title: Serum activities of adenosine deaminase, dipeptidyl peptidase IV and prolyl endopeptidase in patients with fibromyalgia: diagnostic implications.
abstract: Fibromyalgia (FM) is a chronic pain syndrome with number of symptoms that present challenge in terms of diagnosis and treatment. Patients with FM show abnormal profile of purines in plasma. In this work, we measured serum activities of enzymes involved in purine metabolism, namely total adenosine deaminase (ADE) and its isoforms (ADE1 and ADE2), ecto-ATPase, and 5'-nucleotidase (5'-NT). We also measured activity of dipeptidyl peptidase IV (DPPIV) and prolyl endopeptidase (PEP). Spectrophotometric and fluorometric methods were used for enzyme activity determinations. Enzyme activities were measured in sera of 24 patients with FM that were not undergoing pharmacological treatment during the study. Control group comprised 32 healthy control subjects. Significantly higher activities of total ADE (P = 0.025) and ADE2 (P = 0.011) were observed in FM patients, while no significant differences in ADE1, ecto-ATPase, and 5'-NT activities (P > 0.05) were found when compared to healthy controls. Moreover, increase in the activity of DPPIV (P = 0.015) and lower activity of PEP (P = 0.011) were also found in the FM group. ROC analysis pointed to different diagnostic sensitivities/specificities for individual enzyme activities measured as follows: ADE (50.0/87.5), ADE2 (41.7/90.6), DPPIV (62.5/71.9), and PEP (83.3/62.5). ADE2 and PEP were shown to be independent predictors of FM, while combination of the two gives AUC of 0.786 (95 % confidence interval of 0.656-0.885, P < 0.05). Our results are showing that serum activities of ADE2 and PEP could be useful as biomarkers for FM diagnosis. However, relatively low diagnostic sensitivity of ADE2 and specificity of PEP must be taken into account.
authors.affiliation: Faculty of Pharmacy and Biochemistry, University of Zagreb, A. Kovačića 1, 10000, Zagreb, Croatia. oculic@pharma.hr.
authors.forename: Ognjen
authors.initials: O
authors.lastname: Čulić
authors.affiliation: IBiS Institute of Biomedicine of Seville, University Hospital Virgen del Rocío-CSIC-University of Seville, Seville, Spain.
authors.forename: Mario D
authors.initials: MD
authors.lastname: Cordero
authors.affiliation: Department of Medical Biochemistry and Hematology, University of Zagreb, Faculty of Pharmacy and Biochemistry, Kneza Domagoja 2, 10000, Zagreb, Croatia.
authors.forename: Tihana
authors.initials: T
authors.lastname: Žanić-Grubišić
authors.affiliation: Department of Medical Biochemistry and Hematology, University of Zagreb, Faculty of Pharmacy and Biochemistry, Kneza Domagoja 2, 10000, Zagreb, Croatia.
authors.forename: Anita
authors.initials: A
authors.lastname: Somborac-Bačura
authors.affiliation: Department of Chemistry and Biochemistry, University of Rijeka, School of Medicine, Braće Branchetta 20, 51000, Rijeka, Croatia.
authors.forename: Lara Batičić
authors.initials: LB
authors.lastname: Pučar
authors.affiliation: Department of Chemistry and Biochemistry, University of Rijeka, School of Medicine, Braće Branchetta 20, 51000, Rijeka, Croatia.
authors.forename: Dijana
authors.initials: D
authors.lastname: Detel
authors.affiliation: Department of Chemistry and Biochemistry, University of Rijeka, School of Medicine, Braće Branchetta 20, 51000, Rijeka, Croatia.
authors.forename: Jadranka
authors.initials: J
authors.lastname: Varljen
authors.affiliation: Department of Medical Biochemistry and Hematology, University of Zagreb, Faculty of Pharmacy and Biochemistry, Kneza Domagoja 2, 10000, Zagreb, Croatia.
authors.forename: Karmela
authors.initials: K
authors.lastname: Barišić
mesh_terms: D000243:Adenosine Deaminase / Q000097:blood*; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D018819:Dipeptidyl Peptidase 4 / Q000097:blood*; D005260:Female; D005356:Fibromyalgia / Q000097:blood / Q000175:diagnosis*; D006801:Humans; D008875:Middle Aged; D000085822:Prolyl Oligopeptidases; D012697:Serine Endopeptidases / Q000097:blood*
chemical_list: D015415:Biomarkers; D018819:Dipeptidyl Peptidase 4; D012697:Serine Endopeptidases; C000705287:PREPL protein, human; D000085822:Prolyl Oligopeptidases; D000243:Adenosine Deaminase
keywords: Adenosine; Diagnostic biomarker; Fibromyalgia; Serum enzymes