Population pharmacokinetics of cyclosporine A in pediatric patients with thalassemia undergoing allogeneic hematopoietic stem cell transplantation

PURPOSE

To establish the population pharmacokinetics (PPK) model of cyclosporine A(CsA) in pediatric patients with thalassemia undergoing allogeneic hematopoietic stem cell transplantation (HSCT), aiming at providing a reference for clinical dose individualization of CsA.

METHODS

Children with thalassemia who underwent allogeneic HSCT were enrolled retrospectively. The PPK structural model and the random variable model of CsA were established on NONMEN. And goodness of fit plots (GOFs), visual predictive check (VPC), and bootstrap and normalized prediction distribution errors (NPDE) were used to evaluate the final model.

RESULTS

A one-compartment model with first-order absorption was employed to fit the base model. A total of 74 pediatric patients and 600 observations of whole blood concentration were included. The final model included weight (WT) in clearance (CL), alongside post-operative day (POD), fluconazole (FLUC), voriconazole (VORI), posaconazole (POSA), and red blood cell count (RBC) significantly. All the model evaluations were passed.

CONCLUSION

In the PPK model based on the pediatric cohort on CsA with thalassemia undergoing allogeneic HSCT, WT, POD, FLUC, VORI, POSA, and RBC were found to be the significant factors influencing CL of CsA. The reliability and robustness of the final model were excellent. It is expected that the PPK model can assist in individualizing dosing strategy clinically.

Long-term Results of Splenectomy in Transfusion-dependent Thalassemia

Splenectomy is indicated in transfusion-dependent thalassemia (TDT) only in certain situations. This study aimed to present the effectiveness, complications, and long-term follow-up results of splenectomy in children with TDT. We performed a 30-year single-institution analysis of cases of splenectomy for TDT between 1987 and 2017 and their follow-up until 2021. A total of 39 children (female/male: 24/15) were included. The mean age at splenectomy was 11.2±3.2 years, and their mean follow-up duration after splenectomy was 21.5±6.4 years. Response was defined according to the patient's annual transfusion requirement in the first year postsplenectomy and on the last follow-up year. Complete response was not seen in any of the cases; partial response was observed in 32.3% and no response in 67.6%. Thrombocytosis was seen in 87% of the patients. The platelet counts of 7 (17.9%) patients were >1000 (10 9 /L), and aspirin prophylaxis was given to 22 (56.4%) patients. Complications were thrombosis in 2 (5.1%) patients, infections in 11 (28.2%) patients, and pulmonary hypertension in 4 (10.2%) patients. Our study showed that after splenectomy, the need for transfusion only partially decreased in a small number of TDT patients. We think splenectomy can be delayed with appropriate chelation therapy up to higher annual transfusion requirement values.

Pretransplant immunosuppression followed by reduced-toxicity conditioning and stem cell transplantation in high-risk thalassemia: a safe approach to disease control

Patients with class 3 thalassemia with high-risk features for adverse events after high-dose chemotherapy with hematopoietic stem cell transplantation (HSCT) are difficult to treat, tending to either suffer serious toxicity or fail to establish stable graft function. We performed HSCT in 18 such patients age ≥7 years and hepatomegaly using a novel approach with pretransplant immunosuppression followed by a myeloablative reduced-toxicity conditioning regimen (fludarabine and i.v. busulfan [Flu-IV Bu]) and then HSCT. The median patient age was 14 years (range, 10 to 18 years). Before the Flu-IV Bu + antithymocyte globulin conditioning regimen, all patients received 1 to 2 cycles of pretransplant immunosuppression with fludarabine and dexamethasone. Thirteen patients received a related donor graft, and 5 received an unrelated donor graft. An initial prompt engraftment of donor cells with full donor chimerism was observed in all 18 patients, but 2 patients developed secondary mixed chimerism that necessitated withdrawal of immunosuppression to achieve full donor chimerism. Two patients (11%) had acute grade III-IV graft-versus-host disease, and 5 patients had limited chronic graft-versus-host disease. The only treatment-related mortality was from infection, and with a median follow-up of 42 months (range, 4 to 75), the 5-year overall survival and thalassemia-free survival were 89%. We conclude that this novel sequential immunoablative pretransplantation conditioning program is safe and effective for patients with high-risk class 3 thalassemia exhibiting additional comorbidities.

Spectrum of infections in splenectomised thalassaemia patients

Splenectomised thalassaemia patients are at risk of developing sepsis. As the infection may be life-threatening, treatment should be sought and given promptly. A retrospective study was performed amongst our thalassaemia major patients who were splenectomised. The vaccination status of each patient and the types of infections seen were reviewed to obtain a local perspective. In our cohort of 49 splenectomised patients, 25 patients required hospitalization for the treatment of infection. There were a total of 40 febrile episodes within this hospitalised group of which 27.5% were microbiologically documented infection with bacteraemia. The predominant causative organisms were gram negative rods and three patients succumbed to overwhelming septicaemic shock as a result of delayed presentation. Sixty percent of the febrile episodes were clinically documented infection and comprised mainly upper respiratory tract infections. Based on the spectrum of infections seen, there is a need to improve the patients' awareness level so that early treatment is sought. There is also a need to re-address the approach towards vaccination in this immunocompromised group of patients by administering a booster pneumococcal and influenza vaccination in an attempt to reduce morbidity.

Comparison of peripheral blood stem cell transplant with bone marrow transplant in class 3 thalassemic patients

OBJECTIVES

This study aimed to compare outcome of bone marrow transplant with peripheral blood stem cell transplant in class 3 thalassemic patients.

MATERIALS AND METHODS

Respectively, 32 and 20 class 3 thalassemic patients received bone marrow transplant and peripheral blood stem cell transplant from human leukocyte antigen identical sibling donors. Conditioning regimen consisted of busulfan (16 mg/kg) and cyclophosphamide (160 mg/kg) followed by cyclosporine and methotrexate as graft-versus-host disease prophylaxes.

RESULTS

Median time to absolute neutrophil count was significantly shorter in the peripheral blood stem cell transplant group (12 vs 23 days); however, there was no significant difference regarding platelet recovery between the 2 groups (20 vs 28 days). Acute graft-versus-host disease occurred in 47% of patients. Chronic graft-versus-host disease developed in 28% of patients which was significantly higher in the peripheral blood stem cell transplant group (P = .06). During 50 months follow-up, thalassemia recurrence, overall survival, and thalassemia-free survival were 17%, 80%, and 65%, respectively, and there were no significant differences between the 2 groups.

CONCLUSIONS

These results showed that stem cell transplant is an effective treatment in class 3 thalassemic patients with the outcome relatively similar to bone marrow transplant. Although engraftment time is shorter in peripheral blood stem cell transplant method, it is associated with higher rate of chronic graft-versus-host disease.

Asymptomatic brain magnetic resonance imaging abnormalities in splenectomized adults with thalassemia intermedia

BACKGROUND

A high incidence of thrombotic events in thalassemia intermedia (TI) patients led to the identification of a hypercoagulable state. Brain involvement has not been widely studied in TI, although limited reports confirm a low incidence of overt stroke and high incidence of silent brain infarcts.

PATIENTS/METHODS

This was a prospective study conducted on 30 adult, splenectomized TI patients. Patients were screened for absence of neurological signs or symptoms, and stroke-related risk factors. Patient charts were reviewed for demographics, duration since splenectomy, and any history of transfusion therapy. Blood samples were obtained for complete blood counts and serum ferritin. Direct determination of liver iron concentration (LIC) was performed by R2 magnetic resonance imaging (MRI). Brain MRI was performed on all patients, looking for ischemic lesions and/or atrophy.

RESULTS

The mean age of patients was 32.1 +/- 11 years (range, 18-54 years), with a male to female ratio of 13:17. Eighteen patients (60%) had evidence of one or more white matter lesions (WMLs) on brain MRI, all involving the subcortical white matter. Fourteen patients had evidence of multiple WMLs, with a mean of 5 +/- 10 lesions (range, 2 to > 40 lesions). The vast majority of patients (94%) had small (< 0.5 cm) to medium (0.5-1.5 cm) WMLs, with only one patient showing evidence of a large (> 1.5 cm) WML. Eleven patients (37%) had mild cerebral atrophy. On multivariate analysis only age and transfusion history were independently and significantly associated with the occurrence of zero, single or multiple WMLs.

CONCLUSION

WMLs and brain atrophy are a common finding in adult, splenectomized, TI patients. Increasing age and transfusion naivety are associated with a higher incidence and multiplicity of lesions.

Long-term results of survival in patients with thalassemia major treated with bone marrow transplantation

Allogeneic bone marrow transplantation (BMT) is the only available curative approach for thalassemia major, although long-term morbidity and mortality are not established. The aim of this study was to assess the long-term clinical and hematological results in children and adults with thalassemia major treated with BMT. We analyzed the outcome of 115 patients (median age 9 years, range 11 months to 28 years) with thalassemia major undergoing BMT from a related donor between 1983 and 2006. All patients received the same protocol, consisting of busulfan and cyclophoshamide as conditioning therapy and cyclosporin (CSA) alone or CSA and methotrexate for graft-versus-host disease (GvHD) prophylaxis. The cumulative probability of graft rejection was 6.7%. The transplant-related mortality at 1 year was 8.7%. The 20-year Kaplan-Meier estimate of overall survival and disease-free survival was 89.2% and 85.7%, respectively. Ninety-nine patients out of 103 survivors were in excellent clinical and hematological conditions at last visit following a median follow-up of 15 years (range, 1-24 years) with the exception of two patients who had invalidating chronic GvHD. This study conducted with a large cohort of patients and covering a long period of observation time, showed BMT to be curative for the majority of patients with thalassemia major. The impact of long-term transplant-related sequelae was very limited.

Efficacy of a modified improved technique for detecting red cell haemoglobin H inclusions

Alpha-thalassaemia is a common disease in Taiwan. A feature useful in diagnosis is the excess of of beta-chains that result from impaired alpha-chain production. These excess chains assemble into beta 4 tetramers (i.e. Hb H) which can be detected by its rapid anodal migration on alkaline electrophoretic media as seen in Hb H disease. However, this technique cannot, and conventional Hb H inclusion staining rarely can visualize alpha-thalassaemic traits due to small quantities of Hb H formed in these patients. The staining for Hb H inclusion bodies uses brilliant cresyl blue (BCB) or methylene blue (MB) as an oxidant to denature Hb H as intracellular inclusions. We have improved the technique of Jones (who modified the original method in order to obtain enriched young red cells) by prolonging the incubation time from 30 min to 3 h. The sensitivity of this modified improved method was 91% for detecting obligatory alpha-thalassaemic traits as shown in table. No false positive results were seen in beta-thalassaemia or in others. We believe this can be used as a confirmatory test in heterozygous alpha 1-thalassaemia and homozygous alpha 2-thalassaemia.

The human leucocyte antigen-G 14-basepair polymorphism correlates with graft-versus-host disease in unrelated bone marrow transplantation for thalassaemia

The presence of the 14-bp insertion polymorphism of the human leucocyte antigen (HLA)-G gene (HLA-G) promotes immune tolerance through increased synthesis of HLA-G molecules. We investigated this polymorphism in a large cohort of 53 thalassaemia patients transplanted from an unrelated donor. Sixteen patients (30.2%) homozygous for the 14-bp deletion had a higher risk of developing acute graft-versus-host disease (aGvHD) than patients homozygous for the 14-bp insertion (-14-bp/-14-bp vs +14-bp/+14-bp: Relative Risk = 15.0; 95% confidence interval 1.59-141.24; P = 0.008). Therefore, the 14-bp polymorphism could be an important predictive factor for aGvHD following bone marrow transplantation.

Prevention of overwhelming postsplenectomy infection in thalassemia patients by partial rather than total splenectomy

OBJECTIVE

We aimed to evaluate the protective role of partial versus total splenectomy against sepsis in patients with thalassaemia when other preventive measures are not available. Overwhelming postsplenectomy infection is a serious complication of splenectomy in these patients, and most present with pneumococcal septicemia. Pneumococcal vaccine given before surgery is a well-established preventive measure.

METHODS

In this study, we compared 2 populations of patients from Iraq and Saudi Arabia, both of whom underwent splenectomy for thalassaemia. All patients from Saudi Arabia were given a preoperative pneumococcal vaccine and underwent total splenectomy after about 4 weeks. Unfortunately, this vaccine was not available for the Iraqi patients. Partial splenectomy was offered to many of these patients as a protective measure against this fatal complication.

RESULTS

A significant difference was found between the total splenectomy fatalities in the 2 groups. There were 5 deaths in the 30 enrolled Iraqi patients over 4 years. One death over a 12-year period was reported in the 22 patients from Saudi Arabia. Partial splenectomy was associated with a dramatic reduction of mortality in the Iraqi patients. None of the 12 patients died during a follow-up period of 4 years.

CONCLUSIONS

Pneumovax is a powerful prophylactic tool against overwhelming postsplenectomy infection in patients with thalassaemia and should be used whenever available. In poor or problematic countries with limited health resources, partial rather than total splenectomy could offer an alternative measure to avoid this fatal complication.

[Optimization of laparoscopic splenectomy at children]

Treatment results of 130 patients aged 1 to 16 years with benign hematological diseases (congenital microspheric anemia--93 patients, thalassemia--18, severe idiopathic thrombocytopenic purpura--19) who has undergone laparoscopic cholecystectomy due to concomitant cholelithiasis. Optimization of surgical techniques permitted to achieve excellent functional and cosmetic results, to reduce operation time to 35-110 min (64.67+/-10.07 min on average), volume of hemorrhage to 30-110 ml (62.91+/-14.46 ml on average), to avoid intraoperative and postoperative complications. It is concluded that laparoscopy is the method of choice for the treatment of children with benign hematological diseases required splenectomy despite the age of child, spleen size, including the children with severe disorders of hemostasis system.

[Life quality of children with hematological diseases after laparoscopic splenectomy]

Problems of assessment of life quality of children with benign hematological diseases (hereditary microspheric anemia, thalassemia, idiopathic thrombocytopenic purpura) after laparoscopic cholecystectomy are discussed. The standard SF-36 scale was used before and after endoscopic surgery. It is demonstrated that after reasonable laparoscopic splenectomy almost all parameters of life quality are improved. Improvement of physical parameters argues for small surgical trauma and slight postoperative period after laparoscopic splenectomy.

Treatment of hepatitis C virus infection in thalassemia

Treatment of hepatitis C virus (HCV) in the general population has improved over the last decade. Patients treated with peginterferon alfa (PegIFN) and ribavirin (RBV) combination therapy demonstrate overall 50-55% sustained viral response (SVR) with rates as high as 80% in patients with genotypes 2 and 3. Because RBV induces hemolysis and subsequently increases blood transfusion requirements, combination therapy has been considered contraindicated for hemoglobinopathies. This report reviews the response to interferon alfa and RBV (IFN/RBV) and PegIFN/RBV combination therapies in patients treated in the Northern California Comprehensive Thalassemia Center. A total of six thalassemia major patients were treated with IFN/RBV (n = 5; age: 4-38 years) or with PegIFN/RBV (n = 1; age: 26 years). Quantitative HCV RNA polymerase chain reaction and liver iron level assessment were completed. Transfusion volumes were obtained from patients' medical records. On IFN/RBV combination, four of five patients demonstrated SVR. The one patient on PegIFN/RBV showed end-treatment viral response after 6 months of therapy (genotype 3), but subsequently relapsed. Liver iron pretreatment level ranged from 0.2 to 22 mg/g dry weight, with a mean +/- SD of 7.9 +/- 7.7. Transfusion requirement increased by a median of 43.5% (range: 32-137%). Five of the six patients had liver iron measurements within 1 year following completion of treatment, with quantitative liver iron increasing in two patients by 2.5 mg/g dry weight, decreasing in two patients by 3 and 14 mg/g dry weight, and remaining unchanged in one patient. All patients were able to complete combination therapy, although dose reductions were required. Patients with thalassemia and high iron overload can obtain SVR after combination therapy with rates similar to those in the general population and without significant complications. Although transfusion requirements increased in most patients, iron burden was not necessarily increased.

Preimplantation genetics: Improving access to stem cell therapy

There has been progress in the application of stem cell transplantation for treatment of an increasing number of severe congenital and acquired bone marrow disorders, currently restricted by the availability of human leukocyte antigen (HLA)-matched related donors. Preimplantation HLA typing has recently been introduced to improve the access to stem cell therapy for inherited bone marrow failures. Preimplantation genetic diagnosis (PGD) provides an option not only for avoiding an affected pregnancy with thalassemia and other inherited disorders but also for preselection of the HLA-compatible donors for affected siblings. Multiple short tandem repeat markers throughout the HLA region are applied for this purpose, allowing 100% accuracy of HLA typing, through picking up possible recombination in the HLA region, as well as the copy number of chromosome 6, which affect accuracy of preimplantation HLA typing. Present experience of preimplantation HLA typing includes preimplantation HLA typing in 180 cycles, 122 of which were done as part of PGD for Fanconi anemia, thalassemia, Wiscott-Aldrich syndrome, hyper-immunoglobulin M syndrome, hypohidrotic ectodermal dysplasia with immune deficiency, and X-linked adrenoleukodystrophy, and 58 for the sole purpose of HLA typing for leukemias and for aplastic and Diamond-Blackfan anemia. The applied method resulted in the accurate preselection and transfer of 100% HLA-matched embryos, yielding already three dozen clinical pregnancies and the birth of two dozen HLA-matched children to the siblings requiring stem cell transplantation. Successful therapy with HLA-matched stem cells, obtained from these PGD children, has been achieved already for Diamond-Blackfan anemia hypohidrotic ectodermal dysplasia with immune deficiency and thalassemia.

Second allogeneic peripheral blood stem cell transplants with reduced-intensity conditioning

In two institutions in México, twelve patients were given a second allogeneic stem cell transplantation, using the "Mexican" non-myeloablative preparative regimen. Eight had a malignant condition (six acute leukemias, one myelofibrosis and one myelodysplasia), eleven individuals were allografted twice from the same donor and in one case, cells from two different umbilical cords were used. The median time to conduct the second allograft after the first one was 6 months (range 1-41). The five patients who failed to engraft after the first transplant failed also to engraft after the second one; all of them had been heavily transfused. Only three patients were successfully rescued with the second transplant, two with acute leukemia and one with aplastic anemia. Seven patients are alive 10-41 months (median 35) after the second transplant, but only three (25%) remain disease-free. The 52-month overall survival (SV) of the patients is 58%, whereas the median overall SV has not been reached, being above 52 months. Conducting a second allograft may be useful to rescue some individuals relapsing after a first hematopoietic allotransplant.

Measuring Chromosome Breaks in Patients with Thalassemia

Iron-mediated oxidative stress plays an important role in the pathophysiology of thalassemia. Oxidative stress can cause lesions in DNA, including double-strand breaks. DNA damage, which is a cause of cancer (although not the only one), is recognized as deleterious. Unlike cancer, DNA damage can be assayed easily and relatively inexpensively in humans. In this study, a sensitive micronucleus assay was used to measure the frequency of chromosomal breaks in patients with alpha- and beta-thalassemia. The micronucleus test is based on the observation that a secondary nucleus (micronucleus) is formed around a chromosomal fragment, outside the main nucleus of a dividing cell. Micronuclei are readily apparent in red blood cells (RBCs), which otherwise lack DNA. We combined an immunomagnetic separation technique with single-laser flow cytometry to isolate and analyze reticulocytes in peripheral blood for the presence of micronuclei before these cells are removed by the spleen. Blood samples were obtained from patients with thalassemia and healthy volunteers. After immunomagnetic enrichment of CD71-positive reticulocytes, the cells were stained for micronuclei using the DNA dye 7-aminoactinomycin D (7-AAD) and evaluated by flow cytometry. Our findings indicate that higher levels of micronuclei frequencies are present in thalassemic RBCs.

Coagulation and Splenectomy: An Overview

Venous thromboembolic events, such as pulmonary embolism, deep venous thrombosis, and portal vein thrombosis, have been observed in adult thalassemia patients, mainly in beta-thalassemia intermedia. The clinical findings are consistent with the observation of several alterations that indicate a state of activation of the hemostatic mechanisms in thalassemias. These alterations have usually been related to high platelet counts due to splenectomy and/or liver dysfunction. In a retrospective study of a large cohort of adults with thalassemia, we found a larger prevalence of venous thromboembolic events in transfusion-independent patients with thalassemia intermedia (29%) than in regularly transfused patients with thalassemia major (2%); moreover, the higher prevalence occurred particularly in splenectomized thalassemia intermedia patients. More recently, a multicenter study involving 56 tertiary referral centers in 7 countries was planned to assess the magnitude of thrombotic risk in thalassemia patients. The total number of patients who had thrombotic events was 146 (1.65%) out of 8860, with a prevalence of 0.9% in thalassemia major and 4% in thalassemia intermedia. The highest prevalence was confirmed in splenectomized patients. The observation that thrombotic events are more frequent in beta-thalassemia patients who are not receiving regular transfusions (thalassemia intermedia or thalassemia major patients in less developed countries with limited transfusion resources) or in thalassemic patients who have undergone splenectomy strongly supports the procoagulant activity of circulating damaged red blood cells.

Stem Cell Transplantation with S-59 Photochemically Treated T-Cell Add-Backs to Establish Allochimerism in Murine Thalassemia

Hematopoietic cell transplantation (HCT) from HLA-identical sibling donors has curative potential for beta-thalassemia. The probability of surviving free of thalassemia under these conditions is approximately 85%. The application of this therapy is limited because many patients lack an HLA-identical sibling donor. HLA-mismatched stem cell transplantation for thalassemia is severely restricted by graft rejection and the risks for graft-versus-host disease (GVHD). Thus, the development of a novel method that facilitates immunological tolerance and improves the safety of HLA-mismatched HCT would greatly expand the opportunity of HCT for thalassemia patients. We hypothesized that removal of T cells from the donor hematopoietic stem cell preparation and subsequent add-back after photochemical treatment with S-59, a psoralen, would promote and stabilize the engraftment and significantly reduce the risk of GVHD. This was tested in a MHC-mismatched HCT model of murine thalassemia. S-59-treated T cells were infused simultaneously with bone marrow-derived stem cells into mice with a heterozygous deletion of one beta-globin alleles that had been conditioned with a sublethal dose of total body irradiation. Mice that received treated T cells showed increased engraftment compared to those that did not receive T cells. T-cell treatment improved survival without GVHD compared to recipients that received untreated T cells. We conclude that photochemical treatment of T cells facilitates engraftment and minimizes GVHD in allo-HCT for murine thalassemia, and sets the stage for further development of such protocols for the treatment of patients with thalassemia.

Bone Marrow Transplantation in Adults with Thalassemia: Treatment and Long-Term Follow-Up

Current regular blood transfusion programs and chelation treatment have considerably improved survival of patients with thalassemia, which resulted in a larger proportion of adult patients. However, disease- and treatment-related complications in these patients progress over time, causing severe morbidity and shortened life expectancy. Stem cell transplantation still remains the only cure currently available for patients with thalassemia. This study updates transplant outcomes in 107 adult patients with median age of 22 years (range, 17-35 years) who received bone marrow transplantation (BMT) from human leukocyte antigen (HLA)-identical related donors between 1988 and 1996 (group A) and describes the results of BMT in 15 adult patients with median age of 21 years (range, 17-31 years) who were treated with a new treatment protocol (Protocol 26) between 1997 and 2003 (group B). The probability of survival, event-free survival, nonrejection mortality, and rejection for group A patients were 66%, 62%, 37%, and 4%, respectively, with a median follow-up of 12 years (range, 8.3-16.2 years). Group B patients treated with the new protocol had some improvement in thalassemia-free survival (67%) and lower transplant-related mortality (27%) than that of previous protocols. However, transplant-related mortality in these high-risk patients remains elevated. Current myeloablative BMT in adult patients is characterized by higher transplant-related toxicity due to an advanced phase of disease. Although this new approach to transplant adult patients with a reduced-dose intensity-conditioning regimen has improved thalassemia-free survival, transplant-related mortality in these high-risk patients remains elevated.

Laparoscopic splenectomy for hematological disorders

OBJECTIVES

The aim of this prospective study was to evaluate the safety and feasibility of laparoscopic splenectomy (LS) in patients with hematological disorders of the spleen.

SUBJECTS AND METHODS

Between 1999 and 2001, 15 patients (11 female and 4 male), with a mean age of 30 years, underwent LS after preoperative evaluation. If difficulties were encountered in LS, one trocar site incision was enlarged to 7-8 cm to engage the left hand for hand-assisted laparoscopic splenectomy (HALS) and the procedure was completed. Various parameters were reported, including spleen size as assessed by ultrasound scan, postoperative mortality and morbidity rates, accessory spleen removal, conversion rate, operative times and length of hospital stay. LS was successfully completed in 9 patients (60%) and HALS was performed in 4 patients (26.6%). Two patients required conversion to open splenectomy.

RESULTS

The mean operative time was 209 min and the mean hospital stay was 8.1 days. The hospital stay was significantly longer among HALS patients than LS patients. The mean age of patients and splenic size were associated with a significantly higher conversion rate. No deaths were attributed to the procedure. Complications occurred in 2 of 15 patients. Accessory spleens were identified in 2 patients.

CONCLUSIONS

LS is both a safe and feasible procedure, but it requires great technical care to avoid serious complications.

Thyroid, parathyroid, gonadal, and pancreatic β-cell function after bone marrow transplantation with chemotherapy-only conditioning

INTRODUCTION

Radiation and cytotoxic chemotherapy can provoke short- and long-term endocrine dysfunction. We studied the prevalence of thyroid, parathyroid, gonadal, and pancreatic beta-cell function in patients undergoing bone marrow transplantation (BMT).

MATERIALS AND METHOD

Forty-six patients (12 women, 34 men), aged 1.5 to 49 years (mean, 15.1 years), were evaluated for thyroid, parathyroid, gonadal, and pancreatic beta-cell function before and 3, 6, and 12 months after BMT with a little busulfan-cyclophosphamide conditioning regimen.

RESULTS

Thyroid and parathyroid function was unaltered by BMT. Leydig cell function was normal in 11 adult men (G5P5) before and at 3, 6, and 12 months after BMT, but injury to the germinal epithelium (oligo- or azoospermia) was seen before and 12 months after BMT. There was no relationship between serum FSH and germinal epithelial injury. Maturation was normal in six boys (G2P2 or G3P3 at BMT) 12 months post-BMT. Primary hypogonadism was seen in four adult women (B5P5) after BMT. One 14-year-old girl continued to have regular menstrual periods during the 24 months after BMT. Another girl (P1B1 pre-BMT) developed ovarian failure 12 months post-BMT. Pancreatic beta-cell function was normal pre- and post-BMT in 12 thalassemic patients with serum ferritin > 1000 ng/mL.

CONCLUSION

BMT with chemotherapy-only conditioning seems primarily to affect gonadal function, without having any significant effect on thyroid, parathyroid, or pancreatic beta-cell function.

Pediatric laparoscopic splenectomy: benefits of the anterior approach

INTRODUCTION

Splenectomy is frequently performed in children for various hematologic and autoimmune disorders. We reviewed our indication for splenectomy, our technique of laparoscopic, splenectomy, and our results. The aim of this study was to show if an anterior approach with elective vessel endoligature in a patient in decubitus position was a better and safer approach than the other techniques previously published.

PATIENTS AND METHODS

Between January 1996 and December 2002, 54 children underwent laparoscopic splenectomy. We use the anterior pedicle approach and elective vessel endoligature in order to prevent persistence of any exogenous material. Sixteen children also had a concomitant cholecystectomy. Their age ranged between 1 and 18 years (mean 7.5 years). Twenty children had hereditary spherocytosis, 15 were affected by sickle cell disease, six had an idiopathic thrombocytopenia, four had beta-thalassemia, and nine another hemolytic disease.

RESULTS

Mean operative time was 150 min (range, 115-230 min). Hospital stays ranged from 3 to 15 days (mean: 5.4). Seven patients had complications (four pneumonia and three deep abscess with successful antibiotic treatment). Median follow-up was 42 months (2 months-6 years) without problems regarding procedure.

DISCUSSION

With this technique consisting in first elective arterial and secondary venal ligature, we preserved blood splenic sequestration and pancreatic tail lesion. The procedure is safer. For us, considering the low complication rate for this type of patient, and the advantages of a small abdominal trauma in the postoperative period, laparoscopy with anterior approach for elective splenectomy and eventual cholecystectomy in hematologic disorders is the best technique.

Plasma pharmacokinetics of high-dose oral busulfan in children and adults undergoing bone marrow transplantation

We have analyzed the plasma pharmacokinetics of busulfan in 272 patients receiving high-dose oral busulfan and intravenous cyclophosphamide in conjunction with allogeneic or autologous bone marrow transplantation. The patients ranged in age from 2 months to 59 yr (mean 10, median 12 yr) and had the following diagnoses: thalassemia or sickle cell anemia (n = 74); leukemia or myelodysplasia (n = 112); inborn errors of metabolism (n = 41) or immunodeficiency (n = 45). Plasma specimens were collected following the first dose for each patient which ranged from 1 to 4 mg/kg (mean +/- SD, 1.21 +/- 0.41, median 1.15). Busulfan was quantitated using ultraviolet absorbance detection after derivatization and HPLC separation. Pharmacokinetic parameters were derived by modeling the raw data to fit first-order single compartment kinetics. The kinetic parameters showed wide interpatient variability independent of age and diagnosis. There was a statistically significant correlation of age with the following parameters: area under the curve (AUC); maximal concentration; minimum concentration; clearance; volume of distribution and absorption half-time. The coefficients of determination (i.e. correlation coefficient squared) were low ranging from 0.04 to 0.12 implying only a small part (i.e. 4-12%) of the variance was explained by age. Although busulfan pharmacokinetics are age-related most of the variability is not explained by age or diagnosis.

Extramedullary haemopoiesis in thalassemia intermedia presenting as paraplegia

Extramedullary haemopoiesis causing spinal cord compression is a rare manifestation of thalassemia. We describe a 17 year old male with thalassemia intermedia who presented with progressive paraplegia and sphincter disturbance. Magnetic resonance imaging revealed an epidural lesion extending from T5 to T8 compressing the spinal cord. The patient recovered completely after surgical decompression with postoperative radiation therapy. Histological examination of the lesion confirmed the diagnosis of extramedullary haemopoiesis. Clinical awareness of this phenomenon with early treatment is essential for optimizing the neurological outcome.

Splenectomy for children with thalassemia

Twenty-three children with thalassemia (18 with beta-thalassemia major, 3 with Hb H disease, and 2 with thalassemia intermediate) had total splenectomy (nine beta-thalassemia major patients and two thalassemia intermediate patients) or partial splenectomy (nine beta-thalassemia patients and three Hb H disease patients) as part of their management at our hospital. There were 10 males and 1 female in the total splenectomy group (mean age, 7.8 years; range, 4.5-12 years), and 4 males and 8 females in the partial splenectomy group (mean age, 6.9 years; range, 3-10 years). In all, the indication for splenectomy was hypersplenism. In the partial splenectomy group, two children with Hb H disease required no further blood transfusions. The transfusion requirements of the third patient with Hb H disease decreased from 15 to 11 transfusions per year (from 1.2 g/week Hb drop preoperatively to 0.7 g/week postoperatively), but subsequently his transfusion requirements increased as a result of an increase in the size of splenic remnant. He underwent total splenectomy 1.5 years post-partial splenectomy. For those with beta-thalassemia major who had partial splenectomy, there was a reduction in the number of blood transfusions from a preoperative mean of 15.2 transfusions per year (range, 11-22 transfusions per year) to a postoperative mean of 8.2 transfusions per year (range, 2-11 transfusions per year). Their Hb drop decreased from a preoperative mean of 1.6 g/week (range, 0.8-3.5 g/week) to a postoperative mean of 0.5 g/week (range, 0.2-0.75 g/week). Subsequently and as a result of increase in the size of splenic remnant, their transfusion requirements increased, but none of them to this point have required total splenectomy. Eleven children had total splenectomy. Their postsplenectomy transfusion requirements decreased from a preoperative mean of 17.8 transfusions per year (range, 12-23 transfusions per year) to a postoperative mean of 10 transfusions per year (range, 8-12 transfusions per year), and their Hb drop decreased from a preoperative mean of 1.8 g/week (range, 0.5-2.3 g/week) to a postoperative mean of 0.45 g/week (range, 0.3-0.65 g/week). In conclusion, total splenectomy is beneficial for children with thalassemia and hypersplenism because it reduces their transfusion requirements. Partial splenectomy may be beneficial for those with Hb H disease. However, for those with beta-thalassemia, partial splenectomy is beneficial in reducing their transfusion requirements only as a temporary measure, and it is recommended for children who are less than 5 years of age.

Risk of infection and death among post-splenectomy patients

OBJECTIVES

The true incidence of post-splenectomy sepsis remains undetermined.

METHODS

An English literature review on post-splenectomy sepsis was undertaken by means of databases of MEDLINE for the period 1966-96. The data registered included age at splenectomy, indication for splenectomy, incidence of infection and death, interval between splenectomy and infection, and microbial aetiology.

RESULTS

The reports include 19 680 patients having undergone splenectomy with a median follow up of 6.9 years. The incidence of infection after splenectomy was 3.2% and the mortality rate was 1.4%. Only 6942 reports were sufficiently detailed to allow useful analysis. The incidence of infection among children and adults was similar, 3.3% and 3.2%, respectively. However, the death rates among children were higher than adults (1.7% vs. 1.3%). The incidence of infection was highest among patients with thalassemia major (8.2%), and sickle-cell anaemia (7.3%). The highest mortality rates were observed among patients with thalassaemia major (5.1%), and sickle-cell anaemia (4.8%).

CONCLUSION

The incidence of sepsis among post-splenectomy patients is low, however, it carries a high mortality rate especially among children with hematological disorders.

Venous thromboembolism and hypercoagulability in splenectomized patients with thalassaemia intermedia

Thromboembolic phenomena have been described in patients with thalassaemia intermedia and major, although there are relatively few epidemiological data on the overall frequency of these complications. To obtain more insight into the risk and mechanism of venous thromboembolism in thalassaemia, the aims of this study were: (i) to establish retrospectively the prevalence of thromboembolic events in a large group of adults with thalassaemia intermedia and major during a follow up period of 10 years; (ii) to measure in subgroups of these patients sensitive markers of activation of coagulation and fibrinolysis enzymes; and (iii) to look for possible procoagulant mechanisms. A high prevalence of thromboembolic events was found, particularly in splenectomized patients with thalassaemia intermedia (29%). These patients had high plasma levels of markers of coagulation and fibrinolysis activation. Furthermore, thalassaemic red cells and erythroid precursors from splenectomized patients with thalassaemia intermedia had an enhanced capacity to generate thrombin. To evaluate the role of splenectomy per se on procoagulant activity, we evaluated the capacity to form thrombin in healthy individuals who had been splenectomized for trauma. They produced the same amount of thrombin as non-splenectomized controls. In conclusion, the results of this study show the existence of a hypercoagulable state in splenectomized patients with thalassaemia intermedia and that their red and erythroid cells are capable of acting as activated platelets in thrombin generation.

Lymphocyte subsets and specific T-cell immune response in thalassemia

Infection is very common in thalassemia and is one of the major causes of death. To date, it is not quite clear why these patients are susceptible to infection. In this study, lymphocyte immunophenotyping for CD3(+) (T-cells), CD3(+)CD4(+) (T-helper/inducer cells), CD3(+)CD8(+) (T-suppressor/cytotoxic cells), CD3(-)CD19(+) (B-cells), and CD3(-)CD16/56(+) (natural killer cells) subsets and expression of the activation antigen CD69 on CD3(+)CD4(+) and CD3(+)CD8(+) T-cells were determined in the whole blood of thalassemia patients, using a three-color flow cytometric technique. Results showed that only splenectomized beta-thalassemia/hemoglobin (Hb) E patients displayed a marked increase in absolute number of all lymphocytes. In addition, splenectomized beta-thalassemia/Hb E showed a significantly lower percentage of CD3(+) cells, with a corresponding increase in CD19(+) cells. These differences, when compared with normal subjects and other thalassemia patients, may be attributed to splenectomy. alpha-thalassemia patients, on the other hand, showed no significant difference from the normal group. While lymphocyte subsets in splenectomized beta-thalassemia/Hb E patients showed an abnormal distribution, T-cell activation in these patients was not different from the activation seen in normal subjects. This implies that thalassemia patients, during the steady state of disease, appear to have normal T-lymphocyte function with only moderate abnormalities of T- and B-lymphocyte subsets.

Cortisol and adrenocorticotropic hormone response to surgical stress (splenectomy) in thalassemic patients

Many vital organs, including the endocrine glands, are affected by iron deposition in thalassemic (Thal.) patients. Involvement of the adrenal gland, although not uncommon, is usually not clinically evident, especially in non-stressful situations. Although the pituitary-adrenal axis (PAA) has been evaluated by several investigators, the impact of surgical stress has not yet been assessed. Do Thal. patients have an adequate adrenocorticotropic hormone (ACTH) cortisol response upon surgical insult? The PAA of 27 (8 female, 19 male) Thal. patients aged 4-15 years (mean 8.96) admitted during 1996-1997 for splenectomy was evaluated before and after surgical stress. Blood samples for measurement of ACTH and cortisol were taken 1 day before and about 2 h after the surgical insult. For comparison, 22 (9 female, 13 male) non-thalassemic (N. Thal.) patients aged 3.5-14 years (mean 7.95) admitted for elective laparotomy who had no evidence of chronic disease or malnutrition served as controls. Timing of blood sampling was similar to that of the study group. The cortisol response after surgical stress was significantly higher than baseline for both the Thal. (17.4 +/- 6.3 vs 30.81 +/- 11.49 microg/dl; P < 0.001) and N. Thal. groups (20.65 +/- 9.1 vs 36.87 +/- 11.08 microg/dl; P < 0.001). N. Thal. patients showed significant elevation of ACTH upon surgical stress (72.5 +/- 39.5 vs 129.09 +/- 67.9 pg/ml; P < 0.001), while the difference between pre- and post-stress was not statistically remarkable in Thal. patients (104.15 +/- 60.74 vs 186.8 +/- 246.24 pg/ml; P = 0.123). However, ACTH before operation in Thal. was significantly higher than that of N. Thal. patients (104.15 +/- 60.74 vs 72.5 +/- 39.5 pg/ml; P < 0.042), with no remarkable difference after surgical stress between both groups (186.8 +/- 246.24 vs 129.09 +/- 67.9; P = 0.261). The serum ferritin in 8 of 13 young Thal. patients (4-8 years old) was < 2,000 ng/ml and 2,000-3,000 in the remaining 5, while in the 14 older patients (9-15 years) it was < 2,000 in 5, 2,000-3,000 in 7, and more than 3,000 ng/ml in the oldest 2 (13 and 15 years). The PAA is usually intact and responsive in Thal. patients. However, the underlying cause of the significantly increased preoperative ACTH concentrations may be a decreased adrenal reserve, presumably related to age and iron load. For this reason, the possibility of primary partial or early adrenal insufficiency in spite of adequate but probably less than expected cortisol synthesis before and after surgical stress should be considered in every prepubertal or older Thal. patient.

Is splenectomy for massive splenomegaly safe in children?

PURPOSE

To study and analyze the causes, etiology, morbidity, mortality and therapeutic value of splenectomy performed for massive splenomegaly in children.

METHODS

The medical records of 115 children less than 18 years old who had splenectomy for various hematological disorders were reviewed. Twenty of them had splenectomy for massive splenomegaly (spleen weight > or =1,000 g). The records of these were reviewed for age at operation, gender, hematological diagnosis, indication for splenectomy, operative procedures, postoperative complications, and outcome.

RESULTS

Twenty children had splenectomy for massive splenomegaly. There were 16 males and 4 females. Their ages ranged from 4 to 15 years (mean 11.2). Twelve had sickle cell disease, 5 had sickle-beta-thalassemia, 1 had beta-thalassemia major, 1 had thalassemia intermediate, and 1 had chronic myeloid leukemia. The indications for splenectomy were hypersplenism in 11, recurrent splenic sequestration crisis in 8, and splenic abscess in 1. The transfusion requirements in the patient with beta-thalassemia major decreased markedly postoperatively from 18 transfusions/year to only 4 transfusions/year; and for those with hypersplenism, there was a marked improvement in their blood parameters following splenectomy. The patient with thalassemia intermediate required no more blood transfusions. There was no mortality. The immediate postoperative morbidity was 10% for those with massive splenomegaly compared with 6.3% for those with splenomegaly <1,000 g.

CONCLUSIONS

With good perioperative management, splenectomy in children with massive splenomegaly is both safe and effective.

Levels of serum interleukin-6 and tumor necrosis factor in postsplenectomized thalassemic patients

Levels of serum interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-alpha) were studied in 34 nonsplenectomized thalassemic patients (Thal/nonsplenec), 43 postsplenectomized thalassemic patients (Thal/postsplenec), 13 splenectomized non-thalassemic patients (nonThal/ postsplenec) and 18 normal control by enzyme linked immunosorbent assay method. Serum IL-6 concentration in Thal/postsplenec was significantly increased when compared with Thal/ nonsplenec and normal volunteers (3.55 +/- 2.47 pg/ml vs 2.38 +/- 2.31 pg/ml, p = 0.036 and 3.55 +/- 2.47 pg/ml vs 2.66 +/- 0.45 pg/ml, p = 0.028, respectively). This study also demonstrated that TNF-alpha value in Thal/postsplenec was drastically increased above normal control level (15.8 +/- 4.86 pg/ml vs 9.16 +/- 2.18 pg/ml, p = 0.001) and the level was statistically significantly higher than that in Thal/ nonsplenec (15.5 +/- 4.86 pg/ml vs 9.96 +/- 5.19 pg/ml, p = 0.001). There was a trend toward increasing of cytokine levels in Thal/postsplenec with higher platelet count although no correlation was observed. This study addresses the possible role of IL-6 and TNF-alpha in the pathogenesis of reactive thrombocytosis in Thal/postsplenec.

The instability of the membrane skeleton in thalassemic red blood cells

The thalassemias are a heterogeneous group of disorders characterized by accumulation either of unmatched alpha or beta globin chains. These in turn cause the intramedullary and peripheral hemolysis that leads to varying anemia. A partial explanation for the hemolysis came our of our studies on material properties that showed that beta-thalassemia (beta-thal) intermedia ghosts were very rigid but unstable. A clue to this instability came from the observation that the spectrin/band 3 ratio was low in red blood cells (RBCs) of splenectomized beta-thal intermedia patients. The possible explanations for the apparent decrease in spectrin content included deficient or defective spectrin synthesis in thalassemic erythroid precursors or globin chain-induced membrane changes that lead to spectrin dissociation from the membrane during ghost preparation. To explore the latter alternative, samples from different thalassemic variants were obtained, ie, beta-thal intermedia, HbE/beta-thal, HbH (alpha-thal-1/alpha-thal-2), HbH/Constant Spring (CS), and homozygous HbCS/CS. We searched for the presence of spectrin in the first lysate of the standard ghost preparation. Normal individuals and patients with autoimmune hemolytic anemia, sickle cell anemia, and anemia due to chemotherapy served as controls. Using gradient sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis, no spectrin was detected in identical aliquots of the supernatants of normals and these control samples. Varying amounts of spectrin were detected in the first lysate supernatants of almost all thalassemic patients. The identification of spectrin was confirmed by Western blotting using an affinity-purified, monospecific, rabbit polyclonal antispectrin antibody. Relative amounts of spectrin detected were as follows in decreasing order: splenectomized beta-thal intermedia including HbE/beta-thal; HbCS/CS; nonsplenectomized beta-thal intermedia, HbH/CS; and, lastly, HbH. These findings were generally confirmed when we used an enzyme-linked immunosorbent assay technique to measure spectrin in the first lysate. Subsequent analyses showed that small amounts of actin and band 4.1 also appeared in lysates of thalassemic RBCs. Therefore, the three major membrane skeletal proteins are, to a varying degree, unstably attached in severe thalassemia. From these studies we could postulate that membrane association of abnormal or partially oxidized alpha-globin chains has a more deleterious effect on the membrane skeleton than do beta-globin chains.

Does furosemide prevent hypertension during perioperative splenectomy in thalassemic children?

Hemodynamic changes of 50 thalassemic children who had splenectomy under general anesthesia were compared to 40 identical patients who, in addition, received intravenous furosemide 1 mg/kg immediate preoperation. During the anesthetic process, both groups showed a significant increase of heart rate, systolic and diastolic blood pressure more than the preanesthetic values. Hemodynamic variables in the furosemide group declined toward normal range on termination of anesthesia, whereas, the other group's variables were still significantly higher than their control. During the first 24 hours postoperatively, 20 per cent of the furosemide group had blood pressure rising higher than 130/90 mmHg, while 18 per cent was observed in the other group. Antihypertensive drugs were given to reduce the blood pressure in both groups. None of the patients in the furosemide group demonstrated any abnormal neurological symptoms, but 3 out of 50 patients in the other group developed convulsion. We, therefore, conclude that circulatory volume reduction with furosemide does not prevent hypertension during perioperative splenectomy in thalassemic children. However, it's role in prevention of neurological abnormalities needs to be further investigated.

Growth and endocrine function following bone marrow transplantation for thalassemia

Twenty two patients with thalassemia major who received successful bone marrow transplantation (BMT) were followed to verify the impact of the transplant procedure on subsequent growth and development. The transplant preparative regimen consisted of busulphan and cyclophosphamide. Growth and endocrinological function were assessed during the first 4 years following BMT. At the time of transplant most patients showed growth retardation. The median difference between chronological age and bone age was -9.5 months for the boys and -8.5 months for the girls. Patients > 7 years old at the time of BMT showed a significant worsening of their growth delay at 48 months following BMT compared with 12 months before transplantation. Patients < 7 years at the time of BMT had their growth retardation constant over time span after transplantation. Moreover six of 11 younger patients showed an improvement of their growth delay compared with one of 11 older patients. The outcome of height standard deviation score at 24 and 48 months following BMT was strictly correlated with the level of serum transaminases and ferritin. Sixteen patients had impaired growth hormone secretion after a provocative test evaluated at 24 months after transplant. At 48 months there was no significant increase in the mean peak GH levels. This study confirms that the growth retardation of patients with thalassemia major is multifactorial.

Hypertension perioperative splenectomy in thalassemic children

We retrospectively studied the intraoperative hemodynamic changes in 100 thalassemic children undergoing general anesthesia for elective splenectomy. They were divided into 2 groups owing to the postoperative hemodynamic response. Eighty-four patients who had an unremarkable postoperative course were group 1, while 16 patients who developed immediate postoperative hypertension were group 2. There were no differences between the groups regarding age, body weight, sex, anesthetic time and operation time, except for the preoperative hematocrits of group 1 patients were slightly but significantly higher. Both groups similarly showed significant increase of the systolic as well as diastolic blood pressure throughout the anesthetic course. The heart rate was significantly increased at the beginning but declined to normal toward the end of the operation. Although none of the patients died postoperatively, all of group 2 patients needed aggressive treatment with diuretic and antihypertensive drugs. Despite the proper management, 3 of 16 patients developed convulsion and one of them had persistent neurological deficit. Since intraoperative and postoperative hypertension which commonly occur in these patients may lead to more serious neurological complications, the authors suggest that careful hemodynamic monitoring must be considered for all thalassemic children undergoing general anesthesia for splenectomy.

Bone marrow transplant for the haemoglobinopathies: past, present and future

Bone marrow transplantation (BMT) is the only treatment currently available which can cure thalassaemia and sickle cell anaemia. However, it is not without risk and the complications of graft failure, GVHD, veno-occlusive disease, interstitial pneumonitis and infections, together with the toxicity of the conditioning therapy result in a transplant-related mortality in children of 10-20%. For the survivors, long-term sequelae include chronic GVHD, endocrinopathies and an increased incidence of secondary malignancies. The decision to offer BMT to a patient with a haemoglobinopathy must be based on a knowledge of the relative risks of transplant and conventional therapy. However, in sickle cell anaemia, a subset of patients with particularly severe disease can be identified at an early age when the risks associated with BMT are at their lowest. In thalassaemia, chelation therapy can delay the onset of organ damage due to hypertransfusion but is unlikely to prevent it entirely. The results of BMT in children without organ impairment are excellent and BMT must now be considered a real alternative to conventional treatment. Gene therapy is an exciting prospect for the future but recent progress in retroviral gene transfer has been hindered by poor infection efficiencies and expression levels in the target cells. The identification of the positive regulatory elements of both the alpha- and beta-globin genes may resolve some of these problems. Finally, alternative gene delivery systems are being investigated, but the introduction of gene therapy for the haemoglobinopathies into clinical practice may need to await successful gene targeting and replacement.

Second bone marrow transplantation in eight children

Between 1985 and 1989, eight children underwent two successive bone marrow transplantations. The initial disease was chronic myelomonocytic leukemia in three patients, chronic myelocytic leukemia in two, acute M7 nonlymphoblastic leukemia in one, sickle cell anemia in one, and thalassemia major in one. The preparation in view of the second grafting included high-dose chemotherapy in all patients, associated with antithymocytic globulin transfusion and total nodal irradiation in three patients. Hematological recovery was similar after both graftings. Infectious complications were not more common following the second graft than after the first one. On the other hand, the rates of rejection and graft-versus-host disease were lower, probably due to a more intensive immunosuppressive therapy. The prognosis of chronic leukemia relapsing after a first graft does not seem to be improved by a second attempt.

Bone marrow transplantation in adult thalassemia

Early trials of allogeneic marrow transplantation for homozygous thalassemia were disappointing in patients older than 16, with four of six patients dying early of graft-versus-host disease-related complications, one patient dying at 9 months of infection due to graft failure, and one dying at 6 years of recurrent thalassemia. Three classes of risk could be identified in analyses of results of transplantation in younger patients using the criteria of degree of hepatomegaly, the presence or absence of portal fibrosis, and a history of adequate or inadequate chelation therapy. Patients for whom all three criteria were adverse constituted a very high risk group (class 3) for marrow transplantation. On the basis of these analyses, a conditioning regimen was designed that yielded superior results for class 3 patients under 17 years of age. Most patients older than 16 years presenting for transplantation have disease characteristics that place them in class 3 and, because of the improved results with the new class 3 regimen in younger patients, a study was designed to treat patients older than 16 years using treatment regimens assigned on the basis of disease class. Twenty patients were treated using this protocol and, with a minimum follow-up of 9 months, there have been three early deaths, one patient has recurrent thalassemia, and 16 patients are alive disease-free. The actuarial probabilities of survival, disease-free survival, and rejection are 0.85, 0.80, and 0.05, respectively, with a survival plateau extending from 6 months to 3 years. Marrow transplantation is a reasonable option for adults with progressive thalassemia who have suitable donors.