Purpose: In a prior study, the correlation was investigated between circulating hematopoietic stem cells (HSCs) and the activity or severity of choroidal neovascularization (CNV) in patients with age-related macular degeneration (AMD). The present study was designed to explore the role of circulating HSCs in the pathogenesis of CNV in patients with idiopathic (i)CNV.
Methods: Thirteen patients with clinically documented iCNV and 10 age-sex matched patients without iCNV or systemic disease were enrolled in a case-control study. Circulating HSCs were collected from the patients' peripheral blood and cultured. Colony-forming capacity, migration activity, and invasion activity of HSCs were experimentally analyzed.
Results: Colony-forming units by Hill's assay (CFU-Hill) were markedly lower (P<0.001) in patients with iCNV (12.8+/-3.2) than in healthy patients (67.6+/-12.6). Invasion activities of HSCs were reduced significantly in patients with iCNV. CFU-Hill was impaired in the patients (4.0+/-1.2) with CNV more than 1500 microm compared with the patients (20.3+/-4.0) with CNV less than 1500 microm (P=0.006).
Conclusions: Similar to the previous finding of CNV associated with AMD, impaired functional activities of circulating HSCs were observed in patients with iCNV, which correlated with the size of iCNV. These results in young patients provide evidence to support the role of circulating HSCs in the pathogenesis of CNV.