Thrombocytopoiesis and Platelet Homeostasis in Infants With Bronchoplumonary Dysplasia

Inclusion Criteria: 1. presence of clinical and radiologic signs of BPD, according to conventional criteria (Greenough, 1992); 2. presence of peripheral arterial catheter; 3. gestation \<32 weeks; 4. birth weight \<1.5 kg; 5. requiring mechanical ventilation for the treatment of respiratory distress syndrome for at least 3 days during the first weeks of life; 6. ventilator and/or oxygen dependent at time of enrolment; Exclusion Criteria: 1. congenital abnormalities; 2. infection (bacteria infection confirmed by positive blood culture or viral infection confirmed by serological test or viral culture) 3. evidence of complications of perinatal asphyxia including an apgar score \<3 at one or five minute after birth, evidence of hypoxic-ischemic encephalopathy, acute tubular necrosis, or transient myocardial ischemia; 4. identifiable hematologic disease;