Department of Hematology, Zhongshan Hospital Fudan University, Shanghai 200032, China.
Department of Hematology, Zhongshan Hospital Fudan University, Shanghai 200032, China; Department of Hematology, Zhongshan Hospital Qingpu Branch, Fudan University, Shanghai 201700, China.
Thromb Res. 2020 Jun;190:11-19. doi: 10.1016/j.thromres.2020.03.012. Epub 2020 Mar 19.
The intestinal microbiota is essential for the maintenance of the physiology of immune homeostasis. Dysbiosis has been described in some autoimmune diseases, however its role is still elusive in primary immune thrombocytopenia (ITP), which is one kind of autoimmune diseases. This study aimed to characterize the phylogenetic diversity of the fecal microbiota and its relationship with the platelet activation status in patients with ITP.
The platelet activation status was assessed by 2 platelet markers, PAC-1 (antibody that recognizes the activated GPIIb/IIIa complex) and CD62p (Platelet surface P-selectin) by flow cytometry. Total DNA was extracted from fecal samples of ITP patients and healthy controls (HC). Sequencing the V4 hypervariable region of bacterial 16S rRNA genes was used to identify the changes in phylogenetic diversity and composition of the intestinal flora. The obtained sequencing reads were assigned to operational taxonomic units (OTUs, 97% sequence identity) and taxonomically classified to assess composition and diversity.
The percentage of PAC-1+ platelets in ITP patients was higher than that in control group (p < 0.001), The percentage of CD62p+ and PAC-1+CD62p+ platelets in ITP patients both higher than those in control group (p < 0.001). At the phylum level, eight different phyla were identified in ITP individuals, with a majority of Bacteroidetes (45.96%) and Firmicutes (38.59%), followed by Proteobacteria (11.43%), Fusobacteria(1.29%), and Actinobacteria (1.22%). While in the Healthy volunteers, ten phyla were detected, with a predominance of Firmicutes (50.92%) and Bacteroidetes (34.26%), came before Proteobacteria (13.60%), and Actinobacteria (0.90%). The gut microbiota was skewed in ITP, with an increased proportion of Proteobacteria, Bacteroidetes and Bacteroidetes/Firmicutes ratio, a decreased proportion of Firmicutes compared with HC. Disease specific alterations in diversity was also identified, especially the potential markers (Anaerorhabdus, sutterella, Peptostreptococcaceae, Clostridium_XI and carnobacteriaceae, p < 0.05) for ITP.
The results suggested that the distinct microbiota dysbiosis in ITP characterized by alterations in biodiversity and composition, which could provide insights for diet therapy and fecal microbiota transplantation treatment to cure ITP. There might be somehow compensatory enhancement of platelet activation in ITP patients. And there is associate between platelet activation and intestinal microbiota in patients with ITP.
肠道微生物群对于维持免疫稳态的生理学至关重要。在一些自身免疫性疾病中已经描述了微生物群落失调，然而其在原发性免疫性血小板减少症（ITP）中的作用仍然难以捉摸，ITP 是一种自身免疫性疾病。本研究旨在描述粪便微生物群的系统发育多样性及其与 ITP 患者血小板活化状态的关系。
通过流式细胞术，使用 2 种血小板标志物 PAC-1（识别活化的 GPIIb/IIIa 复合物的抗体）和 CD62p（血小板表面 P 选择素）评估血小板活化状态。从 ITP 患者和健康对照者（HC）的粪便样本中提取总 DNA。使用细菌 16S rRNA 基因 V4 高变区的测序来鉴定肠道菌群的系统发育多样性和组成的变化。获得的测序读段被分配到操作分类单元（OTUs，97%序列同一性），并进行分类学分类以评估组成和多样性。
ITP 患者中 PAC-1+血小板的百分比高于对照组（p<0.001），ITP 患者中 CD62p+和 PAC-1+CD62p+血小板的百分比均高于对照组（p<0.001）。在门水平上，在 ITP 个体中鉴定出了 8 个不同的门，其中大多数为拟杆菌门（45.96%）和厚壁菌门（38.59%），其次为变形菌门（11.43%）、梭杆菌门（1.29%）和放线菌门（1.22%）。而在健康志愿者中，检测到 10 个门，其中厚壁菌门（50.92%）和拟杆菌门（34.26%）占主导地位，其次是变形菌门（13.60%）和放线菌门（0.90%）。ITP 患者的肠道微生物群发生了倾斜，变形菌门、拟杆菌门和拟杆菌门/厚壁菌门的比例增加，与 HC 相比，厚壁菌门的比例降低。还确定了多样性的疾病特异性改变，特别是用于 ITP 的潜在标志物（Anaerorhabdus、sutterella、Peptostreptococcaceae、Clostridium_XI 和 carnobacteriaceae，p<0.05）。
结果表明，ITP 中存在明显的微生物群落失调，表现为生物多样性和组成的改变，这可能为 ITP 的饮食治疗和粪便微生物群移植治疗提供依据。ITP 患者的血小板活化可能存在某种代偿性增强。ITP 患者的血小板活化与肠道微生物群之间存在关联。
