ABSTRACT
OBJECTIVE: Β2-microglobulin (ß2M) associated amyloidosis is an inevitable complication of chronic kidney disease (CKD). Testing ß2M 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 ß2M reflects its concentration in the serum. The current study; therefore, aimed to examine the relationship between salivary and serum ß2M 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 ß2M was measured in both serum and saliva. The correlation between serum and salivary ß2M was measured by calculating spearman's ρ. RESULTS: The Spearman's ρ for correlation between serum and salivary ß2M 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 ß2M levels poorly agreed with serum ß2M levels, and thus may not be used as a surrogate for serum ß2M in CKD patients who did not require replacement therapy.
ABSTRACT
BACKGROUND AND OBJECTIVES: We investigated if a combination of plasma or salivary interleukin-2 (IL-2), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), transforming growth factor-beta (TGF-beta), and troponin can improve estimation of the pretest probability of the left ventricular systolic dysfunction (LVSD). SUBJECTS AND METHODS: Eighty patients with newly-diagnosed myocardial infarction (MI) were echocardiographically examined for LVSD (ejection fraction < or =40%). Measurements included traditional MI risk factors, plasma and salivary concentrations of troponin, IL-2, IL-6, TNF-alpha, and TGF-beta. With the LVSD as the outcome variable, we developed logistic regression models, starting with a basic model incorporating traditional risk factors and consecutively adding salivary and plasma biomarkers. Models were compared using several criteria, including (but not limited to) C statistic (discrimination) and net reclassification improvement index (NRI). RESULTS: Apart from troponin, plasma, and salivary values of the biomarkers were correlated: spearman's rho was 0.19 (p=0.088) for troponin, 0.36 (p=0.001) for IL-2, 0.74 (p<0.001) for IL-6, 0.61 (p<0.001) for TNF-alpha, and 0.65 (p<0.001) for TGF-beta. The predictive performances of the basic model for estimating the pretest probability of the presence of LVSD considerably improved when cytokines were added (salivary added: C-statistic from 0.77 to 0.82 and NRI 77%; plasma added: C-statistic to 0.80 and NRI 134%). CONCLUSION: Multiple biomarkers added diagnostic value to the standard risk factors for predicting the presence of post-MI LVSD.
