The formation and rapid clearance of a truncated albumin species in a critically ill patient.

Introduction: Hypoalbuminemia is known to occur in critically ill patients and is associated with increased mortality. We observed a potentially novel, partial explanation for the hypoalbuminemia noticed in a severely traumatized patient.

Case Report: We report of a severely, multi-system traumatized patient in whom hypoalbuminemia was present (1-2 g/dl). The plasma albumin (HSA) was analyzed by liquid chromatography/positive electrospray ionization mass spectrometry. A high percentage of a truncated albumin that lost its carboxy terminal amino acid leucine (HSA-L) associated with a 10-fold increase in plasma carboxypeptidase A (CPA) activity (R(2)=0.994) were found. We estimated the half life of this truncated albumin species to be <80 h.

Conclusions: The increased CPA activity encountered following a traumatic event and subsequent rapid clearance of the resulting HSA-L from plasma might be a contributing factor to the hypoalbuminemia observed in the critically ill patients.