The usefulness of the buffy coat smear and panbacterial polymerase chain reaction in early diagnosis of neonatal sepsis

Objective. In this study are evaluated the usefulness of the buffy coat smear and panbacterial polymerase chain reaction (PCR) as diagnostic tests in the early detection of neonatal sepsis. Material and methods. It was studied 49 patients aged up to 28 days who were hospitalized in the Intensive Care Unit (ICUs) of the Neonatology, with a clinical diagnosis of neonatal sepsis and 49 umbilical cord samples of healthy newborns. Blood cultures and 50 µL of plasma were taken for the DNA and performance of the broad-range PCR primer system (panbacterial PCR). Simultaneously, were taken three capillaries with blood for the leukocyte layer (buffy coat) smear, we performed three stains: Gram; Loeffler blue methylene (LBM), and acridine orange (AO). Statistical analysis included sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) against the clinical diagnosis. Results. With respect to stains of buffy coat smear, they resulted very specific, from 90-97%, with 64-75% sensitivity, 87-94% PPV, and 77-82% NPV. In inverse fashion, PCR resulted very sensitive at 96%, with 91% specificity, 92% PPV, and 96% NPV. Conclusions. Buffy coat smear stains are easy, fast, and specific, while that of PCR was highly sensitive. Thus, both can be utilized as diagnostic tests.