HLA-E*01:01 allele is associated with better response to anti-HCV therapy while homozygous status for HLA-E*01:03 allele increases the resistance to anti-HCV treatments in frequently transfused thalassemia patients.

BACKGROUND: HLA-E binding to NKG2A/CD94 induces inhibitory signals that modulate NK cells cytotoxicity against infected targets. HCV-derived peptides stabilize HLA-E molecule that favours its higher expression. However, HLA-E stability and expression vary in different genotypes where the presence of HLA-E*01:03 allele is associated with higher HLA-E expression on targets that enhances NK cells inhibition and increases the chance of virus to escape from innate immune system. Here, we aimed to investigate whether HLA-E polymorphism affects HCV infection status or its treatment in major thalassemia patients who are more vulnerable to hepatitis C. METHODS AND MATERIALS: Study included 89 cases of major thalassemia positive for HCV-antibody; of those 17 patients were negative for HCV-PCR (spontaneously cleared) and 72 patients were HCV-PCR positive (persistent hepatitis under different anti-viral treatment). 16 major thalassemia patients without hepatitis, negative for HCV-antibody were also considered as patients control group. Genomic DNAs extracted from whole bloods were genotyped for HLA-E locus using a sequence specific primer-PCR strategy. RESULTS: In thalassemia patients, HLA-E*01:03 allele increased susceptibility to HCV infection [p = 0.02; 4.74(1.418-15.85)]. In addition, HLA-E*01:03/*01:03 genotype predicted more resistance to HCV treatment compared to other genotypes [p = 0.037; 3.5(1.1-11.4)]. In other words, we found that the presence of HLA-E*01:01 allele favors better response to anti-HCV therapy [p = 0.037; 3.5(1.1-11.4)]. CONCLUSION: From a mechanistic point of view, the associations between HLA-E polymorphisms and susceptibility to HCV infection or its therapeutic resistance in thalassemia patients may suggest potential roles for the innate and adaptive immune responses to this infection, which are manifested by the acts of HLA-E - NKG2A/CD94 axis in the modulation of NK cell inhibitory function as well as HLA-E associated CD8+ T cell cytolytic activity against HCV, respectively. Notably, from a clinical point of view, paying attention to these associations may not only be useful in increasing the effectiveness of current anti-HCV regimens comprising direct acting antivirals (DAAs) in more complicated patients, but may also suggest antiviral prophylaxis for patients more vulnerable to HCV infection.

Non-transfusion dependent thalassemia is independently associated with higher alloimmunization risk than transfusion dependent thalassemia and would benefit the most from extended red cell antigen-matching.

BACKGROUND: Alloimmunization prevalence is conventionally used to identify RBCs alloimmunization risk factors among thalassemia patients, but it may be confounded by differences in transfusion exposure especially between non-transfusion dependent thalassemia (NTDT) and transfusion dependent thalassemia (TDT) patients. To better identify thalassemia patients with high alloimmunization risks, we used cumulative incidence of first alloimmunization as a function of RBCs transfused to compare alloimmunization risks between TDT and NTDT and to evaluate other risk factors. We also proposed practical strategies to prevent alloimmunization in thalassemia. STUDY DESIGN AND METHODS: Adult TDT and NTDT patients who had received ≥2 transfusions and no alloimmunization before their first transfusion were included. Alloimmunization was defined as the development of clinically significant alloantibodies. We estimated the first alloimmunization incidence from transfusion by Kaplan-Meier analysis with the horizontal axis expressed as cumulative non-antigen-matched RBC units transfused. We compared this incidence between TDT and NTDT, and analyzed for other alloimmunization risk factors and the alloantibody specificities/frequencies. RESULTS: The alloimmunization prevalence was similar between TDT and NTDT (27% vs. 30% respectively, p = .726). However, for the same transfusion exposure, NTDT had higher alloimmunization incidence than TDT (hazard ratio 8.59, 95% confidence interval [2.25-32.74], p = .002), independent of age at first transfusion and last follow-up, gender, and splenectomy. Anti-E, anti-c, anti-Mia , and anti-Jka were most frequent. DISCUSSION: NTDT has the highest alloimmunization risk and would benefit the most from extended RBC antigen-matching, especially C, c, E, and e. Other blood group antigen-matching should be guided by the patient/donor disparities and alloantibody frequencies in different populations.

Skewed intracellular cytokine production of iNKT cells toward Th2-related responses in alloimmunized thalassemia patients.

INTRODUCTION: Red blood cell alloimmunization is a challenging issue in thalassemia patients. Several studies have investigated the role of different immune system compartment in alloimmunization, but the exact mechanism remains unclear. Considering the immunoregulatory function of iNKT cells and their subsets, in this study, we evaluated the possible role of these cells in alloimmunization status of thalassemia patients. METHODS: 78 ß-thalassemia major patients (41 alloimmunized and 37 non-alloimmunized) and 17 healthy controls were engaged in this study. Mononuclear cells were isolated from peripheral blood samples and stimulated for cytokine production. Samples were subjected to flow cytometry for enumeration of iNKT cells and characterized based on their cytokine production pattern. Finally, the results correlated with alloimmunization status, clinical and laboratory data. RESULTS: Results demonstrated that the number of iNKT, iNKT+IFN-ɤ+, and iNKT+IL-4+ cells in thalassemia group was significantly higher than healthy controls while no significant change was observed in the number of these cells between alloimmunized and non-alloimmunized thalassemia patients. Interestingly, the ratio of iNKT+IL-4+: iNKT+IFN-γ+ cells in alloimmunized thalassemia group represent a considerable increase in comparison to both non-alloimmunized thalassemia group and healthy controls. However, evaluating this value in non-alloimmunized group represents an approximately equal ratio of 0.94, which was almost similar to this ratio in the control group (0.99). CONCLUSION: Our results illustrated a noteworthy imbalance in the ratio of iNKT cell subsets in favour of IL-4 producing iNKT cells in alloimmunized thalassemia patients. Regarding the role of IL-4 in stimulating the Th2-related immune responses, this imbalance could consider as a possible mechanism in alloantibody responses of thalassemia patients.

The effect of transfusion on immune responses in thalassemia.

BACKGROUND: Regular transfusions are the gold standard therapy for ß-thalassemia and are often complicated by secondary-iron overload and alloimmunization. We assessed the frequency of regulatory T cells (Tregs) and the levels of cytokines implicated in Th-responses in 49 patients 33 TDT and 16 NTDT in order to investigate the contribution of transfusion and its complications on immune responses. MATERIALS AND METHODS: Tregs were characterized with flow cytometry. Soluble IL-4, IL-6, IL-10, IL-17A, and TGF-ß1 were assessed by ELISA. Clinical data including alloimmunization, age of onset of transfusion splenectomy hepatitis B and C infection, iron overload assessment with MRI T2* (liver and heart) were recorded from the patients' files. RESULTS: Tregs levels, IL-6, IL-10, TGFß and serum ferritin were higher in the TDT compared to the NTDT group (all p < 0.05). There was no difference of Tregs and circulating cytokines in patients in correlation with the extend of iron overload (assessed by T2*liver), the type of chelator or the development of alloantibodies. DISCUSSION: Tregs levels are higher in TDT patients compared to NTDT, a difference which could be ascribed to transfusion. Tregs levels and the cytokines analyzed may play little role in alloimmunization and are not impacted by the extend of iron overload.

Clinical impacts of DNA-based typing and provision of antigen-matched red blood cell units for chronically transfused patients with thalassemia.

CONCLUSIONS: Blood transfusion, the main therapy for patients with severe thalassemia, is challenged by alloantibodies that can lead to hemolytic transfusion reactions. The use of prophylactic antigen-matched units is recommended, but serologic typing, before the first transfusion, is rarely performed and is not reliable after chronic transfusion. Patient DNA-based typing is a promising strategy, but clinical outcome data are lacking. The aim of this study was to determine the benefits of antigenmatched transfusion guided by DNA-based typing in terms of new alloantibody formation and increases in mean pretransfusion hemoglobin (Hb) levels. We performed DNA-based typing on samples from 24 transfusion-dependent patients with thalassemia who had no serologic phenotyping performed before the first transfusion. These patients were then transfused with antigen-matched donor RBC units that were typed serologically. New alloantibody formation and mean pre-transfusion Hb levels were evaluated after implementing this extended common antigen-matching transfusion protocol. Sixty-three percent of the patients in this study were diagnosed as having beta-thalassemia Hb E. Alloantibodies were already present in 87.5 percent (21/24) of these patients, and most of these antibodies were multiple and/ or unidentified. After the enrollment, there were 717 transfusion episodes comprising 1209 RBC units. The number of RBC units transfused to each patient ranged from 22 to 119 units. At the median duration of 25.5 months (range 10-34 months), no new alloantibodies were detected since the beginning of the protocol. Seventy-four transfusion episodes in six patients were crossmatch-positive due to autoantibodies (patients 2, 4, 8, 9, and 14) or anti-Chido (patient 18) that had been identified before the study. There were no hemolytic transfusion reactions in this study. Five patients (patients 1, 2, 12, 15, and 20) showed increased mean pre-transfusion Hb levels (≥1 g/dL) and one patient (patient 16) had longer intervals between transfusions (compared with those before the protocol), suggesting longer RBC survival, although there was no statistical difference in the whole group. Our study highlights the benefits of DNA-based typing in chronically transfused patients with thalassemia who had no phenotyping data before the first transfusion. Patient DNA-based typing for antigen-matched transfusion is safe in thalassemia and allows us to obtain better-matched blood units for complicated patients.

Lymphocyte counts may predict a good response to mesenchymal stromal cells therapy in graft versus host disease patients.

Steroid-resistant GvHD is one of the most significant causes of mortality following allogeneic Hematopoietic Stem Cell Transplantation (HSCT). Treatment with mesenchymal stromal cells (MSC) seems to be a promising solution, however the results from clinical studies are still equivocal. Better selection of candidate patients and improving monitoring of patients following MSC administration can increase treatment effectiveness. In order to determine which characteristics can be used to predict a good response and better monitoring of patients, blood samples were taken prior to therapy, one week and one month after therapy, from 26 allogeneic HSCT patients whom contracted GvHD and were treated with MSCs. Samples were examined for differential blood counts, bilirubin levels and cell surface markers. Serum cytokine levels were also measured. We found that the level of lymphocytes, in particular T and NK cells, may predict a good response to therapy. A better response was observed among patients who expressed low levels of IL-6 and IL-22, Th17 related cytokines, prior to therapy. Patients with high levels of bilirubin prior to therapy showed a poorer response. The results of this study may facilitate early prediction of success or failure of the treatment, and subsequently, will improve selection of patients for MSC therapy.

Comparative study of alloimmunization against red cell antigens in sickle cell disease & thalassaemia major patients on regular red cell transfusion.

BACKGROUND & OBJECTIVES: : Sickle cell disease (SCD) patients require red cell transfusion during different clinical complications of the disease. Such patients are at a high risk for developing alloantibody against red cell antigens. From India, there are limited data available on alloantibody formation in multiply transfused SCD patients. The present study was thus undertaken to fill up this lacunae by looking at the development of red cell alloantibodies in SCD and ß-thalassaemia patients on regular transfusion. METHODS: : All sickle cell disease patients undergoing red cell transfusion between 2008 and 2016, were included. During this period, a large number of ß-thalassaemia major patients also underwent regular red cell transfusion. These thalassaemia patients were also included to compare the tendency of antibody formation between SCD and ß-thalassaemia major patients. All patients before regular transfusion were regularly assessed for the development of red cell antibody. Red cell antigen, antibody screen crossmatch and antibody identification were done using the standard technique. RESULTS: : A total of 138 patients with SCD aged between 4 and 53 yr (mean 17.6 yr) consisting of 83 males and 55 females (male:female, 1.5:1) along with 333 transfusion-dependent ß-thalassaemia patients were studied. Over the last eight years, 15 patients with SCD and four patients with thalassaemia developed alloantibody (P <0.001). Antibody specificity of their alloantibodies was against Rhc, RhE, Kell, Fya and Fyb only. Sickle cell disease patients with and without alloantibody required on the average 11.8 and 8.6 units of red cell concentrate, respectively (P <0.05). INTERPRETATION & CONCLUSIONS: : About 11 per cent of the transfused sickle cells patients developed alloantibodies. The antibody specificity was restricted to Rh, Kell and Duffy blood group systems. Extended antigen matching involving Rh, Kell and Duffy antigens may prevent alloantibody in such patients.

Red Cell Alloantibodies in Thalassaemia Patients Who Received Ten or More Units of Transfusion.

Thalassaemia patients are the highest consumers of blood. Recurrent exposure to allogenic red cell antigen puts this population at increased risk of alloimmunization. This causes delayed hemolytic transfusion reactions. So transfusion requirement increases. But no data regarding alloimmunization was available in Bangladesh. Aim of this study was to estimate the prevalence of alloimmunization and to find out the potential factors associated with its development. This analytical cross sectional study was done by enrolling 97 patients, received at least 10 units transfusions, through convenient sampling. Indirect and direct antiglobulin tests were done to detect immunization by spin tube technique keeping an autocontrol and carried out in the Department of Haematology & Department of Transfusion Medicine, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from March 2016 to March 2017. Polyclonal anti-AHG reagent was used. A total 21 patients developed alloimmunization (21.6%) and 4 patients (4.1%) developed autoimmunization. Age, gender, splenectomy and number of transfusion are shown significant risk factors for alloimmunization. Data from this study demonstrate that the RBC alloimmunization is significantly high in our country. So, pretransfusion antibody screening needs to be initiated in order to ensure safe transfusion and RBC phenotyping should be started before starting first transfusion to prevent alloimmunization.

Red blood cell alloimmunisation in transfusion-dependent thalassaemia: a systematic review.

BACKGROUND: Chronic red blood cell transfusion is the first-line treatment for severe forms of thalassaemia. This therapy is, however, hampered by a number of adverse effects, including red blood cell alloimmunisation. The aim of this systematic review was to collect the current literature data on erythrocyte alloimmunisation. MATERIALS AND METHODS: We performed a systematic search of the literature which identified 41 cohort studies involving 9,256 patients. RESULTS: The prevalence of erythrocyte alloimmunisation was 11.4% (95% CI: 9.3-13.9%) with a higher rate of alloimmunisation against antigens of the Rh (52.4%) and Kell (25.6%) systems. Overall, alloantibodies against antigens belonging to the Rh and Kell systems accounted for 78% of the cases. A higher prevalence of red blood cell alloimmunisation was found in patients with thalassaemia intermedia compared to that among patients with thalassaemia major (15.5 vs 12.8%). DISCUSSION: Matching transfusion-dependent thalassaemia patients and red blood cell units for Rh and Kell antigens should be able to reduce the risk of red blood cell alloimmunisation by about 80%.

HLA-DRB1*15:03 and HLA-DRB1*11: useful predictive alleles for alloantibody production in thalassemia patients.

BACKGROUND AND OBJECTIVES: Recently, thalassemia has been introduced as a chronic disease. In spite of prolonging life in thalassemia patients, the quality of their life has not significantly improved. One of the challenges that makes their quality of life poor is alloimmunisation which causes several complications to patients by restricting their options. Some individuals are more susceptible to developing an alloantibody than others. They are categorised as responders and non-responders. Determining responders before the first transfusion allows transfusion services to provide compatible blood and prevent alloimmunisation. The aim of the present study was to determine the relationship between HLA-DRB1*15:03, HLA-DRB1*11 and HLA-DRB1*09:01 alleles and alloimmunisation in Iranian thalassemia patients. MATERIALS AND METHODS: Antibody screening tests were performed by tube method, and HLA-DRB1 genotyping was determined by Sequence-Specific Primers (SSP-PCR) in 59 alloimmunised and 205 non-alloimmunised patients. HLA-DRB1 allele frequencies were compared between alloantibody-positive and -negative groups through the χ2 test. RESULTS: HLA-DRB1*15:03 allele frequency was significantly different between groups (P = 0·000, odds ratio (OR) = 4·193). There was a correlation between HLA-DRB1*11 and anti-K (P = 0·000, OR = 6·643). There was no association between HLA-DRB1*09:01 and alloimmunisation (P = 0·350). CONCLUSIONS: According to our results, detecting HLA-DRB1*15:03 and HLA-DRB1*11 alleles are useful in the pre-transfusion test and could determine responder patients and improve transfusion safety.

Prevalence and clinical significances of red cell alloimmunization and red cell bound immunoglobulin G in polytransfused patients with thalassemias.

The study was to determine the prevalence and clinical significances of red blood cell (RBC)-bound IgG as detected by flow cytometry in polytransfused patients with thalassemias. Relationship of the presence of RBC-bound IgG with RBC alloimmunization was also evaluated. This study included 59 polytransfused patients with ß-thalassemia disease. We studied the frequency of RBC autoantibodies and alloimmunization. Direct Coombs test and flow cytometry were performed to detect the presence of RBC autoantibodies while RBC alloantibodies were detected by antibody screening and identification assays. Eight (13.6%) and 34 (57.6%) patients were found a positive direct Coombs test and flow cytometry, respectively. Twenty (33.9%) patients developed RBC alloantibodies. The four most frequent RBC alloantibodies were anti-E (55%), anti-Mia (40%), anti-Di(a) (25%) and anti-c (15%), respectively. There was no significant difference in the presence of RBC-bound IgG between polytransfused with thalassemia patients who developed RBC alloimmunization (13 of 20; 65%) and those without RBC alloantibodies (21 of 39; 53.8%), p = 0.412. Splenectomy and increased transfusion requirement were significantly associated with the presence of RBC-bound IgG but not with RBC alloantibody formation. The overall frequency of RBC alloantibody formation in polytransfused patients with thalassemias was 33.9%. The most common RBC alloantibody was anti-E. RBC autoantibody formation was more frequently detected by flow cytometry (57.6%) than by direct Coombs test (13.6%). Splenectomy was significantly associated with the development of autoreactive RBC-bound IgG antibodies in the polytransfused patients with thalassemias. The presence of the anti-RBC autoantibodies may cause an increase of transfusion requirement.

Vibrio vulnificus meningoencephalitis in a patient with thalassemia and a splenectomy.

Vibrio vulnificus usually causes wound infection, gastroenteritis, and septicemia. However, it is a rare conditional pathogen causing meningoencephalitis. We report a case of a young, immunocompromised man presenting with severe sepsis after exposure to sea water and consumption of seafood. The patient subsequently developed meningoencephalitis, and Vibrio vulnificus was isolated from his blood culture. The sequence was confirmed by Next-generation sequencing of a sample of cerebrospinal fluid, as well as from a bacteria culture. After the pathogen was detected, the patient was treated with ceftriaxone, doxycycline, and moxifloxacin for 6 weeks, which controlled his infection. In this case, we acquired his clinical and dynamic MRI presentations, which were never reported. Physicians should consider Vibrio vulnificus infections when they see a similar clinical course, brain CT and MRI findings, susceptibility factors and recent seafood ingestion or exposure to seawater. Due to high mortality, the early diagnosis and treatment of Vibrio vulnificus infections are crucial. Next-generation sequencing was found to be useful for diagnosis.

The prevalence, alloimmunization risk factors, antigenic exposure, and evaluation of antigen-matched red blood cells for thalassemia transfusions: a 10-year experience at a tertiary care hospital.

BACKGROUND: Hemoglobin E-ß0 thalassemia and homozygous ß0 -thalassemia are the most common chronic transfusion-dependent thalassemias in Thailand. Patients with these conditions can experience clinical complications such as RBC alloimmunization. In this study we aimed to determine the prevalence, alloimmunization risk factors, antigenic exposure, and evaluation of antigen- (C, c, E, e, Mia ) matched RBC transfusion. STUDY DESIGN AND METHODS: Thalassemia patients were recruited from a tertiary care hospital for 10 years from 2008 to 2017. The medical records of transfusion history were reviewed for red cell phenotype both of patients and donors, number of units transfused, and type of alloantibodies. RESULTS: A total of 383 thalassemia patients were identified (178 males and 205 females). The frequency of RBC alloantibodies was 19.3%. Some patients tested positive for more than one antibody type. Autoantibodies were detected in nine individuals. Anti-E (49 [39.5%]), anti-Mia (24 [19.4%]), and anti-c (19 [15.3%]) were the most common antibodies detected. A high rate of alloimmunization was found in splenectomized patients. Risk of alloimmunization increased when more total units of blood had been transfused. A trend toward low alloimmunization rates was noted in the antigen-matched RBC group, where 3.5% (5/143) of patients were alloimmunized. Anti-E and anti-Mia , which may be naturally occurring, were identified in this group. CONCLUSION: Thai patients are more prone to develop antibodies against the Rh and Mia than to the Kell blood group antigens. Provision of at least antigen-matched (C, c, E, e, Mia ) RBCs appears to improve the efficacy of transfusion in thalassemia patients.

Hematopoietic Stem Cell Transplantation in Thalassemia.

Although recent advances in gene therapy are expected to increase the chance of disease cure in thalassemia major, at present hematopoietic stem cell transplantation (HSCT) remains the only consolidated curative approach for this disorder. The widest experience has been obtained in the HLA-matched family donor (MFD) setting, with probabilities of overall and thalassemia-free survival exceeding 90% and 85%, respectively. As for most patients a suitable MFD is not available, alternative donors (HLA-matched unrelated donor, unrelated cord blood, HLA-haploidentical relative) have been increasingly explored, translating into the expansion of the number of patients treatable with HSCT.

The Case for High Resolution Extended 6-Loci HLA Typing for Identifying Related Donors in the Indian Subcontinent.

Three-loci low-resolution (LR) or intermediate-resolution HLA typing is generally considered adequate in the related blood and marrow transplantation (BMT) context. However, a single high-resolution (HR) mismatch may have a similar adverse impact on BMT outcome as an LR one. We sought to determine the frequency of mismatches that may go undetected when standard typing (LR or 3-loci HR) is used compared with 6-loci HR typing for related donor compatibility testing, and to assess its impact on relevant BMT outcomes. We analyzed data from a total of 2554 6-loci (HLA-A, -B, -C, -DRB1, -DQB1, and -DPB1) HR sequence-based typing (full typing [FT]) from 754 patients, 1011 siblings, and 789 parents done at DKMS Germany (www.DKMS.de) between January 1, 2014, and June 21, 2016. We also studied 38 cases in which the family had undergone 3-loci HLA typing (standard typing [ST]). Patients were from India (70%), Pakistan (22%), and Sri Lanka (8%). The IMGT/HLA database (www.ebi.ac.uk/ipd/imgt/hla) was used to tease out nonpermissive DPB1 mismatches. HLA disparity-related outcomes, such as rejection and graft-versus-host disease (GVHD) were assessed in a retrospective matched-pair cohort of 50 patients (25 with ST and 25 with FT) who underwent BMT for severe thalassemia from compatible related donors. We found fully matched (either 12/12 HR matches or with a single permissive DPB1 mismatch) related donors for 285 patients (38%). Of these donors, 89% were siblings and 11% were parents. The likelihood of matching on an individual locus on LR but not on HR was found to be 5%. A total of 9 donors (3%; 7 siblings and 2 parents) who would have been considered a full match by HR typing on A, B, and DRB1 alone were not a match by extended 6-loci HR typing. Five of these 9 donors had a mismatch on C or DQB1, and 4 had a nonpermissive DPB1 mismatch. In this group, 5 donors (56%) belonged to a consanguineous family, in 2 donors (22%) there was no reported consanguinity, and in 2 donors (22%) consanguinity was unknown. We identified 18 donors (6%; 13 siblings and 5 parents) who would have been considered a 12/12 match by LR HLA typing alone but were found not to match on extended HR typing. In this group, 11 donors (61%) were from consanguineous families, 3 donors (17%) had no reported consanguinity, and in 4 donors (22%) consanguinity was unknown. Outcome analysis showed that the actuarial proportion of patients with GVHD was 4% in the FT group compared with 16% in the ST group, with log-rank P = .1952. The ST group included 2 patients with grade III-IV acute GVHD and 1 patient each with moderate and severe chronic GVHD, whereas the FT group only 1 patient with grade III acute GVHD. We conclude that even in the context of related donors, the use of LR and/or 3-loci (A, B, and DRB1) HR HLA typing might result in a sizable risk of missing a clinically relevant mismatch, which may have an adverse impact on transplantation outcomes. In the Indian subcontinent, this observation is not limited to putatively compatible parents or consanguineous families; we recommend full 6-loci HR HLA typing even for matched related BMTs.

Study of red blood cell alloimmunization risk factors in multiply transfused thalassemia patients: role in improving thalassemia transfusion practice in Fayoum, Egypt.

BACKGROUND: ß-Thalassemia is considered the most common chronic hemolytic anemia in Egypt. Alloimmunization can lead to serious clinical complications in transfusion-dependent patients. The objective of this study was to determine the frequency and types of alloantibodies, and, in addition, to study the risk factors that might influence alloimmunization in multiply transfused thalassemia patients in Fayoum, Egypt, with the goal that this study could help minimize some of the transfusion-associated risks in those patients. STUDY DESIGN AND METHODS: A total of 188 multiply transfused thalassemia patients attending Fayoum University Hospital were analyzed. Alloantibody identification was performed by DiaMed-ID microtyping system. RESULTS: Alloimmunization prevalence was 7.98%. The most common alloantibody was D-related; anti-D was the most frequent alloantibody found in eight of the 188 patients (4.25 %), followed by anti-C in two patients (1.1%), anti- E in two (1.1 %), anti-c in two (1.1 %), anti-Fya in two (1.1%), anti-K in one (0.53 %), and an unknown antibody in one patient (0.53%). Higher rates of alloimmunization were found in female patients, in patients with ß-thalassemia intermedia, in splenectomized patients, in D- patients, and in patients who started blood transfusion after 3 years of age. CONCLUSION: The study reemphasizes the need for cost-effective strategy for thalassemia transfusion practice in developing countries. Red blood cell antigen typing before transfusion and issue of antigen-matched or antigen-negative blood can be made available to alloimmunized multiply transfused patients. Early institution of transfusion therapy after diagnosis is another means of decreasing alloimmunization.

Optimal Outcomes in Young Class 3 Patients With Thalassemia Undergoing HLA-Identical Sibling Bone Marrow Transplantation.

BACKGROUND: Bone marrow transplantation (BMT) for class 3 patients with thalassemia is challenging due to high rates of graft rejection and transplant-related mortality. Since the first studies of BMT in the late 1980s, a number of conditioning regimens have been designed to improve outcomes, but with suboptimal results. Here we report the outcome of transplantation in class 3 patients using a modified protocol. METHODS: Sixty-three patients between 5 and 16.7 years of age with class 3 thalassemia received HLA-matched sibling BMT following either the original protocol (26 patients) or the modified protocol (37 patients). Both regimens comprised preconditioning cytoreduction with hydroxyurea and azathioprine starting at -45 days pretransplant, and fludarabine from days -16 to -12. Conditioning was performed with busulfan and cyclophosphamide (original protocol) or with busulfan, thiotepa, and cyclophosphamide (modified protocol). RESULTS: The 2 groups showed similar patient demographics. At day 0, the degree of cytoreduction (lymphopenia, neuthropenia, and thrombocytopenia) achieved by the modified protocol was greater than the original protocol. The incidence of graft failure/rejection was significantly higher in the original group (15%; 95% confidence interval [95% CI], 5-32%) compared with the modified group (0%) (P = 0.014). The respective 5-year thalassemia-free survival rates were 73% (95% CI, 51-86%) and 92% (95% CI, 77-97%) (P = 0.047). Both groups showed similar incidences of grades II to IV acute graft-versus host disease. Modified protocol did not increase nonhematological toxicity or infectious complications. CONCLUSIONS: The modified treatment protocol effectively and safely prevented graft failure/rejection and significantly increased thalassemia-free survival of class 3 patients with thalassemia.

Association of erythrocyte deformability with red blood cell distribution width in metabolic diseases and thalassemia trait.

Increased red blood distribution width (RDW) in anemia is related to disturbances in the cellular surface/volume ratio, usually accompanied by morphological alterations, while it has been shown in inflammatory diseases that the activity of pro-inflammatory cytokines disturbing erythropoiesis increases RDW. Recently it has been reported that higher RDW is related with decreased erythrocyte deformability, and that it could be related with the association of RDW and increased risk of cardiovascular diseases. In order to analyze the influence of morphological alterations and proinflammatory status on the relationship between RDW and erythrocyte deformability, we analyzed erythrocyte deformability along with RDW and other hematological and biochemical parameters in 36 α-thalassemia, 20 ß-thalassemia, 20 δß-thalassemia trait carriers, 61 metabolic syndrome patients and 76 morbidly obese patients. RDW correlated inversely with erythrocyte deformability in minor ß-thalassemia (r =-0.530, p <  0.05), and directly in both metabolic syndrome and morbidly obese patients (ρ= 0.270, p <  0.05 and ρ= 0.258, p <  0.05, respectively). Minor ß-thalassemia is often accompanied by more marked cell-shaped perturbations than other thalassemia traits. This could be the reason for this negative association only in this setting. Higher anisocytosis seems to be associated with greater morphologic alterations (shape/volume), which reduce erythrocyte deformability. The proinflammatory profile in metabolic patients can be related to the positive association of RDW with erythrocyte deformability found in these patients. However, further research is needed to explain the mechanisms underlying this association.

RBC alloimmunization and double alloantibodies in thalassemic patients.

PURPOSE: Alloimmunization is a common consequence of chronic blood transfusion. Double alloantibody production may complicate the condition of such patients especially for finding matched blood. In this study, we evaluated the frequency of alloantibodies in thalassemic patients with previous history of transfusion reactions. SAMPLES AND METHODS: This study was performed on 441 multiply transfused thalassemia patients Antibody screening test was carried out using three cell-panel by gel method. Positive patients were followed up for antibody identification using 11-cell panel. Direct combs' test was performed to detect auto antibodies. RESULTS: In a total of 441 cases (362 thalassemia major and 79 intermedia), 234 were males (53.1%) and 207 females (46.9%); mean age 22 years, range 3-61 years. Alloimmunization was detected in 50(11.3%) patients, including 37(74%) patients with one alloantibody, 8(16%) with two antibodies, 4(8%) patients with unknown antibodies and one patient (2%) with autoantibody. The most common alloantibodies were anti-Rh antibodies (-E/e/C/c/Cw) (26%), anti-K (28%), anti-D (16%), and anti-Colton (4%). Double antibodies were detected in eight out of 50 patients, including: Anti-D+anti-C (8%), anti-D+anti-E (2%), anti-Kell+anti-D (2%), and anti-Kell+KPa (2%). A significant association was observed between the transfusion reaction history and the alloantibody detection results (p < 0.05). CONCLUSION: Antibody production against RBC antigens makes hard condition in regular blood transfusion. Double antibodies production may more complicate this situation. Thus, it is advisable to phenotype patients and matches the red cells in multiply transfused thalassemia patients.