Prevalence of Borrelia burgdorferi infection in a series of 98 primary cutaneous lymphomas.

Borrelia burgdorferi has been variably associated with different forms of primary cutaneous lymphoma. Differences in prevalence rates among reported studies could be a result of geographic variability or heterogeneity in the molecular approaches that have been employed. In the present study, we investigated the prevalence of Borrelia burgdorferi sensu lato DNA in diagnostic tissue samples from fresh cutaneous biopsies of 98 primary cutaneous lymphomas and 19 normal skin controls. Three different polymerase chain reaction (PCR) protocols targeting the hbb, flagellin, and Osp-A genes were used. Direct sequencing of both sense and antisense strands of purified PCR products confirmed the specificity of the amplified fragments. Sequence specificity was assessed using the Basic Local Alignment Search Tool, and MultAlin software was used to investigate the heterogeneity of target gene sequences across the different samples. Borrelia DNA was not detected in 19 controls, 23 cases of follicular lymphoma, 31 cases of extranodal marginal zone lymphoma, or 30 cases of mycosis fungoides. A single case of 14 diffuse large B-cell lymphoma cases was positive for B. burgdorferi. This study does not support a pathogenic role of B. burgdorferi in primary cutaneous B- and T-cell lymphomas from areas nonendemic for this microorganism and the consequent rationale for the adoption of antibiotic therapy in these patients.