Desquamative interstitial pneumonitis in a patient with systemic lupus erythematosus

CT Morphologic Characteristics and Variant Patterns of Interstitial Pulmonary Fibrosis in Systemic Lupus Erythematosus

Purpose

To assess CT features of pulmonary fibrosis in patients with systemic lupus erythematosus (SLE) and to assess the presence of several distinctive patterns of fibrosis associated with connective tissue disease.

Materials and Methods

A cross-sectional retrospective analysis was performed. An institutional clinical database was queried for the years of 2005-2015 to identify CT examination reports of patients with SLE and fibrotic lung disease, which yielded 50 patients (median age, 49 years; age range, 22-71 years; 46 women). CT examination reports were scored by two subspecialty thoracic radiologists using a standard multilevel semiquantitative system. Readers noted the presence or absence of several recently described CT signs of variant patterns of fibrosis in connective tissue disease (the "anterior upper lobe," "straight-edge," and "exuberant honeycombing" signs), as well as two other morphologic characteristics (an "island-like" appearance of areas of well-defined fibrosis with angular margins surrounded by normal lung and confluent regions of lucent lung destruction).

Results

The most common CT patterns were characterized as either fibrotic nonspecific interstitial pneumonia (38%, 19 of 50) or variant fibrosis (44%, 22 of 50). CT signs of variant fibrosis were identified by both readers in up to 62% of patients, with good κ agreement (0.44-0.64); the island-like sign (62%) and anterior upper lobe sign (52%) were most commonly observed. Pulmonary function test results showed correlations with several imaging findings but did not show correlations with CT signs of variant fibrosis.

Conclusion

When present, pulmonary fibrosis in SLE often has a distinctive appearance and may also manifest as several variant fibrotic patterns.Keywords: CT, Lung© RSNA, 2021See also the commentary by White in this issue.

The other connective tissue disease-associated interstitial lung diseases: Sjogren's syndrome, mixed connective tissue disease, and systemic lupus erythematosus

PURPOSE OF REVIEW

We review the clinical manifestations of three less common connective tissue disease (CTD)-associated interstitial lung diseases (ILDs): Sjogren's syndrome (SjS), mixed CTD (MCTD), and systemic lupus erythematosus (SLE).

RECENT FINDINGS

SjS is classically associated with lymphocytic interstitial pneumonia and cystic lung disease, but the most common type of ILD in Sjogren's patients is nonspecific interstitial pneumonia. ILD is prevalent in MCTD and associated with worse survival. SLE-associated ILD, while rare, is more common in those with CTD overlap syndromes. Regardless of underlying cause, a subset of patients with fibrotic CTD-associated ILD develop a progressive course for which antifibrotic agents and lung transplantation should be considered.

SUMMARY

An understanding of the characteristics of ILD in SjS, MCTD, and SLE is important for the pulmonary specialist. Future research should identify risk factors for progression and develop additional treatment modalities for both CTD-related autoimmune features and progressive ILD.

Desquamative interstitial pneumonia: a systematic review of its features and outcomes

Background

Desquamative Interstitial Pneumonia (DIP) is a rare form of idiopathic interstitial pneumonia (IIP). Data on clinical features, aetiology, prognosis and effect of treatment strategies are limited. We aimed to collect all published cases to better characterise DIP.

Methods

A systematic literature search was performed for all original cases of adult patients with histopathologically-confirmed DIP. Individual patient data were extracted and summarised.

Results

We included 68 individual cases and 13 case series reporting on 294 cases. Most common presenting symptoms were dyspnoea and cough. Pulmonary function showed a restrictive pattern (71%) with decreased diffusion capacity. We found a high incidence (81%) of ever smoking in patients with DIP and 22% of patients had other (occupational) exposures. Characteristic features on high-resolution computed tomography (HRCT) scan were bilateral ground-glass opacities with lower lobe predominance (92%). Treatment and duration of treatment widely varied. Initial response to treatment was generally good, but definitely not uniformly so. A significant proportion of patients died (25% of individual cases) or experienced a relapse (18% of individual cases).

Conclusion

DIP remains an uncommon disease, frequently but not always related to smoking or other exposures. Furthermore, DIP behaves as a progressive disease more often than generally thought, possibly associated with different underlying aetiology.

This systematic review is the most comprehensive collection of published cases of DIP to date and yields novel information about aetiology, clinical characteristics, radiology and pathology features, treatment and outcomes.http://bit.ly/394YRPv

Association of Interstitial Lung Disease With Clinical Characteristics of Chinese Patients With Systemic Lupus Erythematosus

Objectives

This study aims to evaluate the frequency and clinical and laboratory features of interstitial lung disease (ILD) in Chinese patients with systemic lupus erythematosus (SLE) and to evaluate the association of ILD with the clinical features.

Patients and methods

The study included 505 SLE patients (64 males, 441 females; mean age 35.3±15.3 years; range, 14 to 87 years) who were categorized into two groups as 449 patients without ILD and 56 patients with ILD based on evidence obtained from high-resolution computed tomography images. The demographic data, clinical and laboratory findings, SLE disease activity index score, and Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index of all patients were also recorded and statistically analyzed.

Results

The ILD frequency in patients with SLE was 11.1%. Compared to the group of SLE patients without ILD, the group of SLE patients with ILD possessed the following statistical differences: elderly age, longer illness duration, lower level of anti-double-stranded deoxyribonucleic acid, and higher level of serum complement 3, increased ratios of Raynaud's phenomenon, moist rales and tachypnea. Multivariate logistic regression results suggested that elderly age (≥60 years), long illness duration (1-10 years, ≥10 years), Raynaud's phenomenon, and tachypnea were statistically associated with the occurrence of ILD in SLE patients.

Conclusion

Chinese SLE patients who possessed the factors that were statistically associated with ILD, namely, elderly age (≥60 years old), long illness duration (≥1 years), Raynaud's phenomenon, and tachypnea, were recommended to be monitored for the possibility of ILD.

Overlaps and uncertainties of smoking-related idiopathic interstitial pneumonias

Smoking-related interstitial lung disease (ILD) consists of a heterogeneous group of disorders that are considered a distinct entity. The 2013 American Thoracic Society and European Respiratory Society recommendations classified respiratory bronchiolitis (RB)/RB-ILD and desquamative interstitial pneumonia (DIP) as smoking-related idiopathic interstitial pneumonias (IIPs). The overlapping histopathological and radiological patterns of smoking-related IIPs must be considered. Overlap patterns of smoking-related IIPs are not easily classified as a single disorder. The initial radiological manifestation and follow-up changes are heterogeneous, even when diagnosed pathologically as RB or DIP. Therefore, a clinical–radiological–pathological consensus is important in the diagnosis of smoking-related IIPs, and long-term evaluation is essential to monitor the morphological changes in these patients. In this article, we reviewed the clinical, radiological, and pathological findings, and also the changes in radiological manifestations of smoking-related IIPs over time.

The Spectrum of Interstitial Lung Disease in Connective Tissue Disease

Interstitial lung disease (ILD) is a common cause of morbidity and mortality in patients with connective tissue disease (CTD). In a minority of patients the ILD may be the presenting (or only) manifestation of an underlying CTD. Diagnosis of CTD-related ILD relies on a multidisciplinary team including pulmonologists, pathologists, radiologists, and rheumatologists, as the imaging and pathologic findings may be indistinguishable from idiopathic interstitial pneumonias. Moreover, many patients with ILD are suspected of having an underlying CTD but do not meet all of the necessary criteria for a specific disorder. This article provides a pattern-based approach to the imaging of CTD-related ILD and also reviews relevant clinical, pathologic, and serologic data that radiologists should be familiar with as part of a multidisciplinary team.

Chance, genetics, and the heterogeneity of disease and pathogenesis in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a remarkably complex and heterogeneous systemic autoimmune disease. Disease complexity within individuals and heterogeneity among individuals, even genetically identical individuals, is driven by stochastic execution of a complex inherited program. Genome-wide association studies (GWAS) have progressively improved understanding of which genes are most critical to the potential for SLE and provided illuminating insight about the immune mechanisms that are engaged in SLE. What initiates expression of the genetic program to cause SLE within an individual and how that program is initiated remains poorly understood. If we extrapolate from all of the different experimental mouse models for SLE, we can begin to appreciate why SLE is so heterogeneous and consequently why prediction of disease outcome is so difficult. In this review, we critically evaluate extrinsic versus intrinsic cellular functions in the clearance and elimination of cellular debris and how dysfunction in that system may promote autoimmunity to nuclear antigens. We also examine several mouse models genetically prone to SLE either because of natural inheritance or inheritance of induced mutations to illustrate how different immune mechanisms may initiate autoimmunity and affect disease pathogenesis. Finally, we describe the heterogeneity of disease manifestations in SLE and discuss the mechanisms of disease pathogenesis with emphasis on glomerulonephritis. Particular attention is given to discussion of how anti-DNA autoantibody initiates experimental lupus nephritis (LN) in mice.

Clinical and radiological features of idiopathic interstitial pneumonias (IIPs): a pictorial review

OBJECTIVES

To illustrate the clinical and radiological features of idiopathic interstitial pneumonias (IIPs), according to the American Thoracic Society (ATS)/European Respiratory Society (ERS) classification updated in 2013.

METHODS

IIPs include a subset of diffuse and restrictive lung diseases, resulting from damage to the parenchyma characterised by inflammation and fibrosis of the interstitium. Classification into major and rare IIPs is based on the 2013 ATS/ERS committee.

RESULTS

The diagnosis of idiopathic pulmonary fibrosis (IPF) needs to exclude other well-known causes of interstitial lung diseases. According to the 2011 evidence-based guidelines, usual interstitial pneumonia (UIP) can be diagnosed by HRCT when all criteria are fulfilled. Non-specific interstitial pneumonia (NSIP) is characterised by patchy ground-glass opacities and irregular linear/reticular opacities. The imaging patterns of respiratory bronchiolitis associated-interstitial lung disease (RB-ILD) and desquamative interstitial pneumonia (DIP) show centrolobular nodules and ground-glass opacities. Cryptogenic organising pneumonia (COP) consists of patchy peripheral or peribronchial consolidations, while ground-glass opacities are typically associated with diffuse lung consolidation, evolving to fibrosis, in acute interstitial pneumonia (AIP). Rare IIPs include lymphoid interstitial pneumonia and idiopathic pleuro-parenchymal fibroelastosis (IPPFE).

CONCLUSIONS

The knowledge of IIP imaging features on HRCT images help radiologists in diagnosis. Moreover, the overlap of imaging features needs a multidisciplinary approach.

TEACHING POINTS

• UIP findings are reticulations, bronchiectasis, honeycombing and absence of inconsistent features. • Bilateral patchy ground-glass areas represent the most encountered features in NSIP. • Poorly defined centrilobular nodules are typical of RB-ILD, whereas a ground-glass appearance is typical of DIP. • HRCT features of COP include characteristic peripheral or peribronchial patchy consolidations. • Rare IIPs include idiopathic LIP and idiopathic pleuro-parenchymal fibroelastosis (PPFE).