The diagnostic value of proteoglycan 4 in the differentiation of stable and exacerbation periods in chronic obstructive pulmonary disease: a preliminary study

Abstract

Background and aim: Chronic Obstructive Pulmonary Disease (COPD) is characterized by exacerbation and stable periods. Early diagnosis in the exacerbation period of COPD can reduce morbidity and mortality rates. The aim of this study is to investigate the relationship between Proteoglycan 4 (PRG4) and other parameters, including Procalcitonin (PCT) and C-reactive protein (CRP) levels and White Blood Cell (WBC) count, in the exacerbation period. Materials and methods: This preliminary study was conducted on patients admitted to the Emergency Department and Chest Diseases Department in University Medical Faculty Hospital. Patient demographics, spirometric measurements, clinical scoring used for COPD classification and laboratory test results were recorded for each patient. The final diagnosis of COPD was made by pulmonary physicians. Results: A total of 78 patients (38 in exacerbation and 40 in stable period) with COPD were included in the study. PRG4 levels of patients in the exacerbation period (183.7 ± 9.4 ng/ml) were significantly higher than those of patients in the stable period (177.1 ± 15.9 ng/ml; p=0.034). The sensitivity of PRG4 (88.9%) was equal to that of PCT (88.9%) and higher than that of CRP (86.1%) and WBC (80.6%); the specificity of PRG4 (50%) was higher than that of the other parameters (33.3%, 43.0%, and 40.0%, respectively). Conclusion: PRG4 can be used for discriminating between the exacerbation and stable periods of COPD and is superior in diagnosing the exacerbation period compared with other laboratory parameters.