Objective: To evaluate the concentration of pro-atrial natriuretic peptide in patients with sepsis, severe sepsis and septic shock. To assess the diagnostic and prognostic value of mid-regional pro-atrial natriuretic peptide (pro-ANP) levels with these diagnoses. To assess the correlation of pro-ANP levels with those of interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-10 (IL-10), procalcitonin (PCT), lipopolysaccharide-binding protein (LBP) and physiological scores – APACHE II and SOFA. Design: Observational, prospective. Setting: Department of Clinical Biochemistry, Hematology and Immunology, Hospital Na Homolce, Department of Anaesthesiology and Intensive Care, Thomayer’s Hospital, Prague, Department of Anaesthesiology and Intensive Care, Hospital Na Homolce, Prague. Material and Methods: Serum concentrations of pro-ANP were determined using the immunoluminometric assay in 28 patients admitted to the medical intensive care unit for sepsis (6), severe sepsis (7), and septic shock (15). Pro-ANP levels as well as those of PCT, IL-6, IL-8, IL-10 and LBP were measured on day 1 and during the course of their stay at the intensive care unit. The diagnostic and prognostic value of pro-ANP was compared with that of the Acute Physiology and Chronic Health Evaluation (APACHE II) and SOFA score. Mid-regional pro- ANP was detected in serum using immunoluminometric assay (ILMA). Pro-ANP was also determined in 12 healthy adults.Results: No significant differences of pro-ANP levels were found in patients with sepsis, severe sepsis and septic shock (385.3 pmol/l, 209 pmol/l and 888 pmol/l, respectively). On the day of admission, pro-ANP levels were not significantly different in survivors compared to non-survivors (median 396.4 pmol/l and 816.8 pmol/l, respectively, p = 0.077). In the group of non-survivors pro-ANP levels on the day of admission were significantly lower than pro-ANP levels taken on the last day of their stay on ICU median 816.8 and 1254.4 pmol/l, respectively, p = 0.0108). In a receiver operating characteristic curve analysis for survival, the cut-off 664 pmol/l on the day of admission had a sensitivity of 41.7% and specificity of 87.5%. The area under the curve (AUC) for pro-ANP was 0.625. The cut-of value of 503.4 pmol/l on the last day of their stay was found to have a sensitivity of 83.3% and specificity of 68.7%. The area under the curve was 0.797. We found the correlation between pro-ANP, SOFA and APACHE II score in survivors. In non-survivors only pro-ANP and APACHE II correlation was found. The correlation was determined between pro-ANP and procalcitonin in non- -survivors (r = 0.57, p < 0.0001). No correlation was found between pro-ANP and IL-6, IL-8, IL-10 and LBP. Conclusion: We did not find statistically significant differences of pro-ANP levels in patients with sepsis, severe sepsis and septic shock. Pro-ANP levels on the day of admission were not significantly different in survivors and non- -survivors. In the group of non-survivors pro-ANP levels on the day of admission were significantly lower than the last pro-ANP levels. Further studies are necessary for the evaluation of pro-ANP as a diagnostic and/or prognostic parameter in patients with sepsis, severe sepsis and septic shock.

        Key words: pro-atrial natriuretic peptide, sepsis, diagnostics, prognosis.