Objective: To explore incidence, risk factors and prognosis of the first 6 months infectious events in adults with newly diagnosed primary immune thrombocytopenia (ITP), and evaluate the value of initial absolute lymphocyte count (ALC) in predicting infection.
Methods: The initial clinical records and infectious events during 6 months of 217 adult with newly diagnosed ITP were retrospectively analyzed. Statistical methods were used to analyze risk factors of the 6 months infections in adults ITP, the prediction of ALC in risk of infection, and the association of ALC and prognosis.
Results: Infection rate of ITP patients accepting therapy within 6 months after the initial diagnosis was 13.8% (30/217), and infection rate of patients ≥ 60 years of age 25% (14/56). Multivariate unconditioned Logistic analysis showed that gender and ALC were independent risk factors for the 6 months infection of ITP patients (P<0.05, 95% CI 1.150-7.298, OR 2.722 and P<0.001, 95% CI 6.802-80.749, OR 23.436). Cutoff value of ALC was 1.225 × 10⁹/L, sensitivity and specificity of its value were 0.866 and 0.700 respectively. Infection rate of ALC>1.225 × 10⁹/L in adult ITP was lower than of ALC ≤ 1.225 × 10⁹/L (5.3% vs 45.7%, χ² = 49.151, P<0.001). Furthermore, persistent recovery and the 1-year mortality rate after diagnosis had no difference among patients of different ALC (28.0% vs 26.0%, χ² = 0.071, P>0.05, and 98.6% vs 97.8%, χ² = 0.095, P>0.05). There were no significant differences in persistent recovery in patients with and without infection (30.0% vs 27.3%, χ² = 0.096, P>0.05). The 1-year mortality rate after diagnosis was significantly lower in those patients who developed an infection (93.3% vs 99.3%, χ² = 4.607, P<0.05).
Conclusion: Initial ALC was an independent risk factor of 6 months infection in adult ITP. It could be a predictive index of infection within 6 months of the initial diagnosis in ITP patients. Infection as an important factor affected the survival of ITP patients.
目的: 研究成人原发免疫性血小板减少症（ITP）患者诊断后6个月内感染的发生率、危险因素及预后情况，评估初诊淋巴细胞绝对值（ALC）对感染的预测价值。
方法: 回顾性分析217例初诊成人ITP患者的临床资料，分析6个月内合并感染的危险因素，评估初诊ALC在ITP患者诊断后6个月内合并感染的预测价值以及与预后的相关性。
结果: 217例成人ITP患者诊断后6个月内的感染发生率为13.8%（30/217），≥60岁患者感染发生率为25.0%（14/56）。多因素分析发现性别、ALC是发生感染的独立危险因素（P<0.05，95%CI 1.150~7.298，OR 2.722；P<0.01，95%CI 6.802~80.749，OR 23.436）。ALC预测感染的分界值是1.225×109/L（敏感性0.866，特异性0.700）。ALC≤1.225×109/L组与ALC>1.225×109/L组比较，感染发生率较高（45.7%对5.3%，χ2=49.151，P<0.01），持续缓解率和1年生存率差异无统计学意义（28.0%对26.0%，χ2=0.071，P>0.05；98.6%对97.8%，χ2=0.095，P>0.05）。6个月内发生感染与无感染患者比较，1年生存率较低（93.3%对99.3%，χ2=4.607，P<0.05），持续缓解率差异无统计学意义（30.0%对27.3%，χ2=0.096，P>0.05）。
结论: 初诊ALC可以作为ITP患者诊断后6个月内合并感染风险的预测指标。感染是影响ITP患者预后的主要因素。