Clinical markers dysregulation during HTLV-1 infection and associated diseases

Human T-cell lymphotropic virus type 1 (HTLV-1) infection can lead to HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) or adult T-cell leukemia/lymphoma (ATLL); however, most cases remain asymptomatic. These conditions may alter various laboratory markers, including liver function tests (aspartate transaminase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP)), bone metabolism markers (calcium, vitamin D), lipid profile (high-density lipoprotein (HDL), low-density lipoprotein (LDL), total cholesterol, triglyceride), hematological parameters (absolute lymphocyte count (ALC), platelet count, hemoglobin), lactate dehydrogenase (LDH), and Krebs von den lungen (KL- 6). Among these markers, calcium elevation has been reported in several patients with acute ATLL. Different levels of LDH and ALC have been observed among patients concerned with subtypes of ATLL, which suggests a potential association, requiring further validation for diagnostic utility. Some markers, like vitamin D levels, tend to decrease during HAM/TSP, multiple sclerosis (MS), and neuromyelitis optica spectrum disorder (NMOSD). Recognizing the patterns and severity of these changes may be useful in diagnosing and prognosticating HTLV-1 infection, HAM/TSP, and ATLL. PubMed was searched for articles published between 2005 and 2025 in this study, which aims to clarify the pattern of serum clinical markers’ change during HTLV-1 infection and associated diseases.