Post-transplantation osteoporosis. ACTA ACUST UNITED AC. 2010;54:143-149. [PMID: 20485902 DOI: 10.1590/S0004-27302010000200009]

Long-term skeletal, cephalometric, and volumetric changes in two Helsinki bimaxillary face transplant patients

Analysis of skeletal, cephalometric, and volumetric changes and occlusion during long-term follow-up was performed for two patients who underwent bimaxillary facial transplantation (FT). The study material consisted of the follow-up data of two bimaxillary composite FT performed in Helsinki University Hospital, one in 2016 and the other in 2018. Serial three-dimensional computed tomography scans obtained during follow-up (6 years for patient 1, 4 years for patient 2) were analyzed. The position of the maxilla remained stable in both patients. At 4 and 6 years, the changes in the anterior maxilla were ≤1 mm, while the anterior mandible had moved 2.6-4 mm anteriorly and the mandibular midline 0.4-3.7 mm to the left side. Patient 1 underwent re-osteosynthesis 4 months after transplantation due to mandibular non-union. Patient 2 had a sagittal mandibular osteotomy at 15 months after FT due to lateral crossbite and tension created by temporomandibular joint rotation. Thereafter both patients had a stable occlusion. A continuous bone volume reduction in the mandible was noticed in both patients (6% and 9% reduction of the transplanted volume). The volume of the transplanted maxilla decreased during the early postoperative period but increased back to the original transplanted volume during the follow-up.

Maxillary and Mandibular Healing After Facial Allotransplantation

INTRODUCTION

Facial transplantation has emerged as a viable option in treating devastating facial injuries.Despite the high healing rate of Le Fort III and bilateral sagittal split osteotomies (BSSO) in nontransplant patients, few studies have reported assessment of maxillary and mandibular healing in face transplant patients compared with nontransplant patients. The aim of this study was to examine differences in bone healing in our patients.

PATIENTS AND METHODS

A retrospective chart review was conducted of facial allotransplantation patients at the Cleveland Clinic from December 2008 to inception. Demographics such as age, date of birth, and sex were recorded. Additional variables included procedures, revisions, reoperations, medications, and bone stability and healing. Computed tomography (CT) images assessed the alignment of skeletal components, bony union quality, and stability of fixation.

RESULTS

Three patients were included: 2 had Le Fort III segment transplantation, and 1 had transplantation of both a Le Fort III segment and mandibular BSSO. The Le Fort III segment in all patients exhibited mobility and fibrous union at the Le Fort III osteotomy on CT. In contrast, the BSSO healed uneventfully after transplantation and revision surgery, with bony union confirmed by both CT and histology of the fixation area between the donor and recipient mandible bilaterally. No patients with midfacial fibrous union required revision of the nonunion as they were clinically asymptomatic.

CONCLUSION

Le Fort osteotomy demonstrates inferior healing in facial transplantation compared with the nontransplant population. In contrast, the successful healing in the mandible is likely owing to the high density of rich cancellous bone.

FK506 prevented bone loss in streptozotocin-induced diabetic rats via enhancing osteogenesis and inhibiting adipogenesis

Background

Type 1 diabetes mellitus (DM) is associated with severe osteoporosis, which is still a great challenge in the clinic. This work aimed to investigate the skeletal effects of FK506 in a rat model of streptozocin induced type 1 DM.

Methods

Rats were divided into three groups: control (CTL), DM rats and DM rats treated with FK506. Dual energy X-ray absorption, micro-computed tomography, bone mechanics and bone histology were used for skeletal analysis. Bone marrow adipocytes infiltrations were detected by oil red O stain and H&E stain. In addition, the protein expression of adipocyte-specific makers (PPAR-γ, C/EBP-αβ), osteoblast-specific markers (Runx2, Osterix) and nuclear translocation of β-catenin in femurs were determined by western blot.

Results

In the study, bone mineral density of femurs and lumbar vertebras in diabetic rats were increased after FK506 administration. FK506 treatment resulted in higher cancellous bone volume but had no significant effect on cortical bones in diabetic rats. The ultimate force and work to failure were increased in DM+FK506 group, while they were reduced in the DM group. Compared with the CTL, the infiltration of bone marrow adipocytes was significantly increased in the DM group, which was reduced after the treatment of FK506. Besides, the expression levels of Runx2 and Osterix were up-regulated, and that of PPAR-γ and C/EBP-α were down-regulated in diabetic rats after FK506 treatment. In addition, the nuclear translocation of β-catenin protein levels were increased in diabetic rats after the treatment of FK506.

Conclusions

Our study indicated that FK506 could alleviate bone loss in diabetic rats. This effects could be due to the results of enhancing osteogenesis and inhibiting adipogenesis, which might be regulated by activation the nuclear translocation of β-catenin.

Effect of vitamin D3 on bone turnover markers in critical illness: post hoc analysis from the VITdAL-ICU study

In this post hoc analysis of the VITdAL-ICU study, an RCT in critically ill adults with 25-hydroxyvitamin D levels ≤20 ng/ml, vitamin D3 did not have a significant effect on β-Crosslaps and osteocalcin.

INTRODUCTION

Observational studies have shown accelerated bone loss in ICU survivors. A reversible contributor is vitamin D deficiency. In a post hoc analysis of the VITdAL-ICU study, we evaluated the effect of high-dose vitamin D3 on the bone turnover markers (BTM) β-Crosslaps (CTX) and osteocalcin (OC).

METHODS

The VITdAL-ICU study was a randomized, double-blind, placebo-controlled trial in critically ill adults with 25-hydroxyvitamin D levels ≤20 ng/ml who received placebo or high-dose vitamin D3 (a loading dose of 540,000 IU and starting 1 month after the loading dose five monthly maintenance doses of 90,000 IU). In this analysis on 289 survivors (209 telephone, 80 personal follow-up visits), BTM were analyzed on days 0, 3, 7, 28, and 180; self-reported falls and fractures were assessed. Bone mineral density (BMD) was measured after 6 months.

RESULTS

At baseline, CTX was elevated; OC was low in both groups-after 6 months, both had returned to normal. There were no differences between groups concerning BTM, BMD, falls, or fractures. In linear mixed effects models, CTX and OC showed a significant change over time (p < 0.001, respectively), but there was no difference between the vitamin D and placebo group (p = 0.688 and p = 0.972, respectively).

CONCLUSIONS

Vitamin D supplementation did not have a significant effect on BTM. Further studies should assess the effectiveness of vitamin D on musculoskeletal outcomes in ICU survivors.

Comparison of bone mineral density changes in pediatric thalassemic patients with and without hematopoietic stem cell transplant

OBJECTIVES

Beta thalassemia major is a genetic hemoglobin disorder that affects bone density. The disease leads to deteriorating bone structure but can be treated with hematopoietic stem cell transplant. We aimed to assess bone mineral density changes in pediatric beta thalassemia major patients who had undergone a hematopoietic stem cell transplant compared with similarly affected patients who had not undergone a hematopoietic stem cell transplant.

MATERIALS AND METHODS

Forty beta thalassemia major patients, 20 transplant and 20 nontransplant, younger than 16 years of age were enrolled. The mean age of transplant patients was 8.15 years and nontransplant patients was 9.5 years (P = .242). The female:male ratio was 1:1 in both groups. None of the patients reached puberty during this study. Bone mineral density was evaluated in transplant patients before and 1 year after hematopoietic stem cell transplant. Bone mineral density of nontransplant patients also was evaluated 1 year after their initial bone mineral density test. A Norland XR-46 densitometer was used to make all bone mineral density measurements. None of the patients had a z score < -2.

RESULTS

Mean bone mineral density changes in the femur and spine during this study were 0.008 ± 0.075 g/cm2 and 0.048 ± 0.045 g/cm2 in transplant patients and 0.045 ± 0.072 g/cm2 and 0.036 ± 0.058 g/cm2 in nontransplant patients. No significant differences between bone mineral density changes in transplant and nontransplant patients were detected during the study.

CONCLUSIONS

No significant effects on bone mineral density were detected in hematopoietic stem cell transplant pediatric beta thalassemia major patients compared with similarly affected nontransplant patients. Studies of longer duration may be required to identify significant changes in bone mineral density in hematopoietic stem cell transplant patients.

Hematopoietic stem cell transplantation in adolescents and young adults

BACKGROUND

Adolescents and young adults (AYAs) are a very unique subset of our population journeying through a dynamic stage of their lives. This age group often remains understudied as a separate entity because they are commonly lumped into either pediatric or adult subgroups.

METHODS

Here we review acute and chronic issues surrounding hematopoietic stem cell transplantation (HSCT) with a focus on the AYA age group.

RESULTS

HSCT is a commonly used treatment modality for patients with certain types of cancers. AYA patients undergoing HSCT present a very unique perspective, circumstances, medical, psychological and social issues requiring a diligent workup, care and follow-up.

CONCLUSION

The medical care of these patients should be approached in a multidisciplinary method involving the patient, caregivers, physicians, psychologists and social workers.

Bone disease after transplantation: osteoporosis and fractures risk

Organ transplantation is the gold standard therapy for several end-stage diseases. Bone loss is a common complication that occurs in transplant recipients. Osteoporosis and fragility fractures are serious complication, mainly in the first year post transplantation. Many factors contribute to the pathogenesis of bone disease following organ transplantation. This review address the mechanisms of bone loss including the contribution of the immunosuppressive agents as well as the specific features to bone loss after kidney, lung, liver, cardiac and bone marrow transplantation. Prevention and management of bone loss in the transplant recipient should be included in their post transplant follow-up in order to prevent fractures.

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.

CKD-mineral and bone disorder management in kidney transplant recipients

Kidney transplantation, the most effective treatment for the metabolic abnormalities of chronic kidney disease (CKD), only partially corrects CKD-mineral and bone disorders. Posttransplantation bone disease, one of the major complications of kidney transplantation, is characterized by accelerated loss of bone mineral density and increased risk of fractures and osteonecrosis. The pathogenesis of posttransplantation bone disease is multifactorial and includes the persistent manifestations of pretransplantation CKD-mineral and bone disorder, peritransplantation changes in the fibroblast growth factor 23-parathyroid hormone-vitamin D axis, metabolic perturbations such as persistent hypophosphatemia and hypercalcemia, and the effects of immunosuppressive therapies. Posttransplantation fractures occur more commonly at peripheral than central sites. Although there is significant loss of bone density after transplantation, the evidence linking posttransplantation bone loss and subsequent fracture risk is circumstantial. Presently, there are no prospective clinical trials that define the optimal therapy for posttransplantation bone disease. Combined pharmacologic therapy that targets multiple components of the disordered pathways has been used. Although bisphosphonate or calcitriol therapy can preserve bone mineral density after transplantation, there is no evidence that these agents decrease fracture risk. Moreover, bisphosphonates pose potential risks for adynamic bone disease.

Bone Loss after Heart Transplant: Effect of Alendronate, Etidronate, Calcitonin, and Calcium plus Vitamin D3

Objective

To compare the effects of calcitonin, etidronate, and alendronate in preventing bone loss during the first 2 years after heart transplant.

Methods

A total of 222 heart transplant recipients (mean [SD] age, 52.4 [10] years, 85% male) were evaluated. Patients with normal bone mineral density (reference group, n = 102) received 1000 mg/d calcium plus 800 IU/d vitamin D3. The rest were assigned to 200 IU/d of calcitonin (n = 42), 400 mg/d etidronate orally for 14 days quarterly (n = 33), or 10 mg/d alendronate (n = 45). All patients received calcium and vitamin D. Bone mineral density was assessed by dual-energy x-ray absorptiometry in the lumbar spine, the entire femur, and the femoral neck at baseline and 6, 12, and 24 months after transplant.

Results

At 2 years after transplant, bone mineral density in the lumbar spine had decreased in the reference group (−3.07%), calcitonin group (−0.93%), and etidronate group (−1.87%) but not in the alendronate group (+4.9%; P < .001). After 2 years, bone mineral density in the entire femur decreased in all groups (−3.2% in the reference group, −3.6% in the calcitonin group, −4.6% in the etidronate group, and −0.5% in the alendronate group) but bone loss was significantly lower in the alendronate group ( P < .001). Bone mineral density in the femoral neck also decreased in all groups. The incidence of vertebral fractures did not differ among groups. Adverse events were similar between groups.

Conclusions

Alendronate therapy in heart transplant recipients was associated with a significant increase in bone mineral density in the lumbar spine and less bone loss at the hip.

Effects of immunosuppressants, FK506 and cyclosporin A, on the osteogenic differentiation of rat mesenchymal stem cells

Purpose

The purpose of this study was to investigate the effects of the immunosuppressants FK506 and cyclosporin A (CsA) on the osteogenic differentiation of rat mesenchymal stem cells (MSCs).

Methods

The effect of FK506 and CsA on rat MSCs was assessed in vitro. The MTT assay was used to determine the deleterious effect of immunosuppressants on stem cell proliferation at 1, 3, and 7 days. Alkaline phosphatase (ALP) activity was analyzed on days 3, 7, and 14. Alizarin red S staining was done on day 21 to check mineralization nodule formation. Real-time polymerase chain reaction (RT-PCR) was also performed to detect the expressions of bone tissue-specific genes on days 1 and 7.

Results

Cell proliferation was promoted more in the FK506 groups than the control or CsA groups on days 3 and 7. The FK506 groups showed increased ALP activity compared to the other groups during the experimental period. The ALP activity of the CsA groups did not differ from the control group in any of the assessments. Mineralization nodule formation was most prominent in the FK506 groups at 21 days. RT-PCR results of the FK506 groups showed that several bone-related genes-osteopontin, osteonectin, and type I collagen (Col-I)-were expressed more than the control in the beginning, but the intensity of expression decreased over time. Runx2 and Dlx5 gene expression were up-regulated on day 7. The effects of 50 nM CsA on osteonectin and Col-I were similar to those of the FK506 groups, but in the 500 nM CsA group, most of the genes were less expressed compared to the control.

Conclusions

These results suggest that FK506 enhances the osteoblastic differentiation of rat MSCs. Therefore, FK506 might have a beneficial effect on bone regeneration when immunosuppressants are needed in xenogenic or allogenic stem cell transplantation to treat bone defects.

Outcomes of total hip and knee arthroplasty after cardiac transplantation

The outcomes of 18 primary or revision total hip (THA) and knee arthroplasties (TKA) in 9 patients with cardiac transplants were reviewed. Primary total joint arthroplasties were performed for osteonecrosis (5 hips) or osteoarthritis (5 hips, 4 knees). There were no infections in any of these patients. Final Harris Hip Scores were 71.8 for patients with osteonecrosis and 88.6 for osteoarthritis. Eight of 10 hips were pain-free at final follow-up. Two of the 10 primary THAs required late revision at 7 and 10 years after the index arthroplasty. One patient (2 hips and 1 knee) had chronic bilateral lower extremity pain. Total knee arthroplasty range of motion averaged from 7.5° to 118°. Average final Knee Society function score was 79, and objective score was 88. One of 4 patients with primary TKA required a manipulation under anesthesia. No reoperations were required in this group. Overall, patients with heart transplantations on immunosuppression had generally good pain relief after THA and TKA. There were no infections in this small cohort; however, there were many complications.

Osteoporosis after transplantation

Transplantation is an established therapy for end-stage diseases of kidney, lung, liver, and heart among others. Osteoporosis and fragility fractures are serious complications of organ transplantation, particularly in the first post-transplant year. Many factors contribute to the pathogenesis of osteoporosis following organ transplantation. This review addresses the mechanisms of bone loss that occurs both in the early and late post-transplant periods, including the contribution of the immunosuppressive agents as well as the specific features to bone loss after kidney, lung, liver, cardiac, and bone marrow transplantation. Prevention and treatment for osteoporosis in the transplant recipient are also discussed.

Effects of cyclosporin-a on rat skeletal biomechanical properties

Background

Cyclosprin A (CsA) has been widely used clinically to treat the patients who have undergone organ transplantation or acquired autoimmune disease. The purpose of this study is to determine the effects of three different doses of CsA (1.5, 7.5, 15 mg/kg body weight) on the skeletal biomechanical proprieties at different anatomic sites in rats.

Methods

Fifty-six male 3-month-old Wistar rats were divided into five groups. Eight rats were randomly chosen as the basal group, while the others were randomly distributed into four groups of 12 animals each. One group was used as controls and received daily subcutaneous injection of 1 ml of saline solution; another three experimental groups were injected subcutaneously with CsA in a daily dose of 1.5, 7.5, and 15 mg/kg body weight respectively for 60 days. The bone biomechanical proprieties, the bone mineral density, as well as the trabecular bone architecture were measured at different anatomic sites, i.e. the lumbar vertebra, the middle femur shaft, and the proximal femur.

Results

CsA therapy at 7.5 and 1.5 mg/kg can significantly reduce the ultimate force, the ultimate stress and the energy absorption per unit of bone volume of the lumbar vertebra, with no effect on the middle femur. CsA therapy at 7.5 mg/kg can significantly reduce the ultimate force, the ultimate stress and the Young's modulus of the femoral neck, but not CsA at 1.5 mg/kg. Furthermore, CsA therapy at 7.5 and 1.5 mg/kg can significantly reduce the bone mineral density of the lumber vertebra and the proximal femur, but have no effect on the middle femur. CsA therapy at 7.5 and 1.5 mg/kg can also significantly reduce the bone volume fraction of the proximal tibia and the lumber vertebra, but has no effect on the cortical thickness of the middle femoral shaft. In the 15 mg/kg CsA group only one rat survived, and the kidney and liver histology of the survived rat showed extensive tissue necrosis.

Conclusion

Long-term use of CsA can weaken the biomechanical properties and thus increase the fracture rate of the lumbar vertebra and the proximal femur. However, CsA therapy has less effect on the middle femur shaft. The effects of CsA on skeleton are site-specific.

Chronic liver disease and osteoporosis

Hepatic osteodystrophy, manifesting mainly as osteoporosis, can occur in patients with chronic liver disease (CLD) or after liver transplantation and lead to vertebral compression fracture, radial or femoral fracture. Currently, the pathogenesis of hepatic osteodystrophy is still not completely clear. The reported incidence of osteoporosis in CLD patients ranged from 12% to 55%. For CLD patients, attention should be paid to monitor osteoporosis by measuring bone mineral density on the basis of controlling liver disease to choose safe and effective medication to improve their quality of life.