Head circumference of children with sickle cell disease in Lagos, Nigeria

Abnormal Lower Extremity Hemodynamics at Doppler US in Children with Sickle Cell Anemia

Background Children with sickle cell anemia (SCA) are predisposed to developing leg ulcers in early adolescence; however, the underlying physiologic mechanisms are not well understood, which hinders the development of prophylactic antiulcer interventions. Purpose To determine if occlusive arterial disease or abnormal hemodynamics exist in the lower limb peripheral arteries of children with SCA. Materials and Methods This was a prospective cross-sectional study conducted between July 2020 and May 2021. Two groups of participants were enrolled: children with SCA and healthy controls. Each child had their anthropometric measurements taken, followed by B-mode, color Doppler, and spectral Doppler US evaluation of the distal anterior and posterior tibial arteries. Ankle-brachial index evaluation was also performed. Hemodynamic values were compared between children with SCA and healthy controls, with statistical significance set at the P < .05 level. Results Forty-five children with SCA (mean age, 9.5 years ± 3.7 [SD]; 26 boys) and 45 healthy controls (mean age, 9.3 years ± 3.8; 25 boys) were evaluated. Children with SCA had higher peak systolic velocities, end-diastolic velocities, and blood volume flow in their distal anterior and posterior tibial arteries compared with the healthy participants (P < .001 across all 12 measurements). Children with SCA also had lower resistive index and pulsatility index values compared with healthy controls in at least one of the anterior and posterior tibial arteries bilaterally. Monophasic spectral patterns were exclusively observed in participants with SCA. The ankle-brachial index values for the participants with SCA (mean, 1.09 ± 0.08) and healthy participants (mean, 1.06 ± 0.02) were within normal range. Conclusion Abnormal peripheral hemodynamic characteristics were found in the lower limbs of children with sickle cell anemia. No evidence of occlusive peripheral artery disease was present. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Paltiel in this issue.

Nutritional perspectives on sickle cell disease in Africa: a systematic review

BACKGROUND

Sickle cell disease (SCD) is an inherited blood disorder that predominantly affects individuals in sub-Saharan Africa. However, research that elucidates links between SCD pathophysiology and nutritional status in African patients is lacking. This systematic review aimed to assess the landscape of studies in sub-Saharan Africa that focused on nutritional aspects of SCD, and highlights gaps in knowledge that could inform priority-setting for future research.

METHODS

The study was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Inclusion criteria comprised original, peer-reviewed research published between January 1995 and November 2020 involving individuals in Africa with any phenotypic variant of SCD and at least one nutritional status outcome. Nutritional status outcomes were defined as those that assessed dietary intakes, growth/anthropometry, or nutritional biomarkers. Databases used were Ovid Embase, Medline, Biosis and Web of Science.

RESULTS

The search returned 526 articles, of which 76 were included in the final analyses. Most investigations (67%) were conducted in Nigeria. Studies were categorized into one of three main categories: descriptive studies of anthropometric characteristics (49%), descriptive studies of macro- or micronutrient status (41%), and interventional studies (11%). Findings consistently included growth impairment, especially among children and adolescents from sub-Saharan Africa. Studies assessing macro- and micronutrients generally had small sample sizes and were exploratory in nature. Only four randomized trials were identified, which measured the impact of lime juice, long-chain fatty acids supplementation, ready-to-use supplementary food (RUSF), and oral arginine on health outcomes.

CONCLUSIONS

The findings reveal a moderate number of descriptive studies, most with small sample sizes, that focused on various aspects of nutrition and SCD in African patients. There was a stark dearth of interventional studies that could be used to inform evidence-based changes in clinical practice. Findings from the investigations were generally consistent with data from other regional settings, describing a significant risk of growth faltering and malnutrition among individuals with SCD. There is an unmet need for clinical research to better understand the potential benefits of nutrition-related interventions for patients with SCD in sub-Saharan Africa to promote optimal growth and improve health outcomes.

Asymmetric Dimethylarginine Levels and Its Correlation to Cerebral Blood Flow in Children with Sickle Cell Anemia

Asymmetric dimethylarginine (ADMA) level may play a role in the pathogenesis of cerebrovascular stroke in Children with Sickle Cell Anemia (SCA). To assess the plasma level of ADMA in children with SCA and its correlation to cerebral blood flow. This is a cross sectional study was carried out on 30 children with homozygous SCA under follow up in the Out Patients Clinic, Pediatric Department at Tanta University Hospital and 30 healthy children as a control group. Both groups had undergone the following investigations: Complete blood count, lactate dehydrogenase enzyme, and plasma level of ADMA by a commercial ADMA ELISA Kit. Trans-cranial Doppler were done for both groups. ADMA plasma level was significantly higher in-patient group in comparison to the control group (p < 0.001), with a mean value 1.43 ± 0.20 μmol/l, 0.48 ± 0.16 μmol/l respectively. The time-averaged mean maximum velocities for middle cerebral artery, anterior cerebral artery, inferior cerebral artery and posterior cerebral artery were significantly different between patient and control group, p < 0.05. Trans-cranial Doppler data revealed that, 86.7% of patients have low velocity (< 70 cm/s) and 13.3% having very low velocity (< 10 cm/s) while control group have normal velocity. There was a significant negative correlation between ADMA plasma levels and cerebral blood flow. Elevated ADMA levels may have a role in the pathogenesis of the decreased cerebral blood flow in children with SCA.