Mosaic attenuation in non-fibrotic areas as a predictor of non-usual interstitial pneumonia pathologic diagnosis

[Diagnosis and Treatment of Hypersensitivity Pneumonitis - S2k Guideline of the German Respiratory Society and the German Society for Allergology and Clinical Immunology]

Hypersensitivity pneumonitis (HP) is an immune-mediated interstitial lung disease (ILD) in sensitized individuals caused by a large variety of inhaled antigens. The clinical form of acute HP is often misdiagnosed, while the chronic form, especially the chronic fibrotic HP, is difficult to differentiate from other fibrotic ILDs. The present guideline for the diagnosis and treatment of HP replaces the former German recommendations for the diagnosis of HP from 2007 and is amended explicitly by the issue of the chronic fibrotic form, as well as by treatment recommendations for the first time. The evidence was discussed by a multidisciplinary committee of experts. Then, recommendations were formulated for twelve questions on important issues of diagnosis and treatment strategies. Recently published national and international guidelines for ILDs and HP were considered. Detailed background information on HP is useful for a deeper insight into HP and the handling of the guideline.

Radiological usual interstitial pneumonia pattern is associated with two-year mortality in patients with idiopathic pulmonary fibrosis

Introduction

The new diagnostic guidelines for idiopathic pulmonary fibrosis (IPF) did not rule out the possibility of combining the radiological patterns of usual interstitial pneumonia (UIP) and probable UIP, given the similar management and diagnostic capacity. However, the prognostic implications of these patterns have not been fully elucidated, with different studies showing heterogeneous results. We applied the new criteria to a retrospective series of patients with IPF, assessing survival based on radiological patterns, findings, and their extension.

Methods

Two thoracic radiologists reviewed high-resolution computed tomography images taken at diagnosis in 146 patients with IPF, describing the radiological findings and patterns. The association of each radiological finding and radiological patterns with two-year mortality was analysed.

Results

The two-year mortality rate was 40.2% in IPF patients with an UIP radiological pattern versus 7.1% in those with probable UIP. Compared to the UIP pattern, probable UIP was protective against mortality, even after adjusting for age, sex, pulmonary function, and extent of fibrosis (hazard ratio (HR) 0.23, 95% confidence interval (CI) 0.06-0.99). Receiving antifibrotic treatment was also a protective factor (HR 0.51, 95%CI 0.27-0.98). Honeycombing (HR 3.62, 95%CI 1.27-10.32), an acute exacerbation pattern (HR 4.07, 95%CI 1.84-8.96), and the overall extent of fibrosis (HR 1.04, 95%CI 1.02-1.06) were predictors of mortality.

Conclusions

In our series, two-year mortality was higher in patients with IPF who presented a radiological pattern of UIP versus probable UIP on the initial scan. Honeycombing, an acute exacerbation pattern, and a greater overall extent of fibrosis were also predictors of increased mortality. The prognostic differences between the radiological pattern of UIP and probable UIP in our series would support maintaining them as two differentiated patterns.

Chest imaging classification in Mycoplasma pneumoniae pneumonia is associated with its clinical features and outcomes

BACKGROUND

The imaging findings of Mycoplasma pneumoniae pneumonia (MPP) vary; however, few studies have focused on the relationship of imaging classification with clinical manifestations and outcomes.

OBJECTIVE

To prospectively investigate whether chest imaging classification in Mycoplasma pneumoniae pneumonia (MPP) is associated with its clinical features and outcomes.

METHODS

A total of 1,401 hospitalized children with MPP were enrolled from January 2019 to December 2021. Imaging findings were categorized as bronchopneumonia and consolidation/atelectasis according to X-ray, and bronchopneumonia, consolidation/atelectasis, bronchiolitis, and mosaic pattern according to computed tomography (CT). Clinical characteristics and outcomes of patients with different imaging classifications were prospectively analyzed based on electronic medical records.

RESULTS

Bronchopneumonia was the most common finding (59.6%), while consolidation/atelectasis was the most severe group. Clinical manifestations and laboratory indicators for the consolidation/atelectasis group included serious abnormalities. Further, outcomes of the patients were worse, including having longer total durations of fever and hospitalization, greater hospitalization expenses, and a higher likelihood of developing refractory MPP, necrotizing pneumonia, and bronchiolitis obliterans (BO) in this group. The incidence of bronchiolitis, a disease characterized by a high prevalence of fever, moist rales, and an atopic constitution, tended to increase after the coronavirus disease pandemic and predisposed patients to BO. A mosaic pattern occurred in allergic and young individuals, with wheezing as the main manifestation, with patients having relatively mild symptoms and good outcomes.

CONCLUSION

Different imaging classifications have different clinical features and clinical outcomes; thus, formulating an imaging-based classification system is of great clinical value.