腎移植レシピエントにおけるサイトメガロウイルス（CMV）予防のための論理的絶対リンパ球数（ALC）ガイド前emptive療法対絶対的リンパ球数（ALC）ガイド前emptive療法：ランダム化比較試験

A preemptive approach using plasma cytomegalovirus (CMV) DNA load monitoring is recommended for CMV-seropositive solid organ transplant recipients (SOTr). However, limited access to CMV quantitative nucleic acid amplification testing (QNAT) poses challenges in resource-constrained settings. We hypothesized that absolute lymphocyte count (ALC)-guided monitoring could provide an effective alternative strategy.

We conducted an open-label, randomized controlled trial at a single transplant center in Thailand (February-November 2023). Adult CMV R+ kidney transplant (KT) recipients who did not receive anti-thymocyte globulin induction were randomized 1:1 to either the logical (LOG) group, which underwent routine plasma CMV QNAT every 4 weeks for 12 weeks, or the ALC group, which underwent testing only when the ALC was <1,000 cells/mm³. Participants were followed for 6 months post-transplant to compare CMV infection rates and testing costs.

A total of 98 KT recipients were enrolled (49 per group; mean ± SD age, 46 ± 11 years; 66.3% male). Baseline demographic characteristics were comparable between groups. Overall, 25 participants (25.5%) developed CMV infection within 6 months after KT. CMV infection occurred in 13 participants (26.5%) in the LOG group and 12 participants (24.5%) in the ALC group (p = 0.817). No significant differences were observed between groups in the rates of CMV DNAemia, CMV disease, anti-CMV therapy, or mortality (all p > 0.05). The total cost of plasma CMV DNA load testing was significantly lower in the ALC group than in the LOG group ($2,320 vs. $10,014, p = 0.002).

ALC-guided monitoring could potentially demonstrate comparable effectiveness to routine CMV DNA surveillance for CMV infection prevention in KT recipients. Given its simplicity and availability, ALC may serve as a feasible and cost-efficient adjunct for guiding preemptive therapy in low- to moderate-risk SOT recipients.