Abnormal diurnal variation of B lymphocyte circulation patterns in major depression

Abstract

With the exception of the function of natural killer (NK) cells, few reproducible immune correlates of the syndrome of major depression have been described (for review see Stein et al 1991), Circa(,ian ,nythl~S ,u¢ often dist upted in major depression. These depression.related rhythm abnormalities include neurobiological parameters that have been implicated in central nervous system mediation of immune function, such as levels of cortisol and melatonin and estimates of noradrenergic activity (Halaris 1987). Subsets of circulating lymphocytes exhibit different circadian (or ultradian) rhythms, and it is believed that immunologic rhythms may be entrained to rhythms of central nervous system origin (for review see Ottaway and Husband 1992). Recently, we demonstrated that the diurnal variation of NK cell measures is dismpted in patients with major depression, with the differences observed between depressed and control subjects being pronounced in the morning (Petitto et al 1992). Like NK cells, circulating B cells--antibody-producing lymphocytes that express surface immunogiobulins (lg).--also exhibit normal patterns of diurnal variation, with blood levels increasing from early morning to late afternoon in healthy volunteers (Abo and Kumagi 1978; Abo et al 1981). To explore further the hypothesis that the diurnal variation of other parameters of cellular immune physiology may be dysregulated in major depression, we compared the diurnal variation of surface-lg-positive B lymphocytes of inpatients with major depression with normal comparison subjects (on a schedule of diurnal activity and nocturnal rest) at 8 AM and 4 PM on the same day. Here we report that the diurnal variation in B-lymphocyte circulation patterns in peripheral blood are disrupted in patients with major depression.