Variable Effects of Severe Aplastic Anemia Treatment on the Oral Microbiome

Authors

• NJ Ames
• J Barb
• H Kim
• A Oler
• A Ranucci
• R Childs
• D Townsley
• A Cashion
• G Wallen

Abstract

The human microbiome plays an integral role in maintaining health and preventing disease. Because of its location at the beginning of the aero-digestive tract, the oral microbiome, might be the key to understanding infections. Patients with severe aplastic anemia (SAA) undergoing treatment experience substantial immune system changes putting them at risk for infection. The purpose of this study was to determine if modulation of the immune system during treatment impacts bacterial diversity. We collected tongue brushings prior to and at two other time points after treatment in 24 SAA patients undergoing either hematopoietic stem cell transplant (HSCT=4) or medical immunosuppressive therapy (n=20). Bacterial DNA was subjected to next-generation sequencing using Ion Torrent Personal Genome Machine and the Ion 16S Metagenomic Kit ™ (Life Technologies). Analysis was conducted using a novel analytical pipeline and a published processing pipeline specific to Ion Torrent data. In the transplant patients, the microbiome after transplant (engraftment) demonstrated a striking lack of diversity in 3 out of 4 patients. Indicators of microbial diversity decreased at engraftment from baseline and then increased 100 days post-transplant. In contrast, in the immunosuppressive patients, the microbiome did not demonstrate this trend. Because some immunosuppressive patients showed patient-specific variable changes in diversity across the three time points, a more in-depth analysis will be required to correlate these changes to clinical outcomes. In conclusion, the oral microbiome’s diversity changes after treatment for SAA. This change occurs whether the treatment is HSCT or immunosuppressive therapy.

Scientific Focus Area: Microbiology and Infectious Diseases

This page was last updated on Friday, March 26, 2021