Hemoglobin Levels Significantly Affect Ultrasound Velocities in Children With Sickle Cell Disease

In children with sickle cell disease, transcranial Doppler (TCD) can reveal the importance of higher hemoglobin levels, according to data presented at the American Society of Hematology’s 2021 Annual Meeting.

To determine how TCD ultrasound velocities correlate with hematologic variables and treatments in a pediatric cohort with sickle cell disease, researchers from Italy retrospectively analyzed data from a prospective cohort of these patients who were followed up from January 2009 through December 2020.

Results of TCD imaging were classified according to standard criteria by considering time-averaged maximum mean velocities (TAMMVs) in the terminal internal carotid artery and middle cerebral artery, and the researchers collected hematologic, clinical, and treatment variables from the cohort database. 

Mean hemoglobin values and hemolysis markers were compared between patients with abnormal or conditional TCD imaging results and those without them by using 2-sample and Welch t-tests for unequal variances. Categorical variables were compared by using Fisher and chi-square tests, and the effects of TAMMVs on hemoglobin were assessed by using linear regression models. 

The cohort included 182 patients; the median follow-up period was 80 months, and the median age of patients at the study end was 13 years. Patients with abnormal or conditional TCD imaging results had lower levels of hemoglobin and higher reticulocyte counts, as well as lower levels of lactate dehydrogenase and aspartate aminotransferase than patients with normal or low TCD imaging results.  Moreover, an inverse linear correlation between abnormal or conditional TCD imaging results and hemoglobin was found.

According to the researchers, these results “support the beneficial effect of higher [hemoglobin] levels in reducing TAMMV. Disease-modifying therapies increasing hemoglobin and reducing hemolysis could be helpful in reducing TAMMV.”

—Ellen Kurek

Reference:

Reggiani G, Coppadoro B, Munaretto V, et al. The role of hemoglobin and hemolysis on transcranial doppler velocities in children with sickle cell disease: data from a natural history cohort. Paper presented at: American Society of Hematology 2021 Annual Meeting & Exposition; December 11-14, 2021; Atlanta, Georgia. https://ash.confex.com/ash/2021/webprogram/Paper148043.htm