Efficacy and influencing factors of immunosuppressive therapy for pure red cell aplasia: meta-analysis and systematic review

Acquired pure red cell aplasia (aPRCA) is a rare hematological syndrome characterized by anemia and a significant reduction in erythroid progenitor cells. Immunosuppressive therapy (IST), including Corticosteroids (CS), Cyclosporine (CsA), and cyclophosphamide (CYC), is the primary treatment. However, variations in clinical efficacy and limited comparative studies have created uncertainty in therapeutic choices. This study aims to evaluate the efficacy of IST and the factors influencing treatment outcomes. A systematic search was conducted using PubMed, Embase, Cochrane Library, and Web of Science. Two researchers independently screened studies and extracted data. The quality of studies was assessed using the MINORS scale. Meta-analysis was performed using STATA/MP16, and effect size (ES) was calculated using fixed- or random-effects models based on heterogeneity. A total of 33 studies involving 1,193 patients were included. The overall efficacy of IST was significant, with a pooled ES of 0.656 (95% CI: 0.600-0.710). CsA demonstrated the highest efficacy (ES = 0.699; 95% CI: 0.615-0.779), followed by CYC (ES = 0.592; 95% CI: 0.423-0.752) and CS (ES = 0.568; 95% CI: 0.457-0.676). Subgroup analyses revealed that factors such as etiology, combination therapies, first- vs. second-line treatment, and genetic characteristics significantly influenced outcomes. Notably, the response to IST was higher in primary aPRCA (ES = 0.667; 95% CI: 0.598-0.733) compared to LGLL-associated (ES = 0.515; 95% CI: 0.393-0.637) and thymoma-associated (ES = 0.690; 95% CI: 0.492-0.864) aPRCA. The combination of CS and CsA yielded superior efficacy (ES = 0.761; 95% CI: 0.658-0.853) compared to combination of CS and CsA and monotherapy. First-line treatment demonstrated better efficacy than second-line treatment (ES = 0.659; 95% CI: 0.596-0.720) vs. (ES = 0.452; 95% CI: 0.199-0.715). The important finding was that (ES = 0.861; 95% CI: 0.595-1.000) in the STAT3 mutation (+) group and (ES = 0.375; 95% CI: 0.034-0.801) in the STAT3 mutation (-) group. IST demonstrates overall efficacy in aPRCA, with variations influenced by etiology, drug combinations, and genetic mutations such as STAT3. These findings highlight the need for personalized treatment strategies and further research to validate and optimize IST efficacy.