An Erythroid Gene Expression Signature in Preoperative Whole-Blood RNA-Seq Associated with Rebound Pain After Brachial Plexus Block: A Prospective Observational Study.

BACKGROUND

Preoperative whole-blood transcriptomic profiles may reflect systemic biological variation before surgery, but their association with rebound pain after brachial plexus block remains unclear. This study investigated whether preoperative whole-blood transcriptomic profiles are associated with pain escalation after brachial plexus block resolution.

METHODS

This single center prospective study enrolled patients who underwent upper extremity surgery with ultrasound guided brachial plexus block. Preoperative whole blood RNA sequencing was used to compare the transcriptomic profiles between patients with and without rebound pain. Differential expression, functional enrichment, protein-protein interaction analysis, LASSO regression, and random forest analysis were performed. The selected hub gene was further validated by qRT-PCR in an independent cohort using the same matching strategy.

RESULTS

Among the 47 analyzed patients, 28 experienced rebound pain. The RNA-seq discovery cohort included 24 matched patients, with 12 patients in each group. RNA-seq analysis identified 110 differentially expressed genes, most of which were upregulated in the rebound pain group. Enrichment analyses highlighted erythrocyte differentiation, hemoglobin metabolism, porphyrin biosynthesis, and oxygen-carbon dioxide exchange. Protein-protein interaction analysis identified a 13-gene cluster, from which GYPB was selected by LASSO and random forest analyses. In the independent validation cohort of 45 patients, 15 matched pairs were included in qRT-PCR analysis, which confirmed significantly increased GYPB mRNA expression in patients with rebound pain, showing a 3.390-fold increase compared with patients without rebound pain (95% CI: 1.258-3.523; P < 0.05).

CONCLUSION

Preoperative whole-blood erythrocyte-related transcriptional signals, including GYPB upregulation, were associated with rebound pain after brachial plexus block. As these exploratory findings were based on a limited RNA-seq cohort, larger studies incorporating blood cell composition are needed to validate their clinical relevance and specificity.

TRIAL REGISTRATION: This study was registered with the Chinese Clinical Trial Registry. No. ChiCTR2400081153. Registered 23 February 2024.