Objective To investigate the clinical features of interstitial lung disease (ILD) complicated with severe Pneumocystis pneumonia (PCP). Methods The patients with interstitial lung disease complicated with severe Pneumocystis pneumonia who were admitted to the Respiratory Intensive Care Unit (RICU) of the Department of Respiratory and Critical Care Medicine, Nanjing Drum Tower Hospital from September 2017 to June 2022 were retrospectively analyzed. Laboratory examinations, imaging features, complications and mortality data were used to analyze the clinical characteristics and prognosis of these patients. Results A total of 17 patients admitted to the RICU were finally enrolled in this study. 16 of the 17 patients had a history of corticoids therapy, and none of the 17 patients had received prophylaxis before the onset of PCP; 58.8% (10/17) of them were ILD secondary to connective tissue disease, and 41.2% (7/17) were idiopathic ILD; all patients were tested positive for P. jirovecii with polymerase chain reaction and/or next-generation metagenomic sequencing in sputum, bronchoalveolar lavage fluid or serum; all patients developed respiratory failure (oxygenation index: 146.8±66.4 mm Hg) after onset; within 24 hours of admission, the pneumonia severity index score was 91.9±20.1 and the Acute Physiology and Chronic Health Evaluation Ⅱ score was 16.1±3.0; imaging findings showed diffuse ground-glass opacity in both lungs on the basis of the original ILD; all patients were treated with trimethoprim-sulfamethoxazole (TMP-SMX) and corticoids, 52.9% (9/17) patients were treated with TMP-SMX + caspofungin + clindamycin; 70.6% (12/17) patients were treated with mechanical ventilation; 76.5% (13/17) patients during hospitalization complicated bacterial infection, 9 cases (52.9%) had viral infection. The 28-day mortality was 64.7% (11/17), and the 90-day mortality was 82.4% (14/17), as of telephone follow-up (July 2022) the overall mortality was 88.2% (15/17). Conclusions ILD patients with severe PCP are progressing rapidly. The clinical manifestations are severe which are the same as acute exacerbation of ILD, with poor prognosis.
Objective To summarize the clinical characteristics of pneumocystis pneumonia (PCP) secondary to interstitial lung disease (ILD) to improve the prophylaxis and management level of clinicians. Methods The clinical data of 50 patients with PCP secondary to ILD in the Department of Respiratory and Critical Care Medicine of Nanjing Drum Tower Hospital from January 2015 to December 2022 were collected. SPSS 26.0 software was used for statistical analysis. Results A total of 50 patients with PCP secondary to ILD were screened. Among the 50 patients, there were 23 males and 27 females, with a median age of 64 years old. Forty-eight cases (96%) had a history of glucocorticoid therapy with the median duration of 3 months; 31 (77.5%, 31/40) cases developed PCP in the first 6 months after glucocorticoid therapy; 34 cases had a history of glucocorticoid and immunosuppressants at the same time. None of the 50 ILD patients used drugs for PCP prophylaxis before developing PCP. The major clinical manifestations of PCP secondary to ILD were worse cough and shortness of breath or fever. Laboratory results showed 38 cases (76.0%) had peripheral blood total lymphocyte count <200/µL, 27 cases (54.0%) had CD4+ T cell count <200/µL, 34 cases (68.0%) had CD4+ T cell count <300/µL, 37 cases (74.0%) had CD3+ T cell count <750/µL, 34 cases (68.0%) had β-D-glucan test >200 pg/mL, 35 cases (70.0%) had lactic dehydrogenase > 350 U/L and 41 cases (82.0%) had type Ⅰ respiratory failure. High resolution computed tomography showed added ground-glass opacity and consolidation on the basis of the original ILD. Thirty-six cases were detected the Pneumocystis jirovecii by metagenomic next-generation sequencing with broncho-alveolar lavage fluid as the main source, and 2 cases by smear microscopy. All patients were treated with trimethoprim-sulfamethoxazole. After treatment, 29 cases were discharged with a better health condition, 10 cased died, and 11 cases left hospital voluntarily because of treatment failure or disease deterioration. Conclusions After the use of glucocorticoid and immunosuppressants, ILD patients are susceptible to life-threatening PCP. It is particularly important to make an early diagnosis. Attention should be paid to integrate the symptoms, levels of peripheral blood lymphocyte count, β-D-glucan test, lactic dehydrogenase and imaging findings to make an overall consideration. It is suggested to perform next-generation sequencing with broncho-alveolar lavage fluid at an early stage when patients can tolerate fiberoptic bronchoscopy to avoid misdiagnosis and missed diagnosis. ILD patients often develop PCP in the first 6 months after using glucocorticoid and immunosuppressants. During follow-up, peripheral blood CD4+ and CD3+ T cell count should regularly be monitored so as to timely prevent PCP.