Table 2_The gut-brain-axis one year after treatment with cladribine tablets in patients with relapsing remitting multiple sclerosis: a pilot study.docx

IntroductionCladribine tablets are an effective treatment for relapsing remitting multiple sclerosis (RRMS). However, almost half of the treated patients are not free of disease activity after two years. The aim of this study was to describe the changes that cladribine tablets effectuate in the gut and oral microbiota and the peripheral immunological profile between responders and non-responders.
MethodsIn this pilot study of the multicenter, prospective, observational BIA (Brain-Immune-Intestine Axis) study, we included patients aged 18 to 55 years with RRMS who were scheduled to start treatment with cladribine tablets. We assessed the clinical status and the immunological and microbiological profile prior to the start of the treatment and after three and twelve months. At twelve months, we assessed the response status, based on clinical relapses, radiological activity and disability progression on the Expanded Disability Status Scale.
ResultsThe first twenty-five patients of the BIA study were included in this analysis. Ten patients (40%) were responders twelve months after treatment. Three months after treatment we found a significant decline of naïve and transitional B cells and memory B cells, and of CD57+ CD56dim NK cells. After twelve months the values recovered to baseline levels, except for the memory B cells. We did not find significant changes of the microbiological profile over time, except for a decline of the phylum Bacteroidetes in the oral samples twelve months after treatment. Baseline values and changes over time did not significantly differ between responders and non-responders. However, several phyla, genera or species (Bacteroidetes, Prevotella, Faecalibacterium prausnitzii) showed a higher relative abundance, and several phyla, genera or species (Proteobacteria, Escherichia coli) had a lower relative abundance in responders compared to non-responders.
DiscussionAfter treatment with cladribine tablets, we found significant changes in the immunological landscape. Also, the microbiological profile showed several differences in microbes with known anti- or pro-inflammatory properties between responders and non-responders. Overall, we showed that we can measure a treatment effect from cladribine tablets with our analyses. Future research on data from the BIA study, with a larger sample size and extended follow-up, can possibly confirm the reliability of our findings.

引言
克拉屈滨片剂（cladribine tablets）是治疗复发缓解型多发性硬化（relapsing remitting multiple sclerosis, RRMS）的有效手段。然而，近半数接受治疗的患者在治疗两年后仍未实现疾病活动完全缓解。本研究旨在探究克拉屈滨片剂对应答者与非应答者的肠道、口腔菌群以及外周免疫谱所产生的调控变化。

方法
本研究为多中心前瞻性观察性研究BIA（脑-免疫-肠道轴，Brain-Immune-Intestine Axis）的先导子研究，纳入了18~55岁、计划接受克拉屈滨片剂治疗的复发缓解型多发性硬化患者。我们分别在治疗开始前、治疗后3个月及12个月对患者的临床状态、免疫谱及微生物谱进行评估。于治疗后12个月，基于临床复发情况、影像学活动度及扩展残疾状态量表（Expanded Disability Status Scale）评估的残疾进展情况，判定患者的应答状态。

结果
本分析纳入了BIA研究的首批25例患者。治疗后12个月，共有10例（40%）患者为应答者。治疗后3个月，我们观察到初始B细胞、过渡性B细胞、记忆B细胞以及CD57+CD56dim自然杀伤（NK）细胞的比例显著下降。至治疗后12个月，除记忆B细胞外，其余免疫细胞比例均恢复至基线水平。随时间推移，微生物谱未出现显著变化，仅口腔样本中的拟杆菌门（Bacteroidetes）丰度在治疗后12个月出现下降。应答者与非应答者的基线微生物丰度及随时间的变化幅度均无显著差异，但相较于非应答者，应答者体内多个菌门、菌属及菌种（拟杆菌门、普雷沃菌属、普拉梭菌（Faecalibacterium prausnitzii））的相对丰度更高，而另一些菌门、菌属及菌种（变形菌门、大肠埃希菌（Escherichia coli））的相对丰度更低。

讨论
接受克拉屈滨片剂治疗后，患者的免疫微环境出现了显著变化。同时，应答者与非应答者之间，具有已知抗炎或促炎特性的微生物群落的相对丰度存在显著差异。综上，本研究证实通过相关分析可检测到克拉屈滨片剂的治疗效应。未来可基于BIA研究的更大样本量及更长随访周期的数据开展后续研究，以验证本研究结果的可靠性。