Recent studies with infliximab (Remicadeâ) further show the potential of tumor necrosis factor-alpha (TNF-a) blockers in spondyloarthroathy (SpA). Researchers studied side effects in a large group of SpA patients treated with infliximab, paying special attention to bacterial infections.

Head researcher Dr. Baeten and colleagues from the Department of Rheumatology at Ghent University Hospital in Ghent, Belgium, also believe that because defective host defense is implicated in the pathogenesis of SpA, the potential side effects of TNF-a treatment are a major concern and warrant further research. Host defenses are important in determining whether infection will occur. Defense mechanisms include natural barriers (eg. skin and mucous membranes); nonspecific immune responses; and specific immune responses (eg. antibodies). However, it is very important to note that researchers have not found a definitive cause(s) for SpA.

Participants
107 patients with SpA were treated with infliximab for a total of 191.5 years. All serious and/or treatment related adverse events were treated.

Findings

• Eight severe infections occurred, including two reactivations of tuberculosis and three retropharyngeal abscesses (collection of pus in the tissues in the back of the throat), and six minor infections.
  
• One patient developed a spinocellular carcinoma of the skin. Spinocellular and basocellular carcinomas are responsible for about 90% of all skin cancers -- over 95% of these tumors are curable.
  
• Two patients had an infusion reaction, which did not relapse during the next infusion
  
• Three patients with ankylosing spondylitis developed palmoplantar pustulosis (also known as localized pustular psoriasis) that affects the palms and soles.
  
• All patients recovered with adequate treatment.
  
• Infliximab treatment had to be stopped in five people with severe infections.

Researchers conclude that the global safety of infliximab in SpA is good compared with previous reports in rheumatoid arthritis and Crohn’s disease. However, occurrence of infections highlights the importance of careful screening and follow up.

Nasopharyngeal infections (relating to nose and back of threat), possibly induced by streptococci, occurred frequently, which suggests to these researchers an impairment of specific host defense mechanisms in SpA.

-- Systematic safety follow-up in a cohort of 107 patients with spondyloarthropathy treated with infliximab: a new perspective on the role of host defense in the pathogenesis of the disease? Annals of the Rheumatic Diseases 2003; 62: 829-834.