Role of differential scanning calorimetry (DSC) in the staging of COPD

Abstract

Chronic obstructive pulmonary disease (COPD) is an imminent public health catastrophe. A proper severity marker is desperately needed to reflect the progress of the disease in a stage-specific manner (GOLD I–IV/A–D). The aim of the study was testing the applicability of thermodynamic analysis of blood, identifying different stages of COPD patients against each other and healthy controls. Sera from 63 COPD patients were investigated using differential scanning calorimetry (DSC). Patients formed four groups according to their GOLD severity stages, and smoking or ex-smoking subgroups were further analysed. In total, 18 GOLD A, 17 GOLD B, 16 GOLD C and 12 GOLD D patients’ DSC characteristics were investigated. Nine healthy sera (smoker and non-smoker controls) were evaluated using the same methodology. Enthalpy and melting parameters of severe COPD patients are significantly different from those in the early stages and from healthy subjects. There are clearly visible trends in both features in all stages as COPD progresses. The thermal denaturation parameters are significantly different between the smokers and non-smokers in advanced COPD stages (C&D). Healthy controls do not differ significantly according to their smoking status. The new thermophysical method described here has a potential to be applicable as a stage and/or symptom score of the individual COPD patients. Longitudinal studies are needed to monitor DSC changes of the same patients during progression and/or stagnation.