Department of Clinical Analysis Laboratory, Hospital Universitario Nuestra Señora de Candelaria, Carretera General del Rosario 145, 38010, Santa Cruz de Tenerife, Spain.
BMC Pediatr. 2022 Aug 16;22(1):488. doi: 10.1186/s12887-022-03548-z.
Difficulty in interpreting white blood cell (WBC) counts in cerebrospinal fluid (CSF) complicates the diagnosis of neonatal meningitis in traumatic lumbar punctures (LP). The aim of our study was to determine the correction factor for WBC counts in traumatic LP that offers the greatest diagnostic efficacy in meningitis.
We conducted a retrospective observational study of LP in neonates between January 2014 and December 2020. Traumatic LP was defined as a red blood cell (RBC) count ≥ 1,000 cells/mm CSF and pleocytosis as WBCs ≥ 20 cells/mm CSF. The CSF RBC:WBC ratio was analyzed by linear regression to determine a new correction factor. Cell count adjustments were also studied using the 500:1, the 1,000:1 ratio method, and the peripheral blood RBC:WBC ratio, using ROC curves and studies of accuracy (sensitivity and specificity).
Overall, 41.0% of the 1,053 LPs included in the study were traumatic. The best results for effective WBC correction were the method based on the peripheral blood ratio (sensitivity = 1.0 and specificity = 0.9 for bacterial meningitis and sensitivity = 0.8 and specificity = 0.9 for viral meningitis) and the 400:1 ratio (sensitivity = 1.0 and specificity = 0.8 for bacterial meningitis and sensitivity = 0.8 and specificity = 0.8 for viral meningitis) obtained from linear regression (95% CI 381.7-427.4; R2 = 0.7).
Both the peripheral blood correction and the 400:1 correction reduce the number of neonates classified with pleocytosis who were not eventually diagnosed with meningitis. Both methods might be a useful tool to clarify the neonatal meningitis diagnosis, offering neonatologists the possibility to assess the WBC count in traumatic LP.
在创伤性腰椎穿刺（LP）中，脑脊液（CSF）中白细胞（WBC）计数的解读困难会使新生儿脑膜炎的诊断复杂化。我们的研究目的是确定创伤性 LP 中 WBC 计数的校正因子，该因子在脑膜炎中具有最佳的诊断效果。
我们对 2014 年 1 月至 2020 年 12 月期间的新生儿 LP 进行了回顾性观察性研究。将创伤性 LP 定义为 CSF 中 RBC 计数≥1,000 个/ mm3 和白细胞增多症为 WBC≥20 个/ mm3。通过线性回归分析 CSF RBC：WBC 比值，以确定新的校正因子。还通过 ROC 曲线和准确性（敏感性和特异性）研究，研究了 500:1、1,000:1 比值法和外周血 RBC：WBC 比值的细胞计数调整。
总的来说，研究中纳入的 1053 例 LP 中有 41.0%为创伤性。对于有效的 WBC 校正，最佳结果是基于外周血比值的方法（细菌性脑膜炎的敏感性为 1.0，特异性为 0.9，病毒性脑膜炎的敏感性为 0.8，特异性为 0.9）和线性回归得到的 400:1 比值（细菌性脑膜炎的敏感性为 1.0，特异性为 0.8，病毒性脑膜炎的敏感性为 0.8，特异性为 0.8）（95%CI 381.7-427.4；R2=0.7）。
外周血校正和 400:1 校正都减少了被归类为白细胞增多症但最终未被诊断为脑膜炎的新生儿数量。这两种方法都可能是澄清新生儿脑膜炎诊断的有用工具，为新生儿科医生提供了评估创伤性 LP 中 WBC 计数的可能性。
