nCD64, mHLA-DR: Sensitive Diagnostic Markers of Infection in Term Infants Receiving Antibiotic Treatment

Abstract

Nguyen Thi Ngoc Tu, Le Thanh Hai, Truong Thi Mai Hong, Pham Thu Hien, Le Thi Ha, Doan Thi Mai Thanh.

The diagnosis of neonatal sepsis is difficult because of its nonspecific clinical pictures. Monocytic human leukocyte antigen–DR (mHLA-DR), neutrophil surface CD64 (nCD64) expressions and their ratio (SI), have been used to identify newborns with sepsis. However, there is a lack of studies investigating the expression of these markers in neonatal patients receiving antibiotic treatment. The main aims of the study are: to determine the sensitivity, specificity value of nCD64, mHLA-DR and SI using the QuantiBRITE Anti HLA-DR/Anti-Monocyte, a Becton Dickinson novel reagent that standardizes flow cytometry values for diagnosing infection in term newborns receiving antibiotics; to define the optimal cutoff value of these markers using the receiver operating characteristics (ROC) curve. We determined mHLA-DR and nCD64 expressions in 44 term infants with sepsis receiving antibiotic treatment admitted to neonatal intensive care unit at National Children Hospital, Hanoi, Vietnam, between December 2019 and March 2020. mHLA-DR, nCD64 expressions were quantified on the admission day and the SI (mHLA-DR*100/nCD64) was calculated. We also measured mHLA-DR, nCD64 levels and SI in 17 non-sepsis control patients. Mean nCD64 expressions was significantly lower in septic patients than in controls (p = 0.004). By contract, mHLA-DR expression was notably higher in sepsis group. Sensitivity and specificity to detect sepsis using nCD64 was 73.5% and 88.2%, respectively, while for SI it was 91.2% and 100%, respectively. Specificity was highest for SI>17 (100%). Positive likelihood ratios were highest for nCD64 > 3427.4 ABC (88.2%). We found out that nCD64, SI were beneficial for diagnosis of sepsis in neonatal patients receiving antibiotic whereas mHLA-DR was a marker of low diagnostic value. If further validated, the use of nCD64 and SI as infection markers should allow indication of antibiotic treatment.