Plasma biomarkers in carbon monoxide poisoning

Abstract

Objectives. The severity of acute carbon monoxide (CO) poisoning is often based on non-specific clinical criteria because there are no reliable laboratory markers. We hypothesized that a pattern of plasma protein values might objectively discern CO poisoning severity. This was a pilot study to evaluate protein profiles in plasma samples collected from patients at the time of initial hospital evaluation. The goal was to assess whether any values differed from age- and sex-matched controls using a commercially available plasma screening package. Methods. Frozen samples from 63 suspected CO poisoning patients categorized based on clinical signs, symptoms, and blood carboxyhemoglobin level were analyzed along with 42 age- and sex-matched controls using Luminex-based technology to determine the concentration of 180 proteins. Results. Significant differences from control values were found for 99 proteins in at least one of five CO poisoning groups. A complex pattern of elevations in acute phase reactants and proteins associated with inflammatory responses including chemokines/cytokines and interleukins, growth factors, hormones, and an array of auto-antibodies was found. Fourteen protein values were significantly different from control in all CO groups, including patients with nominal carboxyhemoglobin elevations and relatively brief intervals of exposure. Conclusions. The data demonstrate the complexity of CO pathophysiology and support a view that exposure causes acute inflammatory events in humans. This pilot study has insufficient power to discern reliable differences among patients who develop neurological sequelae but future trials are warranted to determine whether plasma profiles predict mortality and morbidity risks of CO poisoning.

Keywords:

• Inflammatory markers
• Smoke inhalation
• Hyperbaric oxygen
• Cytokines

Acknowledgments

This work was funded by grant ES016720 from the NIH. We are deeply indebted to the staff of the Department of Emergency Medicine and Institute for Environmental Medicine for their help and cooperation with obtaining blood samples. In particular, we thank R.N. Mary Chin.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this paper.