Prognostic factors of immunosuppression therapy combined with eltrombopag in the treatment of childhood severe aplastic anemia
Objective: To analyze the influence factors on the efficacy of immunosuppression therapy (IST) combined with eltrombopag and IST alone in the treatment of childhood severe aplastic anemia (SAA).
Methods: A retrospective cohort study. A total of 124 children with SAA who were initially treated with IST at Beijing Children's Hospital from March 2017 to May 2020 were enrolled. Clinical characteristics, laboratory examination and prognosis data were collected at the time of enrollment. According to the treatment plan, the children were divided into the eltrombopag combined with IST group (eltrombopag group) and the IST group. Binary Logistic regression model was used to analyze the factors affecting the efficacy of the two groups at 6 months of treatment, and the factors affecting the efficacy of the eltrombopag group at the end of follow-up.
Results: There were 75 cases (45 males and 30 females) in the eltrombopag group. The age of diagnosis was 5.9 (3.5, 8.5) years. There were 49 patients in the IST group, including 23 males and 26 females, whose age at diagnosis was 6.2 (4.4, 8.8) years. The absolute lymphocyte count before treatment in the eltrombopag group was significantly lower than that in the IST group (1.1 (0.4, 1.6)×109 vs. 2.1 (1.4, 2.8)×109/L). Absolute reticulocyte count in the eltrombopag group was significantly higher than that of IST group (26.9 (8.7, 54.2)×109 vs. 9.5 (4.0, 19.0)×109/L) (both P<0.05). Influencing factors of 6-month response: a comparison between response and un-response groups in the eltrombopag treated patients showed that, before treatment, hemoglobin (69 (61, 78) vs. 64 (59, 68) g/L), platelet (10 (6, 16)×109 vs. 6 (3, 8)×109/L), absolute reticulocyte count (ARC) (34.0 (15.8, 57.3)×109 vs. 6.5 (4.6, 16.8)×109/L) and the response rate to granulocyte colony stimulating factor (G-CSF) after treatment (82.4% (47/57) vs. 9/18) were significantly different (all P<0.05). Logistic regression model analysis showed that ARC (OR=1.09, 95%CI 1.02-1.18) and absolute neutrophil count were independent influencing factors of 6-month response rate in the eltrombopag group (OR=0.00, 95%CI 0.00-0.89). ARC was also the independent influencing factors of the end of follow-up response rate in the eltrombopag group (OR=1.04, 95%CI 1.01-1.07).
Conclusions: Pre-treatment blood count and response to G-CSF were predictors of overall response to eltrombopag combined with IST. The higher the ARC before treatment, the higher the total response rate and complete response.