title: Histopathology and immunophenotype of acrodermatitis chronica atrophicans correlated with ospA and ospC genotypes of Borrelia species.
abstract: BACKGROUND
  Chronic cutaneous borreliosis (acrodermatitis chronica atrophicans, ACA) is a relatively rare manifestation of borreliosis attributed mainly to Borrelia afzelii. Chronic borreliosis has been associated with ospA and ospC genotypes. Literature on molecular investigations of Borrelia in lesions of ACA is scant.
  
  
  METHODS
  Histopathological and immmunohistochemical features in 22 biopsies of ACA (16 patients) were examined. Paraffin-embedded biopsies were analyzed with polymerase chain reaction (PCR) assays targeting ospA and ospC genes, sequencing and phylogenetic analysis.
  
  
  RESULTS
  Genotyping of ospA identified B. afzelii, serotype 2, in 12 of 16 patients. ospC-PCR was positive in seven patients revealing genotypes Af5 (n = 4), Af2 (n = 2) and Af6 (n = 1). Histopathologically, interstitial granulomatous infiltrates (CD68 positive) were common, combined with thickened collagen bundles and band-like infiltrates of CD4 positive T lymphocytes. Plasma cells were sparse/absent in 9 of 22 specimens even on staining with CD138. On CD34-staining, interstitial fibroblasts were often reduced akin to the situation in morphea.
  
  
  CONCLUSIONS
  With assays targeting ospA and ospC genes we confirmed from paraffin-embedded biopsies that B. afzelii, serotype 2, osp C groups Af5, Af2 and Af6 is the main cause of ACA. Specimens commonly showed a combination of band-like T-cell-rich infiltrates with interstitial granulomatous features, a pattern previously under-recognized in ACA. This finding was particularly typical for lesions infected with ospC genotype Af5.
authors.affiliation: Department of Dermatology, Munster University, Münster, Germany.
authors.forename: Friederike C
authors.initials: FC
authors.lastname: Brandt
authors.affiliation: Dermatologikum Hamburg, Hamburg, Germany.
authors.forename: Beyhan
authors.initials: B
authors.lastname: Ertas
authors.affiliation: Dermatologikum Hamburg, Hamburg, Germany.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Falk
authors.affiliation: Department of Dermatology, Munster University, Münster, Germany.
authors.forename: Dieter
authors.initials: D
authors.lastname: Metze
authors.affiliation: Dermatologikum Hamburg, Hamburg, Germany.
authors.forename: Almut
authors.initials: A
authors.lastname: Böer-Auer
mesh_terms: D000169:Acrodermatitis / Q000276:immunology* / Q000382:microbiology* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000942:Antigens, Bacterial / Q000235:genetics*; D000954:Antigens, Surface / Q000235:genetics*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D001428:Bacterial Vaccines / Q000235:genetics*; D001899:Borrelia Infections / Q000276:immunology* / Q000382:microbiology* / Q000473:pathology; D015748:Borrelia burgdorferi Group / Q000235:genetics*; D005260:Female; D006099:Granuloma / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D006801:Humans; D016130:Immunophenotyping; D008074:Lipoproteins / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D010950:Plasma Cells / Q000276:immunology / Q000473:pathology; D016133:Polymerase Chain Reaction / Q000379:methods; D013601:T-Lymphocytes / Q000276:immunology / Q000473:pathology
chemical_list: D000942:Antigens, Bacterial; D000954:Antigens, Surface; D001425:Bacterial Outer Membrane Proteins; D001428:Bacterial Vaccines; D008074:Lipoproteins; C072045:OspA protein; C079616:OspC protein
keywords: Lyme borreliosis; acrodermatitis chronica atrophicans; granuloma; ospA; ospC