Procalcitonin as a predictor of severity and mortality in a cohort of patients hospitalised with COVID-19

INTRODUCTION: To evaluate the association of Procalcitonin (PCT) with severity in Coronavirus disease 2019 (COVID-19), hospitalised patients and to test the hypothesis that it is an independent predictor of mortality.

MATERIALS AND METHODS: This study was conducted at Chemical Pathology, Department of Pathology and Laboratory Medicine and Department of Medicine, Aga Khan University (AKU), Karachi Pakistan. Electronic medical records of all in-patients including both genders and all age groups with documented COVID-19 from March to August 2020 were reviewed and recorded on a pre-structured performa. The subjects were divided into two categories severe and non-severe COVID-19; and survivors and non-survivors. Between-group differences were tested using the Chi-square and Mann-Whitney's U-test. The receiver operating characteristic curve was plotted for serum PCT with severity and mortality. A binary logistic regression was used to identify variables independently associated with mortality. The data was analysed using SPSS.

RESULTS: 336 patients were reviewed as declared COVID-19 positive during the study duration, and 136 were included in the final analysis including 101 males and 35 females. A statistically significant difference in PCT was found between severe and non-severe COVID-19 (p value=0.01); and survivors and nonsurvivors (p value<0.0001). PCT, older age and increased duration of hospital stay were revealed as variables independently associated with mortality. On ROC analysis, an AUC of 0.76 for mortality prediction was generated for PCT.

CONCLUSION: Baseline serum PCT concentration is a promising predictor of mortality and severity in COVID-19 cases when considered in combination with clinical details and other laboratory tests.