INTRODUCTION: Various metabolic changes were elaborated in patients with chronic kidney disease which often require biochemical analysis of blood regularly. Saliva analysis has many advantages as an alternative to blood analysis.
OBJECTIVE:  Evaluate levels of some parameters in saliva and serum including: urea, creatinine, calcium and phosphorus in children undergoing hemodialysis and to determine the correlation between saliva and serum regarding these parameters in order to evaluate salivary diagnostic potential.
MATERIALS AND METHODS:  A cross sectional analytical study was conducted on children undergoing hemodialysis in Alexandria University Children's Hospital (AUCH). A total of 20 patients were included in the present study of whom, 10 were boys (50%) and 10 were girls (50%) with a mean age 8.85 ± 2.74. Serum and salivary samples were collected from the  participants for analysis. Serum tests including Urea, creatinine (Cr), calcium (Ca), phosphorus (P) and salivary tests including Urea, Cr, Ca and P were recorded in all subjects.
RESULTS: There was significant a positive correlation (P <0.0001) between serum and salivary urea (r = 0.79), as well as between serum and salivary creatinine (r = 0.68). Besides, levels of phosphorus were significantly higher in saliva than in serum. However, levels of creatinine and calcium showed significantly lower levels in saliva compared to serum.
CONCLUSION:  Outcomes of this study found that analysis of salivary creatinine and urea in patients with chronic kidney disease mirrored their levels in serum. Consequently, salivary creatinine and urea levels could be used non-invasively to measure serum urea and creatinine levels respectively in patients with chronic kidney disease which may be helpful in monitoring of these patients.