Recent data implicates the cytokine, tumor necrosis factor alpha (TNF-alpha), in the pathophysiology of rheumatoid arthritis (RA). In vitro data suggest that pentoxifylline may possess anti-TNF-alpha properties. We have therefore carried out a prospective 3-month open evaluation of pentoxifylline in a group of adult patients with RA refractory to conventional disease remittive therapies.
Nineteen patients with RA were included and clinical assessments were performed according to the World Health Organization/International League of Associations for Rheumatology (WHO/ILAR) criteria at baseline, and one and 3 months after the initiation of therapy. Laboratory assessments included a complete blood count, erythrocyte sedimentation rate (ESR), and whole blood assays of TNF-alpha production. TNF-alpha was assayed using ELISA and semiquantitative polymerase chain reaction methodologies.
A significant diminution in number of tender and swollen joints as well as the ESR was noted after 3 months (p < 0.05) although no consistent effects on TNF-alpha production were observed. Furthermore, whole blood assays of TNF-alpha production shortly after initiation of pentoxifylline therapy were not predictive of the clinical response to this agent.
Although pentoxifylline may possess therapeutic properties in RA, any beneficial effects appear to be unrelated to changes in TNF-alpha generation in whole blood assays.