Antibody response to merkel cell polyomavirus associated with incident lymphoma in the epilymph case-control study in Spain

Background: Merkel cell polyomavirus (MCV) has been identified as the cause of Merkel cell carcinoma. The increased incidence of chronic lymphocytic leukemia in Merkel cell cancer cohorts and the lymphotropic properties of the virus suggest a possible viral association with lymphomagenesis. To investigate this potential role, we explored seroreactivity against MCV VP1 capsids within the Epilymph case-control study in Spain. Methods: Serum samples from 468 incident lymphomas, categorized into up to 11 entities, and 522 controls frequency matched by age, sex, and recruitment center were tested for MCV antibodies by enzyme immunoassay using Virus-Like-Particles. Adjusted multinomial logistic regression was used to estimate the OR and 95% confidence interval (CI) associated to MCV seroprevalence. Immunosuppressed subjects were excluded. Results: MCV seroprevalence was 82% in controls and 85% in lymphoma cases. Among 11 lymphoma categories, MCV seropositivity was significantly higher in diffuse large B-cell lymphomas (DLBCL; 96.4%; OR = 6.1, 95%CI = 1.9-19.8), as compared with controls. MCV prevalences were also higher in follicular lymphoma, lymphoplasmacytic lymphoma, chronic lymphocytic leukemia, Hodgkin lymphoma, and mature T-cell lymphoma but differences did not reach statistical significance. Lower prevalences were observed for multiple myeloma and other B-cell lymphoma. Exclusion of samples collected after start of treatment did not change the results. In a subset analysis, no significant association was observed between BKV and JCV seroprevalence and DLBCL. Conclusion: The association observed between serologic evidence of MCV exposure and DLBCL warrants further research. Impact: MCV might be involved in the pathway of DLBCL and other lymphomas.