Bone mineral density in patients undergoing bone marrow transplantation for myeloid malignancies

Bone Mineral Density in Survivors of Childhood Cancer: A Meta-Analysis

CONTEXT

There is an increasing population of childhood cancer survivors (CCS) at risk for treatment-related toxicities, including skeletal morbidities. Bone mineral density (BMD) is a proxy for bone health and reductions are associated with osteoporosis and fractures.

OBJECTIVE

To investigate bone health in CCS by conducting a systematic review and meta-analysis of BMD after completed treatments.

DATA SOURCES

We searched Medline, Embase, Cochrane, and Web of Science in May 2019 and updated in May 2023.

STUDY SELECTION

Studies reporting BMD Z-scores measured with dual-energy x-ray absorptiometry in CCS after treatment completion.

DATA EXTRACTION

We performed a pooled analysis of studies reporting BMD Z-scores and thereafter we analyzed studies comparing BMD in survivors and healthy controls. All analyses were performed based on the site of BMD measurement.

RESULTS

Of 4243 studies, 84 were included (N = 8106). The mean time off-treatment across the studies ranged from 2 months to 24 years. The overall pooled mean Z-score was -0.57 (95% confidence interval [CI] -0.59 to -0.55) in the whole-body, -0.84 (95% CI -0.86 to -0.83) in the lumbar spine, -0.79 (95% CI -0.81 to -0.77) in the femoral neck and -0.14 (95% CI -0.18 to -0.11) in the total hip. When comparing survivors with controls, BMD was significantly lower in survivors at all sites.

LIMITATIONS

English publications, study-level meta-analysis.

CONCLUSIONS

We showed a significant reduction of BMD Z-scores in CCS. Given the increased fracture risk already within -1 SD, these results emphasize the need for BMD surveillance and secondary prevention in CCS.

Endocrine sequelae of hematopoietic stem cell transplantation: Effects on mineral homeostasis and bone metabolism

Hematopoietic stem cell transplantation (HSCT) is an established therapeutic strategy for the treatment of malignant (leukemia and lymphoma) and non-malignant (thalassemia, anemia, and immunodeficiency) hematopoietic diseases. Thanks to the improvement in patient care and the development of more tolerable conditioning treatments, which has extended the applicability of therapy to the elderly, a growing number of patients have successfully benefited from HSCT therapy and, more importantly, HSCT transplant-related mortality has consistently reduced in recent years. However, concomitantly to long term patient survival, a growing incidence of late HSCT-related sequelae has been reported, being variably associated with negative effects on quality of life of patients and having a non-negligible impact on healthcare systems. The most predominantly observed HSCT-caused complications are chronic alterations of the endocrine system and metabolism, which endanger post-operative quality of life and increase morbidity and mortality of transplanted patients. Here, we specifically review the current knowledge on HSCT-derived side-effects on the perturbation of mineral metabolism; in particular, the homeostasis of calcium, focusing on current reports regarding osteoporosis and recurrent renal dysfunctions that have been observed in a percentage of HSC-transplanted patients. Possible secondary implications of conditioning treatments for HSCT on the physiology of the parathyroid glands and calcium homeostasis, alone or in association with HSCT-caused renal and bone defects, are critically discussed as well.

Persistent Musculoskeletal Deficits in Pediatric, Adolescent and Young Adult Survivors of Allogeneic Hematopoietic Stem-Cell Transplantation

Allogeneic hematopoietic stem cell transplantation (alloHSCT) is a common therapy for pediatric hematologic malignancies. With improved supportive care, addressing treatment-related late effects is at the forefront of survivor long-term health and quality of life. We previously demonstrated that alloHSCT survivors had increased adiposity, decreased lean mass, and lower bone density and strength, 7 years (median) from alloHSCT compared to their healthy peers. Yet it is unknown whether these deficits persist. Our longitudinal study characterized changes in muscle and bone over a period of 3.4 (range, 2.0 to 4.9) years in 47 childhood alloHSCT survivors, age 5-26 years at baseline (34% female). Tibia cortical bone geometry and volumetric density and lower leg muscle cross-sectional area (MCSA) were assessed via peripheral quantitative computed tomography (pQCT). Anthropometric and pQCT measurements were converted to age, sex, and ancestry-specific standard deviation scores, adjusted for leg length. Muscle-specific force was assessed as strength relative to MCSA adjusted for leg length (strength Z-score). Measurements were compared to a healthy reference cohort (n = 921), age 5-30 years (52% female). At baseline and follow-up, alloHSCT survivors demonstrated lower height Z-scores, weight Z-scores, and leg length Z-scores compared to the healthy reference cohort. Deficits in MCSA, trabecular volumetric bone density, and cortical bone size and estimated strength (section modulus) were evident in survivors (all p < 0.05). Between the two study time points, anthropometric, muscle, and bone Z-scores did not change significantly in alloHSCT survivors. Approximately 15% and 17% of alloHSCT survivors had MCSA and section modulus Z-score < -2.0, at baseline and follow-up, respectively. Furthermore, those with a history of total body irradiation compared to those without demonstrated lower MCSA at follow-up. The persistent muscle and bone deficits in pediatric alloHSCT survivors support the need for strategies to improve bone and muscle health in this at-risk population. © 2022 American Society for Bone and Mineral Research (ASBMR).

Risk Factors for Hematopoietic Stem Cell Transplantation-Associated Bone Loss

Hematopoietic stem cell transplantation (HSCT), including bone marrow transplantation, is the treatment of choice for many hematologic diseases, including hematologic malignancies and different types of anemia. The use of HSCT is increasing annually, mainly because advanced research that has been conducted in this area has exponentially expanded the indications for HSCT and significantly improved transplantation techniques and supportive care practices. Collectively, these improvements have led to an increase in the overall survival of HSCT patients. However, as post-HSCT survival is increasing, awareness of the potential late complications of HSCT is also growing. Unpredictable bone loss is one of the major post-HSCT complications that can cause significant morbidity and impair the quality of life of survivors. Although the exact mechanism of post-HSCT bone loss is not yet known, previous studies have suggested that numerous factors, including destructive preparative regimens (eg, high-dose chemotherapy, total body irradiation), treatment-related complications (eg, graft-versus-host disease), endocrine abnormalities (eg, diabetes mellitus, thyroid dysfunction, adrenal insufficiency), lack of physical activity, and the underlying disease itself are responsible for HSCT-associated bone loss. Sufficient data have been collected to suggest that post-HSCT bone loss can be prevented and treated using the same preventive and treatment modalities as used for the general population. Various guidelines have been formulated to help keep a check on HSCT recipients' deteriorating bone health.

Bone Mineral Density Evolution and Its Determinants in Long-term Survivors of Childhood Acute Leukemia: A Leucémies Enfants Adolescents Study

This prospective study aimed to analyze determinants that can influence bone mineral density evolution in childhood acute leukemia survivors. Patients included were selected from the long-term follow-up LEA cohort and had dual energy radiograph absorptiometry scan between 10 and 18 years and after the age of 18. All scans were centrally reviewed. Bone mineral density was measured at the lumbar spine, femoral neck, total hip, and whole body, and expressed as z-score. Eighty-nine patients (female 39, lymphoblastic leukemia 68, relapse 25, hematopoietic stem cell transplantation 44, and mean age 15.4 and 20.1 years at the first and second scans, respectively) were studied. The first and second scan z-scores were significantly correlated (P < 10⁻³). Mean femoral neck and total hip z-scores improved significantly between the first and second scans, whereas no significant evolution occurred at the lumbar spine and whole-body level. On the second evaluation, 14.6% of patients had z-score <−2 at the lumbar spine and 4.3% at the femoral neck level. Gender, type of leukemia, transplantation, relapse, cumulative corticosteroid doses, or growth hormone deficiency did not have any significant impact on z-score variation. Younger age at diagnosis (≤8.5 years) proved an unfavorable risk factor for z-score evolution at the lumbar spine (P = 0.041); the trend did not reach statistical significance for metabolic syndrome (P = 0.054). At the femoral neck, both were associated with unfavorable z-score evolution (P = 0.003 and 0.025, respectively). Patients treated at a younger age and those with metabolic syndrome seem to be at higher risk of bone mineral density decline and should benefit from specific interventions.

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.

Bone Health Management After Hematopoietic Cell Transplantation: An Expert Panel Opinion from the American Society for Transplantation and Cellular Therapy

Bone health disturbances commonly occur after hematopoietic cell transplantation (HCT) with loss of bone mineral density (BMD) and avascular necrosis (AVN) foremost among them. BMD loss is related to pretransplantation chemotherapy and radiation exposure and immunosuppressive therapy for graft-versus-host-disease (GVHD) and results from deficiencies in growth or gonadal hormones, disturbances in calcium and vitamin D homeostasis, as well as osteoblast and osteoclast dysfunction. Although the pathophysiology of AVN remains unclear, high-dose glucocorticoid exposure is the most frequent association. Various societal treatment guidelines for osteoporosis exist, but the focus is mainly on menopausal-associated osteoporosis. HCT survivors comprise a distinct population with unique comorbidities, making general approaches to bone health management inappropriate in some cases. To address a core set of 16 frequently asked questions (FAQs) relevant to bone health in HCT, the American Society of Transplant and Cellular Therapy Committee on Practice Guidelines convened a panel of experts in HCT, adult and pediatric endocrinology, orthopedics, and oral medicine. Owing to a lack of relevant prospective controlled clinical trials that specifically address bone health in HCT, the answers to the FAQs rely on evidence derived from retrospective HCT studies, results extrapolated from prospective studies in non-HCT settings, relevant societal guidelines, and expert panel opinion. Given the heterogenous comorbidities and needs of individual HCT recipients, answers to FAQs in this article should be considered general recommendations, with good medical practice and judgment ultimately dictating care of individual patients. Readers are referred to the Supplementary Material for answers to additional FAQs that did not make the core set.

Skeletal Morbidity in Children and Adolescents during and following Cancer Therapy

Skeletal abnormalities are common in children and adolescents diagnosed and treated for a malignancy. The spectrum ranges from mild pain to debilitating osteonecrosis and fractures. In this review, we summarize the impact of cancer therapy on the developing skeleton, provide an update on therapeutic strategies for prevention and treatment, and discuss the most recent advances in musculoskeletal research. Early recognition of skeletal abnormalities and strategies to optimize bone health are essential to prevent long-term skeletal sequelae and diminished quality of life in childhood cancer survivors.

Impaired Bone Mineral Density in Pediatric Patients with Chronic Graft-versus-Host Disease

Pediatric allogeneic hematopoietic stem cell transplantation (AHSCT) recipients with chronic graft-versus-host disease (cGVHD) are at high risk for endocrinopathies, particularly impaired bone mineral density (BMD). However, rates of BMD impairment in pediatric AHSCT recipients with cGVHD have not been well documented. We report 33 patients with cGVHD who were referred to the National Institutes of Health (NIH) for the Natural History of Clinical and Biological Factors Determining Outcomes in Chronic Graft-versus-Host Disease Study (NCT 0092235) and underwent formal BMD assessment via dual-energy X-ray absorptiometry (DEXA). Not surprisingly, we found much higher rates of BMD impairment than previously reported for pediatric AHSCT recipients who were not stratified by the presence or absence of cGVHD. Most of these patients (73%) had a z-score ≤-2 in at least 1 anatomic site. Although we expected the rate to be higher than that observed for pediatric AHSCT recipients in studies that did not analyze patients with cGVHD separately, this rate is nonetheless extremely high. Furthermore, the overall rate of occult vertebral compression fractures (VCFs) in our cohort was 17%, and the rate was 23% in patients with at least 1 z-score of ≤-2. The rates of BMD impairment and VCF in our pediatric cohort were significantly higher than those seen in the adult AHSCT recipients who were concurrently enrolled on the same study at the NIH and had similar cGVHD severity. We found that older age at cGVHD diagnosis and a greater number of systemic therapies were associated with occult VCF. Moreover, the intensity of current immunosuppression negatively impacted lumbar spine and total hip BMD in this cohort. Our study, although limited by small patient numbers and lack of a control AHSCT recipient group without cGVHD, indicates that children with cGVHD are at a greater risk for BMD impairment than previously appreciated. Given the rising incidence of cGVHD in AHSCT recipients and our findings, we recommend that pre-AHSCT DEXA be incorporated into routine pediatric pretransplantation screening studies. A baseline DEXA study could facilitate longitudinal monitoring of BMD in children, who may be more susceptible than adults to the negative effects of AHSCT on BMD. In addition, given the high risk of BMD impairment in pediatric AHSCT recipients with cGVHD, such patients should undergo BMD evaluation upon developing cGVHD, with continued monitoring thereafter to allow intervention before progression of the BMD impairment to its severe manifestation, VCF.

DIAGNOSIS OF ENDOCRINE DISEASE: Endocrine late-effects of childhood cancer and its treatments

Endocrine complications are frequently observed in childhood cancer survivors (CCS). One of two CCS will experience at least one endocrine complication during the course of his/her lifespan, most commonly as a late-effect of cancer treatments, especially radiotherapy and alkylating agent chemotherapy. Endocrine late-effects include impairments of the hypothalamus/pituitary, thyroid and gonads, as well as decreased bone mineral density and metabolic derangements leading to obesity and/or diabetes mellitus. A systematic approach where CCS are screened for endocrine late-effects based on their cancer history and treatment exposures may improve health outcomes by allowing the early diagnosis and treatment of these complications.

National Institutes of Health Hematopoietic Cell Transplantation Late Effects Initiative: The Research Methodology and Study Design Working Group Report

The increasing numbers of hematopoietic cell transplantations (HCTs) performed each year, the changing demographics of HCT recipients, the introduction of new transplantation strategies, incremental improvement in survival, and the growing population of HCT survivors demand a comprehensive approach to examining the health and well-being of patients throughout life after HCT. This report summarizes strategies for the conduct of research on late effects after transplantation, including consideration of the study design and analytic approaches; methodologic challenges in handling complex phenotype data; an appreciation of the changing trends in the practice of transplantation; and the availability of biospecimens to support laboratory-based research. It is hoped that these concepts will promote continued research and facilitate the development of new approaches to address fundamental questions in transplantation outcomes.

Changes in bone mineral density and bone turnover markers in patients undergoing hematopoietic stem cell transplant

INTRODUCTION

Hematopoietic stem cell transplant (HSCT) is frequently complicated by endocrine abnormalities and loss of bone mass. This prospective study was conducted to evaluate the bone loss post-HSCT.

MATERIALS AND METHODS

A total of 50 patients was evaluated pretransplantation, and 25 had HSCT (17 males, 8 females; 19 allogenic, 6 autologous). Bone mineral density (BMD) and bone markers were measured at baseline, 3-6 months and 12 months.

RESULTS

The mean age and body mass index were 25.1 ± 16.3 years and 19.4 ± 4.5 kg/m(2), respectively. There were 15 adults (60%), and 10 adolescents (40%). There was a significant decline in BMD from the baseline at total femur (-8.7%; P < 0.0001), femoral neck (-5.0%; P = 0.003), femoral trochanter (-6.0%; P = 0.001), and Ward's triangle (-9.9%; P < 0.0001) at 6 months posttransplantation. From the 6 months to 12 months, there was a significant improvement in BMD at above sites except at Ward's triangle. The decline in BMD was nonsignificant at the whole body (-0.3%, P = 0.748) and the lumbar spine (-2.7%, P = 0.130) at 6 months posttransplant. Younger patients with allogenic graft and steroid use are more likely to have significant loss of BMD at hip posttransplant. Serum osteocalcin decreased, and N-telopeptide increased at 3-6 months, which return to baseline at 1-year posttransplant.

CONCLUSIONS

A significant bone loss is observed at 6 months in patients with post-HSCT. The bone loss occurs predominantly at cortical bone. There is recovery of bone mass at 12 months posttransplant except at Ward's triangle. Bone loss after HSCT is multifactorial.

Bone morbidity in childhood leukemia: epidemiology, mechanisms, diagnosis, and treatment

Skeletal abnormalities are commonly seen in children and adolescents with leukemia. The spectrum ranges from mild pain to debilitating osteonecrosis (ON) and fractures. In this review, we summarize the skeletal manifestations, provide an update on therapeutic strategies for prevention and treatment, and discuss the most recent advances in musculoskeletal research. Early recognition of skeletal abnormalities and strategies to optimize bone health are essential to prevent long-term skeletal sequelae and diminished quality of life observed in children and adolescents with leukemia.

Low bone mineral content and challenges in interpretation of dual-energy X-ray absorptiometry in children with mucopolysaccharidosis types I, II, and VI

Osteoporosis has been described in animal models of mucopolysaccharidosis (MPS). Whether clinically significant osteoporosis is common among children with MPS is unknown. Therefore, cross-sectional data from whole body (WB; excluding head) and lumbar spine (LS) bone mineral density (BMD) compared with sex-, chronologic age-, and ethnicity-matched healthy individuals (Zage), height-for-age (HAZ) Z-score (ZHAZ) and bone mineral content (BMC) measured by dual-energy X-ray absorptiometry (DXA) in 40 children with MPS were analyzed. A subset of these children (n=24) was matched 1:3 by age and sex to a group of healthy children (n=72) for comparison of BMC adjusted for Tanner stage, race, lean body mass, height, and bone area. Low BMD Z-score was defined as Z-score of -2 or less. In children with MPS, 15% had low WB Zage and 48% had low LS Zage; 0% and 6% had low WB ZHAZ and low LS ZHAZ, respectively. Adjusted WB BMC was lower in MPS participants (p=0.009). In conclusion, children with MPS had deficits in WB BMC after adjustments for stature and bone area. HAZ adjustment underestimated bone deficits (i.e., overestimated WB BMD Z-scores) in children with MPS likely owing to their abnormal bone shape. The influence of severe short stature and bone geometry on DXA measurements must be considered in children with MPS to avoid unnecessary exposure to antiresorptive treatments.

Bone mineral density, vitamin D, and nutritional status of children submitted to hematopoietic stem cell transplantation

OBJECTIVE

The aim of the study was to evaluate the effect of allogeneic hematopoietic stem cell transplantation (HSCT) on bone mineral density (BMD), serum vitamin D levels, and nutritional status of 50 patients between ages 4 and 20 y.

METHODS

We conducted pre-HSCT and 6-mo post-HSCT evaluations. We measured BMD at the lumbar spine (LS) and total body (TB) by dual energy x-ray absorptiometry (DXA); body composition by bioimpedance analysis, and dietary intakes of calcium and vitamin D using the 24-h recall and semiquantitative food frequency questionnaire methods.

RESULTS

We observed a significant reduction in BMD 6 mo post-HSCT. Nearly half (48%) of patients had reductions at the LS (average -9.6% ± 6.0%), and patients who developed graft-versus-host disease (GVHD) had the greatest reductions (-5.6% versus 1.2%, P < 0.01). We also found reductions in serum levels of 25-hydroxyvitamin D (25-OHD), from 25.6 ± 10.9 ng/dL to 20.4 ± 11.4 ng/dL (P < 0.05), and in body weight. Corticosteroid treatment duration, severity of chronic GVHD, serum 25-OHD levels, and family history of osteoporosis were all risk factors associated with variations in BMD at the LS.

CONCLUSION

HSCT in children and adolescents negatively effects their BMD, nutritional status, and vitamin D levels. We suggest that early routine assessment be done to permit prevention and treatment.

Bone mineral deficits in recipients of hematopoietic cell transplantation: the impact of young age at transplant

Low bone mineral density (BMD) has been reported in recipients of pediatric hematopoietic cell transplantation (HCT), but it is unclear whether age at HCT plays a role. The objective of this cross-sectional study was to determine if patients treated with HCT before age 10 years have long-term BMD deficits compared to patients transplanted at an older age and to sibling controls. The study included 151 HCT recipients (87 males), age at study 24.7±8.6 years treated with HCT for hematologic malignancies at age 10.9±6.4 years, and 92 healthy sibling controls (49 males), age at study 22.3±8.0 years. Dual-energy x-ray absorptiometry was performed to measure BMD Z-scores for total body (TBMD), lumbar spine (LBMD), and femoral neck (FNBMD, for subjects ≥20 years at study visit). Patients <10 years at HCT had significantly lower TBMD and FNBMD Z-scores (by 0.5 and 0.8 SD, respectively) compared to controls (P=0.003 and P=0.0001, respectively) and patients >18 years at HCT (P=0.04 and P=0.004, respectively) at an average of 14 years after HCT. In conclusion, this study identified young age at transplant as an important risk factor for bone deficits in young adulthood, suggesting that efforts to reduce bone loss should focus on this patient population.

Changes in biomarkers of bone resorption over the first six months after pediatric hematopoietic cell transplantation

Bone loss has been observed within the first six months after HCT in both children and adults. While there is some evidence that bone formation may be reduced in children after HCT, it is currently unknown whether bone resorption is increased. The objective of this prospective study was to evaluate changes in markers of bone resorption over the first six months after pediatric HCT. Twenty-six participants (eight females) aged 10.9 ± 3.4 yr entered the study prior to HCT. Bone resorption was measured by urine DPD and PYD, and by plasma NTX and CTX. Seventeen participants who completed day +30 visit and either day +100 or +180 visits were included in the analysis. DPD increased between days +30 and +100 (mean change, 11.3 nmol/nmol creatinine; p = 0.012) and between days +30 and +180 (13.7 nmol/nmol creatinine; p = 0.036). PYD increased between days +30 and +100 (32 nmBCE/L; p = 0.019). CTX increased between baseline and day +100 (5.9 μg/L; p = 0.012). Changes in NTX levels were not statistically significant. This study shows that markers of bone resorption increase in children after HCT, suggesting that increased resorption may be a contributing factor to the pathophysiology of bone loss after pediatric HCT.

Bone density and structure in long-term survivors of pediatric allogeneic hematopoietic stem cell transplantation

Children requiring allogeneic hematopoietic stem cell transplantation (alloHSCT) have multiple risk factors for impaired bone accrual. The impact of alloHSCT on volumetric bone mineral density (vBMD) and cortical structure has not been addressed. Tibia peripheral quantitative computed tomography (pQCT) scans were obtained in 55 alloHSCT recipients, ages 5 to 26 years, a median of 7 (range, 3-16) years after alloHSCT. pQCT outcomes were converted to sex- and race- specific Z-scores relative to age based on reference data in >700 concurrent healthy participants. Cortical section modulus (Zp; a summary measure of cortical bone structure and strength), and muscle and fat area Z-scores were further adjusted for tibia length for age Z-scores. AlloHSCT survivors had lower height Z-scores (-1.21 ± 1.25 versus 0.23 ± 0.92; p < 0.001), versus reference participants; BMI Z-scores did not differ. AlloHSCT survivors had lower trabecular vBMD (-1.05; 95% confidence interval [CI], -1.33 to -0.78; p < 0.001), cortical Zp (-0.63; 95% CI, -0.91 to -0.35; p < 0.001), and muscle (-1.01; 95% CI, -1.30 to -0.72; p < 0.001) Z-scores and greater fat (0.82; 95% CI, 0.54-1.11; p < 0.001) Z-scores, versus reference participants. Adjustment for muscle deficits eliminated Zp deficits in alloHSCT. Total body irradiation (TBI) was associated with lower trabecular vBMD (-1.30 ± 1.40 versus -0.49 ± 0.88; p = 0.01) and muscle (-1.34 ± 1.42 versus -0.34 ± 0.87; p < 0.01) Z-scores. Growth hormone deficiency (GHD) was associated with lower Zp Z-scores (-1.64 ± 2.47 versus -0.28 ± 1.24; p = 0.05); however, muscle differences were not significant (-1.69 ± 1.84 versus -0.78 ± 1.01; p = 0.09). History of graft versus host disease was not associated with pQCT outcomes. In summary, alloHSCT was associated with significant deficits in trabecular vBMD, cortical geometry, and muscle area years after transplantation. TBI and GHD were significant risk factors for musculoskeletal deficits. Future studies are needed to determine the metabolic and fracture implications of these deficits, and to identify therapies to improve bone accrual following alloHSCT during childhood.

NCI, NHLBI/PBMTC first international conference on late effects after pediatric hematopoietic cell transplantation: endocrine challenges-thyroid dysfunction, growth impairment, bone health, & reproductive risks

The endocrine system is highly susceptible to damage by high-dose chemotherapy and/or irradiation before hematopoietic cell transplantation (HCT) during childhood. The specific endocrine organs most affected by HCT include the thyroid gland, the pituitary, and the gonads. In addition, hormones that support development and stability of the skeletal system are also affected. Insufficiency of thyroid hormone is 1 of the most common late sequelae of HCT, and occurs more often in young children. Deficiency in the pituitary's production of growth hormone is a problem of unique concern to the pediatric population. The reproductive risks of HCT depend on the patient's gender and pubertal status at the time of HCT. Pubertal or gonadal failure frequently occurs, especially in females. Infertility risks for both genders remain high, whereas methods of fertility preservation are limited in all but postpubertal males. Bone health post-HCT can be compromised by low bone mineral density as well as avascular necrosis, but the data on both problems in the pediatric HCT population are limited. In this paper, the current state of knowledge, gaps in that knowledge, and recommendations for future research are addressed in detail for each of these systems.

Bone mineral density in adult survivors of childhood acute leukemia: impact of hematopoietic stem cell transplantation and other treatment modalities

Femoral and lumbar bone mineral densities (BMDs) were measured in 159 adults enrolled in the Leucémies de l'Enfant et de l'Adolescent program, a French prospective multicentric cohort of childhood leukemia survivors. BMDs were expressed as Z-scores, and multivariate linear regression analyses were used to construct association models with potential risk factors. Mean age at evaluation and follow-up was 23 and 14.7 years, respectively. In the whole cohort, mean femoral Z-score was -0.19 ± 0.08. Two factors were associated with lower femoral BMD transplantation (-0.49 ± 0.15 vs -0.04 ± 0.10 in the chemotherapy group; P = .006) and female sex (-0.34 ± 0.10 vs -0.03 ± 0.13; P = .03). Among patients who received a transplant, the only significant risk factor was hypogonadism (-0.88 ± 0.16 vs -0.10 ± 0.23; P = .04). A slight reduction in lumbar BMD (mean Z-score, -0.37 ± 0.08) was detected in the whole cohort without difference between the transplantation and chemotherapy groups. Among patients who received a transplant, younger age at transplantation was correlated with a low lumbar BMD (P = .03). We conclude that adults who had received only chemotherapy for childhood leukemia have a slight reduction in their lumbar BMD and a normal femoral BMD. Patients who received a transplant with gonadal deficiency have a reduced femoral BMD which might increase the fracture risk later in life.

Screening, prevention and management of osteoporosis and bone loss in adult and pediatric hematopoietic cell transplant recipients

Long-term survivors of hematopoietic cell transplantation (HCT) are at risk for loss of bone mineral density (BMD) and subsequent osteoporosis. There is a lack of clear guidelines for the screening, prevention and treatment of bone loss after HCT. We reviewed the prevailing literature and provide guidelines developed by our center for the screening and management of this complication. Bone loss occurs predominantly within the first 6-12 months after autologous and allogeneic HCT. Recovery first occurs in the lumbar spine and is followed by a slower recovery of BMD in the femoral neck. BMD may not return to baseline levels in patients with continuing exposure to corticosteroids and calcineurin inhibitors. All HCT recipients should be advised general interventions to reduce fracture risk including adequate intake of calcium and vitamin D. We recommend screening all adult allogeneic and autologous HCT recipients with dual-energy X-ray absorptiometry 1 year after transplantation. Patients at high risk for bone loss (for example, patients receiving ≥ 5 mg of prednisone equivalent daily for > 3 months) can be screened earlier (for example, 3-6 months after HCT). Where indicated, bisphosphonates or other anti-resorptive agents (for example, calcitonin) can be used for prevention or treatment of osteoporosis in adult HCT recipients. Pediatric HCT recipients should be referred to a pediatric endocrinologist for evaluation and treatment of bone loss. There remain several areas of uncertainty that need further research in adult and pediatric HCT recipients, such as the optimal timing and frequency of screening for loss of bone mineral density, relationship of bone loss with risk of fractures, selection of appropriate patients for pharmacologic therapy, and optimal dosing schedule and duration of therapy with anti-resorptive agents.

Quantitative ultrasound detects bone changes following bone marrow transplantation in pediatric subjects with hematological diseases: a longitudinal study

BACKGROUND

Bone marrow transplantation (BMT) is associated with bone morbidity. We investigated bone status with quantitative ultrasound (QUS) in pediatric patients with hematological diseases prior to and up to 3 yr following BMT.

METHODS

Phalangeal QUS measures for amplitude- dependent speed of sound (Ad-SoS) and bone transmission time (BTT) were obtained in 40 hematological patients (25 with malignant, 15 with non-malignant disease; 9.7+/-4.9 yr) before BMT and 6, 12, 24, and 36 months after BMT. Bone parameters were expressed as Z-scores based on age-sex-matched normal controls.

RESULTS

Mean Ad-SoS and BTT Z-scores were normal before BMT and reduced at 36 months (analysis of variance: p=0.0542 and p=0.0233). Ad-SoS and BTT Z-scores remained relatively stable in the first 6 months after BMT and then progressively decreased reaching a plateau at 12-36 months. In non-malignant patients, BTT Z-score decreased at 6-12 months (p=0.029) and subsequently increased, while in malignant patients BTT Z-score showed a decrease at 12-24 months. Pre-pubertal subjects displayed a drop of BTT Z-Score values at both 12 (p=0.023) and 36 months after BMT (p=0.049), while BTT Z-score remained relatively unchanged in pubertal subjects. Early impairment of BTT Z-score was found in patients who suffered acute graft versus host disease (GVHD) compared to patients without this clinical condition; BTT Z-score was lower at 36 months (p=0.045).

CONCLUSIONS

Longitudinal assessment by QUS of pediatric BMT survivors evidenced that bone status is mildly affected up to 36 months after BMT, mainly in malignant patients, in pre-pubertal subjects at BMT and in patients who suffered acute GVHD.

Bone mineral density after bone marrow transplantation in childhood: measurement and associations

This study examined the bone mineral density (BMD) of 46 (median age 16.3, 8-29) survivors of autologous and allogeneic bone marrow transplantation (BMT). Areal (g/m2) BMD was acquired with dual energy x-ray absorptiometry and volumetric (g/cm3) BMD values were calculated. Abnormal BMD was identified in 24% (11/46) of survivors with areal measures and 22% (10/46) with volumetric measures. Comparison of areal and volumetric BMD revealed the measures were highly correlated (r = 0.73, p<0.001) but clinical diagnosis of osteopenia/osteoporosis were not consistent. Volumetric z-scores were higher for 7/8 of the survivors who were < 3rd percentile for height. Associations of BMD and body composition and disease and treatment factors were assessed with multiple linear regression. When controlling for other significant associations and cumulative steroid dose, the body composition measure of fat mass index (FMI) was associated with higher volumetric BMD z-scores (CI: 0.006, 0.193; p = 0.037). CNS irradiation (CI: -1.710,-0.200; p = 0.015), age at time of testing (CI: -0.116, -0.024; p = 0.004) and female sex (CI: -1.375, -0.155; p = 0.015) were associated with lower volumetric BMD z-scores.

CONCLUSIONS

Childhood BMT survivors are at risk for diminished BMD. Areal and volumetric DEXA derived measures of BMD are highly correlated and volumetric measures may correct for underestimation of BMD in BMT survivors who are small for age. Survivors who received CNS irradiation, are older and female may be at greater risk for diminished BMD while fat mass is associated with higher BMD in childhood BMT survivors.

The burden of cure: long-term side effects following hematopoietic stem cell transplantation (HSCT) in children

Children who survive hematopoietic stem cell transplantation (HSCT) are at risk for an inordinate number of long-term side effects. Late effects can be secondary to the underlying diagnosis for which the transplant is performed, prior treatment of the disease, the transplant preparative regimen, treatment of the complications of transplant, and immunologic interactions between the graft and the host. This article describes the risks and manifestations of the most commonly reported late effects in survivors of pediatric HSCT.

Pediatric hematopoietic stem cell transplantation and the role of imaging

The use of hematopoietic stem cell transplantation (HSCT) in the treatment of children afflicted with many potentially fatal malignant and nonmalignant diseases is well recognized. Although outcomes continue to improve and the utility of HSCT is increasing, HSCT remains a complicated process necessitating support from many medical disciplines, including radiology. Importantly, children who undergo HSCT are at risk for the development of specific complications that are linked to the timeline of transplantation, as well as to the relationship between the underlying diagnoses, severe immune deficiency, cytoreductive regimen, and graft-versus-host reactions. An understanding of the complex interplay of the immune status, therapeutic regimen, and disease allows increased diagnostic accuracy. Successful treatment of these high-risk children requires that radiologists who are involved with their care be familiar with broad concepts, as well as with specific problems that frequently occur following HSCT. In this article, the clinical aspects of pediatric HSCT are summarized, including common complications, and imaging features of these complications are described.

Quantitative ultrasound detects bone impairment after bone marrow transplantation in children and adolescents affected by hematological diseases

PURPOSE

Bone marrow transplantation (BMT) recipients are at risk of bone mass impairment and skeletal morbidity. We investigated bone status with quantitative ultrasound (QUS) technique in children and adolescents with hematological diseases before and after BMT.

METHODS

Phalangeal QUS measures for amplitude-dependent speed of sound (AD-SoS) and bone transmission time (BTT) were obtained in 144 hematological patients (81M, 63F; 11.6+/-5.2 years); forty two were evaluated before BMT and 102 after allogeneic or autologous BMT. Bone parameters were expressed as Z-scores based on age-sex-matched normal controls.

RESULTS

Mean BTT Z-score was reduced in subjects after BMT compared to patients before BMT (M, -0.35+/-1.04 vs. 0.70+/-1.11, P<0.001; F, -0.60+/-1.23 vs. 0.23+/-1.17, P<0.05). Females and males with hormone deficiencies showed reduced BTT Z-scores when compared with subjects without hormone defects (M, -0.52+/-1.0 vs. 0.05+/-1.17, P<0.05; F, -0.50+/-1.27 vs. -0.19+/-1.26; P=0.06). AD-SoS and BTT Z-scores were reduced in 15 subjects with fractures and/or avascular osteonecrosis compared to patients without bone events (-1.52+/-1.7 vs. -0.41+/-1.32 and -0.85+/-1.19 vs. -0.10+/-1.18; both Ps<0.05). Bone event cumulative incidence was 4 times greater in subjects who suffered from chronic GVHD.

CONCLUSIONS

Assessment of phalangeal QUS in young BMT survivors points towards impairment of bone status and endocrine dysfunction and chronic GVHD as risk factors of adverse bone events.

Bone mineral density deficits in survivors of childhood cancer: long-term follow-up guidelines and review of the literature

The development of curative therapy for most pediatric malignancies has produced a growing population of childhood cancer survivors who are at increased risk for a variety of health problems resulting from their cancer or its treatment. Because of the fact that many treatment-related sequelae may not become clinically apparent until the survivor attains maturity or begins to age, the ability of primary care providers to anticipate late effects of treatment is essential for providing timely interventions that prevent or correct these sequelae and their adverse effects on quality of life. Altered bone metabolism during treatment for childhood cancer may interfere with attainment of peak bone mass, potentially predisposing to premature onset of and more severe complications related to osteopenia and osteoporosis. Bone mineral deficits have been reported after treatment for a variety of pediatric malignancies and represent morbidity that can be reduced or prevented through lifestyle changes and attention to other common cancer-related sequelae such as hypogonadism. The Children's Oncology Group long-term follow-up guidelines for survivors of childhood, adolescent, and young adult cancers provide risk-based surveillance recommendations that are based on expert opinion and review of the scientific literature for potential late effects of pediatric cancer therapy including osteopenia. This review summarizes the existing literature that has defined characteristics of cancer survivors at risk for bone mineral deficits and contributed to the surveillance and counseling recommendations outlined in the Children's Oncology group long-term follow-up guidelines.

Skeletal complications after bone marrow transplant in childhood

Childhood cancer survivors are a growing population with special medical needs. It is projected that 66% of these survivors will have at least 1 adverse health effect and 33% will have a severe, chronic, or lethal health disorder. The Institute of Medicine (2003) has recognized the skeletal system to be at risk for long-term complications from treatment for childhood cancer. Bone marrow transplant is frequently used to treat childhood malignancies and is known to cause skeletal complications. Complex mechanisms contribute to skeletal outcomes after bone marrow transplant, all of which can affect optimal physical functioning. Nurses have taken an important role in providing clinical care and conducting research for this population. A thorough understanding of the mechanisms involved in skeletal complications can help the nurse provide state-of-the-art care and design studies to promote optimal results for bone marrow transplant survivors. This article reviews the literature on skeletal complications associated with allogeneic bone marrow transplant and identifies incidence, etiology, symptoms, monitoring, and treatment of specific complications.

Endocrine complications of hematopoietic stem cell transplantation

Advances in hematopoietic stem cell transplantation (HSCT) have resulted in broader indications for this therapeutic modality in both malignant diseases and nonmalignant conditions. This article focuses on the late endocrine abnormalities that are most commonly observed following successful HSCT, with a special emphasis on pediatric HSCT recipients, for whom long-term follow-up data are increasingly available.

High prevalence of early-onset osteopenia/osteoporosis after allogeneic stem cell transplantation and improvement after bisphosphonate therapy

Osteopenia/osteoporosis (O/O) has been associated with allogeneic stem cell transplantation (alloSCT). We retrospectively reviewed 102 patients undergoing a first alloSCT from 2000 to 2005 at our center to evaluate the prevalence of O/O < or =6 and >6 months post-alloSCT. Fifty-six patients did not have a dual energy X-ray absorptiometry (DXA) scan following alloSCT. Approximately half (n=13/27) of those with a first DXA scan < or =6 months post-alloSCT had O/O and a similar rate (n=9/19) was seen in those with a first DXA scan >6 months. There were no significant differences in patient characteristics between the normal and O/O groups. The dual femur (DF) appeared to be more vulnerable to alloSCT-induced bone mineral density (BMD) loss than the lumbar spine (LS), regardless of screening time. O/O patients were treated with bisphosphonates and 41% had a repeat DXA scan post-treatment. No patient developed jaw osteonecrosis and significant BMD improvement was seen at the LS (mean BMD, 1.03+/-0.13 vs 1.08+/-0.12, P=0.004) but not the DF (mean BMD, 0.84+/-0.06 vs 0.85+/-0.08, P=0.29), indicating BMD loss at the DF is more resistant than the LS to antiresorptive therapy. Our results demonstrate that O/O is an early and late complication post-alloSCT and bisphosphonate treatment reverses BMD loss at the LS.

Bisphosphonate therapy for reduced bone mineral density in children with chronic graft-versus-host disease

Reduced bone mineral density (BMD) occurs frequently in children after hematopoietic cell transplantation (HCT), but therapy for this complication is undefined. To determine the impact of bisphosphonate therapy on reduced BMD after HCT, we compared baseline and follow-up dual energy X-ray absorptiometry (DEXA) scans of 48 patients (controls) who received calcium and vitamin D to 18 patients who also received bisphosphonate therapy. Among the controls, median annualized increase in standardized BMD (sBMD) was 10% (range, -26% to +41%), but the deviation of sBMD from normal, as indicated by the Z-score, did not improve from baseline, -2.46 (range: -5.15 to -1.16) compared to follow-up, -2.79 (range: -5.76 to +0.07). For the bisphosphonate-treated patients, the median annualized increase in sBMD was 33% (range 3% to 147%, P = .0002) and the median Z-score improved from -3.57 (range: -5.13 to -0.86) at baseline, to -1.80 (-4.89 to +0.47) at follow-up (P = .06). The annualized median change in BMD Z-scores per year was +0.12 (-2.28 to +4.24) among the controls and +1.43 (-0.29 to +3.72) for the bisphosphonate group (P = .0002). The greatest improvement in BMD was observed in children who received therapy with bisphosphonates.

Adverse Late Effects of Childhood Cancer and Its Treatment on Health and Performance

More than 12,000 newly diagnosed cases of cancer occur each year in the United States among children ages 20 years or younger, and the current 5-year survival rate is near 80%. An estimated 228,000 among adults 47 years or younger and currently living in the United States had a diagnosis of cancer during childhood or adolescence. Here, we review long-term adverse effects of childhood cancer and its treatment with an emphasis on physical performance and health. We also briefly review existing guidelines that may be used to develop appropriate exercise and diet interventions for childhood cancer survivors. We suggest that there is a need for development of evidence-based, risk-based guidelines and interventions for health promotion among long-term childhood cancer survivors, particularly for those whose physical activity limitations interfere with chances for optimizing their bodies' potential in today's society.

Bone health in children and adolescents after allogeneic stem cell transplantation

BACKGROUND

This cross-sectional study evaluated the overall bone health and the prevalence of vertebral complications after stem cell transplantation (SCT) in prepubertal children and adolescents.

METHODS

A total of 44 children and adolescents (median age, 10 years) were evaluated at a median of 3.8 years after SCT for areal bone mineral density (aBMD) with dual-energy X-ray absoptiometry and for vertebral fractures with instant vertebral assessment. Pretransplant and posttransplant medications and nutritional parameters were recorded, and plasma levels of vitamin D, calcium, phosphate, and parathormone were measured.

RESULTS

Of the 44 patients, 16 (36%) had a BMD Z-score of <-1.0. The patients with low BMD did not differ from the others with regard to their clinical or biochemical characteristics. Prepubertal patients had better BMD Z-scores at all sites compared with pubertal or postpubertal subjects. This was evident especially at the hip, in which the median aBMD Z-score in prepubertal patients (-0.2; range, -0.5 to +1.7) was found to be significantly higher than in pubertal (-1.1; range, -1.5 to +0.4) and postpubertal (-1.1; range, -2.6 to +0.5) patients (P = .03). Five patients (11%) had a history of peripheral fractures. Nine patients (20%) had vertebral compression fractures, which were asymptomatic in 7 patients.

CONCLUSIONS

Approximately one-third of patients who had undergone allogeneic SCT in childhood were found to have a reduced BMD before reaching adulthood. This was due in part to inadequate BMD gain during the pubertal years. The high prevalence of asymptomatic vertebral compression fractures calls for the systematic assessment of spinal health during the posttransplantation follow-up.

Risk factors for reduced areal bone mineral density in young adults with stem cell transplantation in childhood

Slightly, but significantly, reduced bone mineral density (BMD) has been detected as a late effect after stem cell transplantation (SCT) performed in childhood. The aim of the study was to evaluate the risk factors of reduced BMD after SCT in childhood. We evaluated areal BMD of 16 young adults (six males, 10 females), aged 21 yr (range 15-34) by dual-energy X-ray absorptiometry at the lumbar spine, at the femoral neck, in the total hip, and in the total body. Bone turnover rate was evaluated by markers of bone formation and resorption. Six of the 16 patients had reduced BMD with a Z-score of < or = -1 at least at one measurement site. Factors associated with reduced BMD were prepubertal status at transplant (p = 0.03), delayed pubertal growth (p = 0.03), pubertal onset gonadal hormone insufficiency (p = 0.02), and female sex (p = 0.02). Surprisingly, height in SDs and lumbar spine BMD correlated negatively (p = 0.008) in those with reduced bone mass, indicating that low areal density could not be due the small size of the vertebrae. Bone turnover markers were similar for those with normal and reduced BMD. In conclusion, 38% of the SCT long-term survivors had reduced areal BMD. Prepubertal status at transplant with pubertal onset gonadal hormone insufficiency and female sex predisposed to reduced bone mass after SCT performed in childhood.

Preventing organ-specific chemotherapy toxicity

Recent advances in treatment for pediatric cancers has increased overall survival rates. As more and more survive pediatric cancer, we continue to see the emergence of late effects of treatment within pediatric and the growing adult survivor population. The evaluation of late effects was initiated approximately two decades ago, and has become an extremely important facet of pediatric oncology. This review delves into several of the most serious organ-specific late effects of pediatric cancer treatment, outline what we know and what we do not currently understand about preventing or reducing them. Clinical and bench research are necessary to develop interventions that will avoid or mitigate late effects and improve the health of pediatric cancer survivors.

Strategic approaches to osteoporosis in transplantation

Recipients of stem cell transplantation are at risk for osteopenia and osteoporosis. Longitudinal studies performed in adults have shown that significant bone demineralization occurs following myeloablative therapy and subsequent immune suppression. Among children and adolescents, cross-sectional analyses indicate that younger patients are also at risk for long-term bone toxicity. Strategies to detect and manage this disorder in pediatric SCT recipients are presented.

Bone mineral density and osteonecrosis in survivors of childhood allogeneic bone marrow transplantation

Our purpose was to evaluate frequency and severity of bone mineral decrements and frequency of osteonecrosis in survivors of pediatric allogeneic bone marrow transplantation (alloBMT). We retrospectively reviewed demographic information, treatment, magnetic resonance (MR) imaging studies (hips and knees), and bone mineral density (BMD) studies of 48 patients as measured by quantitative computed tomography (QCT). In all, 24 patients were male; 37 were Caucasian. Median age at alloBMT was 10.3 years (1.6-20.4 years). Of the 48 patients, 43 underwent QCT. Median time between alloBMT and imaging was 5.1 years (1.0-10.2 years). Median BMD Z-score was -0.89 (-4.06 to 3.05). BMD Z-score tended to be associated with female sex (P=0.0559) but not with age at BMT, race, primary diagnosis, time from alloBMT, T-cell depletion of graft, total-body irradiation, or acute/chronic graft-versus-host disease (GVHD). MR showed osteonecrosis in 19 of 43 (44%). We found no associations between osteonecrosis and sex, race, diagnosis, age at BMT, history of GVHD, time from BMT, or T-cell depletion. Seven patients (15%) had MR changes of osteonecrosis and BMD Z-scores of less than -1 s.d. We conclude that pediatric alloBMT survivors have decreased BMD and are at risk of osteonecrosis. They should be monitored to assure early intervention that may ameliorate adverse outcomes.

Bone mineral density in pediatric transplant recipients

BACKGROUND

Reduced bone mass and fragility fractures are known complications after transplantation in adults. Far less is known about the skeletal effects of transplantation in children and adolescents.

METHODS

This cross-sectional study examined the skeletal status of children (ages 9-18 years) who were at least 1 year post-cardiac (n=13), post-renal (n=8), or post-bone marrow (BMT; n=15) transplantation. Bone mass at total hip, femoral neck, spine (L2-4), and whole body (WB) was determined by dual energy x-ray absorptiometry and compared with age, sex, and ethnic-specific reference data. Standard deviations (z-scores) were calculated for both areal bone mineral density (BMD) and estimated volumetric bone density (bone mineral apparent density [BMAD]).

RESULTS

Cardiac transplant patients had significantly lower BMD z-scores compared with the reference population at all skeletal sites. BMT recipients had significantly reduced BMD z-scores at total hip, spine, and WB. Kidney transplant patients had a significantly reduced WB BMD z-score only. Spine BMAD z-scores remained significantly reduced in cardiac and BMT subjects. Three of 36 patients had radiographic evidence of spinal fracture after transplantation. No correlation between steroid dosage and any measure of bone mass was observed.

CONCLUSIONS

Cardiac and BMT recipients had reduced BMD at multiple skeletal sites, and renal transplant recipients had reduced WB BMD for age. Deficits in spine bone density persisted after correcting for small bone size using BMAD. Low bone density and the occurrence of vertebral fractures indicate that cardiac, renal, and bone marrow transplantation in children is associated with reduced bone health.

Bone turnover following autologous transplantation in multiple myeloma

Most patients with multiple myeloma have lytic lesions at multiple sites in the axial skeleton. These lesions commonly give pain and are at risk of pathological fracture, and bony disease is therefore a cause of much morbidity in myeloma. Recent data indicates that the Receptor Activator of NF-kappaB ligand (RANKL) and Osteoprotegerin (OPG) may be central to the local pathogenesis of these lytic lesions. Bisphosphonates may ameliorate some of these abnormalities, and clinically these agents improve the skeletal prognosis in myeloma patients. High dose chemotherapy with autologous stem cell rescue is currently under evaluation in the management of myeloma, though little is known of the effect of this therapeutic modality on the skeleton. Studies using biochemical markers of bone turnover suggest that increased osteoclast activity may be present even in apparent plateau phase of myeloma. High dose chemotherapy with autografting may normalise abnormal bone resorption, though the effect may take several weeks to emerge, and may be paralleled by increased osteoblast activity. The findings provide biochemical evidence that autografting may help normalise the abnormal bone turnover characteristic of myeloma.

Dramatic improvement of BMD following vitamin D therapy in a bone marrow transplant recipient

Bone marrow transplantation is now an established successful treatment for several hematologic malignancies. Bone loss is among the long-term adverse effects of this procedure. The underlying pathophysiology is believed to be multifactorial. We report a case of osteoporosis in a young patient who underwent allogenic bone marrow transplantation for acute lymphoblastic leukemia that was complicated by intestinal graft-versus- host disease. Her bone density measurement showed T-scores of -3.46 and -2.47 in the lumbar spine and femoral neck respectively. On evaluation, she had low normal serum calcium, low urine calcium, low 25- hydroxyvitamin D, elevated total and bone specific alkaline phosphatases, and elevated parathyroid hormone. Following treatment with calcifediol, the biochemical markers normalized and the bone mineral density increased by 88% in the lumbar spine and almost 60% in the femoral neck, both of which were above the mean for her age group. We believe that the graft-versus-host disease caused a malabsorptive state that led to vitamin D deficiency and possible resistance and consequent osteomalacia.

High-dose chemotherapy shows a dose-dependent toxicity to bone marrow osteoprogenitors: a mechanism for post-bone marrow transplantation osteopenia

BACKGROUND

Osteoporosis is a sequela of hemopoietic cell transplantation with a complex multifactorial pathogenesis in which the relative role of chemotherapy and irradiation is not completely understood. Therefore, the authors investigated the toxicity of chemotherapy-only conditioning regimens on bone homeostasis and bone marrow osteoprogenitors, its dose dependency, and the mechanism of chemotherapy-induced osteopenia.

METHODS

Fifty-one patients with high-grade non-Hodgkin lymphoma or breast carcinoma who had been treated previously with high-dose + peripheral blood progenitor cell or conventional chemotherapy or who had not received any treatment (prechemotherapy) were enrolled. The authors measured the bone marrow colony-forming unit fibroblast (CFU-f) and long-term culture-initiating cell frequency, forearm bone mineral density, serum osteotropic hormones and metabolic markers of bone formation (plasma osteocalcin), and resorption (urinary collagen I C-crosslinks).

RESULTS

Both high-dose chemotherapy regimens caused a 50% reduction in CFU-f frequency, independently of gonadal function status, whereas conventional chemotherapy and prechemotherapy groups were unaffected. Bone mineral density was measured in 26 non-Hodgkin lymphoma patients and again only high-dose chemotherapy caused a 10% loss in cortical bone and 20% in trabecular bone. No endocrine abnormality was found except for the secondary amenorrhea uniformly induced in the high-dose chemotherapy group. In these patients, plasma osteocalcin unexpectedly failed to increase in response to the menopausal increase in bone resorption rate, showing a selective impairment of the osteoblast compartment to cope with increased functional demand.

CONCLUSIONS

Chemotherapy without irradiation shows a dose-dependent toxicity to bone marrow stromal osteoprogenitors and can cause osteopenia by direct damage of the osteoblastic compartment, as a mechanism distinct from and summable to hypogonadism.

Bone marrow stromal damage after chemo/radiotherapy: occurrence, consequences and possibilities of treatment

High dose chemotherapy (CT) followed by bone marrow transplant (BMT) is increasingly used for the treatment of both hematological and solid neoplasms, but an understanding of its late consequences on the marrow microenvironment is still only at its beginning. It is in fact known that marrow stroma is damaged by high-dose cytotoxic therapy and by radiation exposure. However little is known on the extent of this damage and on the self-repair ability of the stroma. The damage of the stromal microenvironment affects the long-term stem cell engraftment and the maintenance of hemopoietic functions. Furthermore, marrow stroma also represents a progenitor compartment for endosteal osteoblasts, and therefore its damage implies alterations of bone metabolism. Indeed, osteoporosis has recently been recognized as a consequence, of BMT, but only a few studies have been performed to establish the functional status of the stromal compartment after treatment with cytotoxic drugs with or without total body irradiation (TBI) and its role in post-BMT sequelae.

Clinical responses to bone marrow transplantation in children with severe osteogenesis imperfecta

Preclinical models have shown that transplantation of marrow mesenchymal cells has the potential to correct inherited disorders of bone, cartilage, and muscle. The report describes clinical responses of the first children to undergo allogeneic bone marrow transplantation (BMT) for severe osteogenesis imperfecta (OI), a genetic disorder characterized by defective type I collagen, osteopenia, bone fragility, severe bony deformities, and growth retardation. Five children with severe OI were enrolled in a study of BMT from human leukocyte antigen (HLA)-compatible sibling donors. Linear growth, bone mineralization, and fracture rate were taken as measures of treatment response. The 3 children with documented donor osteoblast engraftment had a median 7.5-cm increase in body length (range, 6.5-8.0 cm) 6 months after transplantation compared with 1.25 cm (range, 1.0-1.5 cm) for age-matched control patients. These patients gained 21.0 to 65.3 g total body bone mineral content by 3 months after treatment or 45% to 77% of their baseline values. With extended follow-up, the patients' growth rates either slowed or reached a plateau phase. Bone mineral content continued to increase at a rate similar to that for weight-matched healthy children, even as growth rates declined. These results suggest that BMT from HLA-compatible donors may benefit children with severe OI. Further studies are needed to determine the full potential of this strategy.

Biochemical markers of bone turnover following high-dose chemotherapy and autografting in multiple myeloma

The effect of high-dose chemotherapy and autografting on bone turnover in myeloma is not known. A study of 32 myeloma patients undergoing blood or marrow transplant (BMT), conditioned with high-dose melphalan, was done. Bone resorption was assessed by urinary free pyridinoline (fPyr) and deoxypyridinoline (fDPyr), expressed as a ratio of the urinary creatinine concentration. Bone formation was assessed by serum concentration of procollagen 1 extension peptide (P1CP) and bone-specific alkaline phosphatase (BSAP). Eighteen cases had normal fPyr and fDPyr at transplant, and in all but one of these cases the level remained normal throughout subsequent follow-up. In contrast, in 14 cases urinary fPyr and fDPyr levels were increased at transplant. In these cases, both fPyr and fDPyr fell to normal levels over the next few months (P = .0009 and .0019, respectively). fPyr and fDPyr levels at transplant and their trends post-BMT were unrelated to the use of pre-BMT or post-BMT bisphosphonate or post-BMT interferon. Nine cases had elevated P1CP or BSAP at transplant, which rapidly normalized. In most patients there was an increase in P1CP and/or BSAP several months post-transplant. In conclusion, increased osteoclast activity may be present even in apparent plateau phase of myeloma. High-dose chemotherapy with autografting may normalize abnormal bone resorption, although the effect may take several weeks to emerge and may be paralleled by increased osteoblast activity. The findings provide biochemical evidence that autografting may help normalize the abnormal bone turnover characteristic of myeloma.