Cut-off Levels of CRP to Predict Outcomes in Patients with Influenza Infection DC56-DC60
Dr. Omer Karasahin,
Atatürk Mahallesi Çat Yolu Caddesi, 25040 Yakutiye/Erzurum, Turkey.
Introduction: Seasonal flu is an acute viral infection caused by an influenza virus. People with weakened or suppressed immune system and people with existing chronic disorders are at a greater risk of serious complications after exposure to influenza virus infection. Therefore, determining prognostic markers that are practical, accessible and assessable within the first 24 hours of admission, is of great importance.
Aim: To determine the cut-off levels for several bio-chemical markers to predict mortality and determine which patient would require ICU admission in adults with Influenza A infection.
Materials and Methods: All patients (155) included in the study were above the age of 18 years and diagnosed with Influenza A from December 2015 to March 2016. ROC analysis, Cox regression model and Kaplan-Meier analysis were used to determine the prognostic predictions of the biomarkers, C-Reactive Protein (CRP), Creatine Kinase (CK) and risk factors.
Results: Serum CRP and CK levels were significantly high in patients who required ICU support or died. The highest sensitivity and specificity cut-off value for mortality and intensive care unit needs was 76.5 mg/L for CRP. The highest sensitivity and specificity cut-off value for mortality prediction of CK was 234 U/L, and that for intensive care unit needs was 302 U/L. With each 1 mg/L increase in serum CRP values, the risk of mortality increased by 1.007 times (95% CI 1.001-1.013; p=0.017). The mean life span of patients with serum CRP levels above 76.5 mg/L was shortened.
Conclusion: The cut-off value of CRP for ICU admission and mortality was indicated as 76.5 mg/L. The frequency of development of mortality in cases below this limit value was determined as <1% and survival times were found significantly longer.