DNA methylation profile of a hepatosplenic gamma/delta T-cell lymphoma patient associated with response to interferon-α therapy

We report changes in the DNA methylome in a patient with γδ hepatosplenic T-cell lymphoma (HSTCL) who responded to treatment with interferon-α2c. We studied the methylome by 450k methylation array in 5 blood samples taken within a time period of 20 months. During this time period, the WBC counts dropped from 22,300 to 7,200/μl blood, yet the proportion of γδ T cell lymphoma blasts remained around 90%. We observed time-dependent changes in overall DNA methylation and performed an in-depth bioinformatic analysis of the modulated CpG sites associated with disease progression. We identified a CpG site differentially regulating methylation, possibly related to the interferon response during the course of treatment in this particular case. Therefore, the present case report will help to understand the substantial changes in DNA methylation of lymphoma resulting in a survival benefit of this γδ HSTCL patient. Bisulphite converted DNA from the 5 samples were hybridised to the Illumina HumanMethylation450 Beadchip.