Saliva Analysis for Monitoring Dialysis and Renal Function

Measurement of biological markers that demonstrate distinguishable and regular changes from pre- to postdialysis states can enable necessary monitoring of dialysis efficacy and the level of renal function in patients with end-stage renal disease. In a report in this issue of Clinical Chemistry, Blicharz et al. (1) suggest that the measurement of biomarkers in saliva may be an effective alternative method for monitoring the effectiveness of hemodialysis. In particular, Blicharz et al. highlight as markers of interest 2 small molecules present in saliva, nitrite and uric acid (UA).1 Monitoring of markers in saliva instead of serum is advantageous because saliva collection is a noninvasive, simple, and inexpensive approach with minimal infectious risk that can be performed by the patient with no need for involvement from medical personnel. Saliva can be tested at home, thus saving the need for a visit to the clinic or hospital. Markers for monitoring patients with end-stage renal disease must fulfill 3 requirements: (a) the markers should properly reflect serum concentrations of toxins to be dialyzed, (b) the correlation between the serum and saliva concentrations of the markers should be as high as possible, and (c) the concentrations of the markers in saliva should not be altered by intraoral conditions or by processes associated with marker transport from serum into saliva.