Case Report of a Malignant Melanoma Patient with Longitudinally Extensive Transverse Myelitis: Immune-Related Adverse Event or Human Herpesvirus-7 Infection?

Abstract

Introduction'Immune checkpoint inhibitors' are used in patients with metastatic malignant melanoma. Programmed cell death-1 (PD-1) and cytotoxic lymphocyte-associated protein 4 (CTLA-4) are found on the surface of T cells and are used as targets for the formation of an immune response against the tumor. Anti-CTLA-4 antibody ipilimumab and anti-PD-1 antibodies nivolumab and pembrolizumab are used as treatment options in patients with advanced melanoma. However, immune-related adverse events (irAEs) occur in approximately 40% of patients. Neurological side effects are rare. CaseIpilimumab and nivolumab combination therapy was applied in a 60-year-old male patient due to malignant melanoma after detection of metastasis after pembrolizumab, another immune checkpoint inhibitor. After the last course of treatment, numbness in the legs, loss of strength and inability to walk developed. Neurological examination revealed 5-/5 muscle strength of all upper extremity muscle groups, 1/5 muscle strength in the lower extremities, and loss of sensation in the lower extremities that did not give a clear level. In spinal imaging, the longitudinal, diffuse edematous image extending from the upper cervical to the lower thoracic levels was evaluated as transverse myelitis. Human Herpes Virus-7 (HHV-7) DNA detected in cerebrospinal uid (CSF) could not be demonstrated in serum. A second CSF examination could not be performed regarding the role of HHV-7 in the etiology. ConclusionIn conclusion, patients given immune checkpoint inhibitors should be followed up for signs and symptoms of irAE. Prompt diagnosis and treatment will increase the likelihood of complete recovery from neurological complications.