Height-corrected low bone density associates with severe outcomes in sickle cell disease: SCCRIP cohort study results

Bone quality is associated with fragility fracture in patients with hemoglobinopathies

BACKGROUND

Low bone mass, defined as a bone mineral density (BMD) Z-score ≤-2.0, is common in adults with thalassemia (Thal) and sickle cell disease (SCD), though disease-specific artifacts may contribute to inaccuracies in BMD assessment. Trabecular bone score (TBS), an indicator of bone quality, is not susceptible to these challenges and may improve fracture risk prediction.

METHODS

A retrospective chart review was conducted in patients with Thal or SCD who had at least one spine BMD scan by DXA in the past 10 years. The most recent scan was reanalyzed for bone quality with abnormal defined as TBS <1.2. Fracture prevalence was determined by patient report with medical record validation. Patients were compared to healthy controls who participated in previous research.

RESULTS

Data were abstracted from 126 patients with Thal (31.7 ± 11.9 yrs, 51 % Male), 170 with SCD (24.6 ± 13.5 yrs, 43 % Male), and 64 controls (25.9 ± 8.0 yrs, 17 % Male). Abnormal TBS was more common in Thal (26 %) or SCD (7 %) compared to controls (0 %, p < 0.001). Fracture prevalence was greater in Thal (36 %) compared to SCD (23 %) and controls (16 %, p = 0.005). Fragility fractures were not observed in controls but constituted 21 % of fractures in Thal and 15 % in SCD. After adjusting for age and hypogonadism, low bone mass was associated with an increased fracture prevalence (OR: 1.8, 95 % CI: 1.03, 3.23; p = 0.041), but not with fragility fracture. In contrast, abnormal TBS was strongly associated with fragility fracture after adjustment for age, sex, and BMI (OR: 11.4, 95 % CI: 2.2, 59.1, p = 0.004).

CONCLUSIONS

Bone quality by TBS may be a valuable tool in predicting the risk of fragility fractures in young adults with hemoglobinopathies and should be considered when making decisions for anti-resorptive therapy in those with low BMD naive to fracture or where disease-specific artifacts complicate accurate spine assessment by BMD alone.

Alendronate preserves bone mineral density in adults with sickle cell disease and osteoporosis

Low bone mineral density is highly prevalent in sickle cell disease (SCD); whether bisphosphonates can safely preserve or increase bone mass in SCD adults remains unknown. In this study, lumbar spine bone density remained stable with alendronate use, and treatment-related side effects were mostly mild and self-limited.

PURPOSE

To describe the effects of alendronate in adults with sickle cell disease (SCD) and osteoporosis.

METHODS

We reviewed retrospective clinical data from adults with SCD and osteoporosis treated with alendronate at a single center in Brazil (2009-2019). Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (DXA) of the lumbar spine, femoral neck, and total hip. We analyzed BMD changes by alendronate treatment duration (months), stratified by sex, skeletal site, and SCD genotype.

RESULTS

Sixty-four SCD adults with osteoporosis (69% females, 73% HbSS, mean age ± standard deviation 42.4 ± 10.9 years) received alendronate for a median (interquartile range) of 48 (29, 73) months. Compared with males, females had significantly lower baseline BMD (g/cm2) at the femoral neck (0.72 vs 0.85, p =  < 0.001) and total hip (0.79 vs 0.88, p = 0.009). The between-sex differences in BMD changes were insignificant. Mean lumbar spine BMD significantly changed by 0.0357 g/cm2 (p = 0.028) in those on alendronate for > 5 years. Four adults (6.3%) reported mild therapy-related side effects. An atypical femoral diaphysis fracture, attributed to alendronate, was incidentally noted in a 37-year-old man on treatment for 4 years.

CONCLUSION

In this retrospective cohort of adults with SCD and osteoporosis on alendronate for a median of 48 months, we found no significant interactions between sex and changes in lumbar spine, femoral neck, or total hip BMD with alendronate. Lumbar spine BMD was stable in those on alendronate for < 5 years. Side effects of alendronate were mild, though one patient developed an atypical femoral fracture.

A bone to pick-cellular and molecular mechanisms of bone pain in sickle cell disease

The bone is one of the most commonly affected organs in sickle cell disease (SCD). Repeated ischemia, oxidative stress and inflammation within the bone is largely responsible for promoting bone pain. As more individuals with SCD survive into adulthood, they are likely to experience a synergistic impact of both aging and SCD on their bone health. As bone health deteriorates, bone pain will likely exacerbate. Recent mechanistic and observational studies emphasize an intricate relationship between bone remodeling and the peripheral nervous system. Under pathological conditions, abnormal bone remodeling plays a key role in the propagation of bone pain. In this review, we first summarize mechanisms and burden of select bone complications in SCD. We then discuss processes that contribute to pathological bone pain that have been described in both SCD as well as non-sickle cell animal models. We emphasize the role of bone-nervous system interactions and pitfalls when designing new therapies especially for the sickle cell population. Lastly, we also discuss future basic and translational research in addressing questions about the complex role of stress erythropoiesis and inflammation in the development of SCD bone complications, which may lead to promising therapies and reduce morbidity in this vulnerable population.

Mechanisms underlying the adaptive pulp and jaw bone trabecular changes in sickle cell anemia

OBJECTIVE

Mechanisms underlying the oral outcomes in sickle cell anemia (HbSS) have been less explored. This study aimed to investigate the association of morbimortality indicators and hydroxyurea use with adaptive pulp and jaw bone trabecular changes in HbSS.

METHODS

This cross-sectional study included 123 individuals with HbSS. The exposures were the morbimortality indicators of HbSS (number of vaso-occlusive crises, organ damage, hemoglobin level, and leukocyte count) and the use of hydroxyurea for HbSS treatment. The outcomes were adaptive pulp and jaw bone trabecular changes confirmed by radiographic examination. Associations were estimated by Poisson regression in crude and adjusted analyses for sex, skin color, socioeconomic class, and age.

RESULTS

The vaso-occlusive crises (mean ratio (MR) = 3.5, p = 0.045), lower hemoglobin (MR = 2.4, p = 0.037), and higher leukocyte count (MR = 2.17, p = 0.036) were risk factors, while the use of hydroxyurea was inversely associated with adaptive pulp changes (MR = 0.23, p = 0.024). The vaso-occlusive crises were associated with jaw bone trabecular changes (MR = 1.33, p = 0.02).

CONCLUSION

Adaptive pulp changes may be a potential clinical marker of chronic vasculopathy in HbSS. The use of hydroxyurea may reduce the frequency of adaptive pulp changes.

Functional Outcomes for Children, Adolescents, and Young Adults with Osteonecrosis following Hip Core Decompression

Background

Patients with pediatric leukemia and sickle cell disease are at risk for developing osteonecrosis (ON), a disease that can result in pain, loss of function, and disability. Hip core decompression surgery is an option aimed to prevent femoral head collapse and avoid future arthroplasty.

Objective

Describe functional outcomes and gait quality among a young population with hip ON before and after hip core decompression.

Methods

Study included participants with hip ON secondary to treatment for hematologic malignancy or sickle cell disease, between 8 and 29 years old, requiring hip core decompression surgery. At one-year follow-up, 13 participants (9 male, median age 17 years) completed the Functional Mobility Assessment (FMA), range of motion, and GAITRite® testing.

Results

Participants demonstrated improved mobility and endurance on the FMA at 1-year post-operatively compared to pre-operatively, with higher scores for time on the Timed Up and Go (mean FMA score = 2.92 [SD = 1.32] vs. 2.07 [SD = 1.70]), time on the Timed Up and Down Stairs (3.69 [0.85] vs. 2.92 [1.66]), and 9-Minute Walk Test scores for distance walked (2.69 [0.63] vs. 2.23 [0.93]) and heart rate (4.54 [0.66] vs. 3.31 [1.38]). GAITRite® analysis also showed improvements in many gait parameters at one-year follow-up.

Limitations

Cancer treatment complications other than ON could have contributed to results, not all eligible participants agreed to participate, and follow-up was only one year.

Conclusions

Young patients with hip ON demonstrated improvements in functional mobility, endurance, and gait quality one year following hip core decompression.

Hypothesis: Low Vitamin A and D Levels Worsen Clinical Outcomes When Children with Sickle Cell Disease Encounter Parvovirus B19

Human parvovirus B19 causes life-threatening anemia due to transient red cell aplasia (TRCA) in individuals with sickle cell disease (SCD). Children with SCD experiencing profound anemia during TRCA often require red blood cell transfusions and hospitalization. The prevalence of vitamin deficiencies in SCD is high and deficiencies are associated with respiratory and pain symptoms, but the effects of vitamins on acute infection with parvovirus B19 remain unclear. We performed a clinical study in which 20 SCD patients hospitalized with parvovirus B19 infections (Day 0) were monitored over a 120-day time course to query relationships between vitamins A and D and clinical outcomes. There were significant negative correlations between Day 0 vitamin levels and disease consequences (e.g., red blood cell transfusion requirements, inflammatory cytokines). There were significant positive correlations (i) between Day 0 vitamins and peak virus-specific antibodies in nasal wash, and (ii) between Day 0 virus-specific serum plus nasal wash antibodies and absolute reticulocyte counts. There was a significant negative correlation between Day 0 virus-specific serum antibodies and virus loads. To explain the results, we propose circular and complex mechanisms. Low baseline vitamin levels may weaken virus-specific immune responses to permit virus amplification and reticulocyte loss; consequent damage may further reduce vitamin levels and virus-specific immunity. While the complex benefits of vitamins are not fully understood, we propose that maintenance of replete vitamin A and D levels in children with SCD will serve as prophylaxis against parvovirus B19-induced TRCA complications.

Klotho Level as a Marker of Low Bone Mineral Density in Egyptian Sickle Cell Disease Patients

Bone involvement of sickle cell disease (SCD) patients varies from acute clinical manifestations of painful vaso-occlusive crises or osteomyelitis to more chronic affection of bone mineral density (BMD) and debilitating osteonecrosis and osteoporosis. Secreted klotho protein is involved in calcium (Ca) reabsorption in the kidney. This study aimed to measure serum klotho levels in children with SCD to determine the possibility of using it as a marker of low BMD in children with SCD in correlation with a dual-energy radiograph absorptiometry scan. This study included 60 sickle disease patients and 30 age-matched and sex-matched control participants without SCD. A highly statistically significant difference was found between patients with normal BMD and those with low BMD, with serum Ca and klotho levels being lower in the latter group. Klotho serum level correlated positively with both serum Ca and BMD. Serum klotho level showed 94.9% sensitivity and 95.2% specificity in the detection of low BMD. Both serum Ca and klotho serum levels may be useful markers for detection of low BMD related to SCD with high sensitivity and specificity; however, klotho may be a better indicator as it is less affected by the nutritional and endocrinal status of patients or by intake of Ca supplements.

In-depth phenotyping for clinical stratification of Gaucher disease

BACKGROUND

The Gaucher Investigative Therapy Evaluation is a national clinical cohort of 250 patients aged 5-87 years with Gaucher disease in the United Kingdom-an ultra-rare genetic disorder. To inform clinical decision-making and improve pathophysiological understanding, we characterized the course of Gaucher disease and explored the influence of costly innovative medication and other interventions. Retrospective and prospective clinical, laboratory and radiological information including molecular analysis of the GBA1 gene and comprising > 2500 variables were collected systematically into a relational database with banking of collated biological samples in a central bioresource. Data for deep phenotyping and life-quality evaluation, including skeletal, visceral, haematological and neurological manifestations were recorded for a median of 17.3 years; the skeletal and neurological manifestations are the main focus of this study.

RESULTS

At baseline, 223 of the 250 patients were classified as type 1 Gaucher disease. Skeletal manifestations occurred in most patients in the cohort (131 of 201 specifically reported bone pain). Symptomatic osteonecrosis and fragility fractures occurred respectively in 76 and 37 of all 250 patients and the first osseous events occurred significantly earlier in those with neuronopathic disease. Intensive phenotyping in a subgroup of 40 patients originally considered to have only systemic features, revealed neurological involvement in 18: two had Parkinson disease and 16 had clinical signs compatible with neuronopathic Gaucher disease-indicating a greater than expected prevalence of neurological features. Analysis of longitudinal real-world data enabled Gaucher disease to be stratified with respect to advanced therapies and splenectomy. Splenectomy was associated with an increased hazard of fragility fractures, in addition to osteonecrosis and orthopaedic surgery; there were marked gender differences in fracture risk over time since splenectomy. Skeletal disease was a heavy burden of illness, especially where access to specific therapy was delayed and in patients requiring orthopaedic surgery.

CONCLUSION

Gaucher disease has been explored using real-world data obtained in an era of therapeutic transformation. Introduction of advanced therapies and repeated longitudinal measures enabled this heterogeneous condition to be stratified into obvious clinical endotypes. The study reveals diverse and changing phenotypic manifestations with systemic, skeletal and neurological disease as inter-related sources of disability.

Knowledge gaps in reproductive and sexual health in girls and women with sickle cell disease

There is an immediate need to address long-standing questions about the reproductive health of girls and women with sickle cell disease (SCD). There are many SCD-related reproductive risks and uncertainties across girls' and women's reproductive life span, with particularly outstanding concerns about menstruation, contraception, fertility and pregnancy. Extant literature addressing women's reproductive health topics is mostly descriptive; there are few high-quality interventional studies. In 2020, the Centers for Disease Control and Prevention and the Foundation for Women and Girls with Blood Disorders convened an expert panel to assess the knowledge gaps in women's reproductive health in SCD. The panel identified significant limitations to clinical care due to the need for research. The panel also identified prominent barriers to research and care. In this report, we frame these issues, providing a roadmap for investigators, funding agencies, and policy makers to advance care for girls and women with SCD.

Bone morbidity in pediatric acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL), currently the most common pediatric leukemia, has a high curability rate of up to 90%. Endocrine disorders are highly prevalent in children with ALL, and skeletal morbidity is a major issue induced by multiple factors associated with ALL. Leukemia itself is a predominant risk factor for decreased bone formation, and major bone destruction occurs secondary to chemotherapeutic agents. Glucocorticoids are cornerstone drugs used throughout the course of ALL treatment that exert significant effects on demineralization and osteoclastogenesis. After completion of treatment, ALL survivors are prone to multiple hormone deficiencies that eventually affect bone mineral accrual. Dual-energy X-ray absorptiometry, the most widely used method of measuring bone mineral density, is used to determine the presence of childhood osteoporosis and vertebral fracture. Supplementation with calcium and vitamin D, administration of pyrophosphate analogues, and promotion of mobility and exercise are effective options to prevent further bone resorption and fracture incidence. This review focuses on addressing bone morbidity after pediatric ALL treatment and provides an overview of bone pathology based on skeletal outcomes to increase awareness among pediatric hemato-oncologists and endocrinologists.

Osteonecrosis in sickle cell disease: an update on risk factors, diagnosis, and management

Osteonecrosis, a form of ischemic bone injury that leads to degenerative joint disease, affects ∼30% of people with sickle cell disease. Although osteonecrosis most commonly affects the femoral head (often bilaterally, with asymmetric clinical and radiographic progression), many people with sickle cell disease also present with multifocal joint involvement. We present the case of a young woman with bilateral osteonecrosis of the femoral head at varying stages of progression; we also highlight other important comorbid complications (eg, chronic pain requiring long-term opioids, debility, and social isolation) and postoperative outcomes. In this review, partly based on recommendations on osteonecrosis management from the 2014 evidence-based report on sickle cell disease from the National Heart, Lung and Blood Institutes, we also discuss early signs or symptoms of osteonecrosis of the femoral head, radiographic diagnosis and staging criteria, hydroxyurea effect on progression to femoral head collapse, and surgical outcomes of total hip arthroplasty in the modern era. In summary, we failed to find an association between hydroxyurea use and femoral head osteonecrosis; we also showed that evidence-based perioperative sickle cell disease management resulted in superior postoperative outcomes after cementless total hip arthroplasty in sickle cell-related osteonecrosis of the femoral head.