Proliferative retinopathy is associated with impaired increase in BDNF and RANTES expression levels after preterm birth.
BACKGROUND
Extremely preterm delivery is, amongst other complications, associated with retinopathy of prematurity (ROP). Untreated, ROP can progress to visual impairment and blindness due to an overgrowth of new vessels in the retina and vitreous cavity.


OBJECTIVE
The aim of this study was to identify cytokine markers within the first weeks of life that could be used to predict the risk for development of ROP later in life.


METHODS
Serum levels of 27 different cytokines in infants born at gestational weeks 23-30 were analyzed using a multiplex immunoassay method and compared between infants who did not develop ROP and infants who later developed proliferative ROP. In addition, mRNA levels of brain-derived neurotrophic factor (BDNF) in retinas from mice exposed to hyperoxia were analyzed using quantitative real-time PCR.


RESULTS
At birth, serum levels of IL-5 were higher in infants with no ROP compared to infants with proliferative ROP. 10-14 days after birth, serum levels of BDNF and RANTES were lower in infants who later developed proliferative ROP compared to infants who did not develop ROP. Furthermore, mRNA expression levels of BDNF in retinas from mice exposed to hyperoxia were significantly lower at postnatal day 15 compared to retinas from mice in room air.


CONCLUSIONS
These results indicate that BDNF and RANTES may be important factors in the selective vulnerability of ROP development in preterm infants.
Department of Pediatrics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden. gunnel.hellgren @ vgregion.se
Gunnel
G
Hellgren
Keirnan
K
Willett
Eva
E
Engstrom
Poul
P
Thorsen
David M
DM
Hougaard
Bo
B
Jacobsson
Ann
A
Hellstrom
Chatarina
C
Lofqvist
D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D001724:Birth Weight; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics / Q000378:metabolism*; D018946:Chemokine CCL5 / Q000378:metabolism*; D015897:Comorbidity; D004195:Disease Models, Animal; D020345:Enterocolitis, Necrotizing / Q000453:epidemiology / Q000235:genetics / Q000378:metabolism; D005260:Female; D005311:Fetal Hypoxia / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D012160:Retina / Q000378:metabolism; D012178:Retinopathy of Prematurity / Q000453:epidemiology / Q000235:genetics / Q000378:metabolism*; D013548:Sweden / Q000453:epidemiology
D015415:Biomarkers; D019208:Brain-Derived Neurotrophic Factor; C483024:CCL5 protein, human; D018946:Chemokine CCL5