title: Salivary and serum beta2-microglobulin and gamma-glutamyl-transferase in patients with primary Sjögren syndrome and Sjögren syndrome secondary to systemic lupus erythematosus.
abstract: BACKGROUND
  Sialochemistry has been proposed as a simple and useful tool for the diagnosis of Sjögren syndrome (SS). Although many changes have been detected in several constituents of saliva from patients with SS, none are individually sensitive or specific enough for diagnosing SS. The aim of this study was to assess the value of the combined determination of beta2-microglobulin (beta2m) and gamma-glutamyl-transferase (GGT) activity in serum and saliva as a diagnostic instrument for differentiating primary and secondary [to systemic lupus erythematosus (SLE)] SS patients from normal subjects.
  
  
  METHODS
  Nineteen primary SS (pSS) patients, 15 patients with SS secondary to SLE, and 25 SLE patients without SS were studied. Thirty healthy subjects were included in the study as control group.
  
  
  RESULTS
  By means of a mathematical model, (a) 84.1%, (b) 85.7%, and (c) 87.0% of patients were correctly classified as SS or normal when (a) salivary beta2m and GGT values, (b) serum beta2m and salivary GGT values, and (c) salivary beta2m and GGT along with serum beta2m values, respectively, were considered. To differentiate between pSS and sSS by means of the mathematical model, the combination of serum beta2m and salivary GGT values achieved that 81.8% of the patients were correctly classified.
  
  
  CONCLUSIONS
  Since sialochemistry is an easy, safe and reliable test, the combined determination of beta2m and GGT in saliva and serum was useful for differentiating SS patients from normal subjects, but not excessively good for differentiating pSS from sSS patients.
authors.affiliation: Services of Internal Medicine, Virgen de las Nieves University Hospital, Jefe de Servicio de Medicina Interna, Avda. Fuerzas Armadas, 2, 18014, Granada, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Castro
authors.forename: Juan
authors.initials: J
authors.lastname: Jiménez-Alonso
authors.forename: José Mario
authors.initials: JM
authors.lastname: Sabio
authors.forename: Francisco
authors.initials: F
authors.lastname: Rivera-Cívico
authors.forename: María
authors.initials: M
authors.lastname: Martín-Armada
authors.forename: Miguel Angel
authors.initials: MA
authors.lastname: Rodríguez
authors.forename: Laura
authors.initials: L
authors.lastname: Jáimez
authors.forename: María Jesús
authors.initials: MJ
authors.lastname: Castillo
authors.forename: Julio
authors.initials: J
authors.lastname: Sánchez-Román
mesh_terms: D000465:Algorithms; D015415:Biomarkers; D005260:Female; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000150:complications / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D012463:Saliva / Q000737:chemistry*; D012859:Sjogren's Syndrome / Q000201:enzymology / Q000209:etiology / Q000378:metabolism*; D001613:beta 2-Microglobulin / Q000097:blood / Q000378:metabolism*; D005723:gamma-Glutamyltransferase / Q000097:blood / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D001613:beta 2-Microglobulin; D005723:gamma-Glutamyltransferase