High serum HIF-1α levels are associated with intensive respiratory support in community acquired pneumonia

Abstract

Background: Hypoxemic respiratory failure is the main determinant for hospital admission and the prognosis of pneumonia (CAP). Immune system has the capacity to produce a response in situations of hypoxia mediated by HIF-1α. Some pathogens are capable of interfering with the activity of HIF-1 which demonstrates the important role of HIF in the response to infection.

Objectives: The primary objective of our study was to analyze the prognostic correlation between HIF-1 levels and the need for ICU admission in CAP.

Methods: A prospective study was performed with the analysis of patients with CAP. Clinical, radiological, analytical and microbiological data were collected. The samples for the determination of HIF-1α were collected in the first 24 hours after hospital admission and were analyzed by ELISA. High values of HIF-1α were considered for those above 30 pg/ml.

Results: We analyzed 110 patients with CAP in whom 40.9% had elevated HIF-1α. Elevated HIF-1values were independently associated with respiratory failure [(PaO2<60 mmHg) OR 4.74; 95% CI 1.53-14.67] and pneumococcal etiology (OR 14.40; 95% CI 1.20-173.91). Patients with high values of HIF-1α required more frequently ICU admission and mechanical ventilation (20% vs 6.2%; p=0.027), and developed new onset arrhythmias (8.9% vs 0%; p= 0.011). Mortality was similar in both groups (11.1% vs 6.2%, p=0.822).

Conclusions: High values of HIF-1α were detected more frequently in patients with hypoxemic respiratory failure. Pneumococcal etiology is related to a higher level of HIF-1α. Elevated HIF-1α values at admission can predict the need for ICU admission and mechanical ventilation in CAP.