4.1 General
The age distribution of the 14 patients diagnosed with novel coronavirus infection with PJP was (52-87) years old, with a mean of (67.07±9.86) years old, including 11 male patients with an age distribution of (52-87) years old, with a mean of (67.38±10.41) years old, and 3 female patients with an age distribution of (61-73) years old. The length of hospital stay in 14 patients was (2-57) days, with an average of (25.57±15.50) days. The time interval between confirmed COVID-19 infection and confirmed PJP ranged from (0-44) days, with a median of 7 days. Oxygen saturation at admission was (91-100) %, with an average of (95.71±2.6) %. The lowest oxygen saturation within 3 days before and after the diagnosis of PJP was (73-94) %, with an average of (87.93±87.71) %.
Underlying medical conditions: Among the 14 patients, 4 (28.6%) had hematologic diseases, including 1 case of pure red cell aplasia, 1 case of multiple myeloma, 1 case of diffuse large B-cell lymphoma, and 1 case of follicular lymphoma. There were 3 cases (21.4%) of respiratory system diseases, including 2 cases of interstitial lung disease and 1 case of lung malignancy. 3 cases (21.4%) had renal disease, all of whom were in kidney transplant status; 1 case (7.1%) of skin diseases, suffering from dermatomyositis and Henoch-Schonlein purpura at once; thymoma immunodeficiency syndrome (Good's syndrome) was developed in 1 case (7.1%) (Table 1).
4.2 Clinical manifestation
Fourteen patients all had fever during hospitalization, with a maximum temperature of (38.5 to 40.4) °C. Patients were admitted with respiratory symptoms and cough in 14 cases (100%); 12 cases (85.71%) had sputum production; 6 cases (42.86%) had chest tightness and/or respiratory strain; Shortness of breath 4 cases (28.57%).Other systemic symptoms included fatigue in 3 cases (21.43%); nausea and vomiting in 2 cases (14.29%); 2 cases (14.29%) had sore throat; Dizziness, headache, low back pain, diarrhea, weight loss, hoarseness, and loss of consciousness were 1 case each (7.14%).Six patients (42.86%) had worsening respiratory symptoms, such as labored breathing and shortness of breath, before and after the diagnosis of PJP.
4.3 Laboratory tests
4.3.1 Serologic testing in the diagnosis of PJP
Among the 14 patients, there were 5 cases with white blood cell count greater than 10×109/L, accounting for 35.71%; absolute lymphocyte count decreased in 11 cases (78.57%) and platelets decreased in 10 cases (71.43%).
Among the 11 patients, 9 cases (81.82%) decreased IgG. There were 4 cases of decreased IgA, accounting for 36.36%; There were 4 cases of IgM, accounting for 36.36%.
In blood gas analysis, the average pH of 11 patients was (7.4±0.09), fluctuating in (7.17~7.5); the mean PaCO2 value was (43.41 ± 14.64) mmHg, fluctuating between (24.2 and 75) mmHg; the average PaO2 value was (94.09 ± 33.33) mmHg, fluctuating between (34.7 and 156) mmHg, of which 4 cases of hypoxemia accounted for 36.36%. The mean value of alveolar arterial oxygen partial pressure difference (AaDO2) was (273.48 ± 166.94) mmHg, fluctuating from (7.3 to 565) mmHg, among which 10 patients, accounting for 90.91%, had significantly elevated alveolar arterial oxygen partial pressure difference. Arterial blood gas measurements were performed in 7 patients at the time of admission or diagnosis of novel coronavirus infection., and were all greater than 30 mmHg and up to 164.80 mmHg.
The serum (1,3)-β-D-glucan (BDG) was increased in 10 cases (71.43%) and lactate dehydrogenase (LDH) was increased in 13 cases (92.86%).
Among the inflammation-related indexes, C-reactive protein (CRP) was elevated in 13 cases, accounting for 92.86%; D-dimer was elevated in 12 cases, accounting for 85.71%; among the 10 patients, ESR was elevated in 8 cases (80%). Among the 13 patients, interleukin-6 (IL-6) was elevated in 12 cases, accounting for 92.31%; interleukin-10 (IL-10) was elevated in 11 cases, accounting for 84.62%; interferon-r was elevated in 11 cases, accounting for 84.62%; and ferritin was elevated in 12 cases, accounting for 92.31%.
Among the immune-related indicators, the percentage of T lymphocytes decreased in 4 of the 13 patients, accounting for 30.77%; The percentage of CD4+ T cells decreased in 9 cases, accounting for 69.23%; None of the patients had a decrease in the percentage of CD8+ T cells. In 9 patients, the absolute value of T cells and CD4+ T cells decreased, and; The absolute value of CD8+ T cells decreased in 7 cases, accounting for 77.78%. Among the 9 patients in this study, the absolute value of CD4+ T cells was less than 200 /u l, and the CD4+/CD8+ ratio decreased in 7 cases, accounting for 77.78% (Table 2).
4.3.2 Microbiological testing:
All 14 patients were confirmed to be infected with the novel coronavirus. Bronchoscopic alveolar lavage was performed in 13 of 14 patients and mNGS was sent to confirm the diagnosis of PJP; one patient was diagnosed with PJP by blood mNGS. Fourteen patients had a (0-60) day interval between COVID and PJP. In addition, only one patient was HIV-positive, and four patients were positive for CMV DNA in serum by PCR-fluorescent probe assay (Table 3).
4.4 Chest CT:
Inflammation was bilaterally distributed in 11 out of 14 patients (78.57%); 2 cases of double lower lung distribution; distribution of right upper lung in 1 case. The lesion distribution was roughly symmetrical in 10 patients and asymmetrical in 4 patients. Nine patients had a diffuse distribution and five patients had a scattered distribution of lesions. Twelve patients (85.71%) had high-density lesion density, and 2 cases (14.29%) had ground-glass opacities. Among the characteristic manifestations of the lesion, only 2 cases (14.29%) had crescent signs, in the right upper lung and both lungs; six patients (42.86%) had pulmonary air sacs(multiple in both lower lungs: multiple in both upper lungs: upper right lungs: double upper lungs) = 3:1:1:1; five patients (35.71%) had paving stone signs (Double upper lung: left upper lung: right upper lung: right middle lung) = 2:1:1:1; grid opacity 7 cases (50%) (Double lungs: double upper lungs: double lower lungs: right lower lungs) = 3:1:2:1. In extrapulmonary manifestations, ten patients (71.43%) had a small pleural effusion (Both lungs: left lung = 8:2); scattered small lymph nodes were seen in the mediastinum in 9 patients (64.29%); scattered small lymph nodes were seen at the hilum of lung in 3 patients (21.43%); two patients (14.29%) had pericardial effusion(Table 4). The figure below shows typical imaging of PJP on chest CT in some of the patients with novel coronavirus infection in this article (Fig 1-5).
4.5 Treatment and prognosis
10 of the 14 patients were diagnosed with severe pneumonia; 1 patient had noninvasive ventilator-assisted ventilation; 7 patients were given endotracheal intubation, Transoral: via tracheotomy = 6:1; 1 case experienced extracorporeal membrane pulmonary oxygenation (ECMO).
Ten patients were treated with glucocorticoids before the diagnosis of PJP, and the rate of hormone use was 71.42%, methylprednisolone equivalents fluctuated from (96-1680) mg, with a mean of (420.40±441.21) mg; 1 patient had a history of hormone therapy at an outside hospital, of which the details are unknown; the history of hormone therapy in the remaining three patients was unknown. There were 5 patients who were on immunosuppressants for a long time before hospitalization, including 2 cases of mycophenolate mofetil + cyclosporine; tofacitinib + cyclosporine in 1 case; tacrolimus + mycophenolate mofetil in 1 case; cyclosporine in 1 case.
All 14 patients had a history of COVID-19 infection. Three patients received Paxlovid for antiviral treatment; 2 cases received antiviral treatment with molnupiravir; 2 cases received antiviral treatment with molnupiravir and Paxlovid; one patient received antiviral therapy with azvudine, molnupiravir, and Paxlovid.
All 14 patients received antifungal treatment with SMZCO with a mean duration of 14.5 days, fluctuating between (2-30) days. Nine patients were treated with basic anti-infective therapy in combination with caspofungin (70 mg on the first day and 50 mg/d thereafter) for a mean duration of 12.5 days, fluctuating from (5-22) days. In combination with severe hypoxemia, concomitant intravenous methylprednisolone treatment was given at an initial dose of 30-80 mg/day, 1-2 times/day. In this study, 7 patients were discharged with improvement, 6 patients were discharged spontaneously, and 1 patient died (Table 1). The length of hospital stay of 14 patients was (2-57) days, with an average of (17.14±16.09) days.