BackgroundA considerable knowledge gap exists in predicting severe Pneumocystis pneumonia (PCP) outcomes following PCP diagnosis.MethodsIn this retrospective cohort, we studied immunocompromised patients with PCP admitted to 5 University Health Network centers in Canada (2011–2022). The study outcome included severe PCP, a composite of 21‐day ICU admission or 28‐day all‐cause mortality. Adjusted odds ratios (aOR) estimated the association between severe PCP and comorbidities as well as clinical and laboratory variables at diagnosis.ResultsA total of 44 out of 182 (24.2%) immunocompromised patients (19 [10.4%] HIV‐infected, 55 [30.2%] hematologic malignancies, 32 [17.6%] hematopoietic stem cell transplants, 32 [17.6% solid tumors, 26 solid organ transplants [14.3%], 12 (6.6%) autoimmune diseases, and 6 (3.3%) other immunosuppressive conditions) developed composite outcomes (40 ICU admissions [21.9%], 18 deaths [9.9%]). Patients with composite outcomes more often had acute‐onset PCP (< 7 days) (18/34 [52.9%] vs. 38/126 [30.1%], p = 0.013), shortness of breath (39/44 [88.6%] vs. 96/136 [70.6%], p = 0.002), chronic liver disease (15/44 [34.1%] vs. 9/138 [6.5%], p < 0.001), hypoalbuminemia (median [IQR] albumin (g/L): 27 [25–31] vs. 32 [29–35], p < 0.001), elevated lactate dehydrogenase (median [IQR] LDH (U/L): 537 [324–809] vs. 340 [237–475], p < 0.001), lymphopenia (median [IQR] absolute lymphocyte count [(10*9/L),]: 0.4 [0.2–0.6] vs. 0.7 [0.3–1.2], p < 0.001), or required supplemental oxygen (39/44 [88.6%] vs. 60/136 [44.1%], p < 0.001) than those without composite outcomes. In multivariable analysis, chronic liver disease (aOR: 11.6, 95% CI: 2.2–61.3) and requiring supplemental oxygen on admission (aOR: 19.7, 95% CI: 3.0–128.5) were significantly associated with severe PCP.ConclusionsAlongside hypoxemia upon admission, chronic liver disease appears to significantly predict severe PCP in immunocompromised patients. This biologically plausible finding warrants further investigation.
