Department of Rheumatology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200001, China.
Arthritis Res Ther. 2021 Sep 4;23(1):232. doi: 10.1186/s13075-021-02606-8.
Idiopathic inflammatory myopathies (IIM) are associated with a significantly higher risk of opportunistic infections including Pneumocystis jirovecii pneumonia (PJP), a potentially fatal opportunistic infection. However, no prior studies have evaluated PJP infection in subtypes of IIM.
To investigate the prevalence and mortality rate of PJP infection in subgroups of IIM patients stratified according to myopathy-specific antibodies.
In the first part of the study, 463 consecutive patients with IIM were prospectively followed for a period of at least 1 year to analyze the incidence of PJP. In the second part of the study, we enrolled 30 consecutive PJP patients with any rheumatic disease in order to identify the mortality rate and risk factors by Cox regression analysis. The Kaplan-Meier method with log-rank testing was used to assess differences in survival.
The prevalence of PJP in IIM patients was found to be 3.0/100 person-years, while in MDA5 DM patients it was 7.5/100 person-years and in MDA5 IIM patients 0.7/100 person-years (P < 0.05). PJP typically occurred in the first 2 months in the case of MDA5 DM patients who had a significant decrease in their CD4 T cell counts and lymphocyte counts (P < 0.05). In PJP patients, 3-month mortality was higher for MDA5 DM patients than in those with other rheumatic diseases (83.3% vs 38.9%, P < 0.05). Alarmingly, MDA5 DM patients seemed not to benefit from prompt anti-PJP treatment, unlike patients with other rheumatic diseases whose survival improved when anti-PJP treatment was started within 6 days (P < 0.05).
PJP has an alarming high incidence and mortality in MDA5 DM patients. Timely treatment for PJP seems not to improve the prognosis of patients with this particular subtype. Hence, there remains a crucial unmet need to develop PJP prophylaxis for MDA5 DM patients.
特发性炎性肌病（IIM）与机会性感染（包括卡氏肺孢子虫肺炎，PJP）的风险显著增加相关，PJP 是一种潜在致命的机会性感染。然而，目前尚无研究评估 IIM 亚型患者中 PJP 感染的情况。
探讨根据肌炎特异性抗体对 IIM 患者亚组进行分层后，PJP 感染的患病率和死亡率。
在研究的第一部分，前瞻性随访了 463 例连续的 IIM 患者至少 1 年，以分析 PJP 的发生率。在研究的第二部分，我们纳入了 30 例连续患有任何风湿性疾病的 PJP 患者，通过 Cox 回归分析确定死亡率和危险因素。采用 Kaplan-Meier 方法和对数秩检验评估生存差异。
IIM 患者中 PJP 的患病率为 3.0/100 人年，而 MDA5 DM 患者为 7.5/100 人年，MDA5 IIM 患者为 0.7/100 人年（P<0.05）。MDA5 DM 患者的 PJP 通常发生在发病后的前 2 个月，他们的 CD4 T 细胞计数和淋巴细胞计数显著下降（P<0.05）。在 PJP 患者中，MDA5 DM 患者的 3 个月死亡率高于其他风湿性疾病患者（83.3% vs 38.9%，P<0.05）。令人震惊的是，MDA5 DM 患者似乎不能从及时的抗 PJP 治疗中获益，而其他风湿性疾病患者在开始抗 PJP 治疗后 6 天内，其生存率有所提高（P<0.05）。
MDA5 DM 患者的 PJP 发病率和死亡率令人震惊地高。及时治疗 PJP 似乎并不能改善该特定亚型患者的预后。因此，为 MDA5 DM 患者开发 PJP 预防措施仍存在巨大的未满足需求。
