No Relationship between Serum and Salivary β(2)- Microglobulin Levels in A Sample of Adult Diabetic Men with Chronic Kidney Disease without Renal Replacement Therapy

OBJECTIVE: Β(2)-microglobulin (β(2)M) associated amyloidosis is an inevitable complication of chronic kidney disease (CKD). Testing β(2)M in the blood is invasive and expensive. On the other hand, oral fluid is a perfect medium to be explored for public health and disease surveillance. However, it has never been studied if salivary concentration of β(2)M reflects its concentration in the serum. The current study; therefore, aimed to examine the relationship between salivary and serum β(2)M in a sample of adult diabetic men with CKD. MATERIALS AND METHODS: Among diabetic patients referred to the Nephrology Department of The Golestan Hospital of Ahvaz due to CKD, 40 men not requiring renal replacement therapy were consecutively recruited for this cross-sectional study. Patients were excluded if they had any disease or were using any drugs that might affect the oral mucosa or saliva. The concentration of β(2)M was measured in both serum and saliva. The correlation between serum and salivary β(2)M was measured by calculating spearman’s ρ. RESULTS: The Spearman’s ρ for correlation between serum and salivary β(2)M was -0.017 (p=0.917), indicating lack of correlation. Serum and salivary creatinine (Spearman’s ρ=0.54; p value<0.001) as well as serum and salivary urea nitrogen levels (Spearman’s ρ=0.39; p value=0.014) were correlated. CONCLUSION: Salivary β(2)M levels poorly agreed with serum β(2)M levels, and thus may not be used as a surrogate for serum β(2)M in CKD patients who did not require replacement therapy.