A POSSIBLE ROLE FOR SALIVA AS A DIAGNOSTIC FLUID IN PATIENTS WITH CHRONIC PAIN

Objectives: The focus of this review was on proteins and peptides foun d in saliva. Of greatest interest were those neuropeptides relevant to nociception and to the pathogenesis of chronic pain syndromes. An add itional goal wits to develop a standardized protocol to collect saliva for laboratory assessment. Methods: Data were obtained through discus sion with experts at the medical schools in San Antonio and Heidelberg and a Medline literature search involving all relevant studies from 1 966 to 1997, The literature search was based on the following key term s: saliva, serotonin, neuropeptide, substance P (SP), calcitonin gene- related peptide (CGRP), and nerve growth factor (NGF). Results: The me an concentration of SP in the saliva of healthy normal controls ranged from 9.6 to 220 pg/mL. Generally, the concentration of SP was approxi mately three times higher in saliva than in plasma, In a number of pai nful conditions, particularly tension headache, substantial elevations of salivary SP were found. Mean values for salivary CGRP in healthy c ontrols were approximately 22 pmol/L and were significantly elevated i n patients with migraine attacks or cluster headache. There were no da ta to indicate prior quantitative determination of NGF in human saliva . Conclusions: After sampling and processing techniques have been stan dardized, measurement of neuropeptides in human saliva could provide a valuable tool for the study of patients with chronic painful disorder s such as rheumatoid arthritis, osteoarthritis, and even fibromyalgia syndrome. Copyright (C) 1998 by W.B. Saunders Company.