F13. PLATELET-LYMPHOCYTE RATIO AS A SHORT-TERM TREATMENT-RESPONSE PREDICTOR IN SCHIZOPHRENIA’S RELAPSE

Abstract Background Schizophrenia is a chronic, severe and disabling brain disorder with a still poorly understood heterogeneous neurobiological and genetic background, estimated to affect 1% of the population worldwide. A series of findings have concluded that cellular inflammatory immune alterations are associated with psychopathology variation and may constitute a possible marker of therapeutic response. The Platelet-Lymphocyte Ratio (PLR) is a cost effective, easily obtainable circulating clinical marker of peripheral inflammation that may predict better treatment responses in schizophrenic patients undergoing an acute psychotic episode. Methods We performed a cross-sectional retrospective study using administrative data from Centro Hospitalar Psiquiátrico de Lisboa (CHPL) on all patients diagnosed with schizophrenia (ICD-9 295) who were admitted to the inpatient psychiatric unit at CHPL for psychotic relapse in 2015 (n=202). We performed multivariate logistic regression to obtain the association between PLR, measured at time of admission, and adjusted odds of prolonged length of stay (LOS), defined as LOS greater than 15 days, controlling for potential confounders such as years of diagnosed disease (YDD), number of previous admissions (PA), patient demographics, antipsychotics and other prescribed medications, metabolic variables, inflammation markers and presence or absence of metabolic syndrome. Results Primary analyses demonstrated that greater PLR (>149.9) at time of admission for psychotic relapse was significantly associated with greater adjusted odds of prolonged LOS (OR 3.54, 95% CI 1.54, 8.16). Discussion We found that among schizophrenic patients admitted to the hospital with a psychotic relapse, an elevated PLR (>149.9) is associated with greater adjusted odds of prolonged hospitalization. This study suggests that the measurement of this easily accessible ratio may be helpful to predict which patients may require a longer hospitalization to obtain clinical stabilization. Future understanding of inflammation’s dynamics that lead to these findings may allow for more targeted therapies to improve relapse prevention.