[Platelet glutathione reductase and glutathione-S-transferase in elderly patients with depression]

To compare the activity of platelet glutathione reductase (GR) and glutathione-S-transferase (GST) in elderly patients with depression and in the control group, and to identify a possible relationship between the activity of these enzymes and clinical parameters of the disease.

We examined 42 elderly patients (60-86 years old) with depressive episodes of various nosological categories according to ICD-10: a single depressive episode (F32.0, F32.1), a depressive episode in recurrent depressive disorder (RDR - F33.0, F33.1), and a depressive episode in bipolar disorder (BD - F31.3). The GR, GST activity and the severity of depression were assessed twice: before the beginning of the course of 28-day antidepressant therapy (day 0) and on the 28th day of the course of therapy, using the Hamilton Depressive Scale (HAMD-17) and the Hamilton Anxiety Scale (HARS).

As compared with the control group, a significant decrease in GST activity was found in patients before and after the course of therapy (p<0.0001 and p<0.0003, respectively), no significant difference in GR activity was found. Significant correlations of the platelet GR activity in patients before thetreatment course with the age of disease manifestation (R= -0.44; p=0.004, inverse correlation) and with its duration (R=0.43, p=0.004, direct correlation), estimated after a 28-day course of therapy. A significant inverse correlation of the baseline (before treatment) GR activity with the HAMD score estimated after the course of therapy (R=-0.440; p=0.009) was found only in women subgroup (n=33).

A pilot study has revealed a decrease in platelet GST activity, and a link between platelet GR activity and the severity of depression after a course of therapy. The results obtained indicate the promise of further study of glutathione metabolism enzymes as a biomarker for assessing the state.