Sickle cell disease in children: accuracy of imaging transcranial Doppler ultrasonography in detection of intracranial arterial stenosis

Standard measures for sickle cell disease research: the PhenX Toolkit sickle cell disease collections

Standard measures and common data elements for sickle cell disease (SCD) will improve the data quality and comparability necessary for cross-study analyses and the development of guidelines that support effective treatments and interventions. In 2014, the National Institutes of Health, National Heart, Lung, and Blood Institute (NHLBI) funded an Administrative Supplement to the PhenX Toolkit (consensus measures for Phenotypes and eXposures; https://www.phenxtoolkit.org/) to identify common measures to promote data comparability across SCD research. An 11-member Sickle Cell Disease Research and Scientific Panel provided guidance to the project, establishing a core collection of SCD-related measures and defining the scope of 2 specialty collections: (1) cardiovascular, pulmonary, and renal complications, and (2) neurology, quality-of-life, and health services. For each specialty collection, a working group of SCD experts selected high-priority measures using a consensus process that included scientific community input. The SCD measures were released into the Toolkit in August 2015. The 25 measures included in the core collection are recommended for use by all NHLBI-funded investigators performing human-subject SCD research. The 10 neurology, quality-of-life, and health services measures and 14 cardiovascular, pulmonary, and renal measures are recommended for use within these specialized research areas. For SCD and other researchers, PhenX measures will promote collaborations with clinicians and patients, facilitate cross-study analysis, accelerate translational research, and lead to greater understanding of SCD phenotypes and epigenetics. For clinicians, using PhenX measures will help elucidate the etiology, progression, and treatment of SCD, leading to improved patient care and quality of life.

Transcranial Doppler Screening in 50 Patients With Sickle Cell Hemoglobinopathies in Iran

BACKGROUND

As previous studies had discordant results with regard to the correlation of transcranial Doppler (TCD) screening and brain MRI, the aim of this study was to find the correlation between TCD values and silent ischemia in sickle cell disease (SCD) patients.

METHOD AND MATERIALS

In this cross-sectional study, 50 patients with proven diagnosis of sickle cell hemoglobinopathies based on their hemoglobin electrophoresis were included. Demographic data, their physical exam, information with regard to crises history, and their laboratory data were recorded. Brain MRI and TCD were requested for all patients.

RESULTS

The mean age of the patients was 10.2±5.8 years. Only 3 patients (6%) showed evidence of ischemia on brain MRI. Normal and ischemic patients were not significantly different with respect to TCD values, sex, splenomegaly, aplastic crisis, and laboratory test results (P-value >0.05). Only platelet count was significantly higher in the ischemic group compared with that in the normal group (P=0.002). The pain crisis was significantly associated with the mean velocity values of RMCA, LMCA, RV, and LV arteries (P-value <0.05).

CONCLUSION

On the basis of our results, there was no significant difference in the mean velocity TCD values between patients with and without evidence of ischemic brain damage in brain MRI. The frequency of silent ischemia was much lower than expected. Further studies with larger sample sizes are needed to elucidate the positive predictive value of abnormal TCD in the prediction of silent ischemia in patients with sickle hemoglobinopathy in certain ethnic groups.