Influence Of Pretransplantation Serum Ferritin On Beta-thalassemia Major Undergoing Allogeneic Hematopoietic Stem Cell Transplantation

BackgroundThalassemia is one of the most common hereditary blood disease in the world, also known as the Mediterranean anemia thalassemia, this is because the disease was first discovered in the Mediterranean region is the case for the sake of. The biological basis of thalassemia is a globin gene genetic defects lead to the disorder of globin synthesis, non peptide (alpha, beta, gamma delta) and alpha globin synthesis ratio imbalance, which caused the destruction of red blood cells caused by anemia, hemolysis and ineffective hematopoiesis, including alpha and beta thalassemia is the most important type of thalassemia. The beta thalassemia major (TM), also known as the Cooley anemia, for beta 0, beta+gene homozygous or double heterozygous state, clinical hemolytic anemia, chronic, special face hepatosplenomegaly and hemoglobin F increased significantly as the characteristic, is a kind of common Mediterranean anemia in China, Chinese high risk areas are mainly distributed in the south of the Yangtze River provinces, especially in Guangxi, Guangdong and Hainan provinces.Thalassemia is a progressive disease, the conventional treatment methods mainly include two aspects, one is the blood transfusion treatment, every 10 to 30 days for 1 times, the hemoglobin (Hb) was maintained at 90～120g/L, to correct anemia in patients with severe; second is the correct use of iron chelating agent, chelating iron the mixture can prevent and reverse the excess iron in the cells of savings, while reducing iron in the oxidation of free radicals to prolong life, and improve the quality of life of patients with thalassemia, WHO recommended treatment for thalassemia children reasonable daily continuous subcutaneous deferoxamine injection of at least 10 hours, at least 5 days a week, the treatment is difficult to insist for a long time sure, now there are two kinds of oral iron to (deferiprone and deferasirox), greatly improve the compliance of thalassemia patients during treatment, but there are also more obvious adverse reactions. Although the law of blood transfusion and iron treatment of thalassemia patients to improve the quality of life and prolong the survival time, but this disease eventually leads to death in patients with early death, the main reason is:(1) chronic anemia and its complications; (2) without the proper use of iron chelator resulted in iron deposition disease, long-term blood transfusion leads to iron accumulation, the state promotes gastrointestinal absorption of iron anemia with iron overload in the body, the state, and cause serious complications of chronic heart, liver damage, endocrine system etc.. In China, one patients with thalassemia major, if you accept the regular blood transfusion and iron treatment, the annual cost of more than 50000 RMB. Although there is no exact statistics, the clinical practice shows that, these severe thalassemia patients because of economic reasons most of the lack of effective treatment of death before the age of 15. Even with standard blood transfusion and iron treatment, there are still more than 50% thalassemia patients died at the age of 35. Thus, beta thalassemia major to the family and society caused serious harm, to improve the quality of the population poses a serious threat.Since 1982 Thomas successful application of human leukocyte antigen (HLA) has matched sibling bone marrow transplantation in the treatment of severe thalassemia, allogeneic hematopoietic stem cell transplantation (HSCT) have been used to cure poverty. Allogeneic HSCT is currently the only curative treatment of thalassemia, has been widely accepted by the medical definition. Through the HSCT treatment of thalassemia patients’ quality of life was significantly higher than that of traditional blood transfusion and iron therapy. More than 3000 cases of thalassemia and sickle cell disease patients were cured by HSCT, most patients with hematopoietic stem cells derived from HLA matched sibling bone marrow hematopoietic stem cell transplantation, as there are HLA identical sibling donors with beta thalassemia patients preferred treatment.However, stem related death analysis found that severe infection, graft-versus-host disease (GVHD) cell transplantation, hepatic veno occlusive disease (VOD) is a major cause of death. While the iron overload is one source of many body complications, can provide nutrients for bacteria, fungi, can produce hydroxyl free radical damage to mucosal barrier, can inhibit or aggravate the occurrence of GVHD, can form iron deposition leads to organ failure (such as liver, heart, pancreas, kidney etc.).Pediatric HSC transplant center, Nanfang Hospital Affiliated Southern Medical University began using stem cell transplantation for the treatment of beta thalassemia major since twentieth Century 90’s. In beta thalassemia major in HSCT field has been at the forefront of the world. In order to avoid further transplant related complications, further improve the survival rate, to explore the pre transplant ferritin levels are associated with transplantation related complications and prognosis study. This paper analyzed retrospectively from January 2009 to November 2014 since the children completed nearly 5 years 266 patients with beta thalassemia major pre transplant serum ferritin level effect on transplantation of hematopoietic stem cell transplantation therapy.Objects and MethodObjects:In the 266 cases,166 cases were male,100 were female, the median age was 6 years old (aged 2-14 years), were single transplantation. All cases are in line with HLA HLA matching low resolution 6/6 matched (HLA-A,-B,-DR). Before transplantation,266 cases of severe beta thalassemia patients according to clinical grading (according to the situation of domestic thalassemia enlargement age, serum ferritin levels and liver rib is divided into three degrees), similar to the Pesaro index, including 13 cases of thalassemia were grade Ⅰ, Ⅱ degree of thalassemia was 244 Cases,9 cases of thalassemia. According to the pre transplant serum ferritin ferritin values this study patients were divided into high ferritin group (more than 2500 μg/L) and low ferritin group (< 2500μg/L) two groups.Conditioning Regimen:According to the NF-08-TM regimen, chemotherapy drugs, dosage and medication time. Cyclophosphamide (50～60mg/kg/d, VD, 10d～ 9D); busulfan (2.8～4.4mg/kg/d, Ⅳ～8D 6D (40mg/m2/d, VD); fludarabine,8D～ 4D); thiotepa (10mg/kg/d, VD,5d); anti human T-lymphocyte rabbit immunoglobulin (5～10mg/kg/d, VD,3D～1D) or rabbit antithymocyte globulin (2.5mg/kg/d, VD,3D～1D).Hematopoietic stem cell collection and transfusion:Donor for transplantation before the inspection (including three routine, blood coagulation time, heart and lung, liver and kidney function, genetic and infectious virus detection); donor to collect 4 days before the administration of granulocyte colony stimulating factor (G-CSF) in 10μg/kg/d on hematopoietic stem cell mobilization, with the German Fresenius blood cells separator COM.TEC, cyclic separation collection according to specification acquisition technology of hematopoietic stem cells, unrelated donor hematopoietic stem cells by Taiwan, China bone marrow bank standard of the local collection.266 cases of infusion of TNC was 8*108/kg.Prevention of Complications:(1)GVHD prophylaxis:With respect to the prophylaxis of GVHD, cyclosporine A (CsA) was started at 1.5mg/kg/day i.v. from day-10 to day-2, increased to 3mg/kg/day on day-1 up to day 25, and subsequently administered orally at targeted concentrations of 200±50 μg/L.The dose of CsA was tapered from day 60 until its discontinuation at the end of 1 year. Mycophenolate mofetil (CellCept) was administered on day 1 at 15mg/kg bid and was discontinued on day 30 if there were no signs of ≥grade Ⅱ acute GVHD (aGVHD). Short-term methotrexate (MTX) was administered on days 1,3, and 6 at 15,10, and 10 mg/m2, respectively. When GVHD occurred, we add methylprednisolone or immune inhibitors according to GVHD grading. Unrelated donor for GVHD prevention programs and related donor, change CsA to tacrolimus (FK506), to maintain the concentration of tacrolimus was 10+5μg/L, methotrexate dose was adjusted to 10-15mg/m2 intravenous drip. (2)Hepatic veno-occlusive disease (VOD) prophylaxis:Heparin and ursodiol were used for the prophylaxis of VOD. The dose of heparin was gradually increased from 100 to 200 U/kg to maintain the levels of activated partial thromboplastin time that were slightly higher than normal. After VOD onset, a diuretic agent was used. Ursodiol was used until the end of the third month after the transplant.(3)Hemorrhagic cystitis(HC) prophylaxis:hydration was applied 3L/m2/d before 6 hours preconditioning to maintain a higher 60～100 ml/m2,and mesna was applied when Cy was intravenous infused.The treatment is hydration, platelet infusion and bladder irrigation, if necessary. (4)Prevention of infection:wiping off dental necrosis and other focus of infection before transplantation. All of the patients were given preemptive prophylactic treatment for cytomegalovirus (CMV) infection.before entering the laminar flow ward.All patients were treated in positive-pressure isolation rooms and received a low-bacteria diet and nonabsorbable oral antibiotics for 3 days. Itraconazole was used form the fifth day until the third day after granulocyte rose up to 0.5×109/L on three consecutive days.According to experience,when infection occurred,we used sufficient antibiotics.Observation index and definitions:(1) survival. From the start at the end of the follow-up observation of transplantation, record death incidents and the cause of death. (2) hematopoietic reconstruction. Neutrophil engraftment for three consecutive days of neutrophil counts more than 0.5*109/L; platelet engraftment in the absence of platelet transfusion cases for consecutive 7 days of platelet>20*109/L; (3) transplantation related complications. The infection site, infection sources, nature of the severity of infection; GVHD diagnosis in accordance with the classification system of Glucksberg and Przepiorka; VOD diagnosis according to the diagnostic criteria of Baltimore.Statistical methods:Using SPSS 13 statistical software, descriptive data using x2 test (chi-square test), the quantitative data using t test (student-test), P< 0.05, the difference was statistically significant. To estimate the total survival rate and percentage by Kaplan-Meier method, the difference between the groups with Log-Rank test test.ResultsSurvival:266 cases of thalassemia children, as of April 11,2014, the median follow-up time was 28 months (range 3-62 months), of which 248 cases survived, the overall survival rate (OS) 92.8%. Observation of patients in death accounted for 18 cases, transplantation related mortality was 6.8%(TRM). The final statistics through follow-up, there were 18 deaths, including the transplantation related mortality was 6.8%,3 cases died of GVHD (high ferritin group 2 cases),2 cases died of severe VOD (high ferritin group 1 cases),2 cases died of intracranial hemorrhage (high ferritin group 1 cases),11 cases died from infection the cause of respiratory failure and heart failure (high ferritin group of 10 cases). No clear relationship between ferritin and death, P=0.186, no significant difference between the death group and low protein high ferritin, P=0.439.Hematopoietic reconstruction:high ferritin group and low ferritin group neutrophil reconstruction time average were+19.26 days,+17.34 days, P=0.067, platelet reconstruction time average were+13.78 days,+13.82 days, P=0.969, visible high ferritin group and low ferritin group have no significant difference on hematopoietic reconstitution.HSCT related complication:(1) in 266 cases of transplant patients, only 16 patients had acute GVHD, the incidence rate was 6%, of which 5 cases of GVHD (4 cases high ferritin group),3 cases of GVHD (high ferritin group 3 cases),5 cases of GVHD (4 cases high ferritin group),3 cases of grade GVHD (high ferritin group,2 cases), grade Ⅲ acute GVHD incidence rate was 3%.11 cases of chronic GVHD (high ferritin group 9 cases), the incidence rate was 4%. Pre transplant serum ferritin values of aGVHD and cGVHD after transplantation, there was no direct relationship between the two, P values were 0.185,0.263, visible high ferritin group and low protein of aGVHD, cGVHD had no significant difference, the P values were 0.277, 0.343. (2) in 266 cases of transplant children, infection with the table, which occurred stomatitis 148 cases (55.6%),42 cases of sepsis (15.8%), pulmonary infection occurred in 53 cases (19.9%),5 cases of perineal anus infection,3 cases of intracranial infection,3 cases of urinary tract infection,2 cases clear enteritis,2 cases of skin and soft tissue infection,3 cases of sinusitis, otitis media,1 cases of liver abscess. The virus, HSV-I infection in 34 cases,21 cases of CMV infection, EBV infection in 1 cases. There was a direct correlation between occurrence of infection, serum ferritin values before transplantation and transplantation of P=0.008, taking 3449.5μg/L as the cut-off point high ferritin group and low protein, there were significant differences of infection (P=0.000), and 2500 μg/L as the cut-off point was no difference (P=0.178). (3) VOD patients with 9 cases, the incidence rate was 3.4%, including 4 cases of mild (high ferritin group 3 cases),3 cases of moderate (high ferritin group 2 cases),2 cases of severe VOD (high ferritin group 1 cases), severe VOD patients eventually died. The value of serum ferritin before transplantation and transplantation in the process of VOD is not directly related, P=0.690, high ferritin group and low protein of VOD had no significant difference, P= 1.000. (4) other complications included hemorrhagic cystitis, secondary diabetes, autoimmune hemolytic anemia, implantation syndrome, most can control, does not affect the treatment effect.Conclusions1 Infection in allogeneic hematopoietic stem cell transplantation is the most common complication. Severe infection is one of the leading causes of death underwent HSCT.2 Pre-transplant ferritin levels has relationship with infection, high levels of serum ferritin may bring more infection rate, especially the patients serum ferritin is more than 3449.5μg/L.3 Pre-transplant ferritin levels and GVHD, VOD, death is not directly relationship.4 Regardless of ferritin level before transplantation, the NF-08-TM protocol used for all matched donor in the clinical treatment of thalassemia is satisfactory.