| An allogeneic hematopoietic stem cell transplant (allo-HSCT) remains the only curative option for inherited hematologic conditions such as thalassemia major(TM). The clinical application of HSCT is limited by regimen-related toxicity secondary to the conditioning regimen, immune response by donor cells to recipient antigens resulting in graft versus host disease (GVHD) and delayed or inadequate immune reconstitution leading to infections,and occasionally rejection of the graft.Although immune reconstitution post-HSCT has been extensively studied in adults,there is limited data in the pediatric population.With high-intensity conditioning there is a loss of recipient immune cells; however, recipient plasma cells may persist for months to years post-transplant. Many pre-transplant factors related to transplant may impact immune status after HSCT, including age,stem-cell source,degree of human leukocyte antigen (HLA) matching..Post-transplant factors such as GVHD, serum status for cytomegalovirus (CMV),immunosuppressive drugs for GVHD prophylaxis/therapy,antimicrobial drugs or intravenous immunoglobulin for the prophylaxis of infections, donor lymphocyte infusions (DLI) also affect immune function. Improvement of immune reconstitution after HSCT is a key issue determining the clinical outcome of this widely used therapeutic approach.We retrospectively analyzed the effect of immune reconstitution included T lymphocyte subset recovery and humeral immune markers in a pediatric population of patients with TM undergoing a myeloablative allo-HSCT within2years.The goals of this paper are as follows:to evaluate immune reconstitution and humeral immune system in patients with TM who underwent allo-PBSCT within2years ago and compare their late-stage immune parameters with their already reported early-stage values;to offer potential consideration of CMV for modulating or restoring immune responses after HSCT. to offer potential consideration of donor age and recipient age for modulating or restoring humeral immune system after HSCT.; to review immune effector cells and their function as they relate to HSCT; to speed up the immune reconstitution after transplantation and decrease the risk for infection after transplantation.This retrospective study was conducted at a in the Laminar Air Flow Ward and Nursing Care of the Pediatric department of Nan Fang Hospital of Southern Medical University.to evaluate immune reconstitution,Section1the objects and methods of lymphocyte subset recovery of post-HSCT.First paragraph:40were enrolled in a study designed to evaluate immune reconstitution6months of post-HSCT and effects of CMV infection,20of all with CMV infection were one group, the others as another group.1.1)Criteria for case choosing:(1)All the patients with TM undergoing transplantation from unrelated donor between March1,2009,and June31,2011;(2)Assessment for T Lymphocyte subset including the subset of CD3+,CD4+,CD8+,NK,CD4+CD45RA+,CD4+CD29+,CD8+CD28+,CD8+CD28-and a complete blood count in6months after allo-HSCT;(3)A11the patients without death or rejection occurrence within6months after allo-HSCT.1.2)ConditioningPatients were conditioned using a myeloablative regimen,which consisting of cyclosphosphamide (Cy,d-10to d-9),fludarabine (Flu,d-8to d-4) by40mg/m2/ day,Thiotepa (TT,d-4) by10mg/kg/day,and Ⅳ busulfan (BU,d-7to d-5)9-17.6mg/kg.All patients received cyclosporine A (Cs-A),mycophenolate mofetil (MMF) and antithymocyte globulin (ATG,d-3to d-1) for GVHD prophylaxis.In addition,short methotrexate (MTX) was given on day1,3and6by15,10and10mg/m2, respectively in unrelated donor (UD) PBSCT.Heparin was used for prophylaxis of hepatic veno-occlusive disease (VOD).1.3)The detection prophylaxis and treatment of CMV pre-transplantation and post-transplantationBefore regimen,ganciclovir (5mg/kg/dose2times daily) was administered as pre-emptive treatment for antigenemia for8-10days Prophylactic acyclovir (5mg/kg/dose2times daily) was administered from day30onward, once in1month for7days or in2month for10days up to day180.After transplantation,quantitative detection of HCMV-DNA should be used once the amount of medium-grain cells is over0.5x109/L;Ganciclovir antivirus treatment will be performed according to blood test and virus clones. CMV infection was defined as quantitative detection of HCMV-DNA>500copies/ml.Dose modifications or foscarnet sodium were made for impaired renal function and ganciclovir was discontinued if the absolute neutrophil count dropped below0.5x109/L for2consecutive days.1.4) Criterion of engraftment:the blood type of peripheral blood should be tested in the28th to60th day after implantation,even more as appropriate.A indirect Index:patients was alive more than21days after HSCT;hematopoiesis recover and values of erythrocyte,granulocyte,lymphocyte and megacaryocyte were normal; neutrophil cells in peripheral blood is more than0.5×109/L,platelet is over20×109/L,presentation of clinical GVHD.hepatomegaly and splenomegaly shrink to normal;lactate dehydrogenase(LDH) level reduced to normal.A direct Index:Engraftment was documented by in situ Y chromosome hybridization of blood samples in sex-mismatched donor/recipient pairs and by analysis of variable number of tandem repeat (VNTR) polymorphisms and microsatellite analysis of blood samples in sex-matched donor/recipient pairs.(HLA antigen changed into donor’s,or calculate donor’s genetic mark’s ration). 1.5) SPSS13.0software was used for analysis. For comparison of dichotomous variables and ranked variables, a κ test and two independent samples nonparametric test (Mann-Whitney) were done while continuous variables were compared using t-test as was deemed appropriate. To confirm outcomes, two-sample t Test were also performed. Lymphocyte recovery was also evaluated by one-sample t-Test as cutoff point which was previous described normal values. Statistical significance level was taken as P<0.05.Second paragraph:The objects and methods of lymphocyte subset recovery12months of post-SCT38were also enrolled in a study designed to evaluate immune reconstitution12months of post-SCT. Criteria for case choosing:(1) All the patients with TM undergoing transplantation from unrelated donor between March1,2009,and June31,2011;(2)Assessment for T Lymphocyte subset at least including the subset of CD3+,CD4+,CD8+,NK and a complete blood count above12months after allo-HSCT;(3) All the patients without death or rejection occurrence within12months after allo-HSCT.The others methods as the same as section1. SPSS13.0software was used for analysis.Lymphocyte recovery was also evaluated by one-sample t-Test as cutoff point which was previous described normal values. Statistical significance level was taken as P<0.05.Section2the objects and methods of humeral immune markers recovery of post-HSCT.First paragraph:the objects and methods of humeral immune markers6months of post-SCT.35were also enrolled in a study designed to evaluate for humeral immune markers and the effects of donor age and recipient age groups6months of post-SCT. Criteria for case choosing:(1) All the patients with TM undergoing transplantation between March1,2010, and June31,2011;(2)Assessment for humeral immune system in6months after allo-HSCT;(3) All the patients without death or rejection occurrence within6months after allo-HSCT.The others methods as the same as section1. SPSS13.0software was used for analysis. Humeral immune markers was also evaluated by one-sample t-Test as cutoff point which was normal value adjusted by recipient age groups. Associations between antibody levels after transplantation and donor age and recipient age were tested by Pearson Correlation test. Statistical significance level was taken as P<0.05.Second paragraph:the objects and methods of humeral immune markers12months of post-HSCT.35were also enrolled in a study designed to evaluate humeral immune markers12months of post-HSCT.Criteria for case choosing:(1) All the patients with TM undergoing transplantation between March1,2009,and June31,2011;(2)Assessment for humeral immune system within12months after allo-HSCT;(3) All the patients without death or rejection occurrence within12months after allo-HSCT.The others methods as the same as section1.SPSS13.0software was used for analysis.Humeral immune markers was also evaluated by one-sample t-Test as cutoff point which were normal values adjusted by age groups.Statistical significance level was taken as P<0.05. ResultSection1T lymphocyte subset recoveryFirst paragraph Lymphocyte subset recovery within6months of post-HSCT(1) The mean of T lymphocyte subset were as follows:1.46×109/L for CD3+T cell,0.33×109/L for natural killer (NK),0.25×109/L for CD4+T cell,1.14×109/L for CD8+T cell. CD4+lymphocyte subset count below normal levels as0.5×109/L(t=-6.874, P<0.001).(2) Higher numbers of CD3+, CD8+cells and CD8+CD28-were observed in the TM patients with CMV infection.(the mean and SD1.87±1.47×109/L Vs1.05±0.60×109/L,1.51±1.27×109/L Vs0.78±0.50×109/L,1.20±1.13×109/LVs0.51±0.41×109/L,(t=-2.315.P=0.029;t=-2.414,P=0.024;t=-2.540,P=0.018,respectively;P<0.05),the same as the rate of these CD8+CD28-cells.(46.17%±19.68%Vs33.32%±12.50%;t=-2.465,P=0.018).(3)Positive liner correlation between the number of CD8+CD28-cells and that of CD8+cells were found (r=0.987,P (0.001). Negative correlation between the number of CD8+CD28+cells and that of CD8+cells were found,but not liner correlation(r=0.585,P=0.016).Second paragraph Lymphocyte subset recovery above12months of post-HSCTThe mean of T lymphocyte subset in children with TM above12months after HSCT were as follows:2.22×109/L for CD3+T cell,0.27×109/L for NK,0.63×109/L for CD4+T cell.Section2Humeral immune system state recoveryFirst paragraph humeral immune markers within6months of post-HSCT(1) The mean level of IgA in children aged3-6was0.49±0.22g/L,IgM was0.71±0.35g/L,and IgG was7.17±2.30g/L. There were lower in IgA and IgM compared to age-matched children.(t=-8.467,P(0.001;t=-2.305,P=0.042, respectively).The mean level of IgA in children above aged7was0.81±0.71g/L,IgM was1.02±0.40g/L,and IgG was8.13±3.28g/L. There were lower in humeral immune markers compared to age-matched children.(t=-2.305,P=0.042;t=-6.161,P <0.001;t=-2.733,P=0.019,respectively).(2) No significant correlation was found between the antibody levels at6months post-transplantation and donor age, except for a positive correlation between recipients age and IgA,C3,or C4.(r=0.667, P (0.001, r=0.511, P=0.002, r=0.341, P=0.045, respectively).(3)The mean level of IgA in2patients with splenectomized within6months after HSCT was1.58g/L,IgM was0.76g/L,and IgG was14.25g/L.Second paragraph humeral immune markers above12months of post-HSCTThe mean level of IgA in children aged3-6was0.83±0.40g/L,IgM was0.86±0.27g/L,and IgG was9.81±2.90g/L. The mean level of IgA in children above aged7was1.35±0.74g/L,IgM was1.05±0.53g/L,and IgG was11.45±4.85g/L. There were lower in IgM compared to age-matched children.(t=-8.982>-5.380; P (0.001>(0.001,respectively).1, All lymphocyte subset count reached normal levels within6months after HSCT in children with TM,except for CD4+,witch below normal reference levels. However,all lymphocyte subset count reached normal levels within12months after HSCT.2、CMV infections seemingly linked with a elevated number of CD8+cells in the peripheral blood of TM children after allo-HSCT,with increased number of CD8+CD28-cells. Positive liner correlation between the percentage of CD8+CD28-cells and that of CD8+cells were found.3、There were significant lower in humeral immune markers in the patients with TM after HSCT compared to age-matched children, except in the case of IgG which was normal in the TM patients aged3-6within6months. Positive correlation were found between recipients age and IgA,C3,or C4at6months post-transplantation.4、There were normal in humeral immune markers in the patients with TM after HSCT compared to age-matched children, except in the case of IgM which was significant lower in the TM patients about12months.5、Splenectomized patients undergoing HSCT had a trend of lower IgM, higher IgA and IgG levels. |
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