Confluent fibrosis and fibroblast foci in fibrotic non-specific interstitial pneumonia

Thin-Section CT in the Categorization and Management of Pulmonary Fibrosis including Recently Defined Progressive Pulmonary Fibrosis

While idiopathic pulmonary fibrosis (IPF) is the most common type of fibrotic lung disease, there are numerous other causes of pulmonary fibrosis that are often characterized by lung injury and inflammation. Although often gradually progressive and responsive to immune modulation, some cases may progress rapidly with reduced survival rates (similar to IPF) and with imaging features that overlap with IPF, including usual interstitial pneumonia (UIP)-pattern disease characterized by peripheral and basilar predominant reticulation, honeycombing, and traction bronchiectasis or bronchiolectasis. Recently, the term progressive pulmonary fibrosis has been used to describe non-IPF lung disease that over the course of a year demonstrates clinical, physiologic, and/or radiologic progression and may be treated with antifibrotic therapy. As such, appropriate categorization of the patient with fibrosis has implications for therapy and prognosis and may be facilitated by considering the following categories: (a) radiologic UIP pattern and IPF diagnosis, (b) radiologic UIP pattern and non-IPF diagnosis, and (c) radiologic non-UIP pattern and non-IPF diagnosis. By noting increasing fibrosis, the radiologist contributes to the selection of patients in which therapy with antifibrotics can improve survival. As the radiologist may be first to identify developing fibrosis and overall progression, this article reviews imaging features of pulmonary fibrosis and their significance in non-IPF-pattern fibrosis, progressive pulmonary fibrosis, and implications for therapy. Keywords: Idiopathic Pulmonary Fibrosis, Progressive Pulmonary Fibrosis, Thin-Section CT, Usual Interstitial Pneumonia © RSNA, 2024.

Correlation of monocyte counts with clinical outcomes in idiopathic nonspecific interstitial pneumonia

Higher blood monocyte counts are related to worse survival in idiopathic pulmonary fibrosis. However, studies evaluating the association between blood monocyte counts and clinical outcomes of idiopathic nonspecific interstitial pneumonia (iNSIP) are lacking. We evaluated the impact of monocyte counts on iNSIP prognosis. iNSIP patients (n = 126; median age, 60 years; female, n = 64 [50.8%]) diagnosed by surgical lung biopsy were enrolled and categorized into low (monocyte < 600/µL) and high (monocyte ≥ 600/µL) monocyte groups. The median follow-up duration was 53.0 months. After adjusting for age, sex, and smoking history, the annual decline in forced vital capacity (FVC) showed differences between the monocyte groups (P_interaction = 0.006) (low vs. high; - 28.49 mL/year vs. - 65.76 mL/year). The high-monocyte group showed a worse survival rate (P = 0.01) compared to low monocyte group. The 5-year survival rates were 83% and 72% in the low- and high-monocyte groups, respectively. In the Cox-proportional hazard analysis, older age, male sex, low baseline FVC, and diffusing capacity of the lung for carbon monoxide were independent risk factors for mortality. However, monocyte count (Hazard ratio 1.61, P = 0.126) was not an independent prognostic factor. Although high monocyte count might be associated with faster lung function decline, it could not independently predict survival in iNSIP.

Extracellular Heat Shock Proteins as Therapeutic Targets and Biomarkers in Fibrosing Interstitial Lung Diseases

Interstitial lung diseases (ILDs) include a large number of diseases and causes with variable outcomes often associated with progressive fibrosis. Although each of the individual fibrosing ILDs are rare, collectively, they affect a considerable number of patients, representing a significant burden of disease. Idiopathic pulmonary fibrosis (IPF) is the typical chronic fibrosing ILD associated with progressive decline in lung. Other fibrosing ILDs are often associated with connective tissues diseases, including rheumatoid arthritis-ILD (RA-ILD) and systemic sclerosis-associated ILD (SSc-ILD), or environmental/drug exposure. Given the vast number of progressive fibrosing ILDs and the disparities in clinical patterns and disease features, the course of these diseases is heterogeneous and cannot accurately be predicted for an individual patient. As a consequence, the discovery of novel biomarkers for these types of diseases is a major clinical challenge. Heat shock proteins (HSPs) are molecular chaperons that have been extensively described to be involved in fibrogenesis. Their extracellular forms (eHSPs) have been recently and successfully used as therapeutic targets or circulating biomarkers in cancer. The current review will describe the role of eHSPs in fibrosing ILDs, highlighting the importance of these particular stress proteins to develop new therapeutic strategies and discover potential biomarkers in these diseases.

Tamarind Multifunctional Protein: Safety and Anti-Inflammatory Potential in Intestinal Mucosa and Adipose Tissue in a Preclinical Model of Diet-Induced Obesity

INTRODUCTION

Obesity has emerged as one of the main public health problems. This condition triggers a series of hormonal and metabolic changes related to a low-grade chronic inflammatory condition. The trypsin inhibitor purified from tamarind (TTIp) seeds is a promising anti-inflammatory molecule, but its safety needs to be evaluated. This study aimed to evaluate TTIp bioactive dose effects on organs involved in its metabolism (liver and pancreas) and affected tissues (small intestine and perirenal adipose tissue) in an obesity model.

METHODS

Three groups of adult male Wistar rats were used (n = 5). Two of these groups had diet-induced obesity, and a third group was eutrophic. TTIp was administered by gavage in one of the obese groups for 10 days, while the remaining groups received a vehicle. The chromatographic profile and the inhibition assay corroded the purification of the inhibitor. Physical and behavioral changes, liver enzymes, and stereological and histopathological analyses of tissues were evaluated.

RESULTS

TTIp did not cause visible signs of toxicity, nor caused changes in liver enzymes, the liver, and pancreatic tissues. TTIp did not cause changes in the intestinal mucosa, showing improvement in the villi's histopathological characteristics compared to the group of animals with obesity without treatment with TTIp (p = 0.004). The analysis of perirenal adipose tissue showed that the average sectional area of animals with obesity that received TTIp did not differ from the control. There was a difference between the high glycemic load diet group and the group treated with the inhibitor (351.8 ± 55.5) (p = 0.016). In addition, the group that received TTIp had no inflammatory infiltrates.

CONCLUSION

Based on histological and stereological analysis, the use of TTIp is potentially safe and anti-inflammatory in the evaluated obesity model and can be investigated as a possible adjuvant in obesity therapy.

Expanded acceptance of acute exacerbation of nonspecific interstitial pneumonia, including 7 additional cases with detailed clinical pathologic correlation

Acute exacerbation is uncommonly diagnosed in patients with nonspecific interstitial pneumonia (NSIP) and its pathologic features have received relatively little attention compared to idiopathic pulmonary fibrosis. We retrospectively studied 14 consecutive cases of histopathologically proven NSIP by surgical lung biopsy. The diagnosis of acute exacerbation was confirmed clinically. We analyzed whether four reported pathologic features, including organizing pneumonia lesion, alveolar hemorrhage, many fibroblastic foci, and focal hyaline membranes were present and suggestive of acute exacerbation of NSIP or not. Acute exacerbation in patients with NSIP was diagnosed in 8 cases, while the remaining 6 cases were diagnosed as clinically stable. Seven cases of organizing pneumonia lesion, 7 of alveolar hemorrhage, 6 of many fibroblastic foci, and 3 of focal hyaline membranes were identified as the main pathologic components in patients with acute exacerbation. Organizing pneumonia lesion and many fibroblastic foci were identified in 2 and 3 stable cases, respectively. Having more than two components was significantly associated with acute exacerbation. Evaluation of lung biopsies with NSIP for organizing pneumonia lesions, alveolar hemorrhage, many fibroblastic foci, and focal hyaline membranes may be useful to predict the possibility of acute exacerbation.

Diagnostic Ability of a Dynamic Multidisciplinary Discussion in Interstitial Lung Diseases: A Retrospective Observational Study of 938 Cases

BACKGROUND

The advice of a dynamic multidisciplinary discussion (MDD) is believed to be important in the diagnosis of interstitial lung diseases (ILDs). However, to what extent MDD diagnoses differ from the preliminary diagnoses before formal workup and MDD (preMDD diagnoses) is still insufficiently studied.

METHODS

We compared preMDD and MDD diagnoses in patients discussed at the Leuven University Hospitals MDDs between January 2005 and December 2015.

RESULTS

Of 938 consecutive patients discussed in an MDD, 755 (80.5%) received a specific diagnosis. From the 183 patients with unclassifiable ILD, 150 patients (16.0%) received suggestions concerning further investigations to establish a definite diagnosis. In 191 patients (41.9% of patients with a preMDD diagnosis), the MDD changed the diagnosis. In 384 patients (79.5% of patients without preMDD diagnosis), MDD provided a diagnosis when the referring physician did not. MDD diagnosis showed a trend toward better prognostic discrimination between idiopathic pulmonary fibrosis and other ILDs compared with preMDD diagnosis (Harrell C-index, 0.666 vs 0.631; P = .08), which was particularly clear in patients with discordant MDD and preMDD diagnoses (hazard ratio, 2.68 vs 0.84; P = .012 vs .768).

CONCLUSIONS

The MDD provided a definite diagnosis in 80.5% of presented cases, suggesting further investigations in almost all others. Given the high number of patients without preMDD diagnosis, the rate of change in preMDD diagnoses (41.9% of patients with a preMDD diagnosis) probably is an underestimation. The better prognostic discrimination among ILDs by using MDD indicates the added value of MDD in ILD.