IgA nephropathy is one of the leading causes of chronic kidney disease in Japan. Since the origin and mechanisms by which IgA nephropathy develops currently remain unclear, a confirmed disease diagnosis is currently only possible by highly invasive renal biopsy. With the background of the salivary microbiome as a rich source of biomarkers for systemic diseases, we herein primarily aimed to investigate the salivary microbiome as a tool for the non-invasive diagnosis of IgA nephropathy. In a comparison of salivary microbiome profiles using 16S rRNA amplicon sequencing, significant differences were observed in microbial diversity and richness between IgA nephropathy patients and healthy controls. Furthermore, recent studies reported that patients with IgA nephropathy are more likely to develop inflammatory bowel diseases and that chronic inflammation of the tonsils triggered the recurrence of IgA nephropathy. Therefore, we compared the salivary microbiome of IgA nephropathy patients with chronic tonsillitis and ulcerative colitis patients. By combining the genera selected by the random forest algorithm, we were able to distinguish IgA nephropathy from healthy controls with an area under the curve (AUC) of 0.90, from the ulcerative colitis group with AUC of 0.88, and from the chronic tonsillitis group with AUC of 0.70. Additionally, the genus Neisseria was common among the selected genera that facilitated the separation of the IgA nephropathy group from healthy controls and the chronic tonsillitis group. The present results indicate the potential of the salivary microbiome as a biomarker for the non-invasive diagnosis of IgA nephropathy.

中文翻译：

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与 IgA 肾病相关的唾液微生物群失调——一项日本队列研究。

IgA 肾病是日本慢性肾病的主要原因之一。由于 IgA 肾病发展的起源和机制目前尚不清楚，目前只能通过高侵入性肾活检来确诊疾病。在唾液微生物组作为全身性疾病生物标志物的丰富来源的背景下，我们在此主要旨在研究唾液微生物组作为 IgA 肾病非侵入性诊断的工具。在使用 16S rRNA 扩增子测序比较唾液微生物组谱时，观察到 IgA 肾病患者和健康对照之间微生物多样性和丰富度的显着差异。此外，最近的研究报告称，IgA 肾病患者更容易患上炎症性肠病，扁桃体的慢性炎症引发了 IgA 肾病的复发。因此，我们比较了 IgA 肾病患者与慢性扁桃体炎和溃疡性结肠炎患者的唾液微生物组。通过结合随机森林算法选择的属，我们能够将 IgA 肾病与曲线下面积 (AUC) 为 0.90 的健康对照、AUC 为 0.88 的溃疡性结肠炎组和慢性扁桃体炎组的曲线下面积 (AUC) 区分开来。 AUC 为 0.70。此外，奈瑟菌属在选定的属中很常见，这有助于将 IgA 肾病组与健康对照和慢性扁桃体炎组分开。