Elevation of Memory Cytotoxic T Lymphocytes, Including Human T Lymphotropic Virus Type 1 Tax-Specific and Hepatitis Virus Type C-Specific Cytotoxic T Lymphocytes, in a Patient with Adult T-Cell Leukemia/Lymphoma and Hepatocellular Carcinoma.

Herein, we present the case of a patient who suffered from adult T-cell leukemia/lymphoma (ATLL) and hepatocellular carcinoma (HCC) after obtaining a sustained virological response following treatment with a direct-acting antiviral (DAA) at different points in time. The patient went into complete remission (CR) for ATLL. Unfortunately, subsequent relapse of ATLL was observed. This situation was overcome using chemotherapy with pegylated interferon alpha-2b. Human T lymphotropic virus type 1 Tax-specific cytotoxic T lymphocytes (CTLs) were recognized after obtaining second CR, and those CTLs have been maintained for many years. After 4 years from the second CR, chronic hepatitis type C was treated with a DAA, and sustained virological response was attained. However, the occurrence of HCC was detected. Surprisingly, the tumor disappeared spontaneously. Hepatitis virus type C-specific CTLs were also detected in the patient. T-cell receptor (TCR) gene repertoire analyses revealed oligoclonal expansion of effector and memory CTLs. The number of CTLs expressing the TCR has increased over the years since HCC occurrence. The activation and maintenance of anticancer cellular immunity may have allowed the patient to obtain long-term survival and overcome two lethal neoplasms.