Associations of the circulating levels of cytokines with the risk of myeloproliferative neoplasms: a bidirectional mendelian-randomization study

Abstract Objective In the pathogenesis of myeloproliferative neoplasms (MPN), inflammation plays an important role. However, it is unclear whether there is a causal link between inflammation and MPNs. We used a bidirectional, two-sample Mendelian randomization (MR) approach to investigate the causal relationship between systemic inflammatory cytokines and myeloproliferative neoplasms. Methods A genome-wide association study (GWAS) of 8293 European participants identified genetic instrumental variables for circulating cytokines and growth factors. Summary statistics of MPN were obtained from a GWAS including 1086 cases and 407,155 controls of European ancestry. The inverse-variance-weighted method was mainly used to compute odds ratios (OR) and 95% confidence intervals (Cl). Results Our results showed that higher Interleukin-2 receptor, alpha subunit (IL-2rα) levels, and higher Interferon gamma-induced protein 10 (IP-10) levels were associated with an increased risk of MPN (OR = 1.36,95%CI = 1.03–1.81, P = 0.032; OR = 1.55,95%CI = 1.09–2.22, P = 0.015; respectively).In addition, Genetically predicted MPN promotes expression of the inflammatory cytokines interleukin-10 (IL-10) (BETA = 0.033, 95% CI = 0.003 ~ 0.064, P = 0.032) and monokine induced by interferon-gamma (MIG) (BETA = 0.052, 95% CI = 0.002–0.102, P = 0.043) and, on activation, normal T cells express and secrete RANTES (BETA = 0.055, 95% CI = 0.0090.1, P = 0.018). Conclusion Our findings suggest that cytokines are essential to the pathophysiology of MPN. More research is required if these biomarkers can be used to prevent and treat MPN.