Risk of avascular necrosis of the femoral head in children with sickle cell disease on hydroxyurea: MRI evaluation

Effects of hydroxyurea on fertility in male and female sickle cell disease patients. A systemic review and meta-analysis

BACKGROUND

Evidence supports the benefits of hydroxyurea (HU) in adults with sickle cell disease (SCD), but reservations remain due to long-term concerns of fertility. Retrospective analysis of clinical records of SCD patients (haemoglobin SS genotype) have identified gender-related differences in disease progression. This could inform risk stratification during SCD at diagnosis with the possibility to guide therapeutic decisions.

METHODS

This systemic review and meta-analysis evaluated fertility parameters in both children (aged ≥ 6 years) and adults with SCD receiving HU therapy. Studies were sourced from PubMed and EMBASE from inception to July 2023. A total of 160 potentially relevant articles were identified.

RESULTS

Four studies were included that evaluated the effects of HU on sperm parameters in males. A further 4 studies assessed anti-mullerian hormone (AMH) levels and ovarian reserves in females. Differences from baseline values were used to identify compromised fertility. Amongst males, HU treatment negatively impacted the concentration of spermatozoa (MD = -15.48 million/mL; 95% CI: [-20.69, -10.26]; p< 0.001), which continued following treatment cessation (MD = -20.09 million/mL; 95% CI: [-38.78, -1.40]; P = 0.04). HU treatment also led to lower total sperm counts (MD = -105.87 million; 95% CI: [-140.61, -71.13]; P< 0.001) which persisted after treatment (MD = -53.05 million; 95% CI: [-104.96, -1.14]; P = 0.05). Sperm volume, initial forward motility and morphology were unaffected by HU treatment. In females, HU treatment decreased the mean AMH levels 1.83 (95% CI [1.42, 2.56]. A total of 18.2.% patients treated with HU showed reduced ovarian reserves.

INTERPRETATION & CONCLUSIONS

This systemic review and meta-analysis suggest that the use of HU for SCD impacts seminal fluid parameters in males and can diminish AMH levels and ovarian reserves in females.

Role of hydroxyurea therapy in the prevention of organ damage in sickle cell disease: a systematic review and meta-analysis

BACKGROUND

Hydroxyurea is an affordable drug that reduces vaso-occlusive crises and transfusion requirements in sickle cell disease. However, its effectiveness in preventing chronic organ damage is still unclear. This systematic review and meta-analysis aimed to evaluate the role of hydroxyurea in preventing organ morbidity.

METHOD

We included original articles published in English from 1st January 1990 to 31st January 2023, reporting hydroxyurea therapy and organ damage from PubMed, Google Scholar, Scopus, and CrossRef databases. A total of 45 studies with 4681 sickle cell disease patients were evaluated for organ damage.

RESULTS

Our analysis showed that hydroxyurea intervention significantly lowered transcranial Doppler and tricuspid regurgitant velocity, with a standardized mean difference of - 1.03 (- 1.49; - 0.58); I 2 = 96% and - 1.37 (CI - 2.31, - 0.42); I 2 = 94%, respectively. Moreover, the pooled estimate for albuminuria showed a beneficial effect post-hydroxyurea therapy by reducing the risk of albuminuria by 58% (risk ratio of 0.42 (0.28; 0.63); I 2 = 28%).

CONCLUSION

Our study found that a hydroxyurea dose above 20 mg/kg/day with a mean rise in HbF by 18.46% post-hydroxyurea therapy had a beneficial role in reducing transcranial doppler velocity, tricuspid regurgitant velocity, albuminuria, and splenic abnormality.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42023401187.

Racial and Ethnic Disparities in Metabolic Bone Disease

Racial and ethnic disparities exist in the prevalence and management of osteoporosis, metastatic cancer, and sickle cell disease. Despite being the most common metabolic bone disease, osteoporosis remains underscreened and undertreated among Black women. Skeletal-related events in metastatic cancer include bone pain, pathologic fractures, and spinal cord compression. Disparities in screening for and treating skeletal-related events disproportionately affect Black patients. Metabolic bone disease contributes significantly to morbidity in sickle cell disease; however, clinical guidelines for screening and treatment do not currently exist. Clinical care recommendations are provided to raise awareness, close health care gaps, and guide future research efforts.

Incidence and risk factors for osteonecrosis of the femoral head in five hundred and ten sickle cell disease paediatric patients

PURPOSE

Osteonecrosis of the femoral head (ONFH) is a degenerative and progressive disorder that mainly affects people with sickle cell disease (SCD). Herein, we aimed to search for a better understanding of markers that can act as risk factors for ONFH in patients with SCD.

METHODS

We conducted a retrospective study including 510 SCD patients followed over 23 years. Patients were divided into the ONFH group and the no-ONHF control group. Univariate and multivariate logistic regression analyses were performed to identify risk factors.

RESULTS

Among 510 SCD patients, 41(8%) were diagnosed with ONFH at a mean age of 167 months ± 64 (72-288). The cumulative incidence of ONHF increased from 2.3% at ten years to 18.3% at 20 years of age. The radiological grade 3 ONHF was predominant. No significant differences in sex, age at diagnosis of SCD, and Hb genotype were found between groups. The patient age and the time since diagnosis of SCD were statistically higher in patients with ONHF in univariate and multivariate analysis. ONHF was also associated with higher creatinine level (p = 0.001) lower LDH level (p = 0.006), and higher number of vaso-occlusive crisis (VOC)/patient/year (p < 0.001). The cumulative incidence of ONHF in patients having more than 3 VOC/year was significantly higher (43% versus 18.9% at 20 years, p < 0.001). In addition, infections, gallstones, growth delay, delayed initiation of hydroxyurea, and a higher transfusion rate were significantly associated with ONFH.

CONCLUSION

These findings confirm that ONFH is closely related to the age, severity, and duration of SCD. Better management of this disease prevents acute and chronic complications, and early screening of the ONFH as soon as the first signs of the severity of the disease are detected provides a better functional prognosis.

Repeat transcranial Doppler ultrasound imaging in Kuwaiti children with sickle cell disease after a 10‐year interval: A prospective, cohort study

Objectives

Transcranial Doppler imaging (TCDI) of the cerebral arteries is the method of choice to predict patients with sickle cell disease (SCD) at risk for stroke. This study reports TCDI follow‐up of cerebral blood flow in a cohort of Kuwaiti children with SCD after a 10‐year interval.

Methods

Twenty‐one pediatric patients with SCD, aged 16.0 ± 1.6 years were initially studied when they were aged 6.5 ± 1.2 years. TCDI scanning was carried out using a phased‐array transducer of 1–3 MHz through the trans‐temporal window. Peak systolic velocity (PSV), end‐diastolic velocity (EDV), time‐averaged mean of the maximum velocity (TAMMV), resistive index (RI), and pulsatility index (PI) were obtained in the anterior and posterior Circle of Willis vessels.

Results

The follow‐up indices were mostly lower than in the initial study although they remained within the normal range in all the arteries. TAMMV was less than 170 cm/s, and PSV did not exceed 200 cm/s in all vessels. The initial and follow‐up TAMMV (mean ± SD) were: 77.3 ± 20.9 and 71.6 ± 9.9 in the terminal internal carotid artery, 94.3 ± 25.8 and 82 ± 18.2 in the middle cerebral artery, 76.6 ± 25.6 and 70.6 ± 10.7 in the anterior cerebral artery, and 59.1 ± 15.8 and 63.9 ± 8.5 in the posterior cerebral artery, respectively. The mean differences between the old and follow‐up data for RI, and PI were statistically significant (p < 0.05).

Conclusions

Kuwaiti patients with SCD appear to be largely protected from cerebral artery vasculopathy in childhood.

Stroke is a common complication in sickle cell disease (SCD) in many parts of the world and it tends to be recurrent.

Transcranial Doppler Imaging (TCDI) is used to identify patients at risk for stroke.

Patients with timed average mean of the maximum velocity (TAMMV) > 200 cm/s in the arteries of the Circle of Willis, are at increased risk of stroke and need chronic transfusion for the primary prevention of stroke.

However, stroke is uncommon among Kuwaiti SCD patients with high HbF.

A previous study carried out, about 10 years ago, in a cohort of Kuwaiti pediatric SCD found none with abnormal TAMMV values.

A repeat TCDI study has now been carried out on 21 patients from the cohort that was studied 10 years ago.

We found that TCD remains in the normal range in all the patients and, in fact, the TAMMV and other values were significantly lower in the latest study compared to the initial data.

Cerebral vasculopathy is uncommon among Kuwaiti SCD patients.

Occult ischemic bone lesions in children with sickle cell disease: A study of prevalence

INTRODUCTION

Avascular necrosis (AVN) is a severe complication of sickle cell disease (SCD) and involves principally the femoral head. Few data exist about the prevalence of lesions in other segments.

METHODS

In this cross-sectional study, 42 children (20 males and 22 females) underwent a magnetic resonance imaging (MRI) of the spine, upper arms, and femurs. The primary outcome was to define the prevalence and locations of bone infarcts.

RESULTS

Forty-two patients completed the study; the total median age was 11.9 years (interquartile range = 9.5-13.9). Eleven patients (26.2%) were positive for altered bone findings for a total of 32 lesions. Most of the lesions were in the humerus 17 (53.1%), 11 (34.4%) in the femurs, and 4 (12.5%) in the vertebrae. The median number of vaso-occlusive crises (VOCs) was two and four for patients without and with bone lesions, respectively (p = .01). The annual rate of VOC is the best marker for the positive MRI (odds ratio = 82.6; p = .03), and it is correlated with the number of sites involved (p = .02).

CONCLUSIONS

Our study highlights that the prevalence of skeletal lesions could be underestimated, and it provides the basis for clinical reasoning and tailored therapy in SCD children.

Sickle cell bone disease and response to intravenous bisphosphonates in children

Children with sickle cell disease (SCD) have the potential for extensive and early-onset bone morbidity. This study reports on the diversity of bone morbidity seen in children with SCD followed at three tertiary centers. IV bisphosphonates were effective for bone pain analgesia and did not trigger sickle cell complications.

INTRODUCTION

To evaluate bone morbidity and the response to intravenous (IV) bisphosphonate therapy in children with SCD.

METHODS

We conducted a retrospective review of patient records from 2003 to 2019 at three Canadian pediatric tertiary care centers. Radiographs, magnetic resonance images, and computed tomography scans were reviewed for the presence of avascular necrosis (AVN), bone infarcts, and myositis. IV bisphosphonates were offered for bone pain management. Bone mineral density was assessed by dual-energy X-ray absorptiometry (DXA).

RESULTS

Forty-six children (20 girls, 43%) had bone morbidity at a mean age of 11.8 years (SD 3.9) including AVN of the femoral (17/46, 37%) and humeral (8/46, 17%) heads, H-shaped vertebral body deformities due to endplate infarcts (35/46, 76%), and non-vertebral body skeletal infarcts (15/46, 32%). Five children (5/26, 19%) had myositis overlying areas of AVN or bone infarcts visualized on magnetic resonance imaging. Twenty-three children (8/23 girls) received IV bisphosphonate therapy. They all reported significant or complete resolution of bone pain. There were no reports of sickle cell hemolytic crises, pain crises, or stroke attributed to IV bisphosphonate therapy.

CONCLUSION

Children with SCD have the potential for extensive and early-onset bone morbidity. In this series, IV bisphosphonates were effective for bone pain analgesia and did not trigger sickle cell complications.

Multifocal Osteonecrosis in a 3-Year-old Child With Sickle Beta Plus Thalassemia

Sickle beta+thalassemia is considered to be a mild form of sickle cell disease. However, some patients with mild disease can present with osteonecrosis. Here, we present a rare 3-year-old male who presented with acute pain, a baseline hemoglobin of 13 g/dL, who acutely developed multifocal osteonecrosis, and improved with partial exchange transfusion and hydroxyurea therapy.

Association and Risk Factors of Osteonecrosis of Femoral Head in Sickle Cell Disease: A Systematic Review

OBJECTIVE

The objective was to evaluate the level of evidence about the associated factors and the risk factors of osteonecrosis of femoral head (ONFH) in sickle cell individuals.

METHODS

The review was based on the search and selection of studies available in the electronic databases PubMed, SCIELO, LILACS, BVS. As descriptors, the terms of Medical Subject Headings (MeSH) and Health Sciences Descriptors (DeCS) corresponding to "Osteonecrosis", "Necrosis avascular" and "Aseptic necrosis" and "Femoral head" and "sickle cell disease" and "risk factor" and "predictor".

RESULTS

Among clinical and laboratorial factors the most promising risk factors were the severity of sickle cell disease and acute chest syndrome. As a result, from studies of a moderate level of quality, blood pressure, body weight, previous trauma, haemoglobin to haematocrit ratio (Hb/HCT), and number of hospitalizations can be highlighted. Others, such as genetic markers and male gender, have also been positively associated in lower quality studies.

CONCLUSION

For a better clarification of what the risk factors are for the ONFH, it is necessary to study with populations of different origins, different ages, different profiles of Hb, which present greater methodological rigor and perform a multivariate analysis to control confounding factors. Further study is also needed to understand the genetic determinants of ONFH.

The Genetic and Clinical Significance of Fetal Hemoglobin Expression in Sickle Cell Disease

Sickle cell disease (SCD) is phenotypically heterogeneous. One major genetic modifying factor is the patient's fetal hemoglobin (HbF) level. The latter is determined by the patient's β-globin gene cluster haplotype and cis- and trans-acting single nucleotide polymorphisms (SNPs) at other distant quantitative trait loci (QTL). The Arab/India haplotype is associated with persistently high HbF levels and also a relatively mild phenotype. This haplotype carries the Xmn1 (C/T) SNP, rs7482144, in the HBG2 locus. The major identified trans-acting QTL contain SNPs residing in the BCL11A on chromosome 2 and the HMIP locus on chromosome 6. These collectively account for 15-30% of HbF expression in different world populations and in patients with SCD or β-thalassemia. Patients with SCD in Kuwait and Eastern Saudi Arabia uniformly carry the Arab/India haplotype, but despite this, the HbF and clinical phenotypes show considerable heterogeneity. Pain episodes and avascular necrosis of the femoral head are particularly common, but severe bacterial infections, stroke, priapism, and leg ulcers are uncommon. Moreover, the HbF modifiers appear to be different; the reported BCL11A and HMIP SNPs appear to play insignificant roles. There are probably novel modifiers to be discovered in this population. This review examines the common clinical phenotypes in Kuwaiti patients with elevated HbF and the available information on HbF modifiers. The response of the patients to hydroxyurea is discussed. The presentation of patients with other sickle compound heterozygotes (Sβthal and HbSD), vis-à-vis their HbF levels, is also addressed critically.

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.