novel Mik red cell antigen can be associated with naturally occurring anti-Mik alloantibodies and can elicit an acute hemolytic transfusion reaction after an AB-matched blood transfusion.

Background

Despite progress made in the prevention of transfusion-transmitted infections (TTI) over the last few years, they continue to be a problem in many parts of the world, particularly in multitransfused patients.

Objectives

The aim of this study was to estimate the prevalence of hepatitis B virus (HBV), hepatitis C virus (HCV), and to evaluate the screening and vaccination program among our cohort of multitransfused children from Qena, Upper Egypt.

Patients and Methods

One-hundred children suffering from diseases requiring repeated blood transfusions were included in the study. They were classified into group 1, which included 67 children with thalassemia, and group 2, which included 33 children with hemophilia. Screening for hepatitis B surface antigen, hepatitis B surface antibody, hepatitis B core antibody and antibody to HCV was done using a second-generation enzyme-linked immunosorbent assay technique.

Results

Only 12% of all patients were either acutely or chronically infected with HBV. 46% were immune due to previous vaccination, whereas 39% of patients were not protected from HBV infection. HCV antibodies were positive in 45% of cases. Seventy-eight patients had a complete hepatitis B vaccination in the form of three doses as documented by birth certificate. Thirty-six patients mentioned history suggestive of hepatitis. The prevalence of the studied hepatitis markers was similar in both the thalassemia and hemophilia groups of children.

Conclusions

Transfusion-transmitted hepatitis is still a major problem for multitransfused children in Egypt. More effort is required to reduce the infection rate through proper screening of blood and blood products, strict emphasis on receiving the vaccine, regular follow-up for those children with a hepatitis B antibody titer, and providing booster doses for those in need.

Objective:

To evaluate the rate of seropositivity to hepatitis B and C and Human Immunodeficiency Virus (HIV) infections among children with β-thalassemia major receiving multiple transfusions in Ahmedabad, India, compared with healthy controls.

Materials and Methods:

The study was performed during January 2007 to January 2009 on multi-transfused children suffering with β-thalassemia major registered in the Prathama Blood Centre, Ahmedabad; Jeevandeep hospital, Ahmedabad; and Red Cross Blood Centre, Ahmedabad, and investigated for the prevalence and development of transfusion-transmitted infections. Hepatitis B surface Antigen (HBsAg), anti-Hepatitis C Virus (HCV) Antibodies (Ab), and HIV Ab were checked using a fourth-generation Enzyme-Linked Immunosorbent Assay (ELISA). Positive tests were confirmed by western blots. Healthy blood donors were used for the control group.

Results:

Hepatitis B surface antigen, anti-HCV Ab, and HIV Ab were positive in one of 96 (1.04%; 95% Confidence Interval (CI) = 0.17–1.3), 24 of 96 (25%; 95% CI = 11.4–14.2), and one of 96 (1.04%; 95% CI = 0.12–1.3), respectively. The rate of anti-HCV Ab was significantly higher in multi-transfused children suffering with β-thalassemia major. In thalassemia patients, the rate of positive anti-HCV Ab was significantly higher than that for positive HBsAg (P<0.001) and HIV Ab (P<0.001).

Conclusion:

It is concluded that HCV is the current major problem in multi-transfused children with thalassemia major and more careful pretransfusion screening of blood for anti-HCV must be introduced in blood centers.

BACKGROUND

Red blood cell (RBC) alloimmunization can be a serious complication of blood transfusion, but factors influencing the development of alloantibodies are only partially understood. Within FDA-approved time limits, RBCs are generally transfused without regard to length of storage. However, recent studies have raised concerns that RBCs stored for more than 14 days have altered biologic properties that may affect medical outcomes. To test the hypothesis that storage time alters RBC immunogenicity, we utilized a murine model of RBC storage and alloimmunization.

STUDY DESIGN AND METHODS

Blood from transgenic HOD donor mice, which express a model antigen (hen egg lysozyme [HEL]) specifically on RBCs, was filter leukoreduced and stored for 14 days under conditions similar to those used for human RBCs. Fresh or 14-day-stored RBCs were transfused into wild-type recipients. The stability of the HOD antigen and post-transfusion RBC survival were analyzed by flow cytometry. RBC alloimmunization was monitored by measuring circulating anti-HEL immunoglobulin levels.

RESULTS

Transfusion of 14-day-stored, leukoreduced HOD RBCs resulted in 10- to 100-fold higher levels of anti-HEL alloantibodies as detected by enzyme-linked immunosorbent assay than transfusion of freshly collected, leukoreduced RBCs. RBC expression of the HOD antigen was stable during storage.

CONCLUSIONS

These findings demonstrate that HOD murine RBCs become more immunogenic with storage and generate the rationale for clinical trials to test if the same phenomenon is observed in humans. Length of storage of RBCs may represent a previously unappreciated variable in whether or not a transfusion recipient becomes alloimmunized.

Background

Increased rates of RBC alloimmunization in patients with sickle cell disease may be due to transfusion frequency, genetic predisposition, or immune dysregulation. To test the hypothesis that sickle cell pathophysiology influences RBC alloimmunization, we utilized two transgenic mouse models of sickle cell disease.

Study Design and Methods

Transgenic sickle mice, which express human α and βS globin, were transfused with fresh or 14-day stored RBCs containing the HOD (hen egg lysozyme, ovalbumin, and human Duffyb) antigen; some recipients were inflamed with poly (I:C) prior to transfusion. Anti-HOD alloantibody responses were subsequently measured by ELISA and flow crossmatch; a cohort of recipients had post-transfusion serum cytokines measured by bead array.

Results

Both Berkeley and Townes homozygous (SS) and heterozygous (AS) mice had similar rates and magnitude of anti-HOD RBC alloimmunization following fresh HOD RBC transfusion compared with control animals; under no tested condition did homozygous SS recipients make higher levels of alloantibodies than control animals. Unexpectedly, homozygous SS recipients had blunted cytokine responses and lower levels of anti-HOD alloantibodies following transfusion of 14-day stored RBCs, compared with control animals.

Conclusions

In sum, homozygous βS expression and the ensuing disease state are not alone sufficient to enhance RBC alloimmunization to transfused HOD RBCs in 2 distinct humanized murine models of sickle cell disease under the conditions examined. These data suggest other factors may contribute to the high rates of RBC alloimmunization observed in humans with sickle cell disease.

Purpose:

To study the ocular manifestations in multiple transfused beta-thalassemia major patients and assess the ocular side-effects of iron chelating agents.

Materials and Methods:

In this prospective observational study, 45 multiple transfused beta-thalassemia major children between six months and 21 years of age were enrolled and assigned groups according to the treatment regimens suggested. Group A received only blood transfusions, Group B blood transfusions with subcutaneous desferrioxamine, Group C blood transfusions with desferrioxamine and oral deferriprone and Group D blood transfusions with deferriprone. Ocular status at the time of enrolment was documented. Subjects were observed quarterly for one year for changes in ocular status arising due to the disease process and due to iron chelation therapy. Children with hemoglobinopathies other than beta-thalassemia major, congenital ocular anomalies and anemia due to other causes were excluded.

Results:

Ocular involvement was observed in 58% of patients. Lenticular opacities were the most common ocular finding (44%), followed by decreased visual acuity (33%). An increased occurrence of ocular changes was observed with increase of serum ferritin and serum iron levels as well as with higher number of blood transfusions received. Desferrioxamine seemed to have a protective influence on retinal pigment epithelium (RPE) mottling. Occurrence of lenticular opacities and RPE degeneration correlated positively with use of desferrioxamine and deferriprone respectively. Follow-up of patients for one year did not reveal any change in ocular status.

Conclusion:

Regular ocular examinations can aid in preventing, delaying or ameliorating the ocular complications of thalassemia.

Objective

Sickle cell anemia and the interaction S/Beta thalassemia differ in hematological values due to microcytosis and hypochromia caused by the thalassemic mutation. The clinical benefit of long-term hydroxyurea treatment is undeniable in sickle cell disease with monitoring of the biological action of the drug being by the complete blood count. The objective of this work is to compare changes in some of the erythrocytic indexes between S/Beta thalassemia and sickle cell anemia patients on long-term hydroxyurea treatment.

Methods

The values of erythrocyte indexes (mean corpuscular volume and mean corpuscular hemoglobin) were compared in a retrospective study of two groups of patients (Sickle cell anemia and S/Beta thalassemia) on hydroxyurea treatment over a mean of six years.

Results

The quantitative values of the two parameters differed between the groups. Increases in mean corpuscular volume and reductions in mean corpuscular hemoglobin delay longer in S/Beta thalassemia patients (p-value = 0.018).

Conclusion

Hematological changes are some of the beneficial effects of hydroxyurea in sickle cell disease as cellular hydration increases and the hemoglobin S concentration is reduced. The complete blood count is the best test to monitor changes, but the interpretation of the results in S/Beta thalassemia should be different.

Introduction

Individuals exposed to red blood cell alloantigens through transfusion, pregnancy or transplantation may produce antibodies against the alloantigens. Alloantibodies can pose serious clinical problems such as delayed haemolytic reactions and logistic problems, for example, to obtain timely and properly matched transfusion blood for patients in which new alloantibodies are detected.

Objective

The authors hypothesise that the particular clinical conditions (eg, used medication, concomitant infection, cellular immunity) during which transfusions are given may contribute to the risk of immunisation. The aim of this research was to examine the association between clinical, environmental and genetic characteristics of the recipient of erythrocyte transfusions and the risk against erythrocyte alloimmunisation during that transfusion episode.

Methods and analysis Study design

Incident case–cohort study.

Setting

Secondary care, nationwide study (within the Netherlands) including seven hospitals, from January 2005 to December 2011.

Study population

Consecutive red cell transfused patients at the study centres.

Inclusion

The study cohort comprises of consecutive red blood cell transfused patients at the study centre.

Exclusion

Patients with transfusions before the study period and/or pre-existing alloantibodies.Cases defined as first time alloantibody formers; Controls defined as transfused individuals matched (on number of transfusions) to cases and have not formed an alloantibody.

Statistical analysis

Logistic regression models will be used to assess the association between the risk to develop antibodies and potential risk factors, adjusted for other risk factors.

Ethics and dissemination

Approval at each local ethics regulatory committee will be obtained. Data will be coded for privacy reasons. Patients will be sent a letter and an information brochure explaining the purpose of the study. A consent form in presence of the study coordinator will be signed before the blood taking commences. Investigators will submit progress summary of the study to study sponsor regularly. Investigators will notify the accredited ethics board of the end of the study within a period of 8 weeks.

Article summary

Article focus

Identifying transfusion-related risk factors of alloimmunisation against red blood cell (RBC) antigens.

Identifying clinical risk factors of alloimmunisation against RBC antigens.

Identifying environmental and genetic risk factors of alloimmunisation against RBC antigens.

Key messages

Alloimmunisation against RBC transfusion is a clinically relevant problem faced by transfusion specialists.

Identifying a high-risk group of responders who form allantibodies against transfused RBCs would be the next step towards transfusion of complete phenotyped matched RBC.

In synergy with other ongoing studies, cost-effectiveness of a phenotyped matched RBC approach will be assessed.

Strengths and limitations of this study

Multicentre, matched case–cohort design.

Good representative sample of controls from large base cohort of general population.

Cases and controls matched on the number of RBC transfusions.

Possibility that patients entering cohort have had transfusions prior to start of study period in other hospitals/non-study centres.

Previous pregnancies in women could play a role in alloimmunisation. Retrospective data will not allow for a comprehensive check on previous pregnancies.

There could be a few cases selected who are booster/secondary alloimmune responders, instead of first time ever alloantibody formers.

Human β-thalassemia major is one of the most prevalent genetic diseases characterized by decrease/absence of β-globin chain production with reduction of erythrocyte number. The main cause of death of treated β-thalassemia major patients with chronic blood transfusion is early cardiac complications that have been attributed to secondary iron overload despite optimal chelation. Herein, we investigated pathophysiological mechanisms of cardiovascular dysfunction in a severe murine model of β-thalassemia from 6 to 15-months of age in the absence of confounding effects related to transfusion. Our longitudinal echocardiography analysis showed that β-thalassemic mice first display a significant increase of cardiac output in response to limited oxygen-carrying erythrocytes that progressed rapidly to left ventricular hypertrophy and structural remodeling. Following this compensated hypertrophy, β-thalassemic mice developed age-dependent deterioration of left ventricular contractility and dysfunction that led toward decompensated heart failure. Consistently, murine β-thalassemic hearts histopathology revealed cardiac remodeling with increased interstitial fibrosis but virtual absence of myocardial iron deposits. Importantly, development of thalassemic cardiac hypertrophy and dysfunction independently of iron overload has uncoupled these cardiopathogenic processes. Altogether our study on β-thalassemia major hemoglobinopathy points to two successive phases resulting from severe chronic anemia and from secondarily induced mechanisms as pathophysiologic contributors to thalassemic cardiopathy.

We report a case of two consecutive episodes of acute hemolytic transfusion reactions (HTRs) due to multiple alloantibodies in a 34-yr-old man who suffered from avascular necrosis of left femoral head. He received five units of packed red blood cells (RBCs) during surgery. Then the transfusion of packed RBCs was required nine days after the surgery because of the unexplained drop in hemoglobin level. The transfusion of the first two units resulted in fever and brown-colored urine, but he received the transfusion of another packed RBCs the next day. He experienced even more severe symptoms during the transfusion of the first unit. We performed antibody screening test, and it showed positive results. Multiple alloantibodies including anti-E, anti-c and anti-Jkb were detected by antibody identification study. Acute HTRs due to multiple alloantibodies were diagnosed, and the supportive cares were done for 6 days. We suggest the antibody screening test should be included in the panel of pretransfusion tests for safer transfusion, and it is particularly mandatory for the patients with multiple transfusions, pregnant women, and preoperative patients.

Objective

Hepatitis C virus (HCV) is an etiological agent responsible for occurrence of post-transfusion hepatitis in thalassemic patients. This study identified hepatitis C genotypes in pediatric and adolescent thalassemic patients and their correlation with age, blood transfusion, HCV RNA viral titer and liver function.

Methods

This study considers cross-sectional data from the Center for Thalassemia in Zahedan (Iran) carried out between August 2005 and September 2007. Twenty multitransfused patients suffering from β-thalassemia major and chronic HCV infection (13 males, 7 females) were included in the study. Patients were considered eligible for the study if they were seropositive for HCV RNA polymerase chain reaction (PCR) before initiation of evaluation. Blood sample was taken for HCV genotype and viral titer as well as biochemical markers. Type specific primer and real-time RT-PCR HCV were used for determination of viral genotype and HCV-RNA titer.

Findings

There was a significant positive correlation between serum HCV RNA titer and genotypes (P<0001). Serum HCV RNA levels were found higher in genotype 3a than in others. The most prevalent genotype in thalassemic patients was genotype 3a (40%) followed by 1b (25%), unclassified (20%) and la (15%). There was no meaningful relationship between genotype, Alanine aminotranferease, ferritin and alkaline phosphatase. Age, serum HCV RNA titer and number of transfusions were the only significant factors associated with genotypes (P<015, P<0.0001 and P<0.001 respectively).

Conclusion

This study showed that HCV genotype and viral titer are related to the number of blood transfusions received by thalassemic patients. Screening donated blood in blood banks would prevent the occurrence of hepatitis C in this high-risk group.

The transfusion-medicine specialists and physicians are often in a difficult situation when the patient has severe worsening anemia and all the blood is mismatched. This situation can arise in patients with red cell autoantibodies or alloantibodies due to previous transfusions. We report two cases of immune hemolysis – one due to warm auto antibodies and the second due to alloimmunization from multiple transfusions.

BACKGROUND:

Beta-thalassemia is considered to be the most frequent hereditary blood disorder worldwide. Lipid abnormalities have been detected in different types of beta-thalassemia. The aim of this study is to assess the lipid profiles in beta-thalassemia major (BTM) and beta-thalassemia intermedia (BTI) patients in southern Iran.

METHODS:

The study group consisted of 55 BTM patients and 50 BTI patients. The control group included 130 sex-and age-matched healthy participants. Serum lipids profiles (total cholesterol, triglycerides, LDL-cholesterol, and HDL-cholesterol) as well as hemoglobin (Hb) and ferritin, were compared between the three groups. P value < 0.05 was considered statistically significant.

RESULTS:

There were no significant differences between BTM and BTI patients regarding age or sex. Mean triglyceride concentration was not significantly different between patients and controls. Total cholesterol and LDL-cholesterol were significantly lower in patients with BTM and BTI in comparison with controls (p < 0.001). HDL-cholesterol was significantly lower in patients with BTI than in controls (p < 0.03).

CONCLUSIONS:

In patients with BTM and BTI, total cholesterol and LDL-cholesterol were lower than in control participants. The mechanisms that may account for these findings are increased erythropoiesis and cholesterol consumption in BTI, and iron overload and oxidative stress in BTM.

Blood specimens from 100 thalassemic patients were screened in vitro for inhibitory effects on growth and multiplication of Plasmodium falciparum. The culture medium mixture designated REM consisted of 9 volumes of minimum essential medium (GIBCO Laboratories, Grand Island, N.Y.) and 1 volume of RPMI 1640 (GIBCO) supplemented with 10% heat-inactivated human serum. Parasite multiplication in erythrocytes containing normal hemoglobin cultured in RPMI or REM was similar. Significant reduction in parasite multiplication rates was observed in erythrocytes containing abnormal hemoglobin when these were cultured in REM. The degree of reduction in five types of thalassemic erythrocytes was in the following descending order: hemoglobin H disease with Hb Constant Spring, classical hemoglobin H disease, beta(0)-thalassemia-hemoglobin E in which blood harbored a high percentage of hemoglobin F-containing cells, beta (0)-thalassemia-hemoglobin E in which blood harbored few hemoglobin F-containing cells, and beta-thalassemia heterozygous variant.