Clinical Significance of Neutrophil-lymphocyte and Platelet-lymphocyte Ratios in Bipolar Patients: An 18-month Prospective Study

Neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) have recently been investigated as inexpensive and reproducible markers of systemic inflammation in many diseases. However, few studies evaluate clinical and prognostic value of NLR and PLR in psychiatric patients. The objective of this study is to investigate the clinical repercussions of NLR and PLR in patients with bipolar disorder (BD). An 18-month prospective study followed up eighty euthymic BD outpatients. Baseline data included an interviewer-administered questionnaire, behavioral scales and a blood count to calculate NLR and PLR. The occurrence of mood episodes and hospitalizations was assessed monthly for 18 months. Higher NLR and PRL were associated with more anxious symptoms and poorer functioning. BD patients with Night Eating Syndrome (NES) had higher PLR and tended to higher NLR. No association with other sleep parameters was evidenced. Higher NLR and PRL were also associated with more episodes and hospitalizations after 18 months. However, only higher baseline NLR was related to more (hypo)mania episodes. NLR and PLR are important prognostic factor for BD. This study suggested the importance of a simple blood count, an inexpensive and reproducible exam, in evaluating the course of the BD. Further studies must be performed to confirm these results.