Heparin-binding protein (HBP) in critically ill patients with influenza A(H1N1) infection

Heparin-binding protein (HBP) is an inducer of vascular endothelial leakage in severe infections. Fluid accumulation into alveoli is a general finding in acute respiratory distress syndrome (ARDS). Severe acute respiratory failure with ARDS is a complication of influenza A(H1N1) infection. Accordingly, we studied the HBP levels in critically ill patients with infection of influenza A(H1N1).Critically ill patients in four intensive care units (ICUs) with polymerase chain reaction (PCR) confirmed infection of influenza A(H1N1) were prospectively evaluated. We collected clinical data and blood samples at ICU admission and on day 2. Twenty-nine patients participated in the study. Compared with normal plasma levels, the HBP concentrations were highly elevated at baseline and at day 2: 98 ng/mL (62-183 ng/mL) and 93 ng/mL (62-271 ng/mL) (p 0.876), respectively. HBP concentrations were correlated with the lowest ratio of partial pressure of oxygen in arterial blood to fraction of inspired oxygen (PF ratio) during the ICU stay (rho = -0.321, p <0.05). In patients with and without invasive mechanical ventilation, the baseline HBP levels were 152 ng/mL (72-237 ng/mL) and 83 ng/mL (58-108 ng/mL) (p 0.088), respectively. The respective values at day 2 were 223 ng/mL (89-415 ng/mL) and 81 ng/mL (55-97 ng/mL) (p <0.05). The patients with septic shock/severe sepsis (compared with those without) did not have statistically significant differences in HBP concentrations at baseline or day 2. HBP concentrations are markedly elevated in all critically ill patients with influenza A(H1N1) infection. The increase in HBP concentrations seems to be associated with more pronounced respiratory dysfunction.