Abiramalatha T, Santhanam S, Mammen J J, Rebekah G, Shabeer M P, Choudhury J, Nair S C
Department of Neonatology, Christian Medical College, Vellore, India.
Department of Transfusion medicine and Immunohematology, Christian Medical College, Vellore, India.
J Perinatol. 2016 Sep;36(9):733-8. doi: 10.1038/jp.2016.69. Epub 2016 Apr 28.
The objective of this study was to determine changes in neutrophil volume conductivity scatter (VCS) parameters and their distribution widths (DW) in neonatal sepsis and to estimate their optimal cutoff levels using receiver operating characteristic (ROC) curves.
In a cohort of neonates evaluated for sepsis, blood counts and blood culture were performed initially, with repeat counts and C-reactive protein (CRP) done after 24 to 48 h. Neutrophil VCS parameters from both the initial and repeat blood counts were analyzed. Babies were classified as having blood culture-positive sepsis, probable sepsis (clinical course consistent with sepsis and CRP-positive, but culture-negative) and no sepsis (clinical course not compatible with sepsis, culture- and CRP-negative).
A total of 600 babies were included: 240 (40%) babies in the sepsis group and 360 (60%) babies in the control group. All the neutrophil VCS parameters and their DWs (except for low angle light scatter in the repeat counts) were significantly different between the two groups, with an area under curve in the ROC curve of >0.6 for most parameters. The five most significant VCS parameters (mean neutrophil volume (MNV), median angle light scatter (MALS), lower median angle light scatter (LMALS), MNV-DW and ALL-DW) had around 65 to 75% sensitivity and specificity. A combination of leukopenia, thrombocytopenia, MNV and LMALS had a likelihood ratio (LR)+ of 15.3 and LR- of 0.17. With a pre-test probability of 40%, post-test probability increased to 91% for a positive test and decreased to 10% for a negative test. A prospective validation study was performed recruiting an additional 60 babies, which showed similar results, assuring that the cutoffs were robust.
Neutrophil VCS parameters cannot be considered as stand-alone tests to diagnose or rule out neonatal sepsis, but can be used in combination with other hematological screening tests to improve the diagnostic accuracy of the neonatal sepsis screen.
本研究的目的是确定新生儿败血症中性粒细胞体积传导性散射（VCS）参数及其分布宽度（DW）的变化，并使用受试者工作特征（ROC）曲线估计其最佳截断水平。
在一组接受败血症评估的新生儿中，最初进行血细胞计数和血培养，24至48小时后重复计数并检测C反应蛋白（CRP）。分析初次和重复血细胞计数的中性粒细胞VCS参数。婴儿被分类为血培养阳性败血症、可能败血症（临床病程符合败血症且CRP阳性但培养阴性）和无败血症（临床病程不符合败血症，培养和CRP阴性）。
共纳入600名婴儿：败血症组240名（40%），对照组360名（60%）。两组之间所有中性粒细胞VCS参数及其DWs（重复计数中的低角度光散射除外）均有显著差异，大多数参数的ROC曲线下面积>0.6。五个最显著的VCS参数（平均中性粒细胞体积（MNV）、中位角度光散射（MALS）、较低中位角度光散射（LMALS）、MNV-DW和ALL-DW）的敏感性和特异性约为65%至75%。白细胞减少、血小板减少、MNV和LMALS的组合，其阳性似然比（LR）+为15.3，阴性似然比（LR）-为0.17。预测试概率为40%时，阳性测试的后测试概率增至91%，阴性测试的后测试概率降至10%。进行了一项前瞻性验证研究，额外招募了60名婴儿，结果相似，确保了截断值的可靠性。
中性粒细胞VCS参数不能作为诊断或排除新生儿败血症的独立检测指标，但可与其他血液学筛查检测联合使用，以提高新生儿败血症筛查的诊断准确性。
