{
  "abstract": "Objectives Systemic lupus erythematosus (SLE) and other rheumatic and musculoskeletal diseases (RMDs) patients usually require immunosuppressants regularly. Pneumocystis jirovecii pneumonia (PJP) is a critical opportunistic infection among immunocompromised patients. We aimed to utilize the Chang Gung Research Database (CGRD), the database from the largest health care system in Taiwan, to compare the risk of PJP infection between patients with SLE and other RMDs, and to analyze the predisposing conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) in SLE patients.Methods We included 19148 adult patients who were newly diagnosed as either SLE or other RMDs during 2005-2020 from the CGRD. After propensity score matching, 3745 patients per group were followed until December 2022. We compared the PJP infection risk between the two groups utilizing Cox proportional hazards regression adjusting by age, gender, comorbidities, and medications. We further analyzed the predisposing csDMARDs of PJP infection in SLE group. To determine the associations were causal or the result of the disease characteristics that had warranted initiation of csDMARDs, we used Directed Acyclic Graphs to construct a causal model for each of csDMARDs. We included lymphopenia, neutropenia, low C3, low C4, high anti-dsDNA, proteinuria, renal impairment to represent the effect of SLE disease features as confounders.Results The risk of PJP infection was significantly higher in SLE patients compared with other RMDs in multivariable analysis (adjusted HR=2.144, 95% CI 1.463-3.142, p-value<0.001). In univariable analysis of risk factors of PJP infection among SLE patients, we found a significant positive association between PJP and these csDMARDs: azathioprine, leflunomide, mycophenolate, and cyclosporin. In causal model for each of csDMARDs, the relationship between PJP and azathioprine, leflunomide and cyclosporin remained. A new significant positive association between methotrexate and PJP was found ( figure 1).Abstract PT6:05 Figure 1Comparing SLE patients with other RMDs patients utilizing univariable and multivariable Cox proportional hazards regression of PJP infection risk. The statistically significant risks are denoted as the red dots. Confounders adjusted in multivariable analysis for each of csDMARDs are determined by causal model based on directed acyclic graphs. Abbreviations: SLE, systemic lupus erythematosus; RMDs, rheumatic and musculoskeletal diseases; PJP, Pneumocystis jirovecii pneumonia; csDMARDs, conventional synthetic disease-modifying antirheumatic drugs.Conclusions This large retrospective cohort study revealed that SLE patients have an increased susceptibility to PJP infection compared with other RMDs. We found strong positive associations between commonly used csDMARDs and PJP infection among SLE patients. These associations may be partly attributable to the SLE disease process. However, for most of the csDMARDs investigated, these relationships persisted in causal model, suggesting these csDMARDs have a true role in causing PJP.",
  "authors": [
    {
      "affiliations": [
        "Chang Gung Memorial Hospital-Center for Traditional Chinese Medicine-Division of Chinese Internal Medicine, Taoyuan"
      ],
      "name": "Chen -Ying Wei"
    },
    {
      "affiliations": [
        "University of Leeds-Leeds Institute of Rheumatic and Musculoskeletal Medicine, Leeds, UK",
        "Linkou Chang Gung Memorial Hospital-Division of Rheumatology, Allergy and Immunology, Taoyuan",
        "Chang Gung University-College of Medicine, Taoyuan"
      ],
      "name": "Han -Hua Yu"
    },
    {
      "affiliations": [
        "University of Leeds-Leeds Institute of Rheumatic and Musculoskeletal Medicine, Leeds, UK",
        "Leeds Teaching Hospitals NHS Trust-NIHR Leeds Biomedical Research Centre, Leeds, UK"
      ],
      "name": "Edward M Vital"
    }
  ],
  "title": "PT6:05 Susceptibility to pneumocystis jirovecii pneumonia and predisposing disease-modifying antirheumatic drugs in systemic lupus erythematosus: a cohort study from the largest health care system in Taiwan",
  "uid": "12115fe9-f263-5431-bd51-8d85af8675be"
}