COAGULATIVE BIOMARKERS DIFFERENTLY PREDICT CLINICAL OUTCOMES IN INVASIVE INFECTIONS CAUSED BY NEISSERIA MENINGITIDIS AND STREPTOCOCCUS PNEUMONIAE

Background: Coagulation plays a crucial role in innate immune-response to invasive infections. Coagulative biomarkers might predict clinical outcomes differently depending by etiology.

Methods: A retrospective study was conducted during a 79 months period recruiting 90 patients with meningitis and/or bloodstream infection caused by Neisseria meningitidis or Streptococcus pneumoniae (47 and 43, median age 19 and 58 years, respectively). Biomarkers were assessed within 24 hours.

Results: For N. meningitidis: in univariate analysis, increasing D-dimer was associated with in-hospital mortality (OR 1.360, 95% CI 1.063-1.889), in multivariate regression increasing D-dimer was predictive (OR 1.037, 95% CI 1.001-1.074) of the composite outcome (in-hospital mortality or amputations or hearing loss or neurological sequelae); protein C showed a clear trend toward lower levels in non-survivors (26% vs 48%) and in patients with the composite outcome (32% vs 51%); aPTT was significantly prolonged in non-survivors (51.3 vs 35.3 seconds, p=0.003), confirmed in univariate analysis (OR 1.122, 95% CI 1.031-1.253). For S. pneumoniae: antithrombin was significantly lower in non-survivors (70% vs 81%, p=0.038), confirmed in univariate analysis (OR 0.961, 95% CI 0.921-0.997). For overall population: in multivariate regression, increasing age was associated with mortality (OR 1.043, 95% CI 1.010-1.077), and S. pneumoniae etiology with the composite outcome (OR 6.024, 95% CI 1.798-20.180).

Conclusions: For invasive infections caused by N. meningitidis, D-dimer is a biomarker capable of predicting unfavorable clinical outcomes, a potential role is suggested for aPTT prolongation and protein C decrease, and, in case of S. pneumoniae infections, for antithrombin decrease.