Immunological Indicators of Infl ammation in Late-Life Bipolar Disorder

Abstract

The aim of the study was to determine the immune markers of infl ammation in the blood plasma of the elderly patients with bipolar affective disorders (BD) in relation to the clinical specifi cities of the disease. Patients and methods: 134 blood samples from the elderly patients aged from 52 to 88 years old (mean age 66.7 ± 7.7 years) with diagnose of bipolar disorder were examined. Infl ammatory markers in the blood plasma were determined as follows: the enzymatic activity of leukocyte elastase (LE) and the functional activity of the D1-proteinase inhibitor (D1-PI), as well as the level of autoantibodies (aAB) to S100b and myelin basic protein (MBP), and the protease inhibitor index (PII), which was the ratio of LE and D1-PI activity and characterized the activity of the proteolytic system as the most important component of infl ammation. Cluster analysis was used to reveal immunotypes. Results and discussion: а signifi cant increase in D1-PI and the level of aAB to S100b was revealed in elderly patients diagnosed with bipolar disorders, as well as low proteolytic activity of infl ammation (according to PII). Immune markers of infl ammation in different types of affective episodes (depressions, manias, mixed affective states) and in therapeutic remission did not differ from each other. Immunological parameters in elderly patients with bipolar disorders depended on the severity degree of the affective disorder. A relationship was found between the severity of depression and the level of aAB to S100b; the difference between mania and hypomania in terms of LE and PII activity was shown; in mixed affective states immunological parameters differed from the control only in moderate disorders. Remission with residual symptoms differed from asymptomatic therapeutic remission in terms of LE and PII activity. The two identifi ed clusters (immunotypes) differed in the activity of LE and PII. Conclusion: the results indicated the participation of infl ammation in the pathogenesis of bipolar disorder, and the isolated immunotypes confi rmed the clinical diversity of the disease. The study of the pathogenetic signifi cance of infl ammation and the identifi cation of various immunotypes was aimed at search for new therapy targets, taking into account the contribution of infl ammation.