COMPARISON OF THE ACCURACY OF NEUTROPHIL CD64 AND C-REACTIVE PROTEIN AS A SINGLE TEST FOR THE EARLY DETECTION OF NEONATAL SEPSIS

Abstract

SUMMARY S epsis in neonates hospitalized in the NICU is a global problem and is a significant contributor to morbidity and death. The clinical signs are non-specific and indistinguishable from those caused by a variety of neonatal noninfectious disorders. Early recognition and diagnosis of neonatal sepsis are difficult but is extremely important because prompt institution of antimicrobial therapy improves outcomes. Isolation of bacteria from a central body fluid (usually blood) is the gold standard and most-specific method to diagnose neonatal sepsis which may take up to 7 days for results and may be inconclusive, thus there is an urgent need for a specific marker to aid in early diagnosis of sepsis as live saving measure. Neutrophil surface CD64, the high-affinity Fc λ receptor, is quantitatively unregulated during infection and sepsis, under the influence of inflammatory cytokines; CD64 expression is stable for >24 hours. Technological advances in flowcytometry have made it possible to quantify neutrophil CD64 rapidly, with precision, and with minimal blood volumes. In our study we compared the utility of neutrophil CD64 to CRP as an early marker for neonatal sepsis at Ain Shams university Hospital NICUs. This study conducted at Ain Shams university hospital NICUs and included a total of 30 neonates with sepsis and 15 age and sex matched controls. Twenty tow of the septic neonates had twice estimation of CD64 at admission and after improvement while controls had only single estimation. They are classified into three groups: Group I: Documented sepsis group, in whom sepsis was proved both clinically and by blood culture result, Group II: Clinical sepsis group. Sepsis was suspected clinically with Clinical symptoms or signs of sepsis, in which bacterial culture result negative. Group III: Control group which included newborns with no symptoms or signs of infection. The clinical features used to identify patients at risk for sepsis included two or more of the following features which include (symptoms of respiratory compromise, cardiovascular compromise and metabolic changes and gastrointestinal symptoms). After taking an informed consent, all the studied individuals were subjected to full history taking (through medical records) and complete clinical examination. Blood samples were collected for determination of semi quantitative serum CRP, and determination of CBC, nCD64 expression and blood culture. As regard the comparative statistics conducted between the three studied groups there were a statistically highly significant increase (p < 0.05) in levels of Neutrophil CD64 in both documented sepsis (group I) and clinical sepsis (group II) when compared to the healthy controls (group III), but no statistically significant difference was found when group I and II. As regard CRP levels which is the main conventional marker used in our NICUs, the comparative statistics revealed that there were highly statistically significant increase (p < 0.05) in serum of both documented sepsis (group I) and clinical sepsis (group II) when compared to their matched controls (group III) but, it revealed no statistical significance (p >0.05) in serum levels of CRP in group I when compared with group II alone.