Could co-infection with anaplasma play a role in borrelia-associated Primary Cutaneous Marginal Zone B-Cell Lymphomas?

Background: Borrelia burgdorferi has been associated with primary cutaneous B-cell lymphoma, in particular with cutaneous marginal zone B cell lymphoma. Ixodes ticks, which are vectors of Borrelia burgdorferi, can also transmit many other microorganisms such as Anaplasma phagocytophilum and Rickettsia helvetica. Nowadays data on the frequency of these co-infections are still conflicting, but in our geographical area (north-eastern of Italy) they appear rather frequently. Aim: To investigate the presence of co-infections with Anaplasma phagocytophilum and Rickettsia helvetica, in patients with proven Borrelia burgdorferi-related cutaneous marginal zone B cell lymphoma. Methods: Four consecutive patients with a histopathological diagnosis of cutaneous marginal zone B cell lymphoma were investigated for the presence of Borrelia burgdorferi with conventional serology and with PCR, and for the presence of Anaplasma phagocytophilum and Rickettsia helvetica with conventional serology. Results: Serologic test for Borrelia burgdorferi was positive in 2 cases, while PCR assays for Borrelia burgdorferi performed on DNA from the biopsy and peripheral blood was positive in all four patients. Serologic analysis for Rickettsia helvetica was positive in one patient, while serologic analysis for Anaplasma phagocytophilum was positive in all patients. Conclusions: Our case series have revealed a co-infection between Borrelia burgdorferi and Anaplasma phagocytophilum in all patients with cutaneous marginal zone B cell lymphoma. Therefore more comprehensive analyses on the co-existence of Anaplasma phagocytophilum infection should be performed in patients with Borrelia burgdorferi-related cutaneous marginal zone B cell lymphoma.