Short- and long-term follow-up of thyroid dysfunction after allogeneic bone marrow transplantation without the use of preparative total body irradiation

Maintain Efficacy and Spare Toxicity: Traditional and New Radiation-Based Conditioning Regimens in Hematopoietic Stem Cell Transplantation

Novelty in total body irradiation (TBI) as part of pre-transplant conditioning regimens lacked until recently, despite the developments in the field of allogeneic stem cell transplants. Long-term toxicities have been one of the major concerns associated with TBI in this setting, although the impact of TBI is not so easy to discriminate from that of chemotherapy, especially in the adult population. More recently, lower-intensity TBI and different approaches to irradiation (namely, total marrow irradiation, TMI, and total marrow and lymphoid irradiation, TMLI) were implemented to keep the benefits of irradiation and limit potential harm. TMI/TMLI is an alternative to TBI that delivers more selective irradiation, with healthy tissues being better spared and the control of the radiation dose delivery. In this review, we discussed the potential radiation-associated long-term toxicities and their management, summarized the evidence regarding the current indications of traditional TBI, and focused on the technological advances in radiotherapy that have resulted in the development of TMLI. Finally, considering the most recent published trials, we postulate how the role of radiotherapy in the setting of allografting might change in the future.

Thyroid and Adrenal Dysfunction in Hemoglobinopathies Before and After Allogeneic Hematopoietic Cell Transplant

Purpose

To determine the rate and clinical characteristics associated with abnormal thyroid and adrenal function in recipients of nonmyeloablative hematopoietic cell transplantation (HCT) for sickle cell disease (SCD) and beta-thalassemia.

Methods

We retrospectively reviewed patients who enrolled in 4 nonmyeloablative HCT regimens with alemtuzumab and total body irradiation (TBI). Baseline and annual post-HCT data were compared, which included age, sex, sickle phenotype, thyroid panel (total T3, free T4, thyroid stimulating hormone, antithyroid antibodies), cortisol level, ACTH stimulation testing, ferritin, medications, and other relevant medical history.

Results

Among 43 patients in haploidentical transplant and 84 patients in the matched related donor protocols with mostly SCD, the rate of any thyroid disorder pre-HCT was 3.1% (all subclinical hypothyroidism) and post-HCT was 29% (10 hypothyroidism, 4 Grave's disease, and 22 subclinical hypothyroidism). Ninety-two (72%) patients had ferritin >1000 ng/dL, of which 33 patients (35.8%) had thyroid dysfunction. Iron overload was noted in 6 of 10 patients with hypothyroidism and 12 of 22 patients with subclinical hypothyroidism.Sixty-one percent were on narcotics for pain control. With respect to adrenal insufficiency (AI) pre-HCT, 2 patients were maintained on corticosteroids for underlying rheumatologic disorder and 8 had AI diagnosed during pre-HCT ACTH stimulation testing (total 10, 7.9%). Post-HCT, an additional 4 (3%) developed AI from corticosteroid use for acute graft vs host disease, Evans syndrome, or hemolytic anemia.

Conclusion

Although iron overload was common in SCD, thyroid dysfunction pre-HCT related to excess iron was less common. Exposure to alemtuzumab or TBI increased the rates of thyroid dysfunction post-HCT. In contrast, AI was more common pre-HCT, but no risk factor was identified. AI post-HCT was infrequent and associated with corticosteroid use for HCT-related complications.

Late Effects After Haematopoietic Stem Cell Transplantation in ALL, Long-Term Follow-Up and Transition: A Step Into Adult Life

Haematopoietic stem cell transplant (HSCT) can be a curative treatment for children and adolescents with very-high-risk acute lymphoblastic leukaemia (ALL). Improvements in supportive care and transplant techniques have led to increasing numbers of long-term survivors worldwide. However, conditioning regimens as well as transplant-related complications are associated with severe sequelae, impacting patients' quality of life. It is widely recognised that paediatric HSCT survivors must have timely access to life-long care and surveillance in order to prevent, ameliorate and manage all possible adverse late effects of HSCT. This is fundamentally important because it can both prevent ill health and optimise the quality and experience of survival following HSCT. Furthermore, it reduces the impact of preventable chronic illness on already under-resourced health services. In addition to late effects, survivors of paediatric ALL also have to deal with unique challenges associated with transition to adult services. In this review, we: (1) provide an overview of the potential late effects following HSCT for ALL in childhood and adolescence; (2) focus on the unique challenges of transition from paediatric care to adult services; and (3) provide a framework for long-term surveillance and medical care for survivors of paediatric ALL who have undergone HSCT.

Thyroid dysfunctions in adult patients after allogeneic hematopoietic stem cell transplantation

INTRODUCTION

Thyroid dysfunction (TD) is one of the major endocrinopathies shown after allogeneic hematopoietic stem cell transplantation over the long term. The incidence and the risk factors for TD have varied widely.

PATIENTS AND METHODS

Two hundred and fifty-nine patients with pre-transplant normal thyroid function tests who survived at least 1 year after allo-HSCT between 2006-2016 were included in the study.

RESULTS

Sixty-four patients (25%) developed TD at median of 34 months (range, 1-112 months). Hypothyroidism was detected in 32 patients (12%): 5 patients had primary hypothyroidism, and subclinical hypothyroidism occurred in 27 patients. 18 patients (7%) were diagnosed with hyperthyroidism: 2 patients (0.07%) were treated for primary hyperthyroidism, and 16 patients (6%) were followed for subclinical hyperthyroidism. Euthyroid sick syndrome occurred in 14 cases. None of the patients with thyroid dysfunction developed secondary thyroid malignancy. Receiving high-dose TBI (P = .001) was found to be significant risk for hypothyroidism; older age than median (P = .01) and pre-transplant active disease (P < .0001) were related to hyperthyroidism.

CONCLUSIONS

Thyroid dysfunction, mostly hypothyroidism, is a long-term complication after allo-HSCT in 25% of patients. Older age, pre-transplant active disease, and receiving TBI are among the risk factors. Sustained long-term monitoring of thyroid function test should be considered post allo-HSCT.

Thyroid dysfunction in children with leukemia over the first year after hematopoietic stem cell transplantation

Background Thyroid function in children with leukemia during the first year after hematopoietic stem cell transplantation (HSCT) was investigated. Methods The medical records of 186 subjects [111 boys and 75 girls; lymphoid=75, myeloid=111; median age at HSCT was 10.7 (0.8-21.8) years old] were reviewed retrospectively. Results In children with leukemia, T3 decreased at 1 month (p<0.001) and recovered 9 months to the levels before HSCT. TSH decreased at 1 month (p<0.001), recovered at 3 months and increased at 12 months (p<0.001) to the levels before HSCT. The incidence of euthyroid sick syndrome (ESS, 23.2%, 15.5%, 5.9%, 5.2%, 3.9%, p for trend <0.001) decreased and subclinical hypothyroidism (SH, 0%, 3.9%, 14.8%, 22.1%, 21.3%, p for trend <0.001) increased at 1, 3, 6, 9 and 12 months after HSCT. Out of 55 patients developing ESS during 3 months after HSCT, 54 recovered to normal thyroid function within 5 months without medication. Among the total 186 subjects, 21 patients have been treated with levothyroxine. Both height and weight standard deviation scores continued to decrease over 1 year after HSCT. Conclusions In children with leukemia, one-quarter had ESS at 1 month and one-fifth had SH at 12 months and continued growth impairments were observed during 1 year after HSCT. Most of the ESS patients recovered to normal within 5 months without medication. More long-term follow-up of thyroid function and growth in children with leukemia after HSCT is crucial.

Long-term thyroid disorders in pediatric survivors of hematopoietic stem cell transplantation after chemotherapy-only conditioning

BACKGROUND

Thyroid dysfunction (TD) was usually described in hematopoietic stem cell transplantation (HSCT) recipients who were given total body irradiation (TBI) in the conditioning regimen. Because previous studies have reported discrepant results regarding the presence of long-term thyroid complications in HSCT survivors following chemotherapy-only conditioning, we investigated the frequency of thyroid abnormalities in a series of children treated with HSCT for different disorders without TBI as part of the conditioning protocol.

METHODS

We compared thyroid-stimulating hormone, free thyroxine, total triiodothyronine (TT3), anti-peroxidase (TPO Ab) and anti-thyroglobulin antibodies and thyroid volume z-score in 28 HSCT survivors and 16 healthy subjects matched for age and sex.

RESULTS

HSCT recipients had a higher frequency of TD and thyroid complications in total, including TD and euthyroid Hashimoto thyroiditis, compared to the control group. Patients transplanted for Hodgkin lymphoma (HL) were more likely to develop a thyroid complication compared to patients with non-malignant hematologic diseases and leukemia patients. BEAM (carmustine, etoposide, citarabin and melphalan) conditioning compared to busulfan (Bu) and fludarabine (Flu)-based regimens and autologous compared to allogenic grafting were associated with a higher prevalence of TD in our study. HSCT survivors had higher mean serum TT3 levels. A multivariate analysis revealed that autologous (auto)-HSCT recipients had higher mean serum titers of TPO Ab compared to allogenic (allo)-HSCT recipients and controls and the mean thyroid volume z-score was significantly higher in controls compared to auto-/allo-HSCT survivors.

CONCLUSIONS

We identified a 35.7% prevalence of thyroid abnormalities, emphasizing the need for a long-term surveillance of thyroid function and morphology even in this group of patients who were not exposed to TBI.

Total body irradiation in allogeneic bone marrow transplantation conditioning regimens: A review

Hematologic malignancies may require, at one point during their treatment, allogeneic bone marrow transplantation. Total body irradiation combined with chemotherapy or radiomimetic used in allogeneic bone marrow transplantation is known to be very toxic. Total body irradiation (TBI) induces immunosuppression to prevent the rejection of donor marrow. TBI is also used to eradicate malignant cells and is in sanctuary organs that are not reached by chemotherapy drugs. TBI has evolved since its introduction in the late fifties, but acute and late toxicities remain. Helical tomotherapy, which is widely used for some solid tumors, is a path for the improvement of outcomes and toxicities in TBI because of its sparing capacities. In this article, we first review the practical aspects of TBI with patient positioning, radiobiological considerations and total dose and fractionation prescriptions. Second, we review the use of intensity modulated radiation therapy in bone marrow transplantation with a focus on helical tomotherapy TBI, helical tomotherapy total marrow irradiation (TMI) and total marrow and lymphoid irradiation (TMLI) and their dosimetric and clinical outcomes. Finally, we review the perspective of dose escalation and the extension to older patients and patients with comorbidity who do not benefit from a standard bone marrow transplantation conditioning regimen.

Endocrinopathies after allogeneic and autologous transplantation of hematopoietic stem cells

Early and late endocrine disorders are among the most common complications in survivors after hematopoietic allogeneic- (allo-) and autologous- (auto-) stem cell transplant (HSCT). This review summarizes main endocrine disorders reported in literature and observed in our center as consequence of auto- and allo-HSCT and outlines current options for their management. Gonadal impairment has been found early in approximately two-thirds of auto- and allo-HSCT patients: 90–99% of women and 60–90% of men. Dysfunctions of the hypothalamus-pituitary-growth hormone/insulin growth factor-I axis, hypothalamus-pituitary-thyroid axis, and hypothalamus-pituitary-adrenal axis were documented as later complicances, occurring in about 10, 30, and 40–50% of transplanted patients, respectively. Moreover, overt or subclinical thyroid complications (including persistent low-T3 syndrome, chronic thyroiditis, subclinical hypo- or hyperthyroidism, and thyroid carcinoma), gonadal failure, and adrenal insufficiency may persist many years after HSCT. Our analysis further provides evidence that main recognized risk factors for endocrine complications after HSCT are the underlying disease, previous pretransplant therapies, the age at HSCT, gender, total body irradiation, posttransplant derangement of immune system, and in the allogeneic setting, the presence of graft-versus-host disease requiring prolonged steroid treatment. Early identification of endocrine complications can greatly improve the quality of life of long-term survivors after HSCT.

Long-term follow-up of pediatric patients receiving total body irradiation before hematopoietic stem cell transplantation and post-transplant survival of >2 years

BACKGROUND

Total body irradiation (TBI) treatment eradicates malignant cells and suppresses the immune system before hematopoietic stem cell transplantation (HSCT). The radiation dose is limited by its toxicity to healthy organs. Many reports describe long-term sequelae from TBI in adults, but comparable data for pediatric patients are scarce.

PROCEDURES

We evaluated late effects of a cohort of survivors after at least 2 years from 106 children treated with TBI and HSCT between 1985 and 2008. Follow-up was available from 39 patients with a mean duration of 8.3 (range 2.0-21.9) years. We examined cardiac, pulmonary and renal function, longitudinal growth, weight development, endocrinological parameters, and gastrointestinal problems.

RESULTS

Initial remission status and overall survival were significantly correlated. None of the 39 patients experienced cardiac dysfunction or changes in pulmonal function, but 5 exhibited renal impairment. Gastrointestinal problems were reported by 4 patients, and 10 patients had severe growth impairment. Altogether, our follow-up of pediatric patients who survived TBI-containing conditioning regimens for more than 2 years showed no cardiac morbidity or pulmonary aggravation, but mild renal sequelae and growth impairment.

CONCLUSION

The adverse long-term effects of TBI in our cohort of children surviving at least 2 years after TBI and HSCT seem to be within a tolerable range. Future studies are required to investigate whether conditioning regimens lacking TBI result in a better ratio of benefits to overall side effects.

Risk factors for short term thyroid dysfunction after hematopoietic stem cell transplantation in children

Purpose

The purpose of this study was to evaluate short-term thyroid dysfunction and related risk factors in pediatric patients who underwent hematopoietic stem cell transplantation (HSCT) during childhood.

Methods

We studied 166 patients (100 boys and 66 girls) who underwent HSCT at the Catholic HSCT Center from January 2004 through December 2009. The mean age at HSCT was 10.0±4.8 years. Thyroid function of the patients was tested before and during 3 months of HSCT.

Results

Out of 166 patients, 165 (99.4%) underwent allotransplantation. Acute graft-versus-host disease (GVHD, grades II to IV) developed in 76 patients. Conditioning regimens before HSCT include total body irradiation (n=57), busulfan (n=80), and reduced intensity (n=29). Forty-five (27.1%) had thyroid dysfunction during 3 months after HSCT (29 euthyroid sick syndrome [ESS], 6 subclinical hyperthyroidism, 4 subclinical hypothyroidism, 3 hypothyroxinemia, 2 overt hyperthyroidism, and 1 high T₄ syndrome). In a univariate logistic regression analysis, age at HSCT (P=0.002) and acute GVHD (P=0.009) had statistically significant relationships with thyroid dysfunction during 3 months after HSCT. Also, in a univariate logistic regression analysis, ESS (P=0.014) showed a strong statistically significant association with mortality.

Conclusion

In our study 27.1% patients experienced thyroid dysfunction during 3 months after HSCT. Increase in age and acute GVHD may be risk factors for thyroid dysfunction during 3 months after HSCT. There was a significant association between ESS and mortality.

Endocrine complications after hematopoietic stem cell transplantation during childhood and adolescence

Long-term survivors of hematopoietic stem cell transplantation (HSCT) during childhood and adolescence are at risk of developing endocrine complications. The purpose of this study was to evaluate the long-term endocrine complications and their associated risk factors among such patients. We reviewed the data from 111 patients (59 males and 52 females) who underwent HSCT at the mean age of 8.3+/-4.1 yr. Thirty patients (27.0%) had growth impairment, and seven (21.2%) out of 33 patients who attained final height reached final height below 2 standard deviation (SD). The final height SD score of the patients conditioned with total body irradiation (TBI) was significantly lower than that of the patients conditioned without TBI (-1.18+/-1.14 vs. -0.19+/-0.78, P=0.011). Thirteen patients (11.7%) developed hypothyroidism (11 subclinical, 2 central) 3.8+/-1.8 (range 1.6-6.2) yr after HSCT. Nineteen (65.5%) out of 29 females had evidence of gonadal dysfunction, and 18 (64.3%) out of 28 males had evidence of gonadal dysfunction. The risk for gonadal dysfunction was significantly higher in females conditioned with busulfan/cyclophosphamide (P=0.003). These results suggest that the majority of patients treated with HSCT during childhood and adolescence have one or more endocrine complications. Therefore, multiple endocrine functions should be monitored periodically after HSCT until they reach adult age.

Prolonged chronic graft-versus-host disease is a risk factor for thyroid failure in long-term survivors after matched sibling donor stem cell transplantation for hematologic malignancies

We studied thyroid function in 81 long-term survivors of allogeneic stem cell transplantation (allo-SCT), with a median follow-up of 84 months (range, 45 to 166 months). Median age at transplantation was 35 years (range, 6 to 66). Seventy-two of the patients received a total body irradiation (TBI)-containing conditioning regimen (n = 23, 12 Gy; n = 49, 13 Gy). Twenty-one of the patients (25.9%) had subclinical hypothyroidism, and 9 (11.1%) developed overt hypothyroidism at a median of 28 months (range, 3 to 78 months) after allo-SCT. Multivariate logistic regression analysis demonstrated that prolonged immunosuppressive therapy (IST) was significantly associated with subclinical hypothyroidism (odds ratio [OR] = 3.8) and overt hypothyroidism (OR = 2.6). Antithyroglobulin and thyroid peroxidase antibody were detected in 12 of 60 patients tested (20%). No correlation was found between the occurrence of thyroid antibodies and hypothyroidism (P = .13) or chronic graft-versus-host disease (cGVHD) (P = .55). In conclusion, thyroid dysfunction is relatively common after allo-SCT and is more likely to occur in patients receiving prolonged IST for cGVHD; however, thyroid dysfunction does not appear to be related to an antibody-mediated autoimmune process.

Growth and Endocrine Function in Long-term Adult Survivors of Childhood Stem Cell Transplant

The number of long-term surviving stem cell transplant (SCT) recipients has increased steadily, and attention has now extended to the late complications of this procedure. The objective of this study was to investigate relationship among growth and endocrine functions in long-term adult survivors of childhood SCT. The inclusion criteria of this study were survival at least 5 yr after SCT and achievement of adult height. Fifty-four patients (39 males) fulfilled these criteria and were included in this study. Growth was mainly evaluated by height standard deviation score (SDS) and individual longitudinal growth curves. Among the 54 patients, those that received SCT before 10 yr of age showed significantly greater reductions in changes in height SDS (mean –1.75, range –4.80 to –0.10) compared with those that received SCT at or after 10 yr of age (mean –0.50, range –1.74 to 1.20; P<0.001). The mean loss of height for all patients who received SCT during childhood was estimated to be approximately 1 SDS/6.5 yr (r=0.517). Individual longitudinal growth curves indicated that a significant growth spurt was absent in severe short stature patients during the pubertal period without severe endocrine dysfunctions including GH deficiency. The incidence of growth disorder in long-term adult survivors depends on the age at SCT and whether they received radiation therapy. Life-long follow-up is necessary for survivors to detect, prevent and treat the late endocrine complications in SCT survivors.

Hyperthyroidism as a latent complication of autologous hematopoietic stem cell transplantation

Thyroid dysfunction after hematopoietic stem cell transplantation has been investigated in many studies. Most post-transplant thyroid disorders such as hypothyroidism are recognized as a late complication whilst hyperthyroidism is infrequent and transient, and usually happens early at the onset after transplant. Here, we report two rare hyperthyroid cases, developing more than 2 years after autologous stem cell transplant. We suggest that hyperthyroidism be alerted in the post-transplant care, and special attention be paid to any latent events.

The effect of administration order of BU and CY on engraftment and toxicity in HSCT mouse model

Conditioning regimens are an important issue determining the outcome of hematopoietic stem cell transplantation (HSCT). Less toxicity, early engraftment and no relapse are the aims of efficient conditioning. Our objective was to investigate the long-term effects of BU-CY and their administration order on the toxicity and chimerism in a mouse model of HSCT. Female BALB/c mice were treated with either BU (15 mg/kg/day x 4)-CY (100 mg/kg/day x 2) or CY-BU. Treated mice were transplanted with Sca-1+ cells from male BALB/c mice. Until 90 days after HSCT, the animals were monitored for body weight and analyzed for cellular phenotype of the thymus, spleen and BM, total chimerism, the spleen chimerism of DCs and T regulatory (Treg) cells, and hepatotoxicity. BU-CY and CY-BU treatments exerted comparable myeloablative and immunosuppressive effects. The long-term engraftment of donor cells in the BM and thymus regeneration showed the same features in both groups. However, the two regimens differed; in general, hepatotoxicity and chimerism of DC and Treg cells. In the long term, BU-CY, but not CY-BU caused a marked decrease in body weight and a significant increase in the activities of the liver enzymes, particularly aspartate amino transferase (AST). We conclude that the alteration of the administration order of BU-CY to CY-BU not only gives the same level of engraftment but also reduces the toxicity of the conditioning regimen that might be valuable specially in young patients who are undergoing HSCT.

Autonomous thyroid nodule in an adolescent 10 years after total body irradiation for bone marrow transplant

A male patient with B-cell lymphoma was treated with chemotherapy and allogeneic bone marrow transplant, including preparatory total body irradiation. Ten years later, at age 15 years, the patient developed an autonomous thyroid nodule and an incidental papillary microcarcinoma. This is the first report of an autonomous thyroid nodule after total body irradiation for bone marrow transplant. The case is presented and the literature is reviewed.

Early-onset thyrotoxicosis after unrelated cord blood transplantation for acute myelogenous leukemia

Thyroid dysfunction is a common complication after allogeneic hematopoietic stem cell transplantation (SCT). However, thyrotoxicosis as defined by elevated serum-free thyroxine (FT4) or free triiodothyronine (FT3) levels together with low thyroid-stimulating hormone (TSH) levels is rare after SCT. Here we describe 2 patients who developed thyrotoxicosis within the first 50 days after unrelated cord blood transplantation (CBT). Patient 1 is a 32-year-old woman with acute myelogenous leukemia (AML)-M5a who underwent CBT. On day +41, she developed tachycardia. On day +48, FT4 increased to 2.2 ng/dL and TSH was suppressed to less than 0.1 microU/mL. Antithyroid peroxidase antibody was positive. On day +83, FT4 spontaneously decreased to 1.4 ng/dL. Patient 2 is a 42-year-old man with AML-M4 who underwent CBT. On day +42, he developed tachycardia. On day +48, FT3 increased to 4.75 pg/mL and TSH was suppressed to 0.02 microU/mL. Antithyroid peroxidase antibody was positive. Eight months after CBT, his thyroid function spontaneously returned to normal. The presence of antithyroid peroxidase antibody suggested that immune-mediated reactions might be associated with the development of thyrotoxicosis after CBT in our patients. The present study shows that thyrotoxicosis can occur during very early periods after CBT.

Endocrine dysfunction and parameters of the metabolic syndrome after bone marrow transplantation during childhood and adolescence

Endocrine dysfunction and parameters of metabolic syndrome were assessed in 91 patients aged 4.3-32.5 years who underwent allogeneic or autologous BMT in childhood. Final short stature, found in five of the 35 patients who attained final height, was associated with the underlying disease (specifically, Fanconi anemia) (P=0.0013), previous cranial irradiation (P=0.0007), type of conditioning irradiation (P<0.05) and allogeneic BMT (P=0.05). Growth hormone deficiency (n=10) was associated with previous cranial irradiation (P<0.005) and conditioning total body irradiation (P<0.001). Twelve patients had primary hypothyroidism, one had hyperthyroidism and one papillary thyroid carcinoma. Hypothyroidism was associated with neck/mediastinal (P<0.005) and conditioning irradiation (P<0.05). Primary gonadal failure was found in 24 of the mature patients (62.5% females). Hypogonadism was associated with the underlying disease (especially hematological malignancies) (P<0.05), pretransplant treatment (P<0.05), irradiation conditioning (P<0.001), older age (P<0.005) and advanced pubertal stage at BMT (P<0.05). Obesity (body mass index >2 s.d.) was found in 4.4% and type II diabetes and impaired glucose tolerance in 3.3% each. Dyslipidemia was found in 27.9% of the 43 patients tested. These findings emphasize the need for long-term follow-up of endocrine and metabolic parameters in young patients after BMT in order to offer proper treatment and improve quality of life.

Autoimmune hypothyroidism after unrelated haematopoietic stem cell transplantation in children

We describe two pediatric patients who developed autoimmune hypothyroidism 2 years after unrelated allogeneic hematopoietic stem cell transplantation. The causes of post-transplantation autoimmune hypothyroidism are probably multiple. In these two patients, the presence of chronic graft-versus-host disease may be the most significant contributing factor.

The immune system as a regulator of thyroid hormone activity

It has been known for decades that the neuroendocrine system can both directly and indirectly influence the developmental and functional activity of the immune system. In contrast, far less is known about the extent to which the immune system collaborates in the regulation of endocrine activity. This is particularly true for immune-endocrine interactions of the hypothalamus-pituitary-thyroid axis. Although thyroid-stimulating hormone (TSH) can be produced by many types of extra-pituitary cells--including T cells, B cells, splenic dendritic cells, bone marrow hematopoietic cells, intestinal epithelial cells, and lymphocytes--the functional significance of those TSH pathways remains elusive and historically has been largely ignored from a research perspective. There is now, however, evidence linking cells of the immune system to the regulation of thyroid hormone activity in normal physiological conditions as well as during times of immunological stress. Although the mechanisms behind this are poorly understood, they appear to reflect a process of local intrathyroidal synthesis of TSH mediated by a population of bone marrow cells that traffic to the thyroid. This hitherto undescribed cell population has the potential to microregulate thyroid hormone secretion leading to critical alterations in metabolic activity independent of pituitary TSH output, and it has expansive implications for understanding mechanisms by which the immune system may act to modulate neuroendocrine function during times of host stress. In this article, the basic underpinnings of the hematopoietic-thyroid connection are described, and a model is presented in which the immune system participates in the regulation of thyroid hormone activity during acute infection.

Autoimmune thyroid dysfunction after hematopoietic stem cell transplantation

Autoimmune thyroid disease (AITD) may occur in patients after hematopoietic stem cell transplantation (HSCT). In all, 10 cases of AITD (seven allogeneic and three autologous HSCT) were diagnosed among 721 HSCT recipients, including two patients with sequential hyper- and hypothyroidism. The 5-year actuarial rates for AITD after allogeneic and autologous HSCT were 2.9 and 4%, respectively. Significant risk factors included HSCT for chronic myeloid leukemia, the HLA B46 and DR9 loci and the A2B46DR9 haplotype, while female donors showed trend to significance. On multivariate analysis, only female donors and HLA DR9 remained significant. For autologous HSCT, the associations with HLA B46 and DR9 were also significant. Only three donors had a family history of AITD. A review of other reported cases confirmed the predominance of female donors, although the other associations including graft-versus-host disease, familial AITD and other autoimmune phenomena might be related to reporting bias. Since the actuarial incidence of AITD from female donors with predisposing HLA alleles may be over 30%, susceptible recipients should be carefully monitored. Owing to the small number of reported cases and different HLA associations with AITD in different populations, our observations await confirmatory data from other registries.

Late thyroid toxicity in 153 long-term survivors of allogeneic bone marrow transplantation for acute lymphoblastic leukaemia

The purpose of this study was to identify risk factors for hypothyroidism after bone marrow transplantation (BMT) for high-risk or relapsed acute lymphoblastic leukaemia (ALL) in children. In all, 388 children with acute lymphoblastic leukaemia underwent allogeneic bone marrow transplantation between 1984 and 1994. Overall 5-year survival was 54.6%. Thyroid function was assessed in the 153 patients with more than 5 years of follow-up. In total, 16 patients developed uncompensated hypothyroidism (UH) and 46 compensated hypothyroidism (CH) a median of 2.9 and 2.7 years, respectively, after BMT. Thyroid dysfunction-free survival rates were 73.2% after 5 years and 59.2% after 10 years. Three factors were significantly associated with the onset of hypothyroidism, namely age, bone marrow transplantation in second remission, and single-dose total body irradiation (TBI). Ultrasonography of the thyroid showed nodules in 10 of 35 patients. The median time from BMT to nodule detection was 7.8 years. Cytology (n=5) and surgery (n=4) showed no evidence of thyroid cancer. Four of the 14 patients who received cytoreduction without TBI but with busulphan and cyclophosphamide developed UH (n=2) or CH (n=2). We concluded that children who undergo BMT for ALL are at a high risk of subsequent thyroid dysfunction.

Endocrine disorders during the first year after autologous stem-cell transplant

BACKGROUND

Frequent endocrine disorders have been reported after allogeneic stem-cell transplant, but data on adult survivors of autologous transplants are still scarce.

METHODS

In this prospective study we investigated early (at 3 months) and late (at 12 months) endocrine dysfunctions in 95 consecutive autologous stem-cell transplant recipients (47 men and 48 women) aged 16 to 55 years. The functions of the hypothalamic-pituitary-gonadal/thyroid/adrenal/somatotroph axis were evaluated.

RESULTS

Three months after the transplant, insulin-like growth factor-1 values were below the normal range in 53 patients (56%); 37 of 40 women (93%) of reproductive age experienced precocious ovarian failure; 39 of 46 men (85%) showed high follicular stimulating hormone, and 17 men (37%) showed low testosterone levels. Adrenal insufficiency occurred in 28 patients (30%) during the peritransplant period after corticosteroid withdrawal. Transient subclinical hyperthyroidism was found in 15 patients (16%). Transient "low T(3)" syndrome was revealed in 29 patients (31%). Twelve months after the transplant, insulin-like growth factor-1 values were still low in 36 patients (38%). Menstrual cycles resumed in four women; follicular stimulating hormone, luteinizing hormone, and estradiol levels improved in 10 patients. Testosterone was low in only two men (4%). Seminal analysis revealed azoospermia in 32 (91%) of 35 men examined. Subclinical hypothyroidism was found in 11 patients (12%); eight of them had previously received radiotherapy for the upper half of the body.

CONCLUSION

This study documents frequent endocrine disorders during the first year after autologous stem-cell transplant. Despite a tendency to improve, in more than half of the cases, the complications persisted for more than 1 year. Therefore, to diagnose and correct early and late endocrine dysfunctions, endocrine screening is required during the first year in all patients undergoing autografting.

Thyroid dysfunction after bone marrow transplantation for primary immunodeficiency without the use of total body irradiation in conditioning

Thyroid dysfunction, a common long-term complication following bone marrow transplantation (BMT), is frequently associated with total body irradiation (TBI) given in the pre-BMT conditioning protocol. We report our preliminary observation of the prevalence of thyroid dysfunction in children transplanted for primary immunodeficiency (PID) who were given cytoreductive conditioning with busulphan and cyclophosphamide, but without TBI. We evaluated thyroid-stimulating hormone (TSH) and free thyroxine (fT4) in 83 survivors transplanted between 1987 and 2002. We found nine children (10.8%) with clinical and/or biochemical thyroid dysfunction at 4 months to 4.5 years post-BMT of which three had positive antithyroid microsomal antibodies. Two patients were classified as primary and seven as compensated hypothyroidism (hyperthyrotropinaemia). Four patients with clinical features of hypothyroidism received replacement thyroxine, while five of the seven patients with compensated hypothyroidism remain off thyroxine because we suspect this may be a transient phenomenon. Abnormalities of thyroid function including severe primary hypothyroidism may occur post-BMT in children receiving chemotherapy conditioning without TBI. Thyroid function should be assessed regularly in this group of patients.

Changes in thyroid function after bone marrow transplant in young patients

BACKGROUND

Changes in thyroid function among young patients who received bone marrow transplantation (BMT) were evaluated.

METHODS

The study included 91 patients (50 males) who underwent BMT from 1985 to 1995 at the age of 0.6-21 years. Sixty patients had neoplastic disease such as leukemia or lymphoma, and the remainder had non-neoplastic diseases. Preconditioning regimen for BMT included 12 Gy of fractionated-total body irradiation (TBI) for patients with neoplastic disease and 3-8 Gy of irradiation for the remaining patients, in addition to chemotherapy. Evaluation of thyroid function was performed by serial assessment of basal serum FT4, FT3, TSH concentrations as well as by TRH test.

RESULTS

No patient had overt hypothyroidism or elevated basal TSH concentrations (>10 mU/L). However, 6 (7%) of patients experienced exaggerated peak TSH response to TRH stimulation several years after BMT. In 33 patients whose thyroid status was evaluated before, within 3 months, and 1 year after BMT, serum FT3 concentrations as well as peak TSH response to TRH stimulation significantly decreased immediately after BMT (<3 months) and normalized within 1 year. However, serum FT4 concentrations did not change significantly. One patient developed primary hypothyroidism and another developed follicular adenoma of the thyroid 5 and 12 years after BMT, respectively.

CONCLUSION

Short-term changes in thyroid function after BMT can indicate euthyroid sick syndrome rather than tertiary hypothyroidism. It must be noted that overt hypothyroidism may occur several years after BMT, hence long-term follow-up of thyroid function is warranted.

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.

High prevalence of endocrine dysfunction in long-term survivors after allogeneic bone marrow transplantation for hematologic diseases

BACKGROUND

The progressively increasing number of long-term survivors after allogeneic bone marrow transplantation (allo-BMT) led researchers to focus on the early and late complications of this procedure. Endocrine dysfunction occurred mostly in patients who had undergone total body irradiation (TBI) as part of pretransplantation treatment. The extent to which chemotherapy and immune system derangement affect endocrine function in allo-BMT recipients is still unclear.

METHODS

Forty consecutive patients (21 women, 19 men) with hematologic diseases surviving 12 or more months after allo-BMT from HLA-identical siblings were studied. Patients' age at transplantation ranged from 13 to 45 years and their post-BMT follow-up lasted 12-62 months. The conditioning regimen BUCY2 was employed. Graft versus host disease (GVHD) was observed in the acute form in 13 patients and in the chronic form in 26. The function of hypothalamic-pituitary-gonad, thyroid, somatotrophic, and adrenal axes was assessed.

RESULTS

The most common endocrine dysfunction was ovarian insufficiency (95% of women), followed by an increase in follicle-stimulating hormone in 47% of men, indicating spermatogenesis damage. Hormone replacement therapy was contraindicated in three women because of chronic liver GVHD and it was ineffective partially in four others because of reduced intestinal or cutaneous absorption. Thyroid dysfunction occurred in 47.5% of patients and included low T3 syndrome, chronic thyroiditis, and transient subclinical hyperthyroidism and subclinical hypothyroidism. Adrenal function was abnormal in 10%, mostly related to the prolonged corticosteroid treatment. IGF-I was lower than age-reference values in 27% of all patients and in 38% of those with chronic GVHD. Thyroid, adrenal, and IGF-I impairments were more frequent in patients with chronic GVHD than in patients without this disease (P = 0.048).

CONCLUSIONS

A high prevalence of endocrine dysfunction was detected in a cohort of allo-BMT recipients not treated by TBI. Although gonadal failure was likely related to intensive myeloablative treatments, thyroid, adrenal, and IGF-I impairments were late events, suggesting that immunosuppressive treatment and immune system derangement may play a role in the development of endocrine dysfunction after allografting.

Stem cell transplantation: supportive care and long-term complications

With increasing hematopoietic stem cell transplant (HSCT) activity and improvement in outcomes, there are many thousands of HSCT survivors currently being followed by non-transplant clinicians for their healthcare. Several types of late sequelae from HSCT have been noted, and awareness of these complications is important in minimizing late morbidity and mortality. Late effects can include toxicities from the treatment regimen, infections from immunodeficiency, endocrine disturbances, growth impairment, psychosocial adjustment disorders, second malignancies, and chronic graft-versus-host disease (GVHD). A variety of risk factors for these complications have been noted. The clinician should be alert to the potential for these health issues. Preventive and treatment strategies can minimize morbidity from these problems and optimize outcomes.

Busulfan plus cyclophosphamide compared with total-body irradiation plus cyclophosphamide before marrow transplantation for myeloid leukemia: long-term follow-up of 4 randomized studies

In the early 1990s, 4 randomized studies compared conditioning regimens before transplantation for leukemia with either cyclophosphamide (CY) and total-body irradiation (TBI), or busulfan (Bu) and CY. This study analyzed the long-term outcomes for 316 patients with chronic myeloid leukemia (CML) and 172 patients with acute myeloid leukemia (AML) who participated in these 4 trials, now with a mean follow-up of more than 7 years. Among patients with CML, no statistically significant difference in survival or disease-free survival emerged from testing the 2 regimens. The projected 10-year survival estimates were 65% and 63% with Bu-CY versus CY-TBI, respectively. Among patients with AML, the projected 10-year survival estimates were 51% and 63% (95% CI, 52%-74%) with Bu-CY versus CY-TBI, respectively. At last follow-up, most surviving patients had unimpaired health and had returned to work, regardless of the conditioning regimen. Late complications were analyzed after adjustment for patient age and for acute and chronic graft-versus-host disease (GVHD). CML patients who received CY-TBI had an increased risk of cataract formation, and patients treated with Bu-CY had an increased risk of irreversible alopecia. Chronic GVHD was the primary risk factor for late pulmonary disease and avascular osteonecrosis. Thus, Bu-CY and CY-TBI provided similar probabilities of cure for patients with CML. In patients with AML, a nonsignificant 10% lower survival rate was observed after Bu-CY. Late complications occurred equally after both conditioning regimens (except for increased risk of cataract after CY-TBI and of alopecia with Bu-CY).

Health and functional status of adult recipients 1 year after allogeneic haematopoietic stem cell transplantation

Increasing numbers of patients are surviving after allogeneic haematopoietic stem cell transplantation (SCT). Among these patients, a number of late complications have been described but few data on the risk factors of these long-term effects of SCT are available. We report the analysis on 105 adult patients, surviving free of haematological disease at a median time of 15 months after SCT. At the time of screening, 52% had returned to work, general health status was normal in 67% and 47% were sexually active. Female patient gender odds ratio (OR) 2.9 (P = 0.01) and age > 25 years (OR = 3.2, P = 0.02) were associated with non-return to work. Decreased general status was associated with chronic graft-versus-host disease (GvHD) (OR = 3.2, P = 0.009) and irradiation (OR = 3.6, P = 0.004). Sexual inactivity was associated with younger age (OR = 7.0, P = 0.0002) and chronic GvHD (OR = 3.3, P = 0.006). Risk factors for altered pulmonary function tests included previous smoking habits, irradiation and chronic GvHD. Obstructive lung disease was associated with a previous history of asthma. Sicca syndrome and conjunctivitis were increased in patients with previous acute GvHD and cataracts were less frequent in patients with aplastic anaemia. Persistent impaired hair re-growth was less frequent in patients who received irradiation (OR = 0.18, P = 0.002) but increased in patients with previous acute GvHD (OR = 5.3, P = 0.007). Microalbuminuria was more frequent in irradiated patients (OR = 9.4, P = 0.05). Raised cholesterol was associated with age (OR = 20.8, P < 0.001), previous acute GvHD (OR = 4.7, P = 0.03), steroid use (OR = 6.3, P = 0.001) and familial hypercholesterolaemia (OR = 4.4, P = 0.04). Decreased bone density was associated with chronic GvHD (OR = 3.9, P = 0.001). Thus, using routine tests in adult patients we were able to detect significant numbers of-non-symptomatic complications enabling early treatment.

Thyroid function after bone marrow transplantation: possible association between immune-mediated thyrotoxicosis and hypothyroidism

BACKGROUND

Thyroid dysfunction after bone marrow transplantation (BMT) has been investigated in many studies, and most posttransplant thyroid disorders are now recognized as a late complication of transplantation. However, these studies mainly focused on late thyroid function after BMT, and we have little information on early changes of thyroid function after BMT.

METHODS

We prospectively investigated thyroid function in 57 patients receiving BMT. Serum thyroid-stimulating hormone, free triiodothyronine, and free thyroxine levels were determined at least monthly in the first 3 months, once between 3 and 12 months and once in the second year after BMT.

RESULTS

During the first 6 months after BMT, 24 and 7 patients were diagnosed as having euthyroid sick syndrome (ETS) and thyrotoxicosis, respectively. Of the 52 patients alive 1 year after transplantation, 9 patients were still diagnosed as having ETS, and 8 patients developed hypothyroidism. Patients with thyrotoxicosis showed similar characteristics, and the high incidence of thyrotoxicosis after BMT is a novel finding. The median for the onset of thyrotoxicosis was day 111 after transplantation. Thyrotoxicosis was transient in all of the patients, but in seven patients hypothyroidism followed, the median onset at 12 months after BMT. Serum thyroglobulin levels were elevated in five patients, and antibodies autoreactive to the thyroid gland were detected in seven patients.

CONCLUSIONS

Thyrotoxicosis may be a distinct clinical entity of thyroid dysfunction after BMT and may serve to predict the development of hypothyroidism. Immune-mediated thyroid injury may contribute to the development of posttransplant hypothyroidism.

Management and long-term complications of pediatric cancer

The impact of recently intensified and novel therapies for the treatment of childhood cancer has been an increased number of survivors and an increase in the number of treatment complications among survivors. Thus, it is important for the primary care practitioner to be aware of not only acute but chronic complications of therapy, including the possibility of second malignancies. Long-term follow-up is essential, and continuous education of patients and health care personnel is an important aspect for the complete success of treatment. Primary care practitioners also need to incorporate other subspecialties in the management of these patients to ensure that they receive complete evaluation and treatment.