Prognostic impact of pre-existing interstitial lung disease in non-HIV patients with Pneumocystis pneumonia

Pattern classification of interstitial lung diseases from computed tomography images using a ResNet-based network with a split-transform-merge strategy and split attention

In patients with interstitial lung disease (ILD), accurate pattern assessment from their computed tomography (CT) images could help track lung abnormalities and evaluate treatment efficacy. Based on excellent image classification performance, convolutional neural networks (CNNs) have been massively investigated for classifying and labeling pathological patterns in the CT images of ILD patients. However, previous studies rarely considered the three-dimensional (3D) structure of the pathological patterns of ILD and used two-dimensional network input. In addition, ResNet-based networks such as SE-ResNet and ResNeXt with high classification performance have not been used for pattern classification of ILD. This study proposed a SE-ResNeXt-SA-18 for classifying pathological patterns of ILD. The SE-ResNeXt-SA-18 integrated the multipath design of the ResNeXt and the feature weighting of the squeeze-and-excitation network with split attention. The classification performance of the SE-ResNeXt-SA-18 was compared with the ResNet-18 and SE-ResNeXt-18. The influence of the input patch size on classification performance was also evaluated. Results show that the classification accuracy was increased with the increase of the patch size. With a 32 × 32 × 16 input, the SE-ResNeXt-SA-18 presented the highest performance with average accuracy, sensitivity, and specificity of 0.991, 0.979, and 0.994. High-weight regions in the class activation maps of the SE-ResNeXt-SA-18 also matched the specific pattern features. In comparison, the performance of the SE-ResNeXt-SA-18 is superior to the previously reported CNNs in classifying the ILD patterns. We concluded that the SE-ResNeXt-SA-18 could help track or monitor the progress of ILD through accuracy pattern classification.

High prevalence of pneumocystis pneumonia in interstitial lung disease: a retrospective study

BACKGROUND

Interstitial lung disease (ILD) is a new risk category for pneumocystis pneumonia (PCP) with a high mortality rate. The definite diagnostic criteria of PCP in ILD patients have not been established until now. The aims of this study were to identify potential risk factors of PCP in patients with ILD, and to evaluate the performance of metagenomic next-generation sequencing (mNGS), CD4 + T cell count, (1-3)-β-D-Glucan (BG) and lactate dehydrogenase (LDH) in the diagnosis of PCP in ILD patients.

METHODS

This is a retrospective, single-center, case-control study. ILD patients who underwent mNGS from December 2018 to December 2022 were included in the study. Based on the diagnosis criteria of PCP, these patients were divided into PCP-ILD and non-PCP-ILD groups. The potential risk factors for PCP occurrence in ILD patients were analysed via logistic regression. The diagnostic efficacy of mNGS was compared with serological biomarkers.

RESULTS

92 patients with ILD were enrolled, 31 of which had a definite PCP and were assigned to the PCP-ILD group while 61 were to the non-PCP-ILD group. The infection rate of PJ in ILD patients was 33.7% (31/92). The history of glucocorticoid therapy, CD4 + T cell count, BG level and traction bronchiectasis on HRCT were associated with PCP occurrence in ILD patients. LDH level did not reach statistical significance in the logistic regression analysis. mNGS was confirmed as the most accurate test for PCP diagnosis in ILD patients.

CONCLUSION

ILD is a new risk group of PCP with high PCP prevalence. Clinicians should pay close attention to the occurrence of PCP in ILD patients who possess the risk factors of previous glucocorticoid therapy, decreased CD4 + T cell count, increased BG level and absence of traction bronchiectasis on HRCT. mNGS showed the most excellent performance for PCP diagnosis in ILD patients. Peripheral blood CD4 + T cell count and BG level are alternative diagnostic methods for PCP in ILD patients. However, the diagnostic value of serum LDH level was limited in ILD patients.

Pneumocystis pneumonia in French intensive care units in 2013-2019: mortality and immunocompromised conditions

PURPOSE

The recent epidemiology of Pneumocystis pneumonia (PCP) requiring intensive care unit (ICU) admission and the associated spectrum of immunocompromising conditions are poorly described.

METHODS

We analyzed all adult PCP cases admitted to French ICUs via the French medical database system (PMSI), over the period from 2013 to 2019.

RESULTS

French ICUs admitted a total of 4055 adult patients with PCP. Among all hospitalized PCP cases, the proportion requiring ICU admission increased from 17.8 in 2014 to 21.3% in 2019 (P < 0.001). The incidence of severe PCP rose from 0.85 in 2013 to 1.32/100,000 adult inhabitants in 2019 (P < 0.0001), primarily due to the proportion of HIV-negative patients that increased from 60.6% to 74.4% (P < 0.0001). Meanwhile, the annual number of severe PCP cases among patients with HIV infection remained stable over the years. In-hospital mortality of severe PCP cases was 28.5% in patients with HIV infection and 49.7% in patients without. Multivariable logistic analysis showed that patients with HIV infection had a lower adjusted risk of death than patients without HIV infection (Odds Ratio [OR]: 0.30, 95% confidence interval [95CI]: 0.17-0.55). Comorbidities or conditions strongly associated with hospital mortality included the patient's age, Simplified Acute Physiologic Score II, congestive heart failure, coagulopathy, solid organ cancer, and cirrhosis. A vast array of autoimmune inflammatory diseases affected 19.9% of HIV-negative patients.

CONCLUSIONS

The number of PCP cases requiring ICU admission in France has risen sharply. While the yearly count of severe PCP cases in HIV-infected patients has remained steady, this rise predominantly affects cancer patients, with a recent surge observed in patients with autoimmune inflammatory diseases, affecting one in five individuals.

Pneumocystis jirovecii pneumonia mortality risk associated with preceding long-term steroid use for the underlying disease: A multicenter, retrospective cohort study

OBJECTIVE

Long-term steroid use increases the risk of developing Pneumocystis pneumonia (PcP), but there are limited reports on the relation of long-term steroid and PcP mortality.

METHODS

Retrospective multicenter study to identify risk factors for PcP mortality, including average steroid dose before the first visit for PcP in non-human immunodeficiency virus (HIV)-PcP patients. We generated receiver operating characteristic (ROC) curves for 90-day all-cause mortality and the mean daily steroid dose per unit body weight in the preceding 10 to 90 days in 10-day increments. Patients were dichotomized by 90-day mortality and propensity score-based stabilized inverse probability of treatment weighting (IPTW) adjusted covariates of age, sex, and underlying disease. Multivariate analysis with logistic regression assessed whether long-term corticosteroid use affected outcome.

RESULTS

Of 133 patients with non-HIV-PcP, 37 died within 90 days of initial diagnosis. The area under the ROC curve for 1-40 days was highest, and the optimal cutoff point of median adjunctive corticosteroid dosage was 0.34 mg/kg/day. Past steroid dose, underlying interstitial lung disease and emphysema, lower serum albumin and lower lymphocyte count, higher lactate dehydrogenase, use of therapeutic pentamidine and therapeutic high-dose steroids were all significantly associated with mortality. Underlying autoimmune disease, past immunosuppressant use, and a longer time from onset to start of treatment, were associated lower mortality. Logistic regression analysis after adjusting for age, sex, and underlying disease with IPTW revealed that steroid dose 1-40 days before the first visit for PcP (per 0.1 mg/kg/day increment, odds ratio 1.36 [95% confidence interval = 1.16-1.66], P<0.001), low lymphocyte counts, and high lactate dehydrogenase revel were independent mortality risk factor, while respiratory failure, early steroid, and sulfamethoxazole/trimethoprim for PcP treatment did not.

CONCLUSION

A steroid dose before PcP onset was strongly associated with 90-day mortality in non-HIV-PcP patients, emphasizing the importance of appropriate prophylaxis especially in this population.

Prognostic Analysis of Pneumocystis Jirovecii Pneumonia in Interstitial Lung Disease Patients: A Retrospective Clinical Study

(1) Background: The clinical characteristics and the prognostic factors of HIV-negative Pneumocystis jirovecii pneumonia (PJP) patients (non-HIV-PJP) with interstitial lung disease (ILD) remain unclear. Our objectives were to describe the clinical characteristics and to explore the prognostic factors of non-HIV-ILD-PJP patients. (2) Methods: The enrolled patients in this retrospective study were stratified based on the presence or absence of ILD and fibrotic ILD (FILD). The log-rank test and Cox regression models were used to analyze the prognostic factors. (3) Results: Among 378 non-HIV-PJP patients, there were 133 patients with ILD-PJP, and 70 patients were classified as having FILD-PJP. The all-cause mortality rate for the ILD-PJP group is higher than that of the ILD-PJP group (57.9% vs. 38.4%, p < 0.001). However, the all-cause mortality is similar between the FILD-PJP group and non-FILD-PJP group. Preexisting ILD (HR: 2.156, p = 0.003) and honeycomb appearance on the chest HRCT (HR = 16.3, p < 0.001) are independent survival risk factors for ILD-PJP. Non-invasive ventilation is an independent survival risk factor for ILD-PJP patients (HR = 928.56, p < 0.01) and FILD-PJP patients (HR = 33.86, p < 0.001). (4) Conclusions: Pre-existing ILD and honeycomb appearance on the chest HRCT are independent survival risk factors for PJP patients. Non-invasive ventilation is associated with poor survival for both ILD-PJP and FILD-PJP patients.

Immunomodulatory treatment of interstitial lung disease

Interstitial lung diseases (ILDs) other than idiopathic pulmonary fibrosis (IPF) have an array of immunomodulatory treatment options compared with IPF, due to their inflammatory component. However, there is a relative paucity of guidance on the management of this heterogeneous group of diseases. In ILDs other than IPF, immunosuppression is the cornerstone of therapy, with varying levels of evidence for different immunomodulatory agents and for each specific ILD. Classification of ILDs is important for guiding treatment decisions. Immunomodulatory agents mainly include corticosteroids, mycophenolate mofetil (MMF), azathioprine, methotrexate, cyclophosphamide and rituximab. In this review, the available evidence for single agents in the most common ILDs is first discussed. We then reviewed practical therapeutic approaches in connective tissue disease-related ILD and interstitial pneumonia with autoimmune features, scleroderma-related ILD, vasculitis and dermatomyositis with hypoxemic respiratory failure, idiopathic non-specific interstitial pneumonia, hypersensitivity pneumonitis sarcoidosis, fibrosing organizing pneumonia and eosinophilic pneumonia. The treatment of acute exacerbations of ILD is also discussed. Therapy augmentation in ILD is dictated by the recognition of progression of disease. Criteria for the evaluation of progression of disease are then discussed. Finally, specific protocol and measures to increase patients' safety are reviewed as well, including general monitoring and serologic surveillance, Pneumocystis jirovecii prophylaxis, patients' education, genetic testing for azathioprine, MMF serum levels and cyclophosphamide administration protocols. Immunomodulatory therapies are largely successful in the management of ILDs and can be safely managed with the application of specific protocols, precautions and monitoring.