A Scoring System for Predicting the Prognosis of Late-Onset Severe Pneumonia after Allogeneic Hematopoietic Stem Cell Transplantation

Metagenomic Next-Generation Sequencing in the Diagnosis of Pulmonary Infections after Allogeneic Hematopoietic Stem Cell Transplantation

Early and accurate identification of pathogens in pulmonary infections after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is critically important. The clinical usefulness of metagenomic next-generation sequencing (mNGS) in the diagnosis of pulmonary infections after allo-HSCT remains under discussion. This multicenter retrospective study was conducted to compare mNGS and conventional microbiological tests (CMTs) in identifying the pathogens of pulmonary infections in allo-HSCT recipients. One hundred forty allo-HSCT recipients with suspected pulmonary infections who underwent bronchoscopy were included. mNGS and CMTs performed on bronchoalveolar lavage fluid specimens showed 71.4% positivity on mNGS compared to 55.0% positivity on CMTs. mNGS identified 182 pathogens, including bacteria (n = 88), fungi (n = 35) and viruses (n = 59), compared to 106 pathogens detected by CMTs (bacteria, n = 31; fungi, n = 24; viruses, n = 51). Pulmonary infection was finally diagnosed in 98 patients, including 22 bacterial, 7 fungal, 18 viral, and 48 mixed infections and 3 infections with an unknown pathogen. Mixed infections were identified in 50.5% of the patients with pulmonary infection. The sensitivity of mNGS and CMTs for diagnosing pulmonary infections was 88.8% and 69.4%, respectively (P = .001), and the specificity were 81.0% and 85.7%, respectively (P = .688). Our findings suggest that mNGS may be a promising technology for diagnosing pulmonary infections in allo-HSCT recipients.

Clinical manifestations, prognostic factors, and outcomes of adenovirus pneumonia after allogeneic hematopoietic stem cell transplantation

BACKGROUND

Severe pneumonia is one of the most important causes of mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Adenovirus (ADV) is a significant cause of severe viral pneumonia after allo-HSCT, and we aimed to identify the clinical manifestations, prognostic factors, and outcomes of ADV pneumonia after allo-HSCT.

METHODS

Twenty-nine patients who underwent allo-HSCT at the Peking University Institute of Hematology and who experienced ADV pneumonia after allo-HSCT were enrolled in this study. The Kaplan-Meier method was used to estimate the probability of overall survival (OS). Potential prognostic factors for 100-day OS after ADV pneumonia were evaluated through univariate and multivariate Cox regression analyses.

RESULTS

The incidence rate of ADV pneumonia after allo-HSCT was approximately 0.71%. The median time from allo-HSCT to the occurrence of ADV pneumonia was 99 days (range 17-609 days). The most common clinical manifestations were fever (86.2%), cough (34.5%) and dyspnea (31.0%). The 100-day probabilities of ADV-related mortality and OS were 40.4% (95% CI 21.1%-59.7%) and 40.5% (95% CI 25.2%-64.9%), respectively. Patients with low-level ADV DNAemia had lower ADV-related mortality and better OS than did those with high-level (≥ 106 copies/ml in plasma) ADV DNAemia. According to the multivariate analysis, high-level ADV DNAemia was the only risk factor for intensive care unit admission, invasive mechanical ventilation, ADV-related mortality, and OS after ADV pneumonia.

CONCLUSIONS

We first reported the prognostic factors and confirmed the poor outcomes of patients with ADV pneumonia after allo-HSCT. Patients with high-level ADV DNAemia should receive immediate and intensive therapy.

Clinical characteristics and outcomes of allogeneic hematopoietic stem cell transplantation recipients with coronavirus disease 2019 caused by the Omicron variant: a prospective, observational cohort study

We aimed to describe the clinical characteristics, particularly the occurrence and risk factors of severe/critical illness, in allogeneic hematopoietic stem cell (allo-HSCT) recipients infected with coronavirus disease 2019 (COVID-19) caused by Omicron variant in an observational prospective study (n = 311). The median time from allo-HSCT to COVID-19 diagnosis was 8.5 months (range 0.8-106.1) months. Four patients (1.3%) were reported to be asymptomatic during Omicron variant infection, and 135 (43.4%) patients showed lower respiratory tract disease. Thirty-four (10.9%) patients were categorized into serious infection (severe illness n = 25; critical illness n = 9) and the median duration from COVID-19 diagnosis to serious infections was 6 days (range, 0-29) days. Thirteen (4.2%) and 6 (1.9%) patients required intensive care unit care and invasive mechanical ventilation, respectively. Receiving more than 1 type of immunosuppressive therapies at COVID-19 diagnosis was associated with severity and persistence of infection. Six patients (1.9%) died after diagnosis of COVID-19 infection. The 4-week probability of overall survival after COVID-19 diagnosis was 98.7%, which was 100% and 88.2% for non-serious and serious infection group (P < 0.001), respectively. Thus, we observed a relatively low serious infection and mortality rate in allo-HSCT recipients infected with COVID-19 caused by Omicron variant.

[Relationship between treatment and prognosis in patients with late-onset severe pneumonia after allogeneic hematopoietic stem cell transplantation]

OBJECTIVE

To explore the relationship between drug treatment and outcomes in patients with late-onset severe pneumonia (LOSP) after allogeneic stem cell transplantation (allo-SCT).

METHODS

We retrospectively analyzed the effects of the initiation time of treatment drugs, especially antiviral drugs and glucocorticoids on the clinical outcomes in 82 patients between January 2016 and August 2021 who developed LOSP after allo-SCT in Peking University People's Hospital. Univariate analysis was performed by Mann-Whitney U test and χ² test, and multivariate analysis was performed by Logistic regression. When multiple groups (n>2) were involved in the χ² test, Bonferroni correction was used for the level of significance test.

RESULTS

Of all 82 patients in this study, the median onset time of LOSP was 220 d (93-813 d) after transplantation, and the 60-day survival rate was 58.5% (48/82). The median improvement time of the survival patients was 18 d (7-44 d), while the median death time of the died patients was 22 d (2-53 d). Multivariate analysis showed that the initiation time of antiviral drugs from the onset of LOSP (< 10 d vs. ≥10 d, P=0.012), and the initiation time of glucocorticoids from antiviral drugs (< 10 d vs. ≥10 d, P=0.027) were the factors affecting the final outcome of the patients with LOSP at the end of 60 d. According to the above results, LOSP patients were divided into four subgroups: group A (antiviral drugs < 10 d, glucocorticoids ≥10 d), group B (antiviral drugs < 10 d, glucocorticoids < 10 d), group C (antiviral drugs ≥10 d, glucocorticoids ≥10 d) and group D (antiviral drugs ≥10 d, glucocorticoids < 10 d), the 60-day survival rates were 91.7%, 56.8%, 50.0% and 21.4%, respectively.

CONCLUSION

Our study demonstrated that in patients who developed LOSP after allo-SCT, the initiation time of antiviral drugs and glucocorticoids were associated with the prognosis of LOSP, and the survival rate was highest in patients who received antiviral drugs early and glucocorticoids later. It suggested that for patients with LOSP of unknown etiology should be highly suspicious of the possibility of a secondary hyperimmune response to viral infection.