DO PLATELETS HAVE A ROLE IN THE PATHOGENESIS OF AGGRESSIVE POSTERIOR RETINOPATHY OF PREMATURITY?

Purpose: The purpose of this study was to report the possible role of thrombocytopenia in the pathogenesis of aggressive posterior retinopathy of prematurity (APROP). Methods: The index case described in this study showed spontaneous resolution of APROP with plus disease within 3 days of correcting thrombocytopenia and did not require laser treatment. The retrospective cohort of nine consecutive Asian Indian infants with APROP with similar stage and plus disease as the index case was studied. The mean platelet count of these infants before laser treatment was compared with 21 age- and birth weight-matched control subjects. Correlation of platelet count with APROP is discussed. Results: The mean birth weight of the 10 cases with APROP was 1,030 g (±178 g), and the mean period of gestation was 29.4 weeks (±2.0 weeks). The mean platelet count of the cases was 82,870/mm3 (±58,702/mm3) and that of the control subjects was 178,285 ± 57,051/mm3 (P = 0.0002). Five of the 10 cases (50%) and 1 of the 21 control subjects (4.8%) had a platelet count of <100,000/mm3 (P = 0.007). In all, 19.4% of infants had culture-proven sepsis. There was no correlation between sepsis and thrombocytopenia in our cohort (P = 0.567). Conclusion: The role of low platelets in the etiopathogenesis of APROP has not been previously elucidated. Our study shows that a platelet count of <100,000 was associated with severe disease. Recently, platelets have been reported to play a key role in angiogenic regulatory protein delivery. It is possible that premature infants who develop retinopathy of prematurity in the setting of low platelet counts may lack the function of either delivering the optimal level or incompletely scavenging the excess of vascular endothelial growth factor A present in APROP. The spontaneous resolution of disease in our index case with platelet correction alone needs additional studies to correlate the timing and magnitude of correction that may play a role.

[1]  A. Filouš,et al.  [Retinopathy of prematurity]. , 1998, Ceska a slovenska oftalmologie : casopis Ceske oftalmologicke spolecnosti a Slovenske oftalmologicke spolecnosti.

[2]  W. Tasman,et al.  Revised indications for the treatment of retinopathy of prematurity: results of the early treatment for retinopathy of prematurity randomized trial. , 2004, Archives of ophthalmology.

[3]  A. Fielder,et al.  Preliminary results of treatment of eyes with high-risk prethreshold retinopathy of prematurity in the early treatment for retinopathy of prematurity randomized trial. , 2003, Archives of ophthalmology.

[4]  Anna L. Ells,et al.  The International Classification of Retinopathy of Prematurity revisited. , 2005, Archives of ophthalmology.

[5]  J. Folkman,et al.  Blood Platelets Organize Pro- and Anti-Angiogenic Factors into Separate, Distinct Alpha Granules: Implications for the Regulation of Angiogenesis. , 2006 .

[6]  J. Flynn,et al.  Retinopathy of prematurity: two distinct mechanisms that underlie zone 1 and zone 2 disease. , 2006, American journal of ophthalmology.

[7]  T. Kiehn,et al.  Thrombocytopenia among extremely low birth weight neonates: data from a multihospital healthcare system , 2006, Journal of Perinatology.

[8]  A. Vinekar,et al.  Retinopathy of prematurity in Asian Indian babies weighing greater than 1250 grams at birth: Ten year data from a tertiary care center in a developing country , 2007, Indian journal of ophthalmology.

[9]  J. Folkman.  Angiogenesis: an organizing principle for drug discovery? , 2007, Nature reviews. Drug discovery.

[10]  J. Folkman.  Opinion: Angiogenesis: an organizing principle for drug discovery? , 2007, Nature Reviews Drug Discovery.

[11]  A. Capone,et al.  Current understanding and management of retinopathy of prematurity , 2007, Current opinion in ophthalmology.

[12]  D. Jin,et al.  Regulation of Vasculogenesis by Platelet-Mediated Recruitment of Bone Marrow–Derived Cells , 2007, Arteriosclerosis, thrombosis, and vascular biology.

[13]  A. Vinekar,et al.  AGGRESSIVE POSTERIOR RETINOPATHY OF PREMATURITY IN ASIAN INDIAN BABIES: Spectrum of Disease and Outcome After Laser Treatment , 2009, Retina.