IgG antibody reactivity to Borrelia burgdorferi sensu stricto antigens in patients with morphea in Colombia

Background  Morphea and lichen sclerosus et atrophicus (LSA) are sclerotic skin lesions of unknown etiology involving connective tissue. The hypothesis of a borrelial origin of morphea and LSA is currently controversial. Methods  Immunoglobulin G (IgG) immunoblot serologies against Borrelia burgdorferi in patients with morphea and LSA were analyzed and compared with those from healthy donors and patients with syphilis to determine the association with a probable borrelial agent in Colombia. Results  No significant differences in the number of reactive antigenic bands were found between morphea/LSA patients and syphilis patients or healthy donors. The presence of at least one of the following bands, p28, p39, or p45, was the criterion most able to distinguish morphea/LSA, yielding a specificity of 95% and a sensitivity of 28.6%. Using this criterion as evidence of putative exposure to a causative borrelial agent, sclerotic skin lesions had an odds ratio of 7.60 (95% confidence interval, 1.47–39.23). Conclusions  These results could be explained by cross-reactivity; however, the partial shared reactivity of sera from patients with syphilis and morphea/LSA does not rule out the possibility that a new spirochetal agent, unrelated to B. burgdorferi or Treponemas, may be the causative agent of morphea/LSA in Colombia.