OC 73.2 - Phascolarctobacterium was increased in ITP and negatively correlated with platelet counts

Background: There are few studies on the intestinal flora of primary immune thrombocytopenia (ITP), and different studies present different and inconsistent characteristic flora of ITP. Specific differential flora cannot be determined at present.

Aims: To explore the difference of intestinal flora between ITP and healthy people, and to search for specific differential flora and possible mechanisms.

Methods: Feces from ITP patients and healthy controls (patients' families) were studied using 16S rRNA and metagenomic techniques. KEGG and GO functions were annotated. The relationship between intestinal flora and disease stage, severity and refractory cases was analyzed. Plasma IL-2 and IL-4 levels were detected to investigate the role of intestinal flora in ITP.

Results: 1. The α -diversity and β -diversity of intestinal flora in ITP were significantly altered, indicating that the composition and distribution of intestinal flora in ITP patients and healthy people were significantly different. The functional changes of intestinal flora in ITP were mainly manifested in cell movement, membrane transport, signal transduction and metabolism.
2. The numbers of Phascolarctobacterium were significantly increased in ITP patients (P < 0.005) at the genus level. Correlation analysis showed that increased Phascolarctobacterium was negatively correlated with platelet counts, but had no significant correlation with bleeding score, course of disease, PT, APTT and INR.
3. The intestinal flora of newly diagnosed ITP, persistent ITP and chronic ITP also differed at multiple classification levels.
4. Plasma IL-2 concentration in ITP patients was significantly higher than that in healthy controls (9.871±2.866 pg/mL vs 8.527±3.003 pg/mL, P< 0.05). Phascolarctobacterium were positively correlated with IL-2.

Conclusion(s): Phascolarctobacterium were significantly increased in ITP patients, and were negatively correlated with platelet counts and positively correlated with IL-2. Phascolarctobacterium can be used as a specific differential bacterium of ITP, and its specific mechanism may involve immune changes of ITP, which needs further study.