title: Secretory activity of subcutaneous abdominal adipose tissue in male patients with rheumatoid arthritis and osteoarthritis - association with clinical and laboratory data.
abstract: BACKGROUND
  Adipose tissue exerts widespread effects on the metabolism and immune system, but its activity differs between the genders. In the general population low-grade adipose tissue inflammation contributes to development of diseases of affluence. Little is known about the systemic impact of peripheral fat tissue in osteoarthritis (OA) and rheumatoid arthritis (RA), characterized by chronic, low- and high-grade systemic inflammation, respectively. To clarify this we evaluated the secretory activity of subcutaneous abdominal adipose tissue (SAAT) obtained from male patients affected with RA (n= 21) and OA (n= 13), and assessed its association with body mass and composition, demographic, clinical and laboratory data.
  
  
  METHODS
  Basal and interleukin (IL)-1β-triggered secretion of selected adipocytokines from SAAT explants was measured by specific enzyme-linked immunosorbent assays (ELISA). Patients' body composition was evaluated by bioelectric impendence technique.
  
  
  RESULTS
  Rheumatoid SAAT secreted more adiponectin and macrophage migration inhibitory factor (MIF) than respective osteoarthritis tissue. In both RA and OA patient groups, stimulation of SAAT explants with IL-1β (1 ng/ml/100 mg tissue) significantly up-regulated release of pro-(IL-6, IL-8, tumor necrosis factor - TNF) and anti-inflammatory (IL-10) cytokines but had no effect on the secretion of adiponectin, leptin, MIF and hepatocyte growth factor (HGF). Compared with RA, patients with OA were more obese. In RA patients SAAT-released adiponectin and TNF inversely correlated with body mass index (BMI) and visceral fat rating (FVSC). In addition, SAAT-secreted adiponectin and leptin positively correlated with DAS28 and disease duration, respectively. In the OA group tissue-released TNF positively correlated with patients' age.
  
  
  CONCLUSIONS
  We conclude that in RA male patients adipocytokines originating from SAAT are of clinical importance because: (i) adiponectin and TNF may contribute to maintenance of normal body composition and mass, (ii) in addition adiponectin may play a pathogenic role. Moreover, in both RA and OA male patients secretory activity of SAAT may vary with time.
authors.affiliation: Department of Pathophysiology and Immunology, National Institute of Geriatrics, Rheumatology and Rehabilitation, Warsaw, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Kontny
authors.affiliation: Department of Rheumatology, National Institute of Geriatrics, Rheumatology and Rehabilitation, Warsaw, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Zielińska
authors.affiliation: Department of Rehabilitation in Rheumatology, National Institute of Geriatrics, Rheumatology and Rehabilitation, Warsaw, Poland.
authors.forename: Krystyna
authors.initials: K
authors.lastname: Księżopolska-Orłowska
authors.affiliation: Department of Rheumatology, National Institute of Geriatrics, Rheumatology and Rehabilitation, Warsaw, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Głuszko
keywords: adipose tissue activity; men; osteoarthritis; rheumatoid arthritis