Clinical features and diagnostic value of metagenomic next -generation sequencing in five cases of non-HIV related Pneumocystis jirovecii pneumonia in children.

Pneumocystis jirovecii (PJ) is an opportunistic pathogenic fungus, and PJ pneumonia (PJP) is a commonly problem in HIV-positive patients. While PJP is not caused by HIV, it generally advances rapidly and can quickly lead to severe respiratory failure. To improve pediatricians' understanding of the condition and aid early accurate diagnoses and therapy, we examined the clinical characteristics of five instances of non-HIV related PJP (NH-PJP) in children and the efficacy of metagenomic next-generation sequencing (mNGS) in its diagnosis. From January 2020 to June 2022, five children with NH-PJP were admitted to the PICU of the First Affiliated Hospital of Zhengzhou University. We retrospectively summarize the clinical presentation, previous histories, routine laboratory findings, treatment, outcome of regression, and results of mNGS in these five children. Five male children between the ages of 11 months and 14 years had an acute onset on NH-PJP, three of the children had chest tightness after activity, shortness of breath and paroxysmal dry cough, - and two had high fever and dry cough. All five of the children had several flocculent high-density pictures in both lungs at the beginning of the disease, and lung auscultation revealed coarse breath sounds in both lungs, one of which was accompanied by a modest quantity of dry rales. PJ nuclear sequences were found in one patient and four patients' blood and alveolar lavage fluid. All five children were treated with Trimethoprim-sulfamethoxazole (TMP-SMX) in combination with Caspofungin and corresponding symptomatic treatment. Four patients were cured and one patient died. Children commonly encounter an initial exposure to NH-PJP, which manifests as a high fever, dry cough, chest discomfort, dyspnea that worsens over time, fast disease progression, and a high death rate. The clinical presentation of children with PJ infection should be taken into consideration along with the results for diagnose. mNGS has higher sensitivity and a shorter detection period compared to identification of PJP.

Niu J ，Wang J ，Jia P ，Zhang M ，Wei E ... -  《Frontiers in Cellular and Infection Microbiology》

Metagenomic next-generation sequencing promotes diagnosis and treatment of Pneumocystis jirovecii pneumonia in non-HIV infected children: a retrospective study.

Metagenomic next-generation sequencing (mNGS) excels in diagnosis of infection pathogens. We aimed to evaluate the performance of mNGS for the diagnosis of Pneumocystis jirovecii pneumonia (PJP) in non-HIV infected children. Totally 36 PJP children and 61 non-PJP children admitted to the pediatric intensive care unit from March 2018 to December 2021 were retrospectively enrolled. Clinical features of PJP children were summarized. 1,3-β-D glucan (BDG) test and bronchoalveolar lavage fluid (BALF) mNGS were used for evaluation of PJP diagnostic performance. Antimicrobial management modifications for PJP children after the mNGS results were also reviewed. Pneumocystis jirovecii was detected in all PJP children by mNGS (36/36), and the sensitivity of mNGS was 100% (95% confidence interval [CI]: 90.26-100%). The sensitivity of BDG was 57.58% (95% CI: 39.22-74.52%). Of the 26 (72.2%) PJP patients with mixed infection, twenty-four (66.7%) were detected by BALF-mNGS. Thirteen patients (36.1%) had their antimicrobial management adjusted according to the mNGS results. Thirty-six PJP children included 17 (47.2%) primary immunodeficiency and 19 (52.8%) secondary immunodeficiency, of whom 19 (52.8%) survived and 17 (47.2%) died. Compared to survival subgroup, non-survival subgroup had a higher rate of primary immunodeficiency (64.7% vs. 31.6%, P = 0.047), younger age (7 months vs. 39 months, P = 0.011), lower body weight (8.0 kg vs. 12.0 kg, P = 0.022), and lower T lymphocyte counts. The mortality rate of PJP in immunosuppressed children without HIV infection is high and early diagnosis is challenging. BALF-mNGS could help identify PJP and guide clinical management.

Zhang Z ，Liu T ，Ming M ，Shen M ，Zhang Y ，Chen H ，Chen W ，Tao J ，Wang Y ，Liu J ，Zhou J ，Lu G ，Yan G ... -  《BMC Pulmonary Medicine》

Application of metagenomic next-generation sequencing in the diagnosis and treatment guidance of Pneumocystis jirovecii pneumonia in renal transplant recipients.

Pneumocystis jirovecii pneumonia (PJP) is difficult to be diagnosed, so this study explored if PJP could be diagnosed by metagenomic next-generation sequencing (mNGS) and if mNGS could guide the therapy of PJP. mNGS was successfully diagnosed 13 out of 14 PJP recipients with 11 through peripheral blood samples, verified by PCR. Ten non-PJP recipients were enrolled as the control group. Blood tests revealed a high β-D-glucan (BDG) level in all recipients with PJP during the hospitalization. Four (28.6%) of 14 PJP patients were infected with cytomegalovirus simultaneously, while 8 (57.1%) suffered from a combined infection caused by Torque teno virus. Five (35.7%) of 14 cases died of PJP or the subsequent bacteremias/bacterial pneumonia with a longer interval between the onset and diagnosis of/the available therapy against PJP than survival cases. Univariate analysis of characteristics between PJP and non-PJP recipients revealed that BDG assays was higher at the admission in PJP group (P =0.011). This present study supports the value of mNGS detection of blood sample in diagnosing PJP, which could assist clinical decision for therapy against PJ and improve outcome of PJP. The study also highlights the sensitivity of BDG assays. Cytomegalovirus and Torque teno virus infections often occur at the same time of PJP, thus can be alerts of PJP.

Zhang F ，Chen J ，Huang H ，Deng X ，Zhang W ，Zeng M ，Liu R ，Dai L ，Wan Q ... -  《-》

Single-center retrospective analysis of Pneumocystis jirovecii pneumonia in patients after deceased donor renal transplantation.

To investigate the clinical features, early diagnosis, and treatment methods of Pneumocystis jirovecii pneumonia (PJP) after renal transplantation (RT). We retrospectively analyzed the clinical data of 80 patients with confirmed PJP who underwent RT between 2018 and 2021 in our hospital. In the present study, the incidence of PJP was 6.2% (80/1300). A 50% of cases (40 out of 80 patients) had developed a PJP infection during the first 6 months after RT and 81.3% (65 out of 80 patients) within 12 months. The median onset time of PJP was 6.5 months after RT. The most common symptom was fever (73.8%), followed by progressive dyspnea (51.3%) and dry cough (31.3%). In the initial phase of PJP, the most frequent CT finding was the presence of diffuse ground-grass shadows. In all, 27.5%, 37.5%, and 35% patients were diagnosed by induced sputum metagenomic next-generation sequencing (mNGS), peripheral blood mNGS, and characteristic clinical diagnostic features, respectively. The median 1,3-β-D-glucan level was 500 pg/mL, while the median C-reactive protein level was 63.4 mg/L. In most patients (83.8%), the procalcitonin levels were negative. The mean serum creatinine level was 171.9 ± 87.4 μmol/L. Of the 80 patients, 37 (46.2%) had coexisting cytomegalovirus (CMV) infection. All patients were treated with trimethoprim-sulfamethoxazole and third generation cephalosporin to prevent bacterial infection. The methylprednisolone dose (40-120 mg/d) varied according to illness. PJP usually occurs within 1 year after RT, typically within 6 months. Fever, dry cough, and progressive dyspnea are the most common clinical symptoms. PJP should be highly suspected if the patient has clinical symptoms and diffuse, patchy, ground-glass opacities on CT in both lungs after RT within 1 year. Peripheral blood or induced sputum mNGS is helpful for early diagnosis of PJP. Trimethoprim-sulfamethoxazole is still the first choice for the treatment of PJP. Combined use of caspofungin can reduce the dose and adverse reactions of trimethoprim-sulfamethoxazole in theory.

Zou J ，Wang T ，Qiu T ，Zhou J ，Chen Z ，Ma X ，Jin Z ，Xu Y ，Zhang L ... -  《-》

The diagnostic value of metagenomic next-generation sequencing for identifying Pneumocystis jirovecii infection in non-HIV immunocompromised patients.

Pneumocystis jirovecii pneumonia (PJP) remains an important cause of morbidity and mortality in non-HIV immunocompromised patients especially in transplant recipients. But its diagnosis remains challenging due to the insuffificient performance of conventional methods for diagnosing Pneumocystis jirovecii(P. jirovecii) infection. Therefore, the auxiliary diagnostic function of metagenomics next-generation sequencing (mNGS) in clinical practice is worth of exploring. 34 non-HIV immunocompromised patients who were diagnosed as PJP by clinical manifestations, imaging findings, immune status of the host, and Methenamine silver staining were tested by mNGS from October 2018 to December 2020 in Sichuan Provincial People's Hospital. The clinical performances of mNGS for P. jirovecii infection diagnosis were also evaluated with genome reads abundance and comparing with other traditional diagnostic methods. We diagnosed a total of 34 non-HIV PJP patients by the clinical composite diagnosis. Our data shows that, compared with the clinical microbiological test, the detection rate of mNGS for P. jirovecii in non-HIV infected PJP patients is significantly higher than that of Methenamine silver staining and serum 1-3-β-D-glucan. mNGS can be used as an auxiliary diagnostic tool to help diagnosis. The number of reads mapped to the genome of P. jirovecii and the duration of patients from onset to sampling collection were statistically significant between the two groups (Reads>100 and Reads ≤ 100) (8days vs. 23days, p=0.020). In addition, univariate analysis showed that C-reactive protein (15.8mg/L vs.79.56mg/L, p=0.016), lactate dehydrogenase (696U/l vs. 494U/l, p=0.030) and procalcitonin (0.09ng/ml vs. 0.59ng/ml, p=0.028) was also statistically significant between the two groups. An effective detection rate was achieved in PJP patients using mNGS testing of bronchoalveolar lavage fluid (BALF) or blood. The study also confirmed that the abundance of reads of P. jirovecii is related to the interval between the onset and sample collection. And the inflammation status during simultaneous mNGS detection might determine the abundance of pathogens. Hence, we conclude that the mNGS strategy could benefit disease diagnosis as well as treatment when complicated clinical infections appeared.

Zhao M ，Yue R ，Wu X ，Gao Z ，He M ，Pan L ... -  《-》