[Clinical characteristics of aplastic anemia patients with abnormal autoantibodies and the impact of autoantibodies on immunosuppressive therapy response].

To investigate the clinical characteristics of patients with acquired aplastic anemia (AA) accompanied by abnormal antinuclear antibody (ANA) and autoantibodies and their effects on the efficacy of immunosuppressive therapy (IST). A retrospective case-control study was conducted, analyzing the clinical data of 291 patients with AA who underwent IST and were screened for autoantibodies at initial diagnosis between January 2018 and December 2019 at Blood Diseases Hospital, Chinese Academy of Medical Sciences. According to the titer of ANA at the initial diagnosis, extracted nuclear antigen antibodies (ENAs) abnormality and the change of ANA titer after treatment, the treatment responses of 3 months and 6 months after IST were compared. The correlation between clinical features and ANA abnormality was analyzed by univariate and multivariate logistic regression analysis. The parameters of univariate analysis <0.1 were included in multivariate analysis, stepwise regression analysis and subgroup analysis. A total of 291 patients were included in the study, of which 145 (49.83%) were male. Among all patients, 147 (50.52%) tested positive for ANA at initial diagnosis, with titers of 1∶100, 1∶320, and 1∶1 000 observed in 94, 47, and 6 cases, respectively. Female gender, older age, presence of paroxysmal nocturnal hemoglobinuria (PNH) clone, and higher levels of IgG, IgA, and thyroid hormone were significantly associated with ANA positivity at initial diagnosis, while white cell counts, reticulocytes, and free triiodothyronine were significantly lower than that of ANA-negatively patients (all <0.05). Furthermore, logistic regression analyses revealed that female gender (=1.980, 95% 1.206-3.277), older age (=1.017, 95% 1.003-1.032), and presence of PNH clone (=1.875, 95% 1.049-3.408) were independent risk factors for ANA positivity at initial diagnosis. Subgroup analysis indicated that the risk of ANA positivity at initial diagnosis was even higher in PNH clone-positive patients in the subgroups of females (=1.24, 95% 1.02-1.51), severe AA (=1.26, 95% 1.07-1.47), and age≥40 years (=1.26, 95% 1.05-1.52) (all <0.05). However, ANA titers at initial diagnosis, presence of other abnormal ENAs, and changes in ANA titers after treatment with IST were not correlated with treatment response (all >0.05). Approximately 50% of patients with AA had abnormal ANA, and their presence was significantly associated with female gender, older age, and presence of PNH clone at initial diagnosis. However, the presence of abnormal ANA and changes in ANA titers after treatment did not affect the efficacy of IST in patients with AA.