Stimulated peripheral production of interferon-gamma is related to fatigue and depression in multiple sclerosis

ObjectivesThe aim of the study was to evaluate the stimulated production of interferon-gamma (IFNγ) by peripheral CD3+CD4+ T lymphocytes in patients with multiple sclerosis (MS) with regard to the degree of fatigue, and to investigate relationships between immunological parameters, level of depression and clinical variables.MethodsForty MS patients (30 women, 10 men, aged 22–60 years): 20 fatigued and 20 non-fatigued were involved in the study. Fatigue was evaluated using the Fatigue Severity Scale (FSS) and Modified Fatigue Impact Scale (MFIS), depression level – using Beck Depression Inventory (BDI). Production of IFNγ by stimulated peripheral blood CD3+CD4+ T lymphocytes, assessed using flow cytometry, was compared between MS patients with different levels of fatigue and controls. Correlations were searched out between immunological findings and BDI, age, duration and course of MS, relapse rate, disability (assessed in Expanded Disability Status Scale – EDSS) and its progression.ResultsStimulated production of IFNγ by CD3+CD4+ T lymphocytes was higher in severely fatigued patients in comparison with non-fatigued ones and controls, tended to correlate with FSS and MFIS, and correlated with BDI. No relationships were found between immunological findings and disease-related variables.ConclusionStimulated production of IFNγ by peripheral CD3+CD4+ T lymphocytes is related to fatigue and depression in MS patients.