Shibuma Satoshi, On Jotaro, Natsumeda Manabu, Koyama Akihide, Takahashi Haruhiko, Watanabe Jun, Mitobe Masaki, Nakata Satoshi, Tanaka Yuki, Tsukamoto Yoshihiro, Okada Masayasu, Yoshimura Junichi, Tada Mari, Shimizu Hiroshi, Oya Soichi, Murai Junko, Okamoto Kouichirou, Kawashima Hiroyuki, Kakita Akiyoshi, Oishi Makoto
Department of Neurosurgery, Brain Research Institute, Niigata University, Niigata, Japan.
Advanced Treatment of Neurological Diseases Branch, Brain Research Institute, Niigata University, Niigata, Japan.
Pediatr Blood Cancer. 2025 Apr;72(4):e31535. doi: 10.1002/pbc.31535. Epub 2025 Jan 9.
Leptomeningeal disease (LMD) in diffuse midline gliomas (DMGs) can lead to devastating symptoms such as severe pain, urinary incontinence, and tetraparesis, with limited treatment options. We determined whether detecting H3F3A K27M-mutant droplets in cerebrospinal fluid (CSF) circulating tumor deoxyribonucleic acid (ctDNA) could be a biomarker for detecting LMD in DMGs.
Twenty-five CSF samples were obtained from 22 DMG patients. Histological confirmation of H3F3A K27M mutation was obtained in 10 (45.5%) cases. ctDNA was extracted from CSF, and H3F3A K27M-mutant and wildtype droplets were detected using digital droplet polymerase chain reaction (ddPCR). LMD was diagnosed by CSF cytology and pre- and post-contrast head and spine magnetic resonance (MR) imaging.
The number of H3F3A K27M-mutant droplets (median 27 [range: 1-379] vs. median 0 [range: 0-1]; p < 0.0001) and variant allele frequency (VAF) (median 48.9% [range: 7.5%-87.5%] vs. median 0.0% [range: 0.0%-50.0%]; p < 0.0001) were significantly higher in the LMD/early-LMD group compared to no-LMD group. In two cases (Cases 4 and 11) without clinical evidence of LMD, multiple H3F3A K27M-mutant droplets were detected in CSF ctDNA. In those cases, extensive spinal dissemination was detected 6 months after the initial liquid biopsy. One case (Case 15) with high Schlafen11 (SLFN11) expression responded well to treatment for LMD and survived for 532 days after the diagnosis of LMD.
This study provides evidence that detecting H3F3A K27M-mutant droplets in CSF ctDNA is diagnostic for LMD and is more sensitive than traditional methods such as CSF cytology and MR imaging.
弥漫性中线胶质瘤（DMG）中的软脑膜疾病（LMD）可导致严重疼痛、尿失禁和四肢轻瘫等毁灭性症状，治疗选择有限。我们确定检测脑脊液（CSF）循环肿瘤脱氧核糖核酸（ctDNA）中的H3F3A K27M突变液滴是否可作为检测DMG中LMD的生物标志物。
从22例DMG患者中获取25份脑脊液样本。10例（45.5%）病例获得了H3F3A K27M突变的组织学确认。从脑脊液中提取ctDNA，并使用数字液滴聚合酶链反应（ddPCR）检测H3F3A K27M突变液滴和野生型液滴。通过脑脊液细胞学检查以及对比增强前后的头部和脊柱磁共振（MR）成像诊断LMD。
与无LMD组相比，LMD/早期LMD组中H3F3A K27M突变液滴数量（中位数27[范围：1 - 379]对中位数0[范围：0 - 1]；p < 0.0001）和变异等位基因频率（VAF）（中位数48.9%[范围：7.5% - 87.5%]对中位数0.0%[范围：0.0% - 50.0%]；p < 0.0001）显著更高。在2例（病例4和11）无LMD临床证据的病例中，脑脊液ctDNA中检测到多个H3F3A K27M突变液滴。在这些病例中，初次液体活检6个月后检测到广泛的脊髓播散。1例（病例15）具有高Schlafen11（SLFN11）表达的病例对LMD治疗反应良好，在诊断LMD后存活了532天。
本研究提供了证据表明，检测脑脊液ctDNA中的H3F3A K27M突变液滴可诊断LMD，且比脑脊液细胞学检查和MR成像等传统方法更敏感。
