BACKGROUND:Fractalkine (FKN), a unique chemokine associated with pulmonary hypertension, may be involved in the acute stress response that regulates inflammation after cardiopulmonary bypass (CPB) surgery. We characterized FKN levels and correlated them with clinical parameters in children undergoing cardiac surgery involving CPB. METHODS:Twenty-seven consecutive patients, aged 30 days to 11.5 years, who underwent surgery for correction of congenital heart defects, were prospectively studied. Serial blood samples were collected preoperatively, upon termination of CPB, and at six points postoperatively. Plasma was recovered immediately, aliquoted, and frozen at -70° C until assayed. Clinical and laboratory data were collected. RESULTS:Baseline FKN levels were skewed between patients. Patients with low FKN levels showed significantly higher levels of oxygen saturation in room air compared to patients with high FKN levels (p<0.05). Moreover, there was a positive correlation between preoperative pulmonary arterial hypertension and FKN levels (p<0.05). Surprisingly, FKN elevation from preoperative to postoperative levels displayed no discernible pattern. CONCLUSIONS:FKN levels significantly correlate with preoperative hypoxemia and PAH, suggesting that FKN may be up-regulated during hypoxemia. CPB is not associated with acute changes in circulating FKN levels. The role of FKN in the postoperative course should be further investigated.

We prospectively quantified disease severity associated with epidemiologic and socioeconomic parameters as well as the clinical factors in 195 previously healthy infants with confirmed respiratory syncytial virus (RSV) infection. Infants were enrolled into three subgroups according to disease severity: outpatients (82 patients), inpatients (100 patients), and intensive care unit patients (13 patients). Epidemiologic parameters such as gestational age, birth weight, chronologic age at presentation, and gender as well as socioeconomic factors such as ethnic origin, family history of asthma, exposure to cigarette smoke, number of family members, presence of pets at home, breast-feeding, and day-care attendance were not found to predict the severity of RSV illness in previously healthy infants. Our results emphasize the complexity of predicting disease severity in previously healthy infants with RSV infection and suggest that other parameters such as host genetic background might explain the clinical variability.