Amelioration of antigen-induced arthritis in rabbits by induction of apoptosis of inflammatory cells with local application of transdermal photodynamic therapy

Arthritis Rheum. 1998 Mar;41(3):525-34. doi: 10.1002/1529-0131(199803)41:3<525::AID-ART19>3.0.CO;2-I.


Objective: To study the efficacy and mechanism of local transdermal photodynamic therapy (tPDT) in rabbits with antigen-induced arthritis (AIA).

Methods: AIA in rabbits on day 14 postinduction was treated with an intravenous injection of benzoporphyrin-derivative monoacid ring A (BPD; Verteporfin) and subsequent transdermal exposure of the knee joint to light. BPD uptake and PDT-induced apoptosis of the synovium was studied applying fluorescence confocal microscopy and immunohistochemistry. The (histo)pathology of the joints was assessed at day 28.

Results: Treatment with tPDT resulted in significant amelioration of synovial inflammation and an almost complete prevention of pannus formation and bone and cartilage destruction. BPD uptake was detectable in activated T cells and macrophages, and there was significant PDT-induced increase in the number of apoptotic cells in the synovium.

Conclusion: Because photodynamic therapy is both specific and noninvasive, our findings suggest that it could be used for treating arthritic joints in humans.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Topical
  • Animals
  • Apoptosis / physiology*
  • Arthritis, Experimental / blood
  • Arthritis, Experimental / pathology*
  • Arthritis, Experimental / therapy*
  • Blood Chemical Analysis
  • Female
  • Fluorescence
  • Immunohistochemistry
  • Microscopy, Confocal
  • Photochemotherapy*
  • Photosensitizing Agents / pharmacokinetics
  • Porphyrins / pharmacokinetics
  • Rabbits
  • Verteporfin


  • Photosensitizing Agents
  • Porphyrins
  • Verteporfin