To investigate the clinical characteristics and peripheral blood lymphocytes immunophenotype of adult patients with chronic active Epstein-Barr virus (CAEBV).

A retrospective study included 48 adult patients with CAEBV in Rugao People’s Hospital from March 2017 to March 2019. The general clinical information and EBV virus-related antibody, viral load and cellular immunophenotypic correlation tests were recorded.

The median age of 48 adult patients with CAEBV was (40.8 ± 14.4) years old. All patients had fever symptoms. The incidence of severe liver failure, Hermansky-Pudlak syndrome (HPS), central nervous system (CNS) lesions and interstitial pneumonia were 29.2% (14/48), 47.9% (23/48), 12.5% (6/48) and 22.9% (11/48), respectively. The median copies of EBV DNA of CAEBV patients was 2.9 × 10⁴ copies/ml (5 × 10²-5.8 × 10⁶ copies/ml). A total of 32 patients completed peripheral blood lymphocyte immunophenotyping, with the median of B cells, natural killer (NK) cell, CD4⁺ T cells and CD8⁺ T cells were 25 × 10⁹/L (0, 19.6 × 10⁹/L), 82.5 × 10⁹/L (54 × 10⁹/L, 183 × 10⁹/L), 332.5 × 10⁹/L (178.25 × 10⁹/L, 534.25 × 10⁹/L) and 302 × 10⁹/L (190 × 10⁹/L, 573.5 × 10⁹/L). There were 53.1% (25/48) of patients had a CD4/CD8 ratio inversion (< 1). The median percentage of CD38⁺CD8⁺ T cells was 93.2% (49.1%, 99.7%), and the median percentage of HLA-DR⁺CD8⁺ T cells was 71.25% (17.1%, 97.5%).

The clinical characteristics of adult patients with CAEBV were closely related to peripheral blood lymphocytes immunophenotype, and the levels of B cells, NK cells and CD4⁺ T cells decreased.