Advanced Glycation Endproducts in Saliva of Patients With Multiple Myeloma

Objectives: To analyze the level of AGEs in saliva samples from patients with Multiple Myeloma (MM) and correlate them to clinical characteristics. Spectrometry and ELISA were also used to confirm the presence of Advanced Glycation Endproducts (AGEs) in MM and control subjects.
Methods: Thirty patients with MM were recruited from the University of Florida College of Dentistry Oral Medicine Clinic after approval from the Institutional Review Board. Whole un-stimulated saliva samples were collected in the morning before eating. Consenting patients were asked to spit into a 10 ml test tube for 10 minutes, and saliva samples were stored at negative twenty degress Celsius. On the day of testing, determination of AGEs was based on spectrofluorometric detection using a BioTek Synergy HT plate reader and ELISA.
Results: There was no difference in the level of AGEs in the MM saliva and controls in both the spectrofluorometry study and the ELISA study. There was no significant difference in the level of AGEs and the stage of MM (p = 0.69), no significant difference in the level of AGEs and whether patients are diagnosed with kappa or lambda MM (p = 0.92), and no significant difference in the level of AGEs and Zometa use (p = 0.38). A significant difference of 45% in the mean level of AGEs between MM patients with lytic lesions, 20,509 AU, and those without lytic lesions, 14,193 AU, (p < 0.05) was noted.
Conclusions: In the present study, the concentration of AGEs was higher in MM patients with bone lesions versus those without bone lesions. Detection of elevated levels of salivary AGEs could be a noninvasive way to determine a biomarker for development of bone lesions in MM patients who currently lack good markers for the progression of bone lesions. Though additional research is needed to investigate the role of AGEs in oxidative stress in MM patients, noninvasive techniques for sample collection should be taken into consideration.