Letter to the Editor Regarding “An Evaluation of the Ast/Alt Ratio in Patients With Mycosis Fungoides and Its Association With the Severity of Cutaneous Involvement”

Dear Editor,I read with great interest the original article entitled “An Evaluation of the AST/ALT Ratio in Patients with Mycosis Fungoides and Its Association with the Severity of Cutaneous Involvement” by Pala and Bayraktar, published in the January 2025 issue of your journal (1). I would like to congratulate the authors for addressing a novel and clinically relevant topic in the field of cutaneous T-cell lymphomas.From a pathologist’s perspective, mycosis fungoides (MF) is a biologically heterogeneous malignancy with a highly variable clinical course. Although histopathological evaluation remains the gold standard for diagnosis and classification, it provides limited information regarding systemic disease activity, cumulative tumor burden, and metabolic alterations during longitudinal follow-up (2, 3). Therefore, there is a clear need for adjunctive, easily accessible biomarkers that may complement morphological and clinical assessment.In this context, the authors’ focus on the AST/ALT (De Ritis) ratio is particularly noteworthy. Aspartate aminotransferase (AST) differs fundamentally from alanine aminotransferase (ALT) in that it reflects not only hepatocellular integrity but also mitochondrial function and systemic cellular metabolism, which form the biological basis of the De Ritis ratio (4). In malignant cells, increased mitochondrial activity and aerobic glycolysis are essential to sustain cellular proliferation and tumor progression, processes in which AST plays a key metabolic role (5). Accordingly, elevated AST levels and AST/ALT ratios may reflect increased neoplastic cell turnover rather than isolated liver involvement.The finding that AST levels and AST/ALT ratios were significantly higher in MF patients compared with healthy controls is therefore biologically plausible. From a pathological standpoint, the association between elevated AST levels and abnormal lymphadenopathy detected by ultrasonography and PET/CT is of particular interest. Even in the absence of overt visceral involvement, such findings may indicate subclinical extracutaneous disease activity or increased metabolic turnover within involved lymphoid tissue, which cannot be fully appreciated by histopathology alone.