Objectives. The aim of the present study was the assessment of the levels of sphingosine-1-phosphate (S1P), stromal cell-derived factor 1 (SDF–1) and complement cascade components C3a, C5a, C5b–9 in peripheral blood of patients with bipolar disorder (BD) treated with lithium and without lithium treatment and its relations with very small embryonic-like stem cells (VSELs) and pluripotency markers Oct-4, Sox2, Nanog.
Material and methods. The study comprised 30 patients with bipolar disorder and 15 healthy controls, sex and age matched. Within bipolar group, 15 patients were treated continuously with lithium carbonate for 8–40 years (mean 16 years) and other 15 subjects who hadn't ever received lithium, with illness duration of minimum 10 years. S1P measurement was performed using reversed phase high-performance liquid chromatography. SDF-1 and C5a, C5a, C5b–9 was evaluated using ELISA kits. The assessment of VSELs was performed using flow cytometric analysis and evaluation of pluripotency markers (Oct-4, Sox2, Nanog) was performed using the Real-time quantitative reverse transcription PCR (RQ-PCR) procedure.
Results. There were no differences between groups ac- cording to S1P, SDF-1, C3a, C5a and C5b–9 levels. In the BD group never treated with lithium, negative correlation was observed between complement component C5a and the number of CD34+VSELs, the number of CD133+ VSELs and % of CD133+VSELs, as well as with pluripotency markers Oct-4, Sox2 and Nanog. In patients treated continuously with lithium and the control group, no correlation was noticed between C5a and CD133+ VSELs and pluripotency markers.
Conclusions. The obtained results show significant relation between complement component C5a and VSELs and pluripotency markers in BD group never treated with lithium.