Habis Ralph, Kolchinski Anna, Heck Ashley N, Bean Paris, Probasco John C, Hasbun Rodrigo, Venkatesan Arun
Johns Hopkins Encephalitis Center, Department of Neurology, Johns Hopkins University, School of Medicine, Baltimore, Maryland, USA.
Department of Medicine, Section of Infectious Disease, McGovern Medical School, UTHealth Science Center, Houston, Texas, USA.
Clin Infect Dis. 2025 Aug 1;81(1):179-187. doi: 10.1093/cid/ciae391.
Early diagnosis of encephalitis involves identifying signs of neuroinflammation, including cerebrospinal fluid (CSF) pleocytosis. However, an absence of CSF pleocytosis in encephalitis has been described, most notably in autoimmune encephalitis. We examined clinical characteristics and outcomes associated with the absence or presence of CSF white blood cell pleocytosis (≥5 cells/µL), to inform timely diagnosis and management of encephalitis.
This retrospective study compares initial CSF profiles in 597 adult patients with all-cause encephalitis.
Of the 597 patients, 446 (74.7%) had CSF pleocytosis while 151 (25.3%) did not. CSF pleocytosis occurred more commonly in infectious cases (200/446, 44.8%), along with 59 (13.2%) autoimmune cases, comprised chiefly of anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis (37/59, 62.7%). Notably, the group without pleocytosis comprised similar proportions of infectious (47/151, 31.1%) and autoimmune (38/151, 25.92%; P > .05) encephalitis. Among those with infectious encephalitis, 47/247 (19%) had an absence of pleocytosis, including 18/76 (23.7%) with HSV-1 encephalitis. The absence of pleocytosis was associated with a decreased rate of acyclovir administration (47.7% in patients without pleocytosis vs 71.1% in patients with pleocytosis; P < .001). Despite pleocytosis being associated with some measures of clinical severity at admission such as a Full Outline of UnResponsiveness (FOUR) score ≤14, it was not associated with mortality or prolonged hospitalization.
CSF pleocytosis is an important criterion for encephalitis diagnosis, but 25.3% of patients with all-cause encephalitis and 23.7% of those with HSV-1 encephalitis exhibit an absence of pleocytosis on initial LP. Acyclovir initiation should not be delayed in the absence of pleocytosis in patients with suspected encephalitis.
脑炎的早期诊断涉及识别神经炎症迹象，包括脑脊液（CSF）细胞增多。然而，已有文献报道脑炎患者存在脑脊液细胞增多缺如的情况，最显著的是在自身免疫性脑炎中。我们研究了与脑脊液白细胞增多（≥5个细胞/微升）与否相关的临床特征及预后，以指导脑炎的及时诊断和管理。
这项回顾性研究比较了597例成年全因性脑炎患者的初始脑脊液特征。
597例患者中，446例（74.7%）存在脑脊液细胞增多，而151例（25.3%）不存在。脑脊液细胞增多在感染性病例中更常见（200/446，44.8%），还有59例（13.2%）自身免疫性病例，主要由抗N-甲基-D-天冬氨酸受体（抗NMDAR）脑炎组成（37/59，62.7%）。值得注意的是，无细胞增多的组中感染性脑炎（47/151，31.1%）和自身免疫性脑炎（38/151，25.92%；P>.05）的比例相似。在感染性脑炎患者中，47/247（19%）无细胞增多，包括18/76（23.7%）的单纯疱疹病毒1型（HSV-1）脑炎患者。无细胞增多与阿昔洛韦给药率降低相关（无细胞增多患者为47.7%，有细胞增多患者为71.1%；P<.001）。尽管细胞增多与入院时的一些临床严重程度指标相关，如全面无反应性量表（FOUR）评分≤14，但与死亡率或住院时间延长无关。
脑脊液细胞增多是脑炎诊断的重要标准，但25.3%的全因性脑炎患者和23.7%的HSV-1脑炎患者在初次腰椎穿刺时无细胞增多。对于疑似脑炎且无细胞增多的患者，不应延迟阿昔洛韦的起始使用。
