Elevation of C-reactive protein level and its correlation with psychiatric comorbidities in recipients after liver transplantation

Orthotopic liver transplantation (OLT) is the gold standard procedure for treating end-stage liver disease resulting from a variety of causes. Psychiatric comorbidities are common problems among patients who have undergone OLT; however, the association between psychiatric comorbidity and biological factors in OLT has not been investigated. In our previous study, we found a positive correlation between serum C-reactive protein (CRP) level after OLT and the prevalence of psychiatric comorbidities in recipients. In this retrospective cohort analysis, we enrolled 279 recipients who underwent OLT during a 3-year period (from 2008 to 2011) at a single center. Our retrospective study showed that the recipients with a higher serum CRP level at 1 month after OLT had higher psychiatric comorbidities compared with the recipients with a normal serum CRP level. Additionally, an in vitro study demonstrated that the down-regulation of brain-derived neurotrophic factor (BDNF) gene expression by CRP treatment in retinoic acid (RA) differentiated SH-SY5Y neuroblastoma cells. These clinical and experimental results indicated that the overexpression of CRP may induce psychiatric comorbidities through suppressed expression of the BDNF, suggesting that OLT recipients who developed psychiatric comorbidities might be accompanied by an immunological or acute-phase protein response. In conclusion, an activation of systemic inflammatory processes may be one of the predictable signatures for psychiatric comorbidities in OLT recipients.