The clinical features, laboratory indices, and imaging data of patients with Pneumocystis jirovecii pneumonia (PJP) were described and analyzed, aiming to provide helpful information for the diagnosis and treatment of PJP.

A retrospective study were conducted with data from 154 PJP patients who visited China-Japan Friendship Hospital from May 2017 to August 2020. Their clinical characteristics, laboratory and imaging data, and clinical outcomes were collected for analysis. The patients were further divided into the death group (51 cases) and the survival group(103 cases). The differences between the groups were compared by using t-test, nonparametric test, and chi-square test.

Of the 154 PJP patients, there were 89 males and 65 females, with a mean age of (53.7±14.8) years. Among them, 85.7% (132/154) were on immunosuppressive/glucocorticoids agents within the past month. Besides, 27.9% (43/154) and 33.1% (51/154) had kidney diseases and connective tissue diseases, respectively. The major clinical manifestations in these patients involved fever 82.9% (126/154), cough 59.7% (92/154), and dyspnea 52.6% (81/154). For the laboratory data, the lactate dehydrogenase (LDH) was 561.0 (434.3, 749.0) IU/L and the value increased in 91.3% (95/104) of the patients. The CD4+T-cell lymphocytes in 88.0% (95/108) and 57.4% (62/108) of patients were lower than 400/μl and 200/μl, respectively. Furthermore, (1, 3)-β-D glucan (BG) increased in 74.4% (67/90) of PJP patients (≥100.0 ng/L). For the imaging results, chest computed tomography (CT) showed diffuse ground-glass shadows/grid shadows in 90% (117/130) patients. Compared with the survival group, higher LDH [690.5 (528.8, 932.3) IU/L vs 502.5 (381.8, 657.0) IU/L, Z=-3.375, P=0.001], white blood cell count (WBC) [9.8 (5.8, 12.6) ×10⁹/L vs 7.3 (5.0, 10.1) ×10⁹/L, Z=-2.392, P=0.017], and age [(69.8±14.5) years vs (50.6±14.0) years, t=-3.756, P=0.001] were found in the death group. Lower lymphocyte ratio [5.3 (3.2, 9.3) % vs 9.6 (5.6, 17.2) %, Z=‒3.262, P=0.001] and oxygen partial pressure (PaO₂) levels [(73.2±20.5) mmHg vs (64.8±17.7) mmHg (1 mmHg=0.133 kPa), t=2.345, P=0.021] were also observed in the death group. Furthermore, in the death group, the bacterial and fungal infection rate was higher than the rates in the survival group [55.1% (27/51)vs 21.5% (22/103), χ²=15.372, P=0.001].

Long-term use of immunosuppressive agents or glucocorticoids predispose to PJP. CD4+T-lymphocytes, LDH, and BG might be used as important auxiliary examinations for PJP patients. Age, LDH, WBC, lymphocyte ratio, PaO₂ and possible combinations with bacterial or fungal infections are more closely related to the prognostic of PJP patients.

Lactate dehydrogenases; Pneumocystis jirovecii pneumonia; Pneumocystis jirovecii; (1, 3)-β-D-Glucan