2025 Volume 60 Issue 2 Pages 115-122
【Background】 Preformed donor-specific anti-HLA antibodies (DSA) are associated with antibody-mediated rejection and graft loss in kidney transplantation. To identify immunological risk pre-operatively, our institution has implemented routine anti-HLA antibody screening using LABScreen® Mixed (LSM) for all patients awaiting deceased donor kidney transplantation, regardless of sensitization history. This study aimed to evaluate the prevalence of LSM positivity and its associated risk factors.
【Methods】 Among 203 patients evaluated between January 2019 and December 2023, 168 underwent at least one LSM screening. Patients were categorized into sensitized (history of blood transfusion, pregnancy, or transplantation) and non-sensitized groups. Normalized background (NBG) ratios and LSM positivity rates were compared between groups. Logistic regression was used to identify independent risk factors for LSM positivity. Changes in positivity rates with varying NBG cut-off values (2.5, 3.5, 4.5) were also assessed.
【Results】 Sensitized patients showed significantly higher NBG ratios and LSM positivity rates for both HLA Class I and II. Transfusion and pregnancy were independent predictors for Class I positivity, while pregnancy and prior transplantation were predictors for Class II. Increasing the NBG cut-off from 2.5 to 4.5 resulted in a 6.0-11.2% decrease in positivity rates across all subgroups.
【Conclusions】 Sensitized patients demonstrated higher rates of LSM positivity; however, a notable proportion of non-sensitized patients also tested positive. These findings underscore the clinical importance of universal LSM screening, irrespective of sensitization history, and highlight the need for cautious interpretation of results, particularly in patients without known sensitizing events.
