Development and Validation of a Quantitative LC-MS/MS Method for Measuring CYP4V2 Enzyme Activity via 12-Hydroxylauric Acid in rAAV-hCYP4V2 Gene Therapy Products

Bietti crystalline dystrophy (BCD) is a hereditary retinal disease caused by loss-of-function mutations in the CYP4V2 gene. Gene replacement therapy using rAAV-hCYP4V2 represents a promising therapeutic strategy, requiring robust bioassays for product quality control. This study developed and validated a sensitive LC-MS/MS method for quantifying CYP4V2 enzyme activity. Lysates from HeLa-AAVR cells transduced with rAAV-hCYP4V2 (MOI = 3 × 105) were used, with lauric acid as substrate supplemented