# The Whole Blood Transcriptomic Analysis in Sickle Cell Disease Reveals RUNX3 as a Potential Marker for Vaso-Occlusive Crises

## TL;DR

This study identifies RUNX3 as a potential biomarker for predicting vaso-occlusive crises in sickle cell disease patients through blood transcriptomic analysis.

## Contribution

The study identifies RUNX3 as a novel potential biomarker for vaso-occlusive crises in sickle cell disease.

## Key findings

- RUNX3 is significantly down-regulated during vaso-occlusive crises compared to steady-state in sickle cell disease patients.
- Whole blood transcriptomic analysis revealed 1078 genes differentially expressed during vaso-occlusive crises versus steady-state.
- Immune and hematopoietic pathways are significantly deregulated in sickle cell disease patients.

## Abstract

Sickle cell disease (SCD) is the most common hemoglobinopathy, caused by a mutation in the β-globin gene of hemoglobin. It predisposes patients to painful Vaso-occlusive crises (VOC) and multi-organ dysfunctions. The disease exhibits significant phenotypic variability, making it challenging to predict severity and outcomes. This study aimed to characterize the whole blood gene expression profile of Bahraini SCD patients, identifying differentially expressed genes during steady-state (n = 10) and VOC (n = 10) compared to healthy controls (n = 8). Analysis revealed 2073 and 3363 dysregulated genes during steady-state and VOC, respectively, compared to controls, with 1078 genes differentially expressed during VOC versus steady-state. Gene Ontology (GO) enrichment analysis highlighted significant deregulation in immune and hematopoietic pathways, including down-regulation of critical genes for immune modulation and hematopoietic balance. Notably, the transcription factor RUNX3, involved in immune cell differentiation and inflammation, was among the 668 down-regulated genes. RUNX3 was four-fold down-regulated in microarray analysis, three-fold in PCR, and showed a mean protein concentration of 11.13 pg/mL during VOC compared to 457.93 pg/mL during steady-state (p < 0.01). These findings suggest that RUNX3 may serve as a potential biomarker for VOC. Future large-scale validation, additional proteomic studies, and functional investigations are recommended to confirm its clinical utility and significance.