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

Unusual Cortical Phenotype After Hematopoietic Stem Cell Transplantation in a Patient With Osteopetrosis

The osteopetroses are a group of rare genetic diseases caused by osteoclast dysfunction or absence. The hallmark of osteopetrosis is generalized increased bone mineral density (BMD). However, the bone is fragile and fractures are common. Autosomal recessive osteopetrosis is usually a severe disorder and often life-threatening in childhood. We present male siblings with autosomal recessive osteopetrosis due to biallelic variants in TCIRG1 who survived childhood and underwent hematopoietic stem cell transplant (HSCT) in adulthood. One sibling died of posttransplant complications. After transplant, the other sibling had improvement of multiple clinical parameters, including some decline in BMD Z-scores by dual-energy X-ray absorptiometry (DXA) and cessation of fractures. However, spine quantitative computed tomography 11 years after transplant demonstrated an anvil pattern of sclerosis with BMD Z-score of +18.3. High-resolution peripheral quantitative computed tomography (HR-pQCT) of the tibia demonstrated near complete obliteration of the marrow space combined with an unusual cortical phenotype, suggesting extensive cortical porosity at the distal tibia. This case highlights that despite successful transplantation and subsequent improvement in clinical parameters, this patient continued to have significantly elevated bone density and decreased marrow space. Transplant-associated increased cortical porosity is multifactorial and occurs in two-thirds of non-osteopetrotic patients undergoing HSCT. This finding after transplant in osteopetrosis may suggest particular sensitivity of the cortical bone to resorptive activity of transplanted osteoclasts. The case also suggests HR-pQCT may be a useful modality for imaging and assessing the therapeutic effects on bone in individuals with osteopetrosis. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

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.

Effect of Denosumab on Bone Mineral Density of Hematopoietic Stem Cell Transplantation Recipients

PURPOSE

Denosumab is a monoclonal antibody that prevents the development of osteoclasts. The effect of denosumab in solid organ transplant recipients has been elucidated, but its effect in haematopoietic stem cell transplantation recipients has not been studied yet. The aim of this study was to determine the effectiveness and safety of denosumab in haematopoietic stem cell transplantation recipients.

METHODS

We retrospectively evaluated 33 female patients with osteoporosis (mean age 52.6 ± 9.8 years) following allogeneic haematopoietic stem cell transplantation. Patients were treated with denosumab every 6 months for 12 months. Changes in bone mineral density were evaluated for denosumab-treated patients in a 12-month interval after the first administration of denosumab.

RESULTS

Significant increases in bone mineral density were observed in all measured skeletal sites including 4.39 ± 6.63% in the lumbar spine (p=0.014), 3.11 ± 7.69% in the femoral neck (p=0.048), and 1.97 ± 6.01% in the total hip (p=0.138). The bone turnover marker serum cross-linked C-terminal telopeptide of type 1 collagen was decreased at 18 months (-51.6 ± 17.6%, p < 0.001). No serious symptomatic hypocalcaemia was observed. Serious adverse drug reactions requiring drug discontinuation were not observed.

CONCLUSION

Denosumab improved bone mineral density in haematopoietic stem cell transplantation recipients. The use of denosumab could be a good therapeutic option without causing severe adverse effects in recipients of haematopoietic transplantation.

Do Bone Density, Bone Microarchitecture, and Body Composition Differ in Recipients of Allogeneic Hematopoietic Stem Cell Transplant? A Cross-Sectional Study from Southern India

The significant advancements made in the field of allogeneic hematopoietic stem cell transplantation (allo-HSCT) have ensured increased longevity in transplant recipients. However, they do have late effects that may adversely affect the endocrine system, bone health, and body composition. This study was undertaken to evaluate bone mineral density (BMD), trabecular bone score, and body composition in recipients of allo-HSCT and compare them with age, sex, and body mass index (BMI) matched controls. This was a cross-sectional study done in 63 cases and 65 matched controls. The mean femoral neck BMD was found to be lower in cases than in controls (0.777 [0.119] versus 0.846 [0.122] g/cm², P =  .002). Among cases, the mean BMD at the neck of femur was lower in patients who had received myeloablative conditioning compared with those who had received the nonmyeloablative regimen (0.731 [0.090] versus 0.802 [0.126] g/cm², P = .014]. The mean (SD) bone density at the lumbar spine was significantly lower in the group that had received total body irradiation compared with the group that did not (0.930 [0.111] versus 0.993 [0.127], P = .044). Trabecular bone score did not differ between cases and controls (1.383 [0.877] versus 1.389 [0.750], P = .670). The lean mass was significantly lower (15.9 [2.4] versus 18.6 [4.8] kg/m², P < .001) and the prevalence of sarcopenia (42% versus 11%, P < .001) significantly higher in cases than in controls. Normal-weight obesity was also noted to be higher among those with sarcopenia than in those without (12/26 versus 5/36; P = .009). The procedure of allo-HSCT may thus cause an impairment of bone health and alterations in body composition well after the cure of the primary disease.

Evaluation of endocrine and metabolic dysfunctions after hematopoietic stem cell transplantation in children: a study from Turkey

BACKGROUND

Endocrine organs are highly susceptible to effects of high-dose chemotherapy. The objective of the study was to evaluate endocrine and metabolic complications after hematopoietic stem cell transplantation (HSCT) in children.

METHODS

The patients who underwent HSCT in our center from April 2010 to October 2014 with at least 1 year follow-up were analyzed retrospectively.

RESULTS

One-hundred children (M/F:59/41; mean age 8.9±4.8 years, mean follow-up time 3.4±1.2 years) were included in the study. Female hypogonadism was the most common endocrine dysfunction (35.7%), followed by growth impairment (29.4%), malnutrition (27.4%), dyslipidemia (26%), low bone mineral density (BMD) (25%), hypothyroidism (13%) and insulin resistance (12%). Patients who underwent HSCT >10 years of age were significantly at risk for hypogonadism, metabolic syndrome, growth impairment and malnutrition (p<0.05).

CONCLUSIONS

Endocrine or metabolic dysfunctions are more prevalent in children who are older than 10 years of age at HSCT. Children who underwent HSCT should be followed-up by a multidisciplinary team during puberty and adolescence.

Relationship between endocrine changes and bone markers in pediatric thalassemic patients after hematopoietic stem cell transplantation

BACKGROUND

Beta thalassemia major and its treatment by hematopoietic stem cell transplantation can have deleterious effects on bone integrity and a main part of such effects is due to their deleterious effects on endocrine systems. So, we assessed the effects of endocrine changes during HSCT (Hematopoietic Stem Cell Transplantation) on growing bones of pediatric thalassemic patients.

METHODS

Bone-specific alkaline phosphatase and osteocalcin (bone formation markers), N-terminal telopeptide (NTX, bone resorption marker), calcium (Ca), phosphorus (P), alkaline phosphatase (Alk ph), parathyroid hormone (PTH), vitamin D (vit D), prolactin, luteinizing hormone (LH), follicle-stimulating hormone (FSH), thyroxine (T4), triiodothyronine (T3), thyroid-stimulating hormone (TSH), insulin-like growth factor 1 (IGF-1), testosterone (in males) or estradiol (in females), measured in 20 major thalassemic patients with mean age of 10.8±3.9 years. Parameters at the baseline (before HSCT), and 1 month and 3 months after HSCT.

RESULTS

After stem cell transplantation, changes of mean serum levels of NTX, osteocalcin, prolactin, LH, T4, IGF-1, testosterone (in males), Ca, Alk ph, PTH, and vit D were not significant, but bone specific Alk ph, P, T3, TSH, FSH and estradiol changed significantly (P=0.013, P=0.001, P=0.48, P=0.02, P=0.04 and P=0.001, respectively). After one month, there was a significant positive relationship between osteocalcine and T3 (p= 0.009). After 3 months, also, there was a significant positive relationship between osteocalcine and T3 and T4 as well as a negative one with IGF-1 (P<0.001, P<0.02 and P<0.03, respectively).

CONCLUSIONS

Endocrine disorders do not appear to have an overall positive or negative effect on bone metabolism (anabolism or catabolism) in HSCT pediatric thalassemic patients in short term (three months).