Gonadal function after allogenic bone marrow transplantation for thalassaemia

Iron overload disorders: Growth and gonadal dysfunction in childhood and adolescence

Hemochromatosis (HC) is characterized by the progressive accumulation of iron in the body, resulting in organ damage. Endocrine complications are particularly common, especially when the condition manifests in childhood or adolescence, when HC can adversely affect linear growth or pubertal development, with significant repercussions on quality of life even into adulthood. Therefore, a timely and accurate diagnosis of these disorders is mandatory, but sometimes complex for hematologists without endocrinological support. This is a narrative review focused on puberty and growth disorders during infancy and adolescence aiming to offer guidance for diagnosis, treatment, and proper follow-up. Additionally, it aims to highlight gaps in the existing literature and emphasizes the importance of collaboration among specialists, which is essential in the era of precision medicine.

Fertility preservation for pediatric patients with hemoglobinopathies: Multidisciplinary counseling needed to optimize outcomes

Hemoglobinopathies are autosomal recessive disorders that occur when genetic mutations negatively impact the function of hemoglobin. Common hemoglobinopathies that are clinically significant include sickle cell disease, alpha thalassemia, and beta thalassemia. Advancements in disease-modifying and curative treatments for the common hemoglobinopathies over the past thirty years have led to improvements in patient quality of life and longevity for those who are affected. However, the diseases, their treatments and cures pose infertility risks, making fertility preservation counseling and treatment an important part of the contemporary comprehensive patient care. Sickle cell disease negatively impacts both male and female infertility, primarily by testicular failure and decreased ovarian reserve, respectively. Fertility in both males and females with beta thalassemia major are negatively impacted by iron deposition due to chronic blood transfusions. Hematopoietic stem cell transplant (HSCT) is currently the only curative treatment for SCD and transfusion dependent beta thalassemia. Many of the conditioning regimens for HSCT contain chemotherapeutic agents with known gonadotoxicity and whole-body radiation. Although most clinical studies on toxicity and impact of HSCT on long-term health do not evaluate fertility, gonadal failure is common. Male fertility preservation modalities that exist prior to gonadotoxic treatment include sperm banking for pubertal males and testicular cryopreservation for pre-pubertal boys. For female patients, fertility preservation options include oocyte cryopreservation and ovarian tissue cryopreservation. Oocyte cryopreservation requires controlled ovarian hyperstimulation (COH) with ten to fourteen days of intensive monitoring and medication administration. This is feasible once the patient has undergone menarche. Follicular growth is monitored via transvaginal or transabdominal ultrasound, and hormone levels are monitored through frequent blood work. Oocytes are then harvested via a minimally invasive approach under anesthesia. Complications of COH are more common in patients with hemoglobinopathies. Ovarian hyperstimulation syndrome creates a greater risk to patients with underlying vascular, pulmonary, and renal injury, as they may be less able to tolerate fluids shifts. Thus, it is critical to monitor patients undergoing COH closely with close collaboration between the hematology team and the reproductive endocrinology team. Counseling patients and families about future fertility must take into consideration the patient's disease, treatment history, and planned treatment, acknowledging current knowledge gaps.

Ellagic acid effects on testis, sex hormones, oxidative stress, and apoptosis in the relative sterility rat model following busulfan administration

BACKGROUND

Busulfan is an antineoplastic medication that is broadly utilized for cancer treatment. It affects the testicular function and leads to sterility. The present study aimed to evaluate the effects of ellagic acid on testicular tissue changes, sexual hormones, antioxidant defense system, and caspase-9 and Bcl2 gene expression in the busulfan-induced relative sterile rat model.

METHODS

This is an interventional-experimental animal study that was performed on 65 Adult male rats; they were randomly divided into five groups including control (1 ml of 0.9% normal saline), ellagic acid (50 mg/kg); busulfan (10 mg/kg); and busulfan plus ellagic acid (10 mg/kg and 50 mg/kg). At the end of the experiment, blood samples were collected, and plasma levels of sex hormones, antioxidant system, apoptosis-related genes, and testis histology were assessed.

RESULTS

Busulfan reduced the levels of serum testosterone, total antioxidant capacity, gene expression of Bcl2, testicular volume, seminiferous tubule, germinal epithelium, interstitial tissue volume, and the number of spermatogonia, spermatocyte, round spermatid, elongated spermatid, Sertoli cells and Leydig cells (p < 0.05). Busulfan administration resulted in a significant increase (p < 0.05) in the level of LH, FSH, malondialdehyde, and caspase 9. Busulfan + ellagic acid (50 mg/kg) showed higher serum levels of testosterone, gene expression of Bcl-2 and antioxidant markers, and lower LH, FSH levels, and gene expression of caspase 9 compared to the Busulfan-treated rats (p < 0.05). Stereological parameters were also ameliorated in the group treated with Busulfan+ 50 mg/kg ellagic acid (p < 0.05).

CONCLUSION

In conclusion, the consumption of ellagic acid may have beneficial effects on the antioxidant defense system, sexual hormone abnormality, and testicular tissue damage induced by busulfan.

A Short Review on Growth and Endocrine Long-term Complications in Children and Adolescents with β-Thalassemia Major: Conventional Treatment versus Hematopoietic Stem Cell Transplantation

The conventional treatment of β-thalassemia (β-TM) patients is based on the correction of anemia through regular blood transfusions and iron chelation therapy. However, allogeneic hematopoietic stem cell transplantation (HSCT) remains the only currently available technique that has curative potential. Variable frequency and severity of long-term growth and endocrine changes after conventional treatment as well as after HSCT have been reported by different centers. The goal of this mini-review is to summarize and update knowledge about long-term growth and endocrine changes after HSCT in patients with β-TM in comparison to those occurring in β-TM patients on conventional treatment. Regular surveillance, early diagnosis, treatment, and follow-up in a multi-disciplinary specialized setting are suggested to optimize the patient's quality of life (www.actabiomedica.it).

Curative therapy for hemoglobinopathies: an International Society for Cell & Gene Therapy Stem Cell Engineering Committee review comparing outcomes, accessibility and cost of ex vivo stem cell gene therapy versus allogeneic hematopoietic stem cell transplantation

Thalassemia and sickle cell disease (SCD) are the most common monogenic diseases in the world and represent a growing global health burden. Management is limited by a paucity of disease-modifying therapies; however, allogeneic hematopoietic stem cell transplantation (HSCT) and autologous HSCT after genetic modification offer patients a curative option. Allogeneic HSCT is limited by donor selection, morbidity and mortality from transplant conditioning, graft-versus-host disease and graft rejection, whereas significant concerns regarding long-term safety, efficacy and cost limit the broad applicability of gene therapy. Here the authors review current outcomes in allogeneic and autologous HSCT for transfusion-dependent thalassemia and SCD and provide our perspective on issues surrounding accessibility and costs as barriers to offering curative therapy to patients with hereditary hemoglobinopathies.

Indicators of male fertility potential in adult patients with beta-thalassemia major: a comparative study between patients undergone allogeneic stem cell transplantation and transfusion-dependent patients

BACKGROUND

Allogeneic hematopoietic stem cell transplantation (HSCT) remains the only potentially curative treatment for thalassemia major (TM). Infertility and its indicators have been assessed in transfusion dependent TM men, but in this study, we sought to compare the fertility indicators of TM patients after HSCT with those in patients treated conventionally. The possible influential factors on reproductive capacity in TM patients undergone allogeneic HSCT were also evaluated.

PATIENTS AND METHODS

In this cross-sectional study, we compared the gonadal hormones level, testicular volume, Tanner stage and sperm analysis in transfusion-dependent thalassemia major (TDTM) patients who survived matched sibling HSCT (n = 43) with patients conventionally treated by transfusion and iron chelation (n = 52).

RESULTS

The patients' age range was between 16 to 41 years. Tanner stage 4-5 was seen in 39 patients (41%). The prevalence of hypogonadism in our patients was 32.63% but its frequency was not significantly different between the two groups (p = 0.35). Azospermia, oligospermia, astenospermia, teratospermia and even having dry and low volume ejaculate were all significantly more frequent in the post-transplant patients compared to TDTM group. In the post-HSCT group, neither patients' age at transplantation nor the conditioning regimen used in their transplant process did significantly affect their hormonal status and sperm parameters. Chronic graft versus host disease (GVHD) occurred in 14 (40%) patients. No significant difference was observed between the grade of chronic GVHD and hypogonadism (P = 0.853).

CONCLUSIONS

Thalassemia patients undergone allogeneic HSCT have lower fertility potential, mainly in sperm parameters compared with patients treated with blood transfusion and chelation. This information is important for thalassemic patients considering HSCT.

Current Results and Future Research Priorities in Late Effects after Hematopoietic Stem Cell Transplantation for Children with Sickle Cell Disease and Thalassemia: A Consensus Statement from the Second Pediatric Blood and Marrow Transplant Consortium International Conference on Late Effects after Pediatric Hematopoietic Stem Cell Transplantation

Sustained donor engraftment after allogeneic hematopoietic cell transplantation (HCT) converts to healthy donor hemoglobin synthesis and halts disease symptoms in patients with sickle cell disease and thalassemia major. A disease-free survival probability that exceeds 90% has been reported when HCT using an HLA-matched sibling donor is performed in young patients with low-risk disease or treatment-related risk factors. Alternate donor HCT and HCT in adults is performed infrequently because of a higher risk profile. Transplant-specific risks include conditioning regimen-related toxicity, graft-versus-host disease, graft rejection with marrow aplasia or disease recurrence, and infections associated with immunosuppression and delayed immune reconstitution. The magnitude of risk depends on patient age, clinical status of the underlying disease (eg, organ injury from vasculopathy and iron overload), donor source, and intensity of the conditioning regimen. These risks are commonly monitored and reported in the short term. Documenting very late outcomes is important, but these data are rarely reported because of challenges imposed by patient drop-out and insufficient resources. This report summarizes long-term follow-up results after HCT for hemoglobin disorders, identifies gaps in knowledge, and discusses opportunities for future investigations. This consensus summary will be followed by a second article detailing comprehensive long-term follow-up recommendations to aid in maintaining health in these individuals and identifying late complication risks that could facilitate interventions to improve outcomes.

Hypogonadism in thalassemia major patients

Despite recent advances in iron chelation therapy, excess iron deposition in pituitary gonadotropic cells remains one of the major problems in thalassemic patients. Hypogonadism, mostly hypogonadotropic hypogonadism, is usually detected during puberty. Early diagnosis and treatment are crucial for normal pubertal development and to reduce the complications of hypogonadism. The risks and benefits of hormonal replacement therapy, especially regarding the thromboembolic event, remain a challenge for providers caring for thalassemic patients.

Evaluating the patients with thalassemia major for long-term endocrinological complications after bone marrow transplantation

The aim of this study was to evaluate the endocrinological complications of the patients with thalassemia major (TM) who underwent bone marrow transplantation (BMT) and followed-up more than two years in our center, prospectively. "BMT group" consisted of 41 patients with TM. The mean age was 12.4 ± 5.4 years and transplantation age was mean 7.5 ± 4.9 years. Post-BMT follow-up lasted from 24 to 122 months (mean 65.07 months). Also, 32 TM patients with similar age group and same history of transfusion and chelation therapy were recruited for the study as "control (C) group". The weight SDS score after transplantation was found better than before transplantation (p = 0.010). There was a negative correlation between height SDS and BMT age (p = 0.008). The height SDS scores were better in patients whose BMT age was under seven years old compared to those older than seven years old (p = 0.02). Z-scores of femur neck and L2-4 vertebrae DEXA were decreased (p = 0.032, p = 0.0001) and incidence of insulin resistance increased (p = 0.01) in patients with increased BMT age. The risk of gonadal insufficiency was significantly lower in the patients who underwent BMT <7 years of age (p = 0.009). There was no statistically significant relationship between BMT age and complications such as hypothyroidism, hypoparathyroidism, and adrenal insufficiency. The patients with TM should be evaluated for transplantation in early stage of the disease, especially before the age of seven years. Because the BMT cannot correct the endocrinological complications of TM completely, the patients should be followed up regularly after the transplantation.

Endocrine complications after busulphan and cyclophosphamide based hematopoietic stem cell transplant: A single tertiary care centre experience

INTRODUCTION

Endocrine complications are common after hematopoietic stem cell transplant (HSCT). Although HSCT is performed at various centers in India, no study is available for endocrine dysfunctions among them. This study was carried out with the objective to evaluate endocrine dysfunction among patients undergone HSCT in the past.

MATERIALS AND METHODS

We carried out a cross-sectional study in a 50 post-HSCT recipients (39 allogenic, 11 autologous). All relevant data were collected from patient's records. Samples for hormonal estimation were collected and stimulation tests for cortisol and growth hormone were interpreted based on peak values achieved during insulin tolerance test.

RESULTS

The mean age of patients was 26.3 ± 16.9 years (range 4-74). Adrenal insufficiency (AI) was present in 60%, hypergonadotropic hypogonadism (HH) in 60%, growth hormone deficiency (GHD) in 54%, hypothyroidism in 4%, hyperprolactinemia in 4%, new onset diabetes after transplant in 4%, and impaired fasting glucose in 6%. Multiple endocrine complications were common. GHD was present in 77% of children (n = 22) although height standard deviation score was not statistically different compared to those who didn't have GHD. HH was present in 36% of children. In adults (n = 28), 36% had GHD, all females had HH, and 89% of males had HH. Germ cell dysfunction with compensated Leydig cell dysfunction was the most common pattern of HH in males. Fifteen patients had graft versus host disease (GVHD). GVHD had no bearing on development of endocrine deficiencies. AI was related to duration after and type of transplant, but was unrelated to steroid intake.

CONCLUSIONS

Endocrine manifestations are common after HSCT; they can occur as early or late complications. All HSCT recipients should have endocrine evaluation as per prevailing guidelines.

Gonadal function of beta-thalassemics following stem cell transplantation conditioned with myeloablative and reduced intensity regimens

Gonadal dysfunction is a complication following stem cell transplantation (SCT). There have been no reports of gonadal function in stem-cell-transplanted thalassemic survivors who received a reduced intensity conditioning regimen (RIC). We evaluated gonadal function in 47 β-thalassemic patients following SCT with either myeloablative or reduced intensity regimen. Thirty-six patients received a myeloablative regimen, the remaining 11 patients had an RIC regimen. Their median (range) age was 13.2 (5.9-25.8) years. There were 29 patients (62%) with gonadal dysfunction (26 with primary gonadal dysfunction and three with gonadotropin deficiency). Comparisons between patients who received myeloablative and RIC regimens, revealed no differences in gonadal dysfunction (56% vs. 82%, p=0.113, respectively). In conclusion, our study demonstrated high frequency of gonadal dysfunction in these patients. Even after receiving RIC, gonadal dysfunction was very common. To our knowledge, this study is the first to report gonadal function in children and adolescents with β-thalassemia disease who were pre-transplanted with RIC.

Human chorionic gonadotropin therapy in adolescent boys with constitutional delayed puberty vs those with beta-thalassemia major

We studied 12 adolescent boys with beta-thalassemia major and delayed puberty (age, 15.8 +/- 1 years) with Tanner I sexual development treated with a long-term low-transfusion regimen. Ten nonthalassemic adolescents (> 14 years) with constitutional delay of growth and puberty (CDGP) served as controls. Auxologic parameters and testicular size were measured, and bone age was determined. Measurement of basal gonadotropin (luteinizing hormone [LH] and follicle-stimulating hormone [FSH]) and testosterone (T) levels taken at 8 am revealed prepubertal levels in both groups of patients. Human chorionic gonadotropin (hCG, 2500 U/m(2)) was injected intramuscularly twice weekly for 6 months, and anthropometric data, testicular diameter, and serum T concentrations were remeasured after 1 and 6 months. The testicular diameter after 6 month of hCG therapy was significantly correlated with the testicular diameter and T level after 1 month of therapy (r = 0.93 and 0.39, respectively, P < .01). After 6 months of hCG therapy, the mean growth velocity (GV) increased from 4.1 to 8.6 cm/y in thalassemic patients and from 4.6 to 10.3 cm/y in those with CDGP during hCG therapy. In thalassemic boys, the mean T concentration increased from 0.93 to 2.7 nmol/L (mean increase = 1.8 nmol/L) vs an increase from 0.47 to 4.81 nmol/L (mean increase = 4.32 nmol/L) in those with CDGP. All adolescents with CDGP, but only 7 the 12 thalassemic adolescents, had T secretion above 2 nmol/L after 6 months of hCG therapy and maintained their growth and pubertal development for a year after stopping hCG. The 5 thalassemic patients with defective T secretion after hCG therapy had significantly higher ferritin level (1985 +/- 658 ng/mL) vs the other 7 patients (1100 +/- 425 ng/mL). These findings denoted significant testicular dysfunction in those patients with higher iron overload (testicular siderosis). Statural GV was significantly correlated with insulin-like growth factor 1 (IGF-1) concentrations and testicular diameter after hCG therapy (r = 0.5 and 0.43 respectively, P < .001). In summary, hCG therapy was effective in treating 7 of 12 (58%) of thalassemic adolescents with delayed puberty. In the rest of patients (5/12, 46%) with significantly higher iron overload, hCG therapy failed to stimulate testicular growth and adequate T. Proper iron chelation appears to protect against testicular dysfunction. In the first group of patients, hCG therapy can be used for the treatment of their hypogonadism, whereas T replacement remains the therapy of choice for the second group.

Endocrine complications of high-dose therapy with stem cell transplantation

Evaluations of endocrine function following hematopoietic cell transplantation demonstrate that the endocrine function abnormalities observed are related to the type of transplant preparative regimen received. Children given high dose cyclophosphamide (CY) only have normal thyroid function, normal growth and development. Children who received a busulfan (BU) plus CY preparative regimen usually have normal thyroid function, normal prepubertal growth, delayed or absent pubertal development, and blunted post-pubertal growth. Recipients of preparative regimens containing total body irradiation may be anticipated to have some thyroid dysfunction, impaired growth rates and delayed or absent pubertal development. Post-pubertal teens and young adults are likely to have gonadal function recover if they received a preparative regimen with CY only but are likely to have primary gonadal failure if they received a preparative regimen with BU or total body irradiation. Individuals whose gonadal function becomes normal have become parents of normal children. All patients who receive a marrow transplant should be followed long-term for development of endocrine function abnormalities.

Disturbances of growth and endocrine function after busulphan-based conditioning for haematopoietic stem cell transplantation during infancy and childhood

It is generally assumed that busulphan/cyclophoshamide (Bu/Cy)-based conditioning regimens for haematopoietic stem cell transplantation (SCT) do not affect growth. We evaluated growth and endocrine function after Bu/Cy-based conditioning in 64 children without a history of irradiation. Mean height standard deviation scores remained stable, but unexplained disturbances of growth after SCT were found in 17/48 (35%) of the children without growth-limiting disorders (10/23 in patients treated for haematological malignancies). In 10 patients, growth hormone (GH) secretion status was evaluated, and insufficient GH secretion was diagnosed in four patients. Thyroid function was evaluable in 52 patients. Two developed antibody-mediated thyroid disorders and 10 (19%) compensated primary hypothyroidism. Gonadal function was evaluable in 21 patients and was normal in all seven patients treated with low-dose Bu (8 mg/kg), whereas seven of the 14 children receiving high-dose Bu (16-20 mg/kg) developed gonadal failure; the majority of these patients had not been exposed to gonadotoxic therapy prior to Bu/Cy. Of the 49 evaluable patients, 16 developed subclinical hyperparathyroidism. We conclude that, besides gonadal and thyroid dysfunction, impaired growth and hyperparathyroidism often occur after Bu/Cy conditioning for SCT and that growth impairment may be the result of insufficient GH secretion.

Bone marrow transplantation for beta-thalassaemia major: the UK experience in two paediatric centres

Stem cell transplantation (SCT) remains the only cure for thalassaemia major. Recent advances in medical treatment make it even more important that accurate information is available regarding outcome of SCT in relevant patient populations in order to guide informed decisions regarding the most appropriate treatment for individual thalassaemia patients. We report the results of 55 consecutive first related allogeneic bone marrow transplants (BMT) for children with beta-thalassaemia major performed in two UK paediatric centres over 10 years. Between February 1991 and February 2001, 55 children underwent 57 allogeneic BMT. The median age at BMT was 6.4 years and the majority of patients (73%) originated from the Indian subcontinent. Using the Pesaro risk classification, 17 patients were class 1, 27 were class 2 and 11 were class 3. Actuarial overall survival and thalassaemia-free survival at 8 years were 94.5% (95% CI 85.1-98.1) and 81.8% (95% CI 69.7-89.8) respectively. Despite the majority of patients being in class 2 or 3, transplant-related mortality was low (5.4%). The principal complication was graft rejection accompanied by autologous reconstitution that occurred in 13.2% of transplants. Following modification of the conditioning regimen in 1993, the rejection rate fell to 4.6% and remained low. Acute graft-versus-host disease (GVHD) of grade II-IV occurred in 31% and chronic GVHD in 14.5%. These data compare favourably with survival with medical treatment for thalassaemia major and suggest that allogeneic BMT remains an important treatment option for children with beta-thalassaemia major, particularly when compliance with iron chelation is poor.

Stem cell transplantation for thalassemia

Thalassemia, one of the most common genetic disorders, is considered to be a global problem. Several millions of the patients suffer from severe thalassemic diseases. Stem cell transplantation is currently the only curative therapy. Bone marrow transplantation offers a high probability of cure when performed in young children. There is a higher risk as the patient becomes older, especially the high incidence of graft rejection. Modified conditioning regimens live been developed to overcome graft rejection in patients with class III or full blown manifestations. The alternative use of stem cell from cord blood makes possible earlier transplant with better chance of cure, although the engraftment is slower compared to bone marrow transplantation. More experiences with regard to stem cell transplantation in adult patients, the use of stem cell transplantation from related donors as well as matched unrelated donors are necessary.

Chronic graft-versus-host disease and late effects after hematopoietic stem cell transplantation

Late effects following HSCT are related to either the transplant process or to the transplant preparative regimen. Problems related to the transplant process include delayed recovery of the immune system and chronic GVHD. Chronic GVHD presents between 3-14 months post-HSCT in approximately 20% of matched sibling transplants and 40% of matched unrelated donor recipients. Most commonly involved sites are skin, mouth, liver, gastrointestinal tract, and eye. Patients with platelet count < 100,000/ml and receiving cortocosteroid therapy at day 80 with any clinical manifestations of chronic GVHD require prolonged immune suppressive therapy with prednisone, cyclosporine +/- other agents. Treatment should be administered until all clinical and pathological signs and symptoms of chronic GVHD have resolved which may take one to several years. Problems related to the transplant preparative regimen include those involving the endocrine system, eyes, lungs, bone, and development of secondary malignancies. Endocrine deficiencies include growth failure with growth hormone (GH) deficiency, overt hypothyroidism, primary gonadal failure, Type 1 or Type 2 diabetes, and exocrine pancreatic insufficiency. These problems develop at any time post-HSCT, but usually occur within the first few years and should be treated with appropriate hormone supplementation. Eye problems are primarily related to development of cateracts secondary to total body irradiation (TBI) or prolonged corticosteroid use. Cateracts developing after fractionated frequently do not require removal. Pulmonary problems may be due to bronchiolitis obliterans (BO) or to restrictive lung disease. BO may be associated with chronic GVHD and may respond to chronic GVHD therapy. Restrictive lung disease does not occur for many years after HSCT. There is not therapy for this problem. Development of decreased bone mineral density (BMD) is related to GH deficiency and/or corticosteroid therapy. Treatment includes withdrawal of corticosteroids, administration of GH and calcium, Vitamin D and antiresorptive agents. All malignant disease survivors are at risk for development of secondary malignancies, including survivors of HSCT. Recipients of TBI are at highest risk as are children. All pediatric and adult survivors of HSCT should be followed for their life-time for development of delayed effects of transplantation.

Allogeneic transplantation for haemoglobinopathies

Beta-thalassaemia major and sickle-cell disease (SCD) reduce lifespan and quality of life for >300000 children and young adults worldwide. The only cure for both disorders is allogeneic stem cell transplantation (SCT). The decision-making processes in recommending SCT for patients with thalassaemia and SCD are different. For thalassaemia, where transfusion-related iron overload is universal, SCT should be offered to all patients <17 years because long-term survival and thalassaemia-free survival are about 80 and 70% respectively. For thalassaemics unable to comply with medical treatment, SCT offers a significant survival advantage; however, for patients with optimal medical care, short-term survival after SCT is inferior to medical treatment, and SCT instead offers a life free from transfusions and iron chelation. The clinical heterogeneity of SCD means that SCT is recommended only for selected patients with severe disease, particularly sickle-related neurological problems, for whom long-term survival and SCD-free survival after SCT approach 92 and 86% respectively. We here review the evidence available to help physicians evaluate the role of SCT for individual patients with thalassaemia major or SCD.

Endocrine complications of bone marrow transplantation in children

Eighty-seven patients had a bone marrow transplantation (BMT) at our institution between 1980 and 1992. We wished to study the endocrine complications that accompany this procedure as long-term survival is now much more common. Forty-three patients were retrospectively available for review and their records were examined for evidence of thyroid, pubertal, and growth complications. Fifteen per cent of the patients showed evidence of thyroid involvement. Pubertal delay or gonadal damage was almost universal in pubertal-aged girls treated with busulfan/cyclophosphamide. Gonadal involvement was more frequent in girls than in boys (70% vs. 47%). Sixty per cent of children were shorter or grew at a slower rate. Sixty-five per cent of the children presented with one or more endocrine complications. These are the combined effects of different treatment regimens (chemotherapy, radiotherapy, combined therapy). It is essential to know the natural history of these patients in order to offer proper guidance and treatment as survival rates are increasing.

Bone marrow transplantation in thalassemia. The experience of Pesaro

Early trials of allogenic bone marrow transplantation (BMT) for homozygous beta thalassemia and the analyses of results of transplantation in patients under 17 years of age have allowed us to identify 3 classes of risk using the criteria of degree of hepatomegaly, the degree of portal fibrosis, and the quality of the chelation treatment given before the transplant. Patients for whom all 3 criteria were adverse constituted Class 3, patients with none of the adverse criteria constituted Class 1, and patients with 1 or various associations of 2 of the adverse criteria formed Class 2. Most patients older than 16 years have disease characteristics that place them in Class 3, with very few in Class 2. For all the patients with an HLA identical donor we are actually using 2 protocols to which the patient is assigned on the basis of the Class he belongs to at the time of BMT and independently from the age of the patient. For 104 patients in Class 1 and for 262 patients in Class 2 prepared for the transplant with busulfan 14 mg/kg, cyclophosphamide 200 mg/kg and cyclosporine alone, the probabilities of survival and of event-free survival are 95% and 90% for Class 1 and 87% and 84% for Class 2. For 33 Class 3 patients prepared for the transplant with busulfan 14 mg/kg, cyclophosphamide reduced to 160 mg/kg, cyclosporine, and "short" methotrexate, the probabilities of survival and event-free survival are 89% and 64%. For 57 adult patients (17 to 35 years), who underwent the transplant after preparation with the same protocol used for Class 3, the probabilities of survival and of event-free survival are 70% and 68%, respectively. BMT remains the only form of radical treatment for thalassemia in those patients with an HLA-identical donor.

Current status of stem cell therapy and prospects for gene therapy for the disorders of globin synthesis

Sickle cell anaemia and beta-thalassaemia are today curable through the use of stem cell transplantation. Nevertheless, the disadvantages inherent in stem cell transplantation underscore the need for better therapies. A recent finding of potentially major importance is that complete eradication of host haematopoiesis is not an absolute requirement for achieving therapeutic effects in thalassaemia and sickle cell anaemia. Future stem cell transplantation protocols will use less toxic conditioning regimens in an effort to achieve a state of stable mixed chimerism between donor and host haematopoietic elements. An improved understanding of globin gene regulation and stem cell biology will allow for the first gene therapy trials for sickle cell anaemia and beta-thalassaemia in the relatively near future. Initial gene therapy protocols will emphasize safety, are likely to target progenitor cells, and will involve repeated cycles of mobilization, transduction and reinfusion, with little or no conditioning. These first generation gene therapy trials are unlikely to confer major therapeutic benefits, but will provide the foundation upon which subsequent, more effective protocols will be based.

Efficacy and toxicity of radiation in preparative regimens for pediatric stem cell transplantation. II: Deleterious consequences

There has been a dramatic improvement in the treatment of both allogeneic and autologous stem cell transplants, especially in children and young adults. However, attempts to apply more intensive conditioning treatments to the more refractory pediatric malignancies have also increased the risks of deleterious consequences. This review examines the risks, and reports important variations in the toxic effects of using different conditioning techniques.

Mechanism and management of treatment-related gonadal failure in recipients of high dose chemoradiotherapy

For the last two decades, the use of bone marrow transplantation for leukaemia, and most recently for lymphomas and other cancers, has increased dramatically and all of the systemic chemotherapy or radiotherapy used in these patients has a potential for causing infertility. This review describes the normal reproductive function of relevance to patients at risk of chemotherapy- or radiotherapy-induced infertility. The mechanism by which fertility may be affected by these agents is also described and therapeutic strategies for reducing or preventing these problems are outlined. The treatment of men and women who are infertile after chemotherapy or radiotherapy is addressed, as are the ethical and legal aspects of assisted fertilization.

Bone marrow transplantation in thalassemia

Early trials of allogeneic bone marrow transplantation (BMT) for homozygous beta-thalassemia and the analyses of results of transplantation in patients less than 16 years old have allowed us to identify three classes of risk based on the following criteria: (a) hepatomegaly, (b) presence of liver fibrosis at histological examination, and (c) quality of chelation treatment given before transplant. Patients with none of these adverse criteria were assigned to Class 1; patients with either one or two adverse criteria comprised Class 2; and patients for whom all three criteria were adverse constituted Class 3. Most patients older than 16 years have disease characteristics that place them in Class 3, with very few falling into Class 2. All patients with a histocompatibility leukocyte antigen (HLA)-identical donor are actually assigned to one of two conditioning regimens on the basis of the class they belong to at the time of BMT and independently of age. For Class 1, Class 2, and Class 3 patients, the probabilities of survival and event-free survival are 95 and 90%, 86 and 82%, and 87 and 63%, respectively. For those patients older than 16 years at the time of transplant, the probabilities of survival and of event-free survival are 78 and 74%, respectively. Allogeneic BMT is currently the only rational therapeutic modality for the eradication of beta-thalassemia.

Pubertal development in thalassaemic patients after allogenic bone marrow transplantation

To obtain further insight into gonadal function, a series of 50 prepubertal patients with beta-thalassaemia major (24 boys and 26 girls) aged from 12.6 to 18 years (mean 15 years) who had received a bone marrow transplantation (BMT) during childhood or the peripubertal period, at the age of 3.6-14.5 years (mean 10.8 years), were periodically re-evaluated at intervals of 6-12 months. The last evaluation was done 1-9 years (mean 4.2 years) after BMT. At each examination we measured height, pubertal stage, plasma gonadotrophins (LH and FSH) before and after the GnRH stimulation test (i.v.), sex steroids (total and free testosterone in males, and 17 beta-oestradiol in females), serum ferritin and bone age. Fourty percent of patients entered or passed through puberty normally despite clinical and hormonal evidence of gonadal dysfunction in most of them. A correlation was not found between the pubertal stage and age at BMT, and no statistical difference between patients who did not enter into puberty and patients with spontaneous pubertal development was found in serum ferritin levels. Our data confirm that gonads in male and female thalassaemic patients are exposed to the cytotoxic effects of the preparative transplant regime with alkylating agents. In some patients absence of pubertal development was due to gonadotrophin insufficiency, probably secondary to previous iron overload. These findings emphasize the need for a vigilant long-term follow up study of thalassaemic patients who have had BMT.

Long-term complications following bone marrow transplantation in children

Seventeen children who underwent bone marrow transplantation (BMT) between 1975 and 1985 and survived for more than 2 years were evaluated for growth and development. The patients had a follow up of 2.1-13.1 years. Prior to transplant, children with malignancy had received multi-agent chemotherapy and nine had also received central nervous system irradiation. Transplant preparation for malignancy (group 1; n = 13) included high-dose cyclophosphamide (CPA) 120-200 mg/kg and total body irradiation (TBI) 10-13.2 Gy, whereas conditioning for non-malignant disorders (group 2; n = 4) included high-dose CPA 200 mg/kg with or without busulphan. Patients in group 1 showed a steady decline in height velocity following initial chemotherapy and cranial irradiation and the decline was even greater following BMT. Growth hormone (GH) deficiency developed in eight of nine children tested, hypergonadotrophic hypogonadism developed in 11 who reached puberty, thyroid hormone abnormalities were encountered in four out of 10 tested and 11 of 13 developed cataracts. Patients in group 2 did not show decline in linear growth rate, thyroid hormone abnormalities or cataracts after BMT. The only child tested had normal GH levels and the two patients who reached puberty showed delayed but complete gonadal recovery. Our data demonstrate that TBI leads to significant late effects on growth and gonadal function. Contrary to previous reports, a high incidence of cataract formation is observed after fractionated TBI. Conditioning regimens TBI should be considered in children undergoing BMT.

Bone marrow transplant for sickle cell disease--the dilemma

Sickle cell disease is the family of clinically significant haemoglobin disorders which have in common the inheritance of the sickle beta haemoglobin chain gene. The homozygous SS condition, also known as sickle cell anaemia, can present a varied clinical picture from asymptomatic through to frequent painful vaso-occlusive crises and even death as a result of complications of the disease. S beta zero thalassaemia and the rate haemoglobin SD disease present a similar picture to SS, while S beta plus thalassaemia and haemoglobin SC disease generally have milder clinical features than SS and present somewhat later in life. The present debate about bone marrow transplant (BMT) for sickle cell disease, among both physicians and community, relates to SS patients, definition and markers of disease severity, the effect of BMT on sickle related organ damage, the efficacy of BMT for SS, and its complications, both early and long-term.

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.