CLAUDIU PUIAC, IOAN JUNG, LUCIAN PUSCASIU, JANOS SZEDERJESI THE POSTOPERATIVE PLASMATIC LEVEL OF NEUTROPHIL GELATINASE-ASSOCIATED LIPOCALIN DOES NOT REFLECT ITS TISSUE EXPRESSION IN CRITICALLY ILL PATIENTS WITH HIGH ABDOMINAL PRESSURE The aim of this study was to evaluate the correlation between serum and tissue level of the Neutrophil gelatinase-associated lipocalin (NGAL), a peptide that seems to be predict the postoperative evolution of patients with high abdominal pressure. From 30 consecutive patients hospitalized in the Intensive Care Unit, we have randomly selected five cases that undergo abdominal surgical interventions, received postoperative mechanical ventilation and abdominal pressure was monitorized for at least 48 hours. In all of these cases, the plasmatic level of NGAL was measured using the Elisa method and immunohistochemical (IHC) stains with the anti-NGAL biomarker were performed in the surgically removed tissues. All of the five patients were overweight, showed high serum level of NGAL (over 950 ng/ml) and died with postoperative or septic shock. The NGAL serum level was not correlated with the abdominal pressure. No IHC positivity was observed in the examined tissues, except NGAL positivity for intravascular neutrophils. In conclusion, the postoperative high serum NGAL level may indicate unfavorable evolution. NGAL seems to be syntesized by the circulating neutrophils and its preoperative tissue expression does not reflect the serum value.