β-Thalassemia is an autosomal recessive genetic disorder caused by defects in the synthesis of the β-globin chains. Due to ineffective erythropoiesis and premature destruction of red blood cells, patients suffer from anemia, iron overload, organ damage, and impaired immune system. The impairment of the immune system is mainly due to the increase in the levels of reactive oxygen species (ROS) caused by iron overload, which induces DNA oxidation and leads to DNA damage. The treatment strategies for β-thalassemia mainly include gene therapy and allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, iron overload in patients cannot be eliminated promptly after gene therapy and transplantation. Therefore, even if allo-HSCT is performed, the patient's hematopoietic function may still be impaired. Iron chelators and antioxidants have been proven to effectively intervene in the immune damage caused by iron overload. This article aims to review the research progress on the effects of iron overload on the immune system in patients with β-thalassemia, and provides relevant treatment recommendations for immune recovery.
Humans ; beta-Thalassemia/immunology* ; Iron Overload/therapy* ; Immune System ; Hematopoietic Stem Cell Transplantation

Accumulating evidence has shown that allogeneic blood transfusions can induce significant immunosuppression in recipients, and thereby increase the risk of postoperative infection and/or tumor relapse. Although it is well known that natural killer (NK) cells are responsible for the immunodepression effects of transfusion, the underlying mechanisms remain obscure. In this study, we investigated the role of NK cells in transfusion-induced immunodepression in β-thalassemia major. The proportion of circulating NK cells and the expression of NK receptors (NKG2A, CD158a, NKP30, NKP46 and NKG2D) as well as CD107a were detected by multicolor flow cytometry. IFN-γ production by circulating NK cells was detected by intracellular cytokine staining. Our results showed that the proportion and cytotoxicity (CD107a expression) of circulating NK cells in transfusion-dependent β-thalassemia major patients were remarkably lower than those of β-thalassemia minor patients or healthy volunteers. Expression of NKG2A inhibitory receptor on circulating NK cells in patients with β-thalassemia major was remarkably up-regulated, but there were no significant differences in the expression levels of NKP30, NKP46, NKG2D, CD158a and IFN-γ. These results indicate NKG2A inhibitory receptor may play a key role in transfusion-induced immunodepression of NK cells in patients with β-thalassemia major.
Adolescent ; Child ; Female ; Flow Cytometry ; Gene Expression Regulation ; Humans ; Immunosuppression ; Killer Cells, Natural ; immunology ; metabolism ; Male ; NK Cell Lectin-Like Receptor Subfamily C ; blood ; immunology ; NK Cell Lectin-Like Receptor Subfamily K ; blood ; immunology ; Natural Cytotoxicity Triggering Receptor 1 ; blood ; immunology ; Natural Cytotoxicity Triggering Receptor 3 ; blood ; immunology ; Receptors, KIR2DL1 ; blood ; immunology ; Transfusion Reaction ; beta-Thalassemia ; blood ; immunology ; pathology

The study was purposed to explore the effect of panel reactive antibody (PRA) serum from patients with β-thalassemia on proliferation and apoptosis of the CD34(+)cells from cord blood and its mechanism. CD34(+) cells of umbilical cord blood were incubated with different sera and complement respectively. After incubation, the samples were centrifuged and the supernatants were collected for lactate dehydrogenase (LDH) detection, and the CD34(+) cells were harvested and measured for the apoptosis by flow cytometry with Annexin V/PI. The intracellular DNA synthesis were also quantified by [(3)H]TdR incorporation using liquid scintillation counter. The results showed that concentration of LDH in PRA positive groups was higher as compared with control group, and the DNA synthesis of CD34(+) cells in PRA positive groups were inhibited. There were no differences in the percentage of cell apoptosis and necrosis among different groups. It is concluded that thalassemic serum PRA impairs the cell membrane, inhibits the DNA synthesis, which can be increased by addition of the complement, but PRA had no significant effect on apoptosis of CD34(+) cells.
Antibodies ; blood ; immunology ; Antigens, CD34 ; Apoptosis ; immunology ; Cell Proliferation ; Child ; Fetal Blood ; cytology ; Humans ; beta-Thalassemia ; blood ; immunology ; pathology

OBJECTIVETo investigate the effect of human cytomegalovirus (HCMV) infection on T lymphocyte subsets in children with β-thalassemia major (TM) during the initial 6 months after allogeneic hematopoietic stem cell transplantation (Allo-HSCT).

METHODSFrom January, 2010 to January, 2011, 35 children with TM underwent Allo-HSCT. Peripheral blood samples were obtained from the children 6 month after the transplantation to examine the changes of T lymphocytes subsets in relation to HCMV seropositivity.

RESULTSThirteen children were found seropositive and 22 were seronegative for HCMV. The HCMV-seropositive children had a higher CD8⁺ cell percentage but a lower CD4⁺ cell percentage than those without HCMV infection. Compared with those seronegative for HCMV, the children with HCMV seropositivity showed increased percentages of CD8⁺ cells and CD8⁺CD28⁻ cells with a decreased percentage of CD8⁺CD28⁺ cells. A positive linear correlation was found between the percentages of CD8⁺CD28⁻ cells and CD8⁺ cells.

CONCLUSIONHCMV infection can lead to the accumulation of CD8⁺CD28 cells to cause increased CD8⁺ T cells in the peripheral blood in TM children after Allo-HSCT. The percentages of CD8⁺CD28⁻ cells has a positive linear correlation to that of CD8⁺ cells.

Adolescent ; CD8-Positive T-Lymphocytes ; immunology ; Child ; Child, Preschool ; Cytomegalovirus ; Cytomegalovirus Infections ; immunology ; Female ; Hematopoietic Stem Cell Transplantation ; Humans ; Male ; Postoperative Period ; T-Lymphocyte Subsets ; beta-Thalassemia ; immunology ; surgery ; virology

OBJECTIVETo investigate the effects of different doses of antithymocyte globubin-fresenius (ATG-F) for allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with beta-thalassemia Major.

METHODSSixty-four children with beta-thalassemia major undergoing allo-HSCT were divided into two equal groups to receive ATG-F pretreatments at high (30 mg/kg) or low (15 mg/kg) doses as part of the conditioning regimen including mainly cyclophosphamide, busulfan, fludarabine, and thiotepa. The outcomes of the patients were compared between the two groups.

RESULTSNo obvious difference were noted in the time to leukocyte and platelet engraftment between the two groups. The incidence of grade II-IV acute graft-versus-host disease (aGVHD) appeared to be higher in the low-dose group than in the high-dose group (12.5% vs 9.4%). The incidence of grade III-IV aGVHD was also higher in the low dose group (12.5% vs 6.3%), but the difference was not statistically significant. Application of high-dose ATG-F was associated with a higher rate of probable and possible fungal infection (P<0.05).

CONCLUSIONThe two doses of ATG-F is feasible as a part of the conditioning regimen for allo-HSCT in children with beta-thalassemia major.

Adolescent ; Animals ; Antilymphocyte Serum ; administration & dosage ; immunology ; Child ; Child, Preschool ; Female ; Hematopoietic Stem Cell Transplantation ; methods ; Humans ; Lymphocytes ; immunology ; Male ; Rabbits ; Transplantation Conditioning ; methods ; beta-Thalassemia ; immunology ; surgery

OBJECTIVETo analyze the relationship between cell-mediated immune function during conditioning and graft rejection in patients with beta-thalassemia major.

METHODSAllogeneic hematopoietic stem cell transplantation was performed in 25 children with beta-thalassemia major and 11 with acute leukemia group. The percentages of T lymphocytes and natural killer (NK) cells in peripheral blood of these patients were detected with dual color immunofluorescence on day -10 (before conditioning) and day -5 (after conditioning), and the relationship between the cellular immune function and graft rejection was analyzed.

RESULTSAll the patients with acute leukemia showed engraftment. The rate of graft rejection was 34.8% in the patients with beta-thalassemia major. Compared with the leukemic patients, the patients with beta-thalassemia showed significantly increased percentage of CD3(+)CD8(+) T lymphocytes before and after the conditioning (P<0.05). The percentage of CD3(-)CD56(+) NK cells increased significantly in patients with beta-thalassemia major after the conditioning (P<0.05), but decreased markedly after conditioning in the leukemic patients (P<0.05). In patients with beta-thalassemia major and graft rejection, the CD3(-)CD56(+) cell phenotype was predominant after conditioning but remained unchanged in those with engraftment.

CONCLUSIONCD3(-)CD56(+) NK cells are probably associated with graft rejection in patients with beta-thalassemia major, and may serve as an index for predicting graft rejection following allogeneic hematopoietic stem cell transplantation.

Adolescent ; Case-Control Studies ; Child ; Child, Preschool ; Female ; Graft Rejection ; immunology ; Graft vs Host Disease ; etiology ; immunology ; Hematopoietic Stem Cell Transplantation ; adverse effects ; Humans ; Immunity, Cellular ; Infant ; Killer Cells, Natural ; cytology ; immunology ; Lymphocyte Count ; Male ; beta-Thalassemia ; immunology ; surgery

OBJECTIVEThe low rate of engraftment in children with beta-thalassemia has seriously restricted the popularity of the hematopoietic stem cell transplantation (HSCT). Panel reactive antibody (PRA) has been regarded as one of the important factors for the success of kidney transplantation. Poly-transfusion before transplantation is associated with the production of PRA. Also PRA is produced in the children with beta-thalassemia major who need poly-transfusion for life. PRA might be one of factors inducing the low rate of engraftment in children with beta-thalassemia. This study focused on observing the effect of PRA on the proliferation, differentiation, apoptosis and necrosis of cord blood CD34(+) cells in vitro by incubating the cord blood CD34(+) cells with serum containing PRA.

METHODSeven samples of cord blood were collected and the HLA typing for every sample was done. Seven sera positive for PRA and seven negative sera were selected respectively. Mononuclear cells (MNCs) were obtained by Ficoll-Hypaque density gradient centrifugation. CD34(+) cells were isolated from MNCs by positive selection using an immunomagnetic separation (CD34(+) progenitor cell isolation kit and auto-MACS). The CD34(+) cells of umbilical cord blood were incubated with the serum and complement in the following groups: A (absence of serum), B (presence of PRA positive serum), C (presence of PRA positive serum and complement), D (presence of complement), and E (presence of PRA negative serum). After incubation the samples were centrifuged and the supernatant was collected for LDH detection. At the same time the CD34(+) cells were harvested for assessing the expression of Annexin V and CD95 of the CD34(+) cells by flow cytometry and also for the detection of the DNA synthesis by (3)H-TaR incorporation. Meanwhile the cells were inoculated into the methylcellulose cultural system. The proliferation and hematopoietic potential of the CD34(+) cell of cord blood by the colony formation assay were detected on the day 10.

RESULTThe concentration of LDH in group A was (20.71 +/- 2.81) U/L, which was significantly lower than that in group B (64.28 +/- 5.12) U/L and group C (84.29 +/- 4.99) U/L. The concentration of LDH in group B was significantly lower than that in group C, while there were no significant differences in the concentration of LDH among groups A, D and E (P > 0.05). The cpm in group A was (22 629 +/- 3288), which was significantly higher than that in group B (4598 +/- 2178) and group C (1626 +/- 1192). And the cpm in group B was significantly higher than that in group C. There were no significant differences in the cpm among groups A, D and E (P > 0.05). On day 10 of culture, the total colonies, granulocyte-macrophage colony forming unit (CFU-GM), mixed colony forming unit (CFU-GEMM) and erythroid burst colony forming unit (BFU-E) in group A were significantly higher than that in group B and C. The total colonies, CFU-GM and CFU-GEMM in group B were significantly higher than those in group C. No significant differences were found in the total colonies, CFU-GM, CFU-GEMM and BFU-E among groups A, D and E (P > 0.05). There were no statistically significant differences in the CD95 and Annexin V expression among all the groups (P > 0.05).

CONCLUSIONPRA could impair the membrane, decrease the DNA synthesis, and inhibit the colony formation of CD34(+) cord blood cells, which could be strengthened by the presence of the complement at the given concentration in our study. PRA had no significant influence on the apoptosis of CD34(+) cells in vitro.

Antibodies ; immunology ; Antigens, CD34 ; Apoptosis ; immunology ; Cell Differentiation ; immunology ; Cell Proliferation ; Cells, Cultured ; Child ; Fetal Blood ; cytology ; immunology ; metabolism ; Flow Cytometry ; Humans ; Quorum Sensing ; immunology ; beta-Thalassemia ; immunology

OBJECTIVETo study the CDR3 spectratyping and clonal expansion of T cells in the peripheral blood mononuclear cells (PBMCs) of patients with beta-mediterranean anemia patient undergoing allogeneic peripheral blood stem cell (PBSC) transplantation.

METHODSThe total RNA was isolated from the PBMCs of a nine-year-old boy with beta-mediterranean anemia before and after PBSC transplantation, and at the time of occurrence of graft-versus-host disease (GVHD). The CDR3 length was analyzed using immunoscope technique, and the characteristics of the T cell receptor (TCR) on the T cells with clonal expansion were examined by gene sequencing.

RESULTSThe 24 TCR BV CDR3 repertoire showed Gaussian distribution in the PBMCs isolated before the transplantation, and some of the TCR BV family CDR3 showed skewing in the PBMCs isolated 23 days after transplantation and at the onset of GVHD (28 days after transplantation), suggesting the clonal expansion of the donor PBSCs.

CONCLUSIONThe host PBMCs show muti-clonal expansion 23 days after PBSC transplantation, and in the stage of GVHD, some of the TCR BV family T cells show significant monoclonal expansion. Analysis of TCR CDR3 spectratyping and the molecular characteristics of specific TCR may help evaluate the immune reconstitution following the transplantation and indicate specific treatment for potential GVHD.

Child ; Complementarity Determining Regions ; genetics ; immunology ; Graft vs Host Disease ; etiology ; immunology ; Humans ; Male ; Peripheral Blood Stem Cell Transplantation ; adverse effects ; methods ; Receptors, Antigen, T-Cell, alpha-beta ; genetics ; immunology ; beta-Thalassemia ; immunology ; surgery

The objective of this study was to investigate the curative effect of combined sibling umbilical cord blood and bone marrow transplantation in treatment of beta-thalassemia major. Combined umbilical cord blood and bone marrow transplantation from an HLA-identical sibling were performed for 3 patients with beta-thalassemia major. The nucleated cells infused into 3 recipients were 19.5 x 10(7)/kg, 20.8 x 10(7)/kg and 23.3 x 10(7)/kg respectively. They accepted the conditioning regimen consisting of busulfan, cyclophosphamide, antithymocyteglobulin. The results showed that three patients gained protracted and stable engraftment. The time to achieve more than 0.5 x 10(9)/L neutrophils in three patients was 16, 18, and 17 days respectively; the time to achieve more than 50 x 10(9)/L platelet in three patients was 48, 50, and 49 days respectively. The speed of hematopoietic recovery was faster than that of umbilical cord blood transplantation (UCBT) only. Three patients all suffered from acute graft-versus-host disease (aGVHD) of I grade. They had lived with free-thalassemia for 1.5, 2.0 and 2.1 years respectively. Their Hb had been maintained at normal level without transfusion. It is concluded that combined UCBT and BMT may be an effective and safe way to treat pediatric beta-thalassemia major.
Blood Donors ; Bone Marrow Transplantation ; Child ; Child, Preschool ; Combined Modality Therapy ; Cord Blood Stem Cell Transplantation ; methods ; Female ; Graft vs Host Disease ; immunology ; prevention & control ; Humans ; Siblings ; Transplantation, Homologous ; Treatment Outcome ; beta-Thalassemia ; therapy

Allogeneic hematopoietic stem cell transplantation is the only curative therapy for severe beta-thalassemia. This time, the experience of utilizing HLA 2-loci mismatched sibling cord blood transplantation (CBT) in a child with severe beta-thalassemia was firstly reported in our country. A 3-year-male patient had been diagnosed with severe beta-thalassemia at 6 months of age (HbF 86.6%, HbA1 1.7%, HbA2 1.7%, beta globin gene mutation CD17, A-->T/IVS-II-654, C-->T). The patient's HLA typing was A 24,11, B 58,35 and DRB1 03,15. During a subsequent maternal pregnancy. The prenatal diagnosis for thalassemia and prenatal HLA typing analysis were performed on 18 weeks of pregnancy. The results indicated that the male fetus was a heterozygote (beta globin gene mutation N/CD17, A-->T), HLA typing was A 24,11, B 58,51 and DRB1 03,12. 120 ml cord blood was collected at time of delivery, the total numbers of nucleated cells, CFU-GM and CD34(+) cells were 1.830 x 10(9), 16.653 x 10(5) and 3.11 x 10(6), respectively. A new conditioning regimen including: hypertransfusion, continuous i.v. desferrioxamine, busulfan, cyclophosphamide, antithymocyte globulin plus hydroxyurea and fludarabine. GVHD prophylaxis comprised cyclosporin A and mycophenolate mofetil. The viability of cord blood at the time infusion was 92%, The total numbers of nucleated cells, CFU-GM and CD34(+) cells in the transfused cord blood were 12.06 x 10(7)/kg, 1.098 x 10(5)/kg, and 2.04 x 10(6)/kg, respectively. Results showed that the patient's clinical course after cord blood transplantation was unremarkable. Acute GVHD grade I developed on day 15, methylprednisolone 2 mg/kg was given to cure. Neutrophil engraftment (ANC > 0.5 x 10(9)/L) on day 17, platelet engraftment (> 50 x 10(9)/L) on day 50. The patients became independent from red blood cell transfusion since day 80 (when his hemoglobin level kept > 12.5 g/L). His beta globin gene mutation and HLA typing were all the same as the donor's analyzed on day 60 and 200. There was also a switch in blood group from A pre-transplant to O post-transplant. It is concluded that the new conditioning and GVHD prophylaxis regimens allow a successful engraftment in this case. This observation may contribute in developing UCBT as an alternative when matched sibling donors are not available.
Child, Preschool ; Cord Blood Stem Cell Transplantation ; adverse effects ; Globins ; genetics ; Graft vs Host Disease ; etiology ; HLA Antigens ; immunology ; Histocompatibility ; genetics ; immunology ; Histocompatibility Testing ; methods ; Humans ; Male ; Mutation ; Siblings ; Transplantation Tolerance ; immunology ; Transplantation, Homologous ; beta-Thalassemia ; therapy