Circulating hematopoietic stem cells in patients with neovascular age-related macular degeneration.
OBJECTIVE
Circulating hematopoietic stem cells (HSCs) appear to have roles in the formation of choroidal neovascularization (CNV) in age-related macular degeneration (AMD). This study was conducted to investigate whether the number or function of HSCs plays a role in neovascular AMD.


METHODS
Eighty-one patients with neovascular AMD who underwent comprehensive fundus examinations every 3 months were included. The number of CD34(+) HSCs isolated from peripheral blood was counted by flow cytometry. Serum cytokine levels were assessed by enzyme-linked immunosorbent assay. To examine the function of circulating HSCs, mononuclear cells were cultured and then colony forming unit (CFU-EC) and migration were measured.


RESULTS
The number of circulating CD34(+) HSCs was significantly increased in the patients with active CNV without major systemic diseases (stable: 3.8 +/- 0.3 cells/microL, active: 5.5 +/- 0.7 cells/microL, stable versus active: P < 0.05). The number of HSCs correlated positively with the erythropoietin serum level (r = 0.47, P = 0.002). Although there was no significant difference in the CFU-EC between the patients with CNV and the control subjects, a significant decrease of CFU-EC was observed in the patients with bilateral or larger CNV.


CONCLUSIONS
The findings suggest that CD34(+) HSCs may be recruited from bone marrow through a signal from active CNV. Furthermore, HSCs may play a role in the severity of CNV.
Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto, Japan.
Yuko
Y
Yodoi
Manabu
M
Sasahara
Takanori
T
Kameda
Nagahisa
N
Yoshimura
Atsushi
A
Otani
D000368:Aged; D000369:Aged, 80 and over; D042683:Angiopoietin-1 / Q000097:blood; D018952:Antigens, CD34 / Q000097:blood; D001772:Blood Cell Count; D018929:Cell Culture Techniques; D002465:Cell Movement; D054377:Chemokine CXCL12 / Q000097:blood; D020256:Choroidal Neovascularization / Q000097:blood*; D003114:Colony-Forming Units Assay; D004797:Enzyme-Linked Immunosorbent Assay; D004921:Erythropoietin / Q000097:blood; D005260:Female; D005434:Flow Cytometry; D006412:Hematopoietic Stem Cells / Q000502:physiology*; D006801:Humans; D008268:Macular Degeneration / Q000097:blood*; D008297:Male; D008875:Middle Aged; D042461:Vascular Endothelial Growth Factor A / Q000097:blood
C467630:ANGPT1 protein, human; D042683:Angiopoietin-1; D018952:Antigens, CD34; D054377:Chemokine CXCL12; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D004921:Erythropoietin