On 21 February 2019, Jacqueline W. Mays from the National Institutes of Health, Bethesda, MD, USA, presented results on behalf of colleagues of a study evaluating whole saliva for the presence of a diagnostic biomarker profile at first onset of oral chronic graft-versus-host disease (cGvHD) prior to initiation of topical steroid therapy at the 2019 TCT Transplantation and Cellular Therapy Meetings of ASBMT and CIBMTRin Houston, Texas, USA.
Patients and methods
- Samples were collected at oral cGvHD onset from NIH protocols: NCT00331968, NCT00520130, or NCT01851382
- Patients had biopsy-proven oral GvHD
- Kruskal-Wallis test was used for protein identification
- Selected proteins were validated by Western blot (WB) in two independent cohorts
- Cohort 1: post-hematopoietic stem cell transplantation (HSCT) patients with (n = 10) and without (n = 10) oral cGvHD
- Cohort 2: post-HSCT patients with (n = 12) and without (n = 12) oral cGvHD
Key findings
- The dataset included 569 confidently-identified proteins, with 77 significantly differentially expressed at the onset of cGvHD
- Zymogen granule protein 16B (ZG16B) was reduced 2-fold in the saliva of post-HSCT patients with oral cGVHD (898.1 ± 371.8 AU) compared with post-HSCT patients without oral cGVHD (1905 ± 598.6 AU) P< 0.05)
- Immunohistochemically (IHC) staining for ZG16B demonstrated a significant decrease in ZB16B protein expression in patient labial salivary gland tissue after oral cGVHD onset
Conclusion
Jacqueline W. Mays concluded that ZG16B is present in lower amounts in unstimulated whole saliva and within the salivary gland acinar units at oral cGvHD onset. Reduction in the ZG16B protein may indicate cGvHD activity as well as potentially causing salivary gland damage. Dr. Mays added that further investigation in a larger cohort is required to assess whether saliva can be used to identify a diagnostic biomarker profile for oral cGvHD.