Evolution of diagnostic UIP computed tomography patterns in idiopathic pulmonary fibrosis: Disease spectrum and implications for survival

Diagnostic finding on high-resolution computed tomography (HRCT) predicts a good response to pirfenidone in patients with idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a debilitating condition, with a life expectancy of 2 to 5 years after diagnosis. Pirfenidone is a drug that has been shown to reduce the decline in forced vital capacity (FVC). We sought to identify whether different patterns on high-resolution computed tomography (HRCT) have different clinical effects through a retrospective comparison of baseline values and changes in pulmonary function tests (PFTs) after treatment with pirfenidone. We retrospectively analyzed data from IPF patients treated with pirfenidone at Nanjing Drum Tower Hospital in Jiangsu Province, China. According to the HRCT pattern, the patients were divided into usual interstitial pneumonitis (UIP) and possible UIP groups. Baseline clinical characteristics and changes every 6 months in the PFTs during the follow-up period were compared between the 2 groups. A total of 65 consecutive patients were enrolled. According to the HRCT pattern, patients were clustered into the UIP group (n = 46) and possible UIP group (n = 19). No difference was observed in the baseline PFTs ratio between the 2 groups. The FVC values of the 2 groups were not significantly different at the initial treatment and at 6 and 12 months after pirfenidone treatment (P = .081, 0.099, and 0.236, respectively). The improvement in % diffusion capacity of the lung for carbon monoxide (%DLCO) was higher in the possible UIP group after 6 and 12 months of pirfenidone treatment (P = .149, 0.026, and 0.025, respectively). The annual decrease in FVC was not significantly different between the 2 groups, and the annual decrease in %DLCO in the UIP group was significantly higher than that in patients with the possible UIP type (-7.767 ± 12.797 vs 0.342 ± 20.358, P < .05). These results indicate that patients with IPF with a possible UIP pattern on HRCT showed indications of a good response to pirfenidone.

Early Diagnosis and Treatment of Idiopathic Pulmonary Fibrosis: A Narrative Review

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive fibrosing interstitial lung disease of unknown aetiology. Patients typically present with symptoms of chronic dyspnoea and cough over a period of months to years. IPF has a poor prognosis, with an average life expectancy of 3-5 years from diagnosis if left untreated. Two anti-fibrotic medications (nintedanib and pirfenidone) have been approved for the treatment of IPF. These drugs slow disease progression by reducing decline in lung function. Early diagnosis is crucial to ensure timely treatment selection and improve outcomes. High-resolution computed tomography (HRCT) plays a major role in the diagnosis of IPF. In this narrative review, we discuss the importance of early diagnosis, awareness among primary care physicians, lung cancer screening programmes and early IPF detection, and barriers to accessing anti-fibrotic medications.

What parameters can be used to identify early idiopathic pulmonary fibrosis?

Elucidating the disease process of early idiopathic pulmonary fibrosis (IPF) will help clinicians in addressing the contentious issues of when and in which patients, therapeutic intervention should be initiated. Here, we discuss several possible parameters for diagnosing early IPF and their clinical impacts. Physiologically, early IPF can be considered as IPF with normal or mild impairment in pulmonary function. Radiologically, early IPF can be considered as IPF with a small extent and/or early features of fibrosis. Symptomatically, early IPF can be considered as asymptomatic or less symptomatic IPF. IPF at Gender-Age-Physiology index stage I can be considered early IPF. Interstitial lung abnormalities are defined as parenchymal abnormalities in more than 5% of the lung in patients with no prior history of interstitial lung disease, and in some cases, this seems to be equivalent to early IPF. Previous clinical trials showed the effect of antifibrotic therapies in early IPF, but the effects of therapy are uncertain in early IPF outside of clinical trials, such as in cases of IPF with normal pulmonary function, IPF without honeycombing or traction bronchiectasis, and asymptomatic IPF. Moreover, little has been reported on disease progression in such conditions. Because the conceptual framework of early IPF may vary depending on its definition, not only is a diagnosis of early IPF important but prediction of disease progression is also crucial. Further investigations are needed to identify biomarkers that can detect patients who may experience greater degrees of disease progression and require treatment even with those forms of early IPF.

Comparison of Clinical Measures Among Interstitial Lung Disease (ILD) Patients with Usual Interstitial Pneumonia (UIP) Patterns on High-Resolution Computed Tomography

PURPOSE

Idiopathic Pulmonary Fibrosis is a progressive and fatal interstitial lung disease (ILD) characterized by a typical radiographic or histologic usual interstitial pneumonia (UIP) pattern. In 2018, diagnostic categories of UIP based on computed tomography patterns were revised by the Fleischner Society. The study aimed to describe differences in comorbidities and spirometry in ILD patients that were characterized by high-resolution computed tomography (HRCT) images as having a typical, probable, indeterminate, and alternative diagnosis of UIP.

METHODS

We retrospectively studied 80 ILD patients from 2017 to 2019. Typical UIP was defined using the Fleischner Society diagnostic criteria for IPF. Atypical UIP was reached by consensus after a multidisciplinary clinical-radiological-pathological review of patient data. Baseline characteristics, comorbidities, and spirometry were compared among the four subgroups.

RESULTS

Among 80 patients, 59% were male, 61% had a history of smoking, and the mean age was 67.7 ± 10 years (SD). A typical UIP pattern was more frequently observed among patients with chronic obstructive pulmonary disease (COPD) (p < 0.001) and pulmonary hypertension (p = 0.03). Of 30 patients with COPD, 14 had emphysema, while 10 had IPF. After adjusting for forced expiratory volume in one second (FEV₁) in liters, change of FEV₁% from baseline to 6-12 months, age, and sex, only COPD remained significantly associated with typical UIP (p = 0.018). Tobacco use was not significantly associated with any radiographic type (p = 0.199).

CONCLUSION

Typical UIP was prevalent among COPD/emphysema patients. Although smoking has a strong association with IPF, we did not find a significant association with smoking and typical UIP in our cohort.

Impact of radiological honeycombing in rheumatoid arthritis-associated interstitial lung disease

BACKGROUND

Interstitial lung disease (ILD) is the most common and important pulmonary manifestation of rheumatoid arthritis (RA). A radiological honeycomb pattern has been described in diverse forms of ILD that can impact survival. However, the clinical course and sequential radiological changes in the formation of the honeycomb pattern in patients with RA-ILD is not fully understood.

METHODS

We evaluated the sequential changes in computed tomography findings in 40 patients with chronic forms of RA-ILD without the honeycomb pattern at initial diagnosis. We classified the patients into the Non-honeycomb group and Honeycomb group, and then analyzed the characteristics and prognosis of the two groups. The term "honeycomb formation" indicated a positive finding of honeycombing on any available follow-up CT.

RESULTS

Our RA-ILD cohort included patients with probable usual interstitial pneumonia (UIP) (35%), nonspecific interstitial pneumonia (NSIP) (20%), and mixed NSIP/UIP (45%). Among all RA-ILD patients, 16 (40%) showed honeycomb formation on follow-up CT (median time between initial and last follow-up CT was 4.7 years). Patient characteristics and prognosis were not significantly different between the Non-honeycomb and Honeycomb groups. However, Kaplan-Meier survival curve for the time from the date of honeycomb formation to death showed a poor median survival time of 3.2 years.

CONCLUSIONS

A certain number of patients with RA-ILD developed a honeycomb pattern during long-term follow-up, regardless of whether they had UIP or NSIP. Prognosis in the patients with characteristics of both progressive ILD and honeycomb formation could be poor. Although radiological findings over the disease course and clinical disease behavior in RA-ILD are heterogenous, clinicians should be alert to the possibility of progressive disease and poor prognosis in patients with RA-ILD who form a honeycomb pattern during follow-up observation.

Comparing effectiveness of prognostic tests in idiopathic pulmonary fibrosis

Introduction: Idiopathic pulmonary fibrosis (IPF) is a debilitating and progressive fibrotic interstitial lung disease often resulting in death over several years. Prediction of disease course or survival remains of keen interest for clinicians and patients though a commonly used test or tool remain elusive. Areas covered: We undertook a comprehensive review of the published literature highlighting prognostic indicators and predictors of survival in IPF. Baseline and longitudinal clinical, functional, histopathologic, and radiologic findings have been extensively studied as prognostic predictors, both individually and in composite models. Recent approaches include automated quantifiable radiologic scoring, circulating biomarkers, and genetic polymorphisms or abnormalities. This review highlights individual and composite predictors and their relative utility in clinical practice and research studies. Expert opinion: There is a growing body of knowledge highlighting readily available individual and composite predictors of outcome, though none have come to the forefront for common clinical use. Recent advances include quantitative imaging analysis, circulating serologic markers, and genetic testing, which may be more standardized and less prone to lead-time bias or related complications and comorbidities.

Obstacles to early treatment of idiopathic pulmonary fibrosis: current perspectives

Idiopathic pulmonary fibrosis is a progressive and fatal fibrotic lung disease which has seen new opportunity for drug treatment in the last several years with the approval of nintedanib and pirfenidone, two antifibrotic agents aimed at slowing decline in lung function as defined by FVC on pulmonary function testing. Despite these promising effects, delays in drug initiation have been reported undermining the premise that earlier drug initiation may sustain lung function and prolong survival. This review explores obstacles to earlier treatment, inclusive of defining so-called early idiopathic pulmonary fibrosis, difficulties in achieving a confident diagnosis in that setting, and uncertainties regarding drug-related benefits among specific patient subgroups such as those with no symptoms or advanced disease at presentation. Goals of therapy balanced with the burdens associated with antifibrotic drug therapy are negotiated on an individual basis. We review the evidence for and against earlier initiation of antifibrotic drug therapy along with its role in patient-centered outcomes.