RESUMO
Background: Recent developments in antibodies targeting checkpoint molecules have improved the overall survival of patients with melanoma. Case Report: A case of metastatic melanoma was treated with antibodies to cytotoxic T-lymphocyte-associated protein 4 and programmed cell death protein 1. Stable disease was achieved but the patient died from systemic metastasis 23 months after the diagnosis of melanoma. An autopsy was performed, and immunohistochemical analysis was carried out using primary melanoma (pre-treatment) and autopsy (post-treatment) samples. The down-regulation of human leukocyte antigen class I and II, melanin, and melanoma antigens was seen in the post-treatment tumor cells. Tumor-infiltrating lymphocyte numbers were significantly reduced in the post-treatment tumor microenvironment. Although programmed death ligand 1 expression was seen in the pre-treatment tumor tissues, it was not seen in the post-treatment tumor tissues. Conclusion: A phenotypical change in the tumor cells was suggested to be associated with the resistance to immune checkpoint inhibitor therapy.
RESUMO
Although most immune-related adverse events (irAEs) secondary to immune checkpoint inhibitors can be managed with immunosuppressive therapies; they can induce reactivation of infectious diseases, including cytomegalovirus (CMV). Here, we show a case of CMV enterocolitis during steroid therapy for an irAE. A 77-year-old man with unresectable malignant melanoma was treated with ipilimumab. He suffered from immune-related colitis (irColitis) and was treated with methylprednisolone. Although corticosteroids initially improved his symptoms, CMV reactivation occurred and colitis was exacerbated. Antiviral therapy improved his symptoms without augmenting the immunosuppressive therapy. CMV colitis should be considered when a patient with irColitis shows resistance to immunosuppressive therapy.