White blood cells and chronic rhinosinusitis: a Mendelian randomization study

Area of Science:

• Immunology and genetics
• Investigating disease pathogenesis

Background:

• Chronic rhinosinusitis (CRS) pathogenesis is complex and not fully understood.
• White blood cell (WBC) counts, crucial in inflammation, are understudied as CRS risk factors.

Purpose of the Study:

• To explore causal associations between various WBC counts and CRS risk.
• Utilize Mendelian randomization (MR) for robust genetic association analysis.

Main Methods:

• Two-sample MR analysis using GWAS summary statistics for WBC counts (neutrophils, eosinophils, basophils, lymphocytes, monocytes) and CRS.
• Employed inverse-variance weighted MR, with sensitivity analyses including weighted median, MR-Egger, and MR-PRESSO.

Main Results:

• A significant causal association was found between higher blood eosinophil counts and increased CRS risk (OR=1.55, P=4.3E-14).
• No significant causal links were identified for neutrophil, lymphocyte, monocyte, or basophil counts with CRS.
• Sensitivity analyses confirmed the eosinophil finding, and no significant pleiotropic bias was detected.

Conclusions:

• Blood eosinophil count is a potential causal risk factor for CRS.
• Other WBC counts do not appear to have a causal relationship with CRS.
• Further research into genetic variations in CRS is warranted to confirm these genetic causal effects.