Plasma D-dimer level in early and late-onset neonatal sepsis

Neonatal sepsis is a life-threatening disease. Early diagnosis is essential, but no single marker of infection has been identified. Sepsis activates a coagulation cascade with simultaneous production of the D-dimers due to lysis of fibrin. D-dimer test reflects the activation of the coagulation system.

To assess the D-dimer plasma level, elaborating its clinicopathological value in neonates with early-onset and late-onset neonatal sepsis.

The study was a prospective cross-sectional study that included ninety neonates; divided into three groups: Group I: Early-onset sepsis (EOS); Group II: Late-onset sepsis (LOS); and Group III: Control group. We diagnosed neonatal sepsis according to our protocol. C-reactive protein (CRP) and D-dimer assays were compared between EOS and LOS and correlated to the causative microbiological agents.

D-dimer was significantly higher in septic groups with a considerably higher number of cases with positive D-dimer. Neonates with LOS had substantially higher levels of D-dimer than EOS, with no significant differences in CRP. Neonates with LOS had a significantly longer hospitalization duration and higher gram-negative bacteriemia and mortality rates than EOS (P < 0.01). Gram-negative bacteria have the highest D-dimer levels (Acinetobacter, Klebsiella, and Pseudomonas) and CRP (Serratia, Klebsiella, and Pseudomonas); while gram-positive sepsis was associated with relatively lower levels. D-dimer had a significant negative correlation with hemoglobin level and platelet count; and a significant positive correlation with CRP, hospitalization duration, and mortality rates. The best-suggested cut-off point for D-dimer in neonatal sepsis was 0.75 mg/L, giving a sensitivity of 72.7% and specificity of 86.7%. The D-dimer assay has specificity and sensitivity comparable to CRP in the current study.

The current study revealed a significant diagnostic value for D-dimer in neonatal sepsis. D-dimer can be used as an adjunct to other sepsis markers to increase the sensitivity and specificity of diagnosing neonatal sepsis.