Abstract

Langerhans cell histiocytosis (LCH) is a rare inflammatory myeloid neoplasia with a broad spectrum of clinical manifestations. The activation of the MAP kinase pathway plays an integral role in its pathogenesis with genetic alterations found in the majority of cases that most frequently involve a somatic mutation of the oncogenic BRAF^V600E variant. In this study we investigated the prevalence of the BRAF^V600E mutation and its clinical relevance in adult Greek patients with LCH. Among 37 patients studied, the BRAF^V600E mutation was identified in 12 out of 31 (38.7%), whereas in six patients (19.3%) the results were in conclusive. The presence of the mutation did not correlate with age at diagnosis, organ involvement, disease extent, response to initial treatment, development of diabetes insipidus and relapse risk. In our series the prevalence of the BRAF^V600E mutation is at the lower range of the relative percentage found in children, but in line to that obtained in previous studies of adult patients with LCH that have found an up to 50% prevalence of the BRAF^V600E mutation in these patients. Further studies with a larger number of adults are needed to identify the exact prevalence of mutations in the RAS-RAF-MEK-ERK pathway and their role on clinical parameters and disease outcomes.

Supplemental data for this article is available online at https://doi.org/10.1080/08880018.2022.2029988 .

摘要

朗格汉斯细胞组织细胞增生症（LCH）是一种罕见的炎症性骨髓瘤，临床表现广泛。MAP 激酶通路的激活在其发病机制中起着不可或缺的作用，在大多数情况下都发现了基因改变，这些改变最常涉及致癌 BRAF ^V600E变体的体细胞突变。在这项研究中，我们调查了 BRAF ^V600E突变的患病率及其在希腊成年 LCH 患者中的临床相关性。在研究的 37 名患者中，BRAF ^V600E31 名患者中有 12 名（38.7%）发现了突变，而 6 名患者（19.3%）的结果是结论性的。突变的存在与诊断年龄、器官受累、疾病程度、对初始治疗的反应、尿崩症的发展和复发风险无关。在我们的系列中，BRAF ^{V600E突变的患病率处于儿童中发现的相对百分比的较低范围，但与先前对成年 LCH 患者的研究中获得的结果一致，这些研究发现}BRAF ^V600E的患病率高达 50%这些患者的突变。需要对更多成年人进行进一步的研究，以确定 RAS-RAF-MEK-ERK 通路突变的确切发生率及其对临床参数和疾病结果的作用。

本文的补充数据可在 https://doi.org/10.1080/08880018.2022.2029988 在线获取。