Thrombosis is a leading cause of morbidity and mortality in paroxysmal nocturnal hemoglobinuria (PNH). Multiple factors are responsible for the thrombotic tendency in these patients. Endothelial progenitorcells (EPCs) originate from primitive hematopoietic stem cells. The EPC count is considered indicative of potential damage and restoration capacity in vascular disease; lower EPC counts are deemed as a risk factor in cardiovascular diseases. We aimed to investigate the count of circulating EPCs in PNH and aplastic anemia (AA) patients receiving eculizumab treatment or not receiving treatment and their relationship with thrombosis. Seventeen PNH patients, 18 AA patients, and 10 healthy volunteers were included in the study. The CD309, CD133, and CD34 antibodies were used to determine counts of circulating EPCs using flowcytometry. EPC levels were compared between the PNH, AA, and healthy control groups. Kolmogorov–Smirnov test. ANOVA, Kruskal–Wallis, and Mann–Whitney U testswereperformedto analyze the quantitative data, while χ2 testing was performed to analyze the qualitative data. Therewasnosignificantdifference in EPC levelsbetweenpatientswithandwithout a history of thrombosis (P > 0.05). Further, therewasnosignificantdifference in thelevels of EPCsbetweenthe AA and PNH groups (P  > 0.05). However, there was a significant positive correlation between levels of EPCs and lactate dehydrogenase (LDH) in multivariate analysis (P < 0.05). The study findings suggest that hemolysis promotes vascular endothelial and new blood vessel formation. Increased EPCs in PNH may indirectly indicatevascular endothelial damage in PNH.

血栓形成是阵发性睡眠性血红蛋白尿症 (PNH) 发病率和死亡率的主要原因。多种因素导致这些患者的血栓形成倾向。内皮祖细胞 (EPC) 起源于原始造血干细胞。EPC 计数被认为是血管疾病潜在损伤和恢复能力的指标；较低的 EPC 计数被认为是心血管疾病的危险因素。我们旨在调查接受依库丽单抗治疗或未接受治疗的 PNH 和再生障碍性贫血 (AA) 患者的循环 EPC 计数及其与血栓形成的关系。该研究包括 17 名 PNH 患者、18 名 AA 患者和 10 名健康志愿者。CD309、CD133 和 CD34 抗体用于使用流式细胞术确定循环 EPC 的计数。比较 PNH、AA 和健康对照组之间的 EPC 水平。Kolmogorov-Smirnov 检验。进行方差分析、Kruskal–Wallis 和 Mann–Whitney U 检验来分析定量数据，而进行 χ2 检验来分析定性数据。有无血栓病史的患者EPC水平无显着差异（P  > 0.05）。此外，AA组和PNH组EPCs水平差异无统计学意义（P  > 0.05）。但多因素分析显示，EPCs水平与乳酸脱氢酶（LDH）呈显着正相关（P <  0.05）。研究结果表明，溶血促进血管内皮和新血管形成。PNH 中 EPC 的增加可能间接表明 PNH 中的血管内皮损伤。