ELECTRON-MICROSCOPY OF LANGERHANS CELLS AND BORRELIA-BURGDORFERI IN LYME-DISEASE PATIENTS

To investigate dermal and epidermal involvement in the presence of Bor relia burgdorferi and to analyze the role of Langerhans cells and kera tinocytes, 14 cases of erythema chronicum migrans and two controls wer e studied by means of electron microscopy, using negative staining and sectioning techniques. Using immunoelectron microscopy and histochemi stry, positive results for B. burgdorferi were disclosed in 5 cases of erythema chronicum migrans and 3 cases of neuroborreliosis which were confirmed by cultivation. We cultured 4 strains of B. burgdorferi fro m the skin, 1 from blood and 2 from cerebrospinal fluid in BSK medium. Near to the centre of erythema chronicum migrans with focal necrosis were both a dissolved basal membrane and keratinocyte desmosomes surro unding damaged B. burgdorferi cells in the epidermis. Markedly oedemat ous keratinocytes and Langerhans cells with B. burgdorferi were releas ed into lymphocyte infiltraties. At the periphery of all erythema chro nicum migrans lesions, keratinocytes were well preserved while all den dritic cells seemed to be vacuolated. Above foci of B. burgdorferi loc ated perivascular or among collagen fibers, Langerhans cells were freq uent and more granulated. The possible role of Langerhans cells in the identification and elimination of B. burgdorferi is discussed.