CALCA and Sepsis: In this current study, the cut-off value for PCT to differentiate patients with bacteremia or sepsis versus those without infection is lower than what has been published in a study in immunocompromised patients of > 0.5 ng/ml with 100% sensitivity but only 63% specificity for diagnosing bacterial sepsis [26] and another of 2 ng/ml with 75% specificity and 90% sensitivity [27].