Objective: To explore the effects of peri-immunosuppressive treatment（IST）infection on outcomes of severe and very severe aplastic anemia（SAA/VSAA）patients.
Methods: Medical record and follow-up data of 105 SAA/VSAA who underwent first-line IST were retrospectively analyzed to find out the characters of infections（1 month before to 3 months after IST）, and its effects on hematologic response and survival.
Results: Of 105 patients, a total of 270 febrile episodes were recorded in 97 patients（92.4%）during their peri- IST periods, with the median infections of 2（1-7）episodes in each patient with the median febrile duration of 7（1-47）days. Respiratory system（35.1%）was the primary anatomic site of infection. Bacteria（88.2%）were common causes of total 169 pathogenic bacteria in 96 clear pathogenic bacteria episodes. And patients who got infection 1 month before IST had much lower 6- month hematologic response rate than their counterpart ones（50.8% vs 80.0%, P=0.004）. Multiple febrile episodes （ ≥3 times） and the total febrile duration ≥4 days showed the best sensitivity and specificity according to the ROC curve analysis. The 5-year overall survival of the 105 patients was 76%. The 5- year OS of patients with multiple febrile episodes （ ≥3 times） were much lower than their counterpart ones［（59.6±7.2）% vs（89.5±4.0）%］（P＜0.01）. The 5-year OS of the total febrile duration ≥4 days was much lower than their counterpart ones［（63.4±5.8）% vs 100.0%］（P＜0.01）.
Conclusion: Infections 1 month before IST were associated with hematologic response. Multiple febrile episodes（≥3 times） and infections with the febrile duration ≥4 days presented inferior hematologic response and survival.
目的: 探索围免疫抑制治疗(IST)期(IST前1个月至IST后3个月)感染对重型／极重型再生障碍性贫血(SAA/VSAA)患者IST疗效的影响。
方法: 回顾性分析一线行IST的105例SAA/VSAA患者临床资料，研究围IST期感染特征及其对IST疗效的影响。
结果: 全部105例患者中，97例(92.4%)发生270例次围IST期感染，中位感染2(1~7)次，中位发热7(1~47) d，发病部位以呼吸道最为常见，占35.1%。致病微生物明确的感染96例次(35.6%)，共检出169株病原菌，以细菌为主，占88.2%。IST前1个月感染与未感染患者IST后6个月血液学反应率比较差异有统计学意义(50.8％对80.0%，P=0.004)。ROC曲线优化IST后6个月能否获得血液学反应的感染次数界限值为3次，发热时间界限值为4 d。全部105例患者5年总生存(OS)率为76%，感染3次及以上患者5年OS率为(59.6±7.2)%，明显低于感染少于3次患者[(89.5±4.0)%] (P<0.01)；发热时间≥4 d患者5年OS率为(63.4±5.8)%，明显低于发热时间<4 d患者(100.0%)(P<0.01)。
结论: IST前1个月感染对IST疗效有影响，围IST期感染3次及以上、发热时间≥4 d患者IST血液学反应率低，生存时间短。