OBJECTIVETo compare peripheral blood hematopoietic progenitor cells (HPCs), plasma atrial natriuretic peptide (ANP) and stromal cell-derived factor-1alpha (SDF-1alpha) among patients with paroxysmal, permanent atrial fibrillation (AF) or sinus rhythm.

METHODSPeripheral blood concentration of CD34+HPCs were quantified by flow cytometric analysis (FCM), plasma ANP levels were measured by radioimmunoassay (RIA) method, plasma levels of SDF-1alpha were determined by enzyme linked immunosorbent assay (ELISA) in 30 patients with permanent AF, 28 patients with paroxysmal AF, and 30 patients with sinus rhythm (SR). HPCs were separated, cultured and stained for ANP by the use of alkaline phosphatase-anti-alkaline phosphatase technique (APAAP) in 30 patients (10 from each group).

RESULTS(1) The number of CD34+HPCs in permanent AF group [(5.31 +/- 1.67) x 10(6)/L] were significantly higher comparing to paroxysmal AF group [(2.33 +/- 1.29) x 10(6)/L] (P < 0.05) and SR group [(2.03 +/- 0.64) x 10(6)/L] (P < 0.05) while CD34+HPCs was similar between paroxysmal AF group and SR group (P > 0.05). (2) Plasma levels of ANP (0.312 +/- 0.121) microg/L and SDF-1alpha (3210.2 +/- 1234.7) ng/L were also significantly higher in permanent AF group than paroxysmal AF group and SR group (all P < 0.05) and were similar in paroxysmal AF group and SR group (all P > 0.05). (3) The plasma levels of ANP and SDF-1alpha were both positive correlated with peripheral blood concentration of CD34+HPCs (r = 0.783, P < 0.01; r = 0.427, P < 0.01). (4) After 3 days of culture, ANP was weakly expressed in HPCs from patients with permanent AF but not from patients with paroxysmal AF and SR.

CONCLUSIONSPeripheral blood HPCs together with plasma ANP and SDF-1alpha were significantly increased in patients with permanent AF. CD34+HPCs were positive correlated with the plasma levels of ANP and SDF-1alpha.