Salivary and serum periostin in kidney transplant recipients.

The superiority of saliva as a diagnostic fluid includes ease of collection and storage, and non-invasiveness, all of which can lead to the replacement of blood with this bio-fluid. The significant results of salivary POSTN may be due to the lack of serum disturbing factors. Saliva is an ultra-filtered fluid from serum and therefore there are fewer proteins and polysaccharides attached to biomarkers in saliva and the accuracy of measuring these biomarkers in the saliva is more valuable than serum.