Apolipoprotein-A is a potential prognostic biomarker for severe aplastic anemia patients treated with ATG-based immunosuppressive therapy: a single-center retrospective study

Background Anti-thymoglobulin (ATG)-based immunosuppressive treatment (IST) is the standard first-line management for patients with severe AA/very severe AA (SAA/VSAA) and is not suitable for allogeneic stem cell transplantation. The response predictor was not fully investigated. Objective The present study attempted to explore other characteristics, such as serum lipid changes, during ATG-based IST and analyzed their significance in predicting IST response and survival. Methods A total of 61 newly diagnosed SAA/VSAA patients who received ATG-based IST were enrolled from January 2011 to June 2019. The blood lipid levels, immunoglobulins, and peripheral T lymphocytes were retrospectively collected, and their correlations with IST response, estimated 8.5-year overall survival (OS) and event-free survival (EFS) were analyzed. Results The overall response (OR)/complete remission (CR) at 3, 6, and 9 months was 24.6%/6.6%, 52.5%/14.8%, and 65.6%/23.0%, respectively. Based on the 9-month response effect, patients were divided into IST-response (IST-R) and IST-nonresponse (IST-NR) groups. The subgroup baseline characteristics showed that the disease severity grade, absolute neutrophil granulocyte count (ANC), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and apolipoprotein-A (Apo-A) differed between the IST-R and IST-NR groups. Patients with lower Apo-A (< 1.205 g/L) level pretreatment had a better event-free survival (EFS), and a moderate negative correlation was established between the pretreatment Apo-A and 9-month response (P = 0.004). In addition, the T-cell subset and immunoglobulin analyses showed that the responsive patients had a low serum IgA level, which decreased further after therapy. Additionally, a moderate negative correlation was established between the 3-month IgA and 9-month response (P = 0.006). Conclusion Serum Apo-A is a prognostic biomarker for newly diagnosed < 60-year-old SAA/VSAA patients who received ATG-based IST (registered at chictr.org.cn as # ChiCTR2100052979).

Automated summary

This study aimed to explore the relationship between serum lipid changes and responses to ATG-based IST treatment for newly diagnosed SAA/VSAA patients. The results demonstrated that lower levels of Apo-A were associated with better event-free survival.