HO-1 Levels Elevated in Children Versus Adults with Sickle Cell Disease

Children with SCD have significantly higher heme-oxygenase-1 (HO-1) levels compared with adults, according to recent data from the SickleGenAfrica Network project. Researchers believe this is the first study to show these findings.

More than 2,000 children and adults are enrolled in the SickleGenAfrica Network. Participants joined between 2018 and 2021 and are from three sites in Ghana. All participants gave consent of samples in future studies.

In this study, which was presented during the 65th ASH Annual Meeting & Exposition, the researchers evaluated HO-1 levels using the enzyme-linked immunosorbent assay in 1,971 patients. More than half (55%) were female, with a median age of 13 years. Nine age groups were represented from 0 to older than 40 years. Participants were grouped by age using five-year intervals.

Most patients had hemoglobin SS (58%), followed by sickle-hemoglobin C disease (30%), sickle-hereditary persistence of fetal hemoglobin (9%), and hemoglobin–S-beta + (3%).

The researchers determined that children had elevated HO-1 levels versus older participants, and there was a three-fold drop-off in median HO-1 levels during adolescence (11-15 years old [73.9 ng/ml] and 16-20 years old [25.1 ng/ml]). Compared with females, males had higher average HO-1 levels (63.1 ng/ml vs 85.5 ng/ml, respectively).

The pairwise Wilcoxon test, with Bonferroni correction for multiple comparisons, was used to examine and compare the median HO-1 level across the different age groups.

“To the best of our knowledge, this is the first study of HO-1 levels in patients with SCD at different ages,” the researchers said. “HO-1 may serve as a protective SCD factor, contributing to enhanced [acute chest syndrome (ACS)] survival rates in children versus adults.”

This study is just the beginning for the researchers, who hope to determine if baseline blood HO-1 levels can predict ACS incidence and severity. Furthermore, they aim to investigate genetic and epigenetic mechanisms controlling HO-1 expression.

Reference

Sowa A, Kudzi W, Paintsil V, et al. Enhanced expression of heme oxygenase-1 (HO-1) among children with sickle cell disease: results of the Sickle Cell Disease Genomics of Africa (SickleGenAfrica) study. Abstract #150. Presented at the 65th American Society of Hematology Annual Meeting & Exposition; December 9-12; San Diego, California.