The Presence of Biofilms in Gouty Tophi

The Presence of Biofilms in Gouty Tophi

Author Info

Corresponding Author
Herbert B. Allen
Drexel University College of Medicine, Department of Dermatology


In patients who had confirmed gout, we have pathologically identified biofilms in cutaneous tophi. Clinically, these lesions were asymptomatic, off-white papules on the ears and/or extremities. The methods used for confirmation were the same as those used for biofilms in other organs, namely staining for the extracellular polysaccharides which make up the bulk of the biofilm with colloidal iron (CFE), and Congo red (CR) that stains the amyloid that serves as infrastructure of the biomass. CFE was used, instead of periodic acid Schiff (PAS), because of the presence of uric acid crystals in the tophi; CFE, which stains acidic mucin, was used and showed more positivity than PAS that stains neutral mucins. These stains were positive in the areas of the tophus and negative in the surrounding tissue. CD 282 (Toll-like receptor 2) immunostain was negative in all, save for faint staining in one specimen, indicating the immune system was not involved.

Article Info

Article Type
Research Article
Publication history
Received: Wed 06, Feb 2019
Accepted: Fri 01, Mar 2019
Published: Mon 18, Mar 2019
© 2021 Herbert B. Allen. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Hosting by Science Repository. All rights reserved.
DOI: 10.31487/j.CMR.2018.01.007