Study on the expression of lactate transport-related proteins in follicular lymphoma and their relationship with clinicopathologic features

Objective: To investigate the expression of the lactate transport-related proteins MCT1, MCT4, and their chaperone CD147 in follicular lymphoma (FL), and to delineate their potential correlations with clinicopathological parameters predictive of prognosis. Methods: Immunohistochemistry was employed to evaluate the expression of MCT1, MCT4, and CD147 in tumor cells. Associations between protein expression and clinicopathological variables relevant to patient outcome were statistically analyzed. Results: 1. MCT1-positive immunoreactivity was significantly associated with elevated serum β2-microglobulin (β2-M, a small circulating protein that rises with disease activity and serves as a marker of tumor load and adverse outcomes in lymphomas) level, male sex, and Ki-67 ≥ 30%; MCT4-positive immunoreactivity was significantly associated with Ki-67 ≥ 30%; CD147-positive immunoreactivity correlated significantly with low-grade FL. 2. Four distinct expression patterns of MCT1/MCT4 were identified: double-positive, double-negative, MCT1-positive only, and MCT4-positive only. High-grade FL demonstrated a significant predilection for either double-positive or single-positive expression; Ki-67 < 30% was significantly linked to the double-negative expression; elevated serum β2-M was significantly associated with MCT1-positive only expression; age ≥60 years and female sex were significantly associated with MCT4-positive only expression. Conclusion: The expression of MCT1, MCT4, and CD147 in FL is correlated with adverse clinicopathological features, thereby furnishing additional evidence for refinement of the Follicular Lymphoma International Prognostic Index (FLIPI, a five-parameter clinical score predicting outcome in newly diagnosed follicular lymphoma). Targeted inhibition of MCT1 and MCT4 may represent a novel therapeutic strategy. Furthermore, the heterogeneous expression of these three proteins suggests metabolic heterogeneity within FL, offering a mechanistic basis for future investigations.