A relative resistance of T cells to dexamethasone in bipolar disorder

• Published in: Bipolar disorders 2006-12, Vol.8 (6), p.740-750
• Main Authors: Knijff, Esther M, Breunis, M Nadine, Van Geest, Marielle C, Kupka, Ralph W, Ruwhof, Cindy, De Wit, Harm J, Nolen, Willem A, Drexhage, Hemmo A
• Format: Article
• Language: English
• Subjects: Adult; bipolar disorder; Bipolar Disorder - immunology; Bipolar Disorder - physiopathology; CD3 Complex; Cells, Cultured; dexamethasone; Dexamethasone - pharmacology; Diagnostic and Statistical Manual of Mental Disorders; Female; Glucocorticoids - pharmacology; Humans; Interleukin-2 Receptor alpha Subunit; Lymphocyte Activation; Male; Middle Aged; resistance; Severity of Illness Index; T cells; T-Lymphocytes - drug effects
• ISSN: 1398-5647; 1399-5618
• DOI: 10.1111/j.1399-5618.2006.00359.x

Objective:  A relative resistance of immune cells to steroids has been established in patients with major depression (MD). In this study, we investigated the in vitro responsiveness of T cells to dexamethasone (DEX) of patients with bipolar disorder (BD). Methods:  T cells of outpatients with DSM‐IV BD (n = 54) and of healthy control subjects (HC; n = 29) were isolated, cultured and stimulated with phytohemagglutinin (PHA) for 72 h. The suppressive effect of graded concentrations of DEX (5 × 10−9–10−5 M) on PHA‐induced CD25 (IL‐2R) expression was measured by fluorescence‐activated cell sorting (FACS) analysis. Data were correlated to the T‐cell activation status in the peripheral blood of the same patients and to their diagnosis, current mood state, ultradian cycling pattern and current use of medication, including lithium. Results:  T cells of patients with BD were less sensitive to DEX‐induced suppressive effects as compared with T cells of HC. These data were particularly evident at 10−7 M DEX (mean % suppression ± SEM BD: 18.9% ± 3.5 versus HC: 35.8% ± 4.7, p = 0.001). We found no correlations of this relative in vitro DEX resistance of T cells neither with the previously mentioned clinical characteristics nor with the actual activation status of the T cells in the BD patients. Conclusion:  A relative T‐cell resistance to steroids, as has been observed in MD previously, may be a trait phenomenon of BD, independent of mood state.