Niveles plasmáticos de triptófano en pacientes cubanos con esquizofrenia

Introduction. Schizophrenia is a heterogeneous psychiatric disorder that affects 1% of the world's population. The pathophysiology of this disease has been reported to be involved with several neurotransmitter systems, such as serotonin. Because serotonin synthesis depends on the availability of tryptophan, we studied plasma tryptophan levels in Cuban patients with schizophrenia. Objective. To determine plasma concentrations of tryptophan in patients with schizophrenia. Materials and Methods. A descriptive crosssectional study was performed. The sample consisted of 400 patients treated at the Psychiatric Hospital of Havana with clinical diagnoses of schizophrenia. Patient's psychopathological assessment were completed using Schedules for Clinical Assessment in Neuropsychiatry (SCAN) protocols. The reference population group comprised 157 apparently healthy individuals of both sexes. Plasma tryptophan levels were quantified by HPLC. Results. A significant decrease in plasma tryptophan concentrations (p = 0,0001) were observed as related to the sex of the patient, with the female patients presenting the lowest values of tryptophan compared to reference values. It was observed that patients with concentrations below 370 μM tryptophan, had the most severe degrees of SCAN as evaluated by clinical variables related to negative symptoms with schizophreniform speech abnormalities (64.3%) and negative syndrome (61.8%). Conclusion. Patients with schizophrenia with low concentrations of tryptophan may have alterations in their serotonergic systems, which could explain the severity observed in relation to the negative symptoms of the disease and could also point to candidates in the search for genes associated with serotonin pathways. Based on these findings, it is recommended that the measurement of plasma tryptophan concentrations should be considered when selecting therapies for treating schizophrenia. Introducción. La esquizofrenia es un trastorno psiquiátrico muy heterogéneo, que afecta el 1 % de la población mundial. Se ha descrito que en la patofisiología de esta enfermedad pueden estar implicados varios sistemas de neurotransmisores, como el serotoninérgico. La síntesis de la serotonina depende de la disponibilidad de triptófano. Objetivo. Determinar las concentraciones plasmáticas de triptófano en pacientes con esquizofrenia. Materiales y Métodos. Se realizó un estudio descriptivo de tipo transversal. La muestra estuvo conformada por 400 pacientes atendidos e