Reactivation and dynamics of cytomegalovirus and Epstein‐Barr virus after rabbit antithymocyte globulin and cyclosporine for aplastic anemia

Objectives This study aimed to identify the natural course of cytomegalovirus (CMV)/Epstein‐Barr virus (EBV) after rabbit antithymocyte globulin and cyclosporine (rATG‐CsA) for aplastic anemia (AA). Methods In 113 prospectively observed AA patients treated with rATG‐CsA, the CMV/EBV cohort was classified into two groups by baseline viremic status: no viremia (CMV‐G1, n = 112; EBV‐G1, n = 98) and the presence of viremia (CMV‐G2, n = 1; EBV‐G2, n = 13). Results In CMV‐G1, the mean CMV load increased up to 3 months but was completely resolved from 6 months. The mean EBV load of EBV‐G1 showed a peak at 1 month and then gradually decreased over time but remained detectable throughout the observation period. EBV‐G2 showed fluctuating EBV dynamics. With reactivation rates of 38.4% in CMV‐G1 and 62.2% in EBV‐G1, a longer time to rATG‐CsA from diagnosis and a lower absolute lymphocyte count at 1 month from rATG‐CsA were significantly associated with CMV and EBV reactivation, respectively. The mean peak CMV and EBV loads of patients with CMV‐related (3.5%) and EBV‐related (0.9%) diseases were evidently higher than those of the remaining patients without CMV and EBV diseases in the respective cohort. Conclusion Considering frequent reactivation and distinct courses of CMV/EBV, virologic surveillance is recommended after rATG‐CsA for AA.