D-dimer and histamine in early stage bacteremia: A prospective controlled cohort study

Introduction: Plasma histamine levels and D-dimer predict disease severity and mortality in advanced septic shock. We hypothesized that increased plasma histamine levels parallel coagulation activation and yield prognostic significance already at a very early stage of bacteremia. Patients and methods: This prospective controlled cohort study enrolled 72 consecutive non-surgical non-ICU-ward inpatients with newly culture-diagnosed bacteremia and a Pitt Bacteremia score <= 2 to determine the extent of histamine and D-dimer release and their predictive role on outcome at the earliest stage of blood stream infection. Age-matched healthy adults served as internal controls (n=36). A binominal logistic regression and a Cox proportional hazards regression analysis were performed to ascertain the effects of D-dimer and histamine on in-hospital mortality. Results: In contrast to plasma histamine, D-dimer levels were significantly higher within hours of culture-proven bacteremia. In-hospitalmortality occurred in 17%. Histamine levels were neither associated with D-dimer level (r=0.04; p > 0.05) nor with ICU admissions (r=0.06; p > 0.05) and outcome (crude OR 0.8, 95% CI 0.3-1.9; p=0.6). In contrast, early-elevated D-dimer levels predicted mortality: the odds to die increased with the D-dimer level, and was 12.6 (crude OR, 95% CI 3-52; p = 0.001) in patients with a D-dimer = 4 mu g/mL (n=13). Conclusion: Histamine levels are elevated in only few patients (4%) with newly diagnosed bacteremia. Our findings suggest that D-dimer, but not plasma histamine, could be a promising marker of lethality already at a very early stage of blood stream infection. (C) 2015 The Authors. Published by Elsevier B.V. on behalf of European Federation of Internal Medicine.