The first proteomics analysis of tonsils in patients with periodic fever, aphthous stomatitis, pharyngitis, and adenitis syndrome (PFAPA).

BACKGROUND

Periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome is a recurrent fever syndrome. The exact etiopathogenesis of PFAPA syndrome remains unknown. Biological fluids or tissues may provide disease-specific biomarkers that may help clinicians to find new pathogenic pathways.

METHODS

Tonsil tissues of seven patients with PFAPA were collected during the tonsillectomy. Seven patients who underwent tonsillectomy for reasons other than chronic tonsillitis were enrolled as a control group. The nHPLC LC-MS/MS system was used for protein identification and label-free quantification. Bioinformatics analysis was carried out using the UniProt accession numbers of the identified proteins.

RESULTS

Proteomics analysis revealed to identity of proteins of which at least 23 were up and 57 were downregulated. Bioinformatics analysis of differentially regulated proteins by STRING indicated that protein folding and clearance machinery were interrupted in PFAPA patients compared to the controls. The affected pathways underlined the importance of the mitochondrial electron transport chain and ATP biosynthesis process.

CONCLUSION

Although it is not clear that changes in tonsil protein expression whether directly related to pathogenesis or simply result of chronic inflammation, the identification of tonsil biomarkers for PFAPA may provide clinicians an opportunity to understand disease pathogenesis or develop new molecular targets for treatments.

IMPACT

Proteomics analyses of tonsils revealed the identity of 80 proteins of which at least 23 were up and 57 were downregulated. Bioinformatics analysis underlined the importance of mitochondrial ETC and regulation of ATP biosynthetic process. This is the first study evaluating the proteomics of the tonsils of PFAPA patients. The identification of tonsil biomarkers for PFAPA may provide clinicians an opportunity to understand disease pathogenesis or develop new molecular targets for treatments.