Clinical features of usual interstitial pneumonia with anti-neutrophil cytoplasmic antibody in comparison with idiopathic pulmonary fibrosis

Interstitial lung disease in rheumatic diseases: an update of the 2018 review

INTRODUCTION

Interstitial lung disease (ILD) is a potential severe complication of various rheumatic diseases, typically connective tissue diseases (CTD), associated with significant morbidity and mortality. ILD may occur during the course of the disease but may also be its first manifestation. Several cell types are involved in ILD's pathogenesis, and if not controlled, pulmonary inflammation may lead to pulmonary fibrosis.

AREAS COVERED

We searched PubMed, Medline, and the Cochrane Library for papers published between 1995 and February 2017 in the first version, and between 2017 and April 2023 using combinations of words. The most frequent systemic rheumatic diseases associated with ILD are systemic sclerosis (SSc), rheumatoid arthritis (RA), and idiopathic inflammatory myositis. Treatment and monitoring guidelines are still lacking, and current treatment strategies have been extrapolated from the literature on SSc and established treatments for non-pulmonary systemic rheumatic manifestations.

EXPERT OPINION

Given the complexity of diagnosis and the paucity of treatment trials, managing CTD patients with ILD is challenging. It requires the skills of multidisciplinary CTD-ILD clinics including at least rheumatologists and lung specialists.

Clinical Profiles, Survival, and Lung Function Outcomes in ANCA-Associated Interstitial Lung Disease: An Observational Study

Background/Objectives: Anti-neutrophil cytoplasmic antibodies (ANCAs) have been found in interstitial lung disease (ILD) in recent years, although its impact on ILD prognosis is less known. To date, ANCAs are not included in the interstitial pneumonia with autoimmune features (IPAF) definition criteria. Therefore, ANCA-ILD, in the absence of known ANCA-associated vasculitis (AAV), could be underdiagnosed. Our aim was to analyze the clinical profile and prognosis of ANCA-ILD patients. Methods: Patients diagnosed with ILD and positive ANCA were enrolled in a retrospective, monocentric cohort study. Lung function outcomes and mortality were assessed according to clinical, serological, radiological, and treatment characteristics. Survival was analyzed using Kaplan-Meier curves and Cox regression models. Results: A total of 23 patients were included, mostly women, with a median time from ILD diagnosis of 36 (24-68) months and a predominant anti-MPO pattern (56.5%). Nearly half of the patients had AAV, mostly microscopic polyangiitis (MPA). The presence of AAV was significantly associated with anti-MPO antibodies and an NSIP radiographic pattern. Overall, the fibrotic pattern (either UIP or fibrotic NSIP) was the most common (73.9%), mainly UIP (51.2%). However, it appeared less frequently in the AAV-ILD group. During follow-up, lung function impairment or radiological progression was observed in 65.2% of patients. Cumulative mortality incidence was high (43.4%), largely due to ILD itself (80%). A UIP pattern was associated with a higher and earlier mortality (HR 34.4 [1.36-132]), while the use of immunosuppressants showed a trend towards lower ILD-related death. Conclusions: In our cohort, ANCA-ILD patients mostly presented with fibrotic patterns, with AAV in almost half of the cases and a high and early mortality rate, which suggests the need to assess ANCA in all ILD patients.

Clinical features, radiological findings and prognosis of microscopic polyangiitis with interstitial lung disease: a retrospective matched control study

BACKGROUND

The association between interstitial lung disease (ILD) and microscopic polyangiitis (MPA) has received increasing attention in recent years. However, there are still no studies comparing clinical characteristics and prognoses between MPA-ILD patients and patients with ANCA-negative ILDs. Therefore, the purpose of this study was to analyse a group of patients presenting MPA-ILD matched with patients exhibiting ANCA-negative ILDs to identify differences in their clinical characteristics and survival.

METHODS

This study retrospectively reviewed the data of 60 patients with MPA-ILD and 60 patients with ANCA-negative ILDs who were matched for age, sex, and patterns on chest high-resolution CT (HRCT) images. The baseline clinical information, laboratory parameters and chest CT data were collected and analysed at each patient's initial diagnosis.

RESULTS

Sixty of the 682 (8.8%) ILD patients were diagnosed with MPA-ILD. MPA-ILD patients tended to be older and have higher CRP and ESR levels. ILD antedated MPA in 61.7% (37/60) of the patients, and MPA occurred on average (45.1 ± 33.4) months after the ILD diagnosis. Compared with matched ANCA-negative ILD patients, MPA-ILD patients had higher CRP and serum creatinine levels and lower haemoglobin levels. UIP (63.3%) was the most common chest HRCT pattern, and the proportion of patients with oddly shaped cysts (P = 0.04) was significantly greater in the MPA-ILD group than in the matched ANCA-negative ILD group. The number of MPA-ILD patients was significantly shorter than that of ANCA-negative ILD patients (P = 0.005). Survival analysis revealed that acute exacerbation (AE) of ILD (HR 2.40, 95% CI 1.03-5.59, P = 0.043) and diffuse alveolar haemorrhage (HR 3.42, 95% CI 1.09-10.73, P = 0.036) were independently associated with shorter survival and that receiving glucocorticoids combined with immunosuppressants (HR 0.11, 95% CI 0.03-0.37, P < 0.001) was independently associated with prolonged survival in MPA-ILD patients.

CONCLUSIONS

The proportion of MPA-ILD patients with total ILD is not low, and ANCA testing of ILD patients is necessary. Oddly shaped cysts with a UIP pattern may be a characteristic chest imaging manifestation of MPA-ILD. The prognosis of MPA-ILD is poor, especially for patients who are older, have DAH, and have experienced AEs.

Performance of the 2022 ACR/EULAR Classification Criteria in Comparison With the European Medicines Agency Algorithm in Antineutrophil Cytoplasmic Antibody-Associated Vasculitis

OBJECTIVE

This study aimed to compare the 2022 American College of Rheumatology (ACR)/European Alliance of Associations for Rheumatology (EULAR) classification criteria with the European Medicines Agency (EMA) algorithm for antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV).

METHODS

All consecutive, newly diagnosed patients with AAV according to the 2012 Chapel Hill Consensus Conference who visited Keio University Hospital between March 2012 and May 2022 were retrospectively reviewed. Patients were reclassified according to the EMA algorithm and the 2022 ACR/EULAR criteria, and their clinical characteristics were statistically analyzed.

RESULTS

A total of 114 patients with AAV were included in the analyses. Using the EMA algorithm as a reference, reclassification of the patients revealed sensitivity and specificity of the 2022 ACR/EULAR criteria of 100% and 96% for eosinophilic granulomatosis with polyangiitis, 40% and 97% for granulomatosis with polyangiitis (GPA), and 90% and 49% for microscopic polyangiitis (MPA), respectively. Approximately half of patients classified as EMA-GPA or EMA-unclassifiable were reclassified as 2022-MPA; these patients were older, were more disposed to be positive for myeloperoxidase (MPO)-ANCA, and had interstitial lung disease (ILD) more frequently than patients with 2022-GPA or non-2022-MPA. Further, some patients positive for MPO-ANCA with biopsy-proven granulomatous inflammation were also reclassified from EMA-GPA to 2022-MPA. Over the mean observation period of 4.0 years, 16 patients died. Overall survival for each classification group differed significantly from the 2022 ACR/EULAR criteria (P = 0.02), but not with the EMA algorithm (P = 0.21).

CONCLUSION

Among the patients classified as EMA-GPA or EMA-unclassifiable, older patients with MPO-ANCA and ILD tended to be reclassified as 2022-MPA. The 2022 ACR/EULAR criteria were more useful in prognostic prediction than the EMA algorithm.

Progression to ANCA-associated vasculitis in patients with idiopathic interstitial pneumonia and positive ANCA

OBJECTIVE

This study explored the development of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) and its risk factors in patients with idiopathic interstitial pneumonia (IIP) and positive ANCA results.

METHODS

Data of patients diagnosed with IIP with positive ANCA results at a single tertiary center in South Korea were retrospectively reviewed from January 2013 to August 2023. Cox regression analysis was performed to identify variables associated with AAV occurrence following IIP diagnosis. Kaplan-Meier curves were employed to investigate the relationship between autoantibodies and the occurrence of AAV.

RESULTS

In a cohort of 154 IIP-diagnosed patients with positive ANCA results but without AAV, 10.4 % of them eventually developed AAV. The AAV and non-AAV groups did not significantly differ by sex, age, smoking status, urinalysis, or chest computed tomography findings. All the patients who subsequently developed AAV were anti-myeloperoxidase (MPO) positive, while 48.8 % of the non-AAV patients were anti-MPO positive (P < 0.001). Rheumatoid factor (RF) positivity differed significantly (62.5 % vs. 29.2 %, P = 0.007) between the AAV and non-AAV groups. Multivariate Cox regression and Kaplan-Meier analyses revealed RF (HR 4.02; P = 0.004) and anti-MPO (HR 38.10; P < 0.001) positivity as risk factors associated with AAV occurrence.

CONCLUSION

Approximately 10 % of ANCA-positive IIP patients developed AAV after an IIP diagnosis. Anti-MPO or co-occurring positive RF poses a significant risk for subsequent AAV occurrence. This emphasizes the importance of careful monitoring in patients with high-risk antibody profiles, even if the complete features of AAV are not present at IIP diagnosis.

Comparison of Interstitial Lung Disease Between Antineutrophil Cytoplasmic Antibodies Positive and Negative Patients: A Retrospective Cohort Study

OBJECTIVE

Positive antineutrophil cytoplasmic antibodies (ANCAs) may occur in the setting of interstitial lung disease (ILD), with or without ANCA-associated vasculitis (AAV). We aim to compare the characteristics and clinical course of patients with ILD and positive ANCA (ANCA-ILD) to those with negative ANCA.

METHODS

We performed a single-center retrospective cohort study from 2018 to 2021. All patients with ILD and ANCA testing were included. Patient characteristics (symptoms, dyspnea scale, and systemic AAV), test results (pulmonary high-resolution computed tomography and pulmonary function tests), and adverse events were collected from electronic medical records. Descriptive statistics and the Fisher exact test were used to compare the outcomes of patients with ANCA-ILD to those with ILD and negative ANCA.

RESULTS

A total of 265 patients with ILD were included. The mean follow-up duration was 69.3 months, 26 patients (9.8%) were ANCA positive, and 69.2% of those with ANCA-ILD had another autoantibody. AAV occurred in 17 patients (65.4%) with ANCA-ILD. In 29.4% of patients, AAV developed following ILD diagnosis. Usual interstitial pneumonia was the most common radiologic pattern in patients with ANCA-ILD. There was no association between ANCA status and the evolution of dyspnea, diffusing capacity of the lungs for carbon monoxide, and lung imaging. Forced vital capacity improved over time in 42% of patients with ANCA-ILD and in 17% of patients with negative ANCA (P = 0.006). Hospitalization occurred in 46.2% of patients with ANCA-ILD and in 21.8% of patients with negative ANCA (P = 0.006). Both groups had similar mortality rates.

CONCLUSION

Routine ANCA testing should be considered in patients with ILD. Patients with ANCA-ILD are at risk for AAV. More research is required to better understand and manage patients with ANCA-ILD.

Presentation and progression of MPO-ANCA interstitial lung disease

The association between MPO-ANCA-associated vasculitis (AAV) and interstitial lung disease (ILD) has been well established. Pulmonary fibrosis may coexist with, follow, or even precede the diagnosis of AAV, and its presence adversely affects the prognosis. The optimal approach to investigating ANCA in patients with ILD remains a subject of ongoing debate. Here we aim to describe presentation and progression of MPO-ANCA ILD. We conducted a retrospective evaluation of a cohort of individuals diagnosed with MPO-ANCA ILD, with or without accompanying renal impairment, at the Immunology and Cell Therapy Unit, Careggi University Hospital, Florence, Italy, between June 2016 and June 2022. Clinical records, imaging studies, pathologic examinations, and laboratory test results were collected. Among the 14 patients identified with MPO-ANCA ILD, we observed a significant association between MPO-ANCA titers assessed at the time of ILD diagnosis and renal involvement. Renal impairment in these cases often manifested as subclinical or slowly progressive kidney damage. Interestingly, complement C3 deposits were consistently found in all renal biopsy specimens, thereby suggesting the potential for novel therapeutic targets in managing renal complications associated with MPO-ANCA ILD. The presentation of MPO-ANCA vasculitis as ILD can be the first and only clinical manifestation. MPO-ANCA levels at ILD diagnosis could warn on the progression to renal involvement in patients with MPO-ANCA ILD, hence caution is needed because renal disease can be subclinical or smoldering.

Myeloperoxidase-specific antineutrophil cytoplasmic antibody-associated vasculitis

Myeloperoxidase (MPO)-specific antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (MPO-ANCA-associated vasculitis) is one of two major ANCA-associated vasculitis variants characterised by systemic necrotising vasculitis with few or no immune deposits. MPO-ANCA-associated vasculitis predominantly affects small blood vessels and, in contrast to its counterpart proteinase 3-ANCA-associated vasculitis, is generally not associated with granulomatous inflammation. The kidneys and lungs are the most commonly affected organs. The pathogenesis of MPO-ANCA-associated vasculitis is characterised by loss of tolerance to the neutrophil enzyme MPO. This loss of tolerance leads to a chronic immunopathological response where neutrophils become both the target and effector of autoimmunity. MPO-ANCA drives neutrophil activation, leading in turn to tissue and organ damage. Clinical trials have improved the therapeutic approach to MPO-ANCA-associated vasculitis. However, there remains substantial unmet need regarding relapse frequency, toxicity of current treatment, and long-term morbidity. In this Series paper, we present the current state of research regarding pathogenesis, diagnosis, and treatment of MPO-ANCA-associated vasculitis.

Successful treatment of PR3-ANCA-positive interstitial pneumonia with a moderate dose of glucocorticoid and rituximab

Antineutrophil cytoplasmic antibody (ANCA)-positive interstitial pneumonia (IP) is reported as IP that is ANCA-positive and does not involve organ damage associated with vasculitis other than the lungs. While the combination of glucocorticoid and rituximab is effective in ANCA-associated vasculitis, the treatment strategy for ANCA-positive IP has not been established. Here, we report the first case of successful treatment of proteinase 3 (PR3)-ANCA-positive IP with a moderate dose of glucocorticoid and rituximab. The patient was an 80-year-old male who presented with subacute dry cough and dyspnoea. Blood tests revealed elevated levels of C-reactive protein, Krebs von den Lungen 6 (KL-6), and PR3-ANCA. Chest computed tomography (CT) showed interstitial shadows and infiltrates around honeycomb cysts. 18F-fluorodeoxyglucose (FDG) positron emission tomography CT revealed an uptake of FDG in the IP area. After starting treatment with a moderate dose of prednisolone and rituximab, the patient's clinical symptoms disappeared, C-reactive protein and KL-6 turned to be normal, and infiltrates around the cysts of honeycomb lungs disappeared. Prednisolone was gradually decreased to 2 mg, and no relapse or adverse events were observed during the course of treatment. Our case suggests that early treatment with a moderate dose of glucocorticoid and rituximab is effective for PR3-ANCA-positive IP.

Clinical significance of microscopic polyangiitis with interstitial lung disease and bronchiectasis: probability of preexisting comorbidities

BACKGROUND

The association between pulmonary involvement and microscopic polyangiitis (MPA) has been increasingly recognized in recent years. Whether interstitial lung disease (ILD) and bronchiectasis (BE) are disease manifestations of MPA, preexisting comorbidities or important complications remains unclear. The purpose of this study was to determine the clinical characteristics and prognosis of MPA with pulmonary involvement to further guide clinical management.

METHODS

The data for 97 patients with a definitive diagnosis of MPA were retrospectively reviewed. The MPA diagnosis was based on the 2012 revised Chapel Hill Consensus Conference (CHCC) criteria. The baseline clinical information and laboratory parameters were collected and analysed at each patient's initial diagnosis.

RESULTS

Forty-seven out of the 97 (48.5%) patients who were diagnosed with MPA presented with pulmonary involvement, including 37 patients with ILD, 12 patients with BE and two patients with diffuse alveolar haemorrhage (DAH). ILD and BE antedated MPA in 56.76% and 75.00% of the patients, respectively. Compared with that in the MPA-BE group, the serum LDH level (222.86 ± 68.19 vs. 171.58 ± 31.43, p = .016) in the MPA-ILD group was significantly higher. In the multivariate Cox analysis, elevated serum creatinine (HR 4.08, confidence interval (CI) 1.38-12.05, p = .011) was an independent risk factor for shorter survival in MPA patients with pulmonary involvement, and treatment with glucocorticoid pulse cyclophosphamide therapy (HR 0.095, 95% CI 0.019-0.47, p = .004) was independently associated with prolonged survival. Among the patients in the MPA-ILD group, acute exacerbations of ILD (HR 4.55 CI 1.16-17.86, p = .029) and elevated serum creatinine (HR 4.95, CI 1.39-17.54, p = .014) were independently associated with a poor prognosis, and treatment with glucocorticoids (HR 0.057, 95% CI 0.012-0.28, p < .001) was independently associated with significant prolongation of survival.

CONCLUSIONS

Patients with MPA have a high prevalence of pulmonary involvement, and ILD is the most common subtype of MPA. ILD and BE can be considered preexisting comorbidities of MPA. Elevated serum creatinine was associated with shorter survival. However, remission induction regimens with glucocorticoids and/or immunosuppressants may improve this outcome.

Outcomes and prognosis of progressive pulmonary fibrosis in patients with antineutrophil cytoplasmic antibody-positive interstitial lung disease

Approximately one-third of fibrosing interstitial lung diseases exhibit progressive pulmonary fibrosis (PPF), a clinicopathological condition distinct yet resembling idiopathic pulmonary fibrosis (IPF). PPF in ANCA-positive ILD (ANCA-ILD) is poorly documented. To clarify incidence, predictors of PPF in ANCA-ILD, and their prognostic impact, 56 patients with ANCA-ILD were followed for ≥ 1 year (April 2004 to April 2021). PPF was defined per ATS/ERS/JRS/ALAT PPF 2022 guideline. We compared PPF and non-PPF in 38 patients with pulmonary function tests and ≥ 1 year follow up. ANCA-ILD (19 male, 19 female; mean age 72 years) comprised 21 patients with microscopic polyangiitis ILD (MPA-ILD) and 17 with ANCA-positive IP without systemic vasculitis (ANCA-IP). PPF occurred in 15/38 (39.5%) overall, and 27% of patients with MPA-ILD and 53% with ANCA-IP. Patient characteristics did not differ between PPF and non-PPF, however, the survival was significantly worse in patients with PPF than those with non-PPF. On multivariate regression analysis, higher age, higher serum SP-D level, and lower baseline %FVC were associated with PPF. In ANCA-ILD, 39.5% of patients demonstrated PPF, which is associated with increased mortality. Predictors of PPF were older age, higher SP-D, and lower baseline %FVC.

Interstitial lung disease in ANCA-associated vasculitis: associated factors, radiographic features and mortality

OBJECTIVE

To evaluate the prevalence, clinical and radiographic features, and long-term outcomes of interstitial lung disease (ILD) in a United States-based ANCA-associated vasculitis (AAV) cohort.

METHODS

In this retrospective cohort study, we identified cases of ILD within the 2002-2019 Mass General Brigham AAV Cohort, a consecutive inception cohort of PR3- or MPO-ANCA+ AAV patients. ILD diagnosis and classification as fibrotic or non-fibrotic were confirmed by review of available chest imaging by two board-certified radiologists. Cox proportional hazard models, with age as the time scale, were used to estimate the association of AAV-ILD with all-cause mortality.

RESULTS

Of 684 patients in the MGB AAV Cohort, 91 (13%) had ILD which preceded the diagnosis of AAV by a mean of 2.2 years. AAV-ILD patients were older (67 vs 60 years, P < 0.001) than patients without ILD but the distribution of sex and race was similar. AAV-ILD patients were more often MPO-ANCA+ (93% vs 65%, P < 0.001); among MPO-ANCA+ patients (n = 470), 85 (18%) had ILD. The majority of ILD was fibrotic (76%) and UIP was the most common ILD pattern (42%). The baseline forced vital capacity (FVC) % predicted among ILD patients was 81 ± 20%. Fibrotic AAV-ILD was associated with a 58% higher risk of death (aHR 1.58, 95% CI 1.06, 2.37) compared with AAV patients without ILD.

CONCLUSION

ILD is a frequent complication of AAV, especially MPO-ANCA+ AAV, often preceding recognition of AAV. Fibrotic AAV-ILD is associated with a higher risk of death than AAV without ILD.

Long-term clinical course and outcomes of patients with microscopic polyangiitis-associated interstitial lung disease

Background: Interstitial lung disease (ILD) is a significant complication associated with microscopic polyangiitis (MPA) that has a poor prognosis. However, the long-term clinical course, outcomes, and prognostic factors of MPA-ILD are not well defined. Hence, this study aimed to investigate the long-term clinical course, outcomes, and prognostic factors in patients with MPA-ILD. Methods: Clinical data of 39 patients with MPA-ILD (biopsy proven cases, n = 6) were retrospectively analyzed. High resolution computed tomography (HRCT) patterns were assessed based on the 2018 idiopathic pulmonary fibrosis diagnostic criteria. Acute exacerbation (AE) was defined as the worsening of dyspnea within 30 days, with new bilateral lung infiltration that is not fully explained by heart failure or fluid overload and that does not have identified extra-parenchymal causes (pneumothorax, pleural effusion, or pulmonary embolism). Results: The median follow-up period was 72.0 months (interquartile range: 44-117 months). The mean age of the patients was 62.7 years and 59.0% were male. Usual interstitial pneumonia (UIP) and probable usual interstitial pneumonia patterns on high resolution computed tomography were identified in 61.5 and 17.9% of the patients, respectively. During the follow-up, 51.3% of patients died, and the 5- and 10-year overall survival rates were 73.5% and 42.0%, respectively. Acute exacerbation occurred in 17.9% of the patients. The non-survivors had higher neutrophil counts in bronchoalveolar lavage (BAL) fluid and more frequent acute exacerbation than the survivors. In the multivariable Cox analysis, older age (hazard ratio [HR], 1.07; 95% confidence interval [CI], 1.01-1.14; p = 0.028) and higher BAL counts (HR, 1.09; 95% CI, 1.01-1.17; p = 0.015) were found to be the independent prognostic factors associated with mortality in patients with MPA-ILD. Conclusion: During the 6 years-follow-up, about half of patients with MPA-ILD died and approximately one-fifth experienced acute exacerbation. Our results suggest that older age and higher BAL neutrophil counts mean poor prognosis in patients with MPA-ILD.

Clinical significance of acute exacerbation in interstitial lung disease with antineutrophil cytoplasmic antibody: an indicator of poor prognosis

BACKGROUND

The association between interstitial lung disease (ILD) and antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) has been increasingly recognized in recent years. The clinical features and prognostic differences between AAV-associated ILD and isolated ANCA-positive idiopathic interstitial pneumonias (IIPs) remain unclear. The purpose of this study was to determine the clinical significance and prognosis of ANCA-positive ILD to further guide clinical management.

METHODS

This study retrospectively reviewed the data of 379 ILD patients with available ANCA results and ultimately analysed 49 ANCA-positive patients. AAV diagnosis was based on the 2012 revised Chapel Hill Consensus Conference (CHCC) criteria, and 33 of 49 patients were diagnosed with microscopic polyangiitis (MPA). The baseline clinical information and laboratory parameters were collected and analysed at each patient's initial diagnosis.

RESULTS

Among 49 ANCA-positive ILD patients, the high-resolution computed tomography (HRCT) pattern was mainly usual interstitial pneumonia (UIP) (59.18%), followed by nonspecific interstitial pneumonia (NSIP) (26.53%). The C-reactive protein (CRP) level (43.89± 40.61 versus 18.74± 20.05, p = 0.028) and erythrocyte sedimentation rate (ESR) (71.97± 42.73 versus 40.69± 28.46, p = 0.011) were significantly higher in the MPA-ILD group than in the ANCA-IIP group. Haemoglobin (113.09 ± 24.47 versus 132.19± 13.34, p = 0.006) and albumin (32.95± 5.84 versus 36.52± 3.94, p = 0.032) levels were significantly lower. Survival was shorter among MPA-ILD patients than among ANCA-IIP patients [hazard ratio (HR) 3.38, 95% confidence interval (CI) 1.32-8.67, p = 0.040]. In the multivariable Cox analysis, a diagnosis of MPA (HR 3.91, 95% CI 1.07-14.08, p = 0.038) and acute exacerbation (AE) of ILD (HR 9.43, 95% CI 2.89-30.30, p < 0.001) were significantly independently associated with shorter survival in ANCA-positive ILD patients, and the NSIP pattern (HR 0.07, 95% CI 0.01-0.41, p = 0.003) was independently associated with prolonged survival.

CONCLUSION

ANCA-ILD patients mostly have myeloperoxidase (MPO)-ANCA positivity and an MPA diagnosis. Survival was shorter among MPA-ILD patients than among ANCA-IIP patients. Respiratory failure and AE were associated with poorer prognosis. Early antifibrotic treatment may be a reasonable treatment option in fibrotic ILD patients with ANCA positivity.

Interstitial Pneumonia with HLA-B54 Antigen that Responded Well to Erythromycin

A 65-year-old Japanese man with interstitial pneumonia demonstrated honeycomb lung with thickened walls on chest high-resolution computed tomography (HRCT) and predominance of neutrophils in the cell fraction of the bronchoalveolar lavage fluid. Although there were no centrilobular nodular or branching shadows on chest HRCT suggestive of diffuse panbronchiolitis, he exhibited sinusitis and had the human leukocyte antigen (HLA)-B54 antigen. With long-term macrolide therapy, the cough and sputum production markedly improved, wall thickening of the honeycomb lung on chest HRCT decreased, and the forced vital capacity increased. Confirming the presence of HLA-B54 antigen may help determine the indication for long-term macrolide therapy in interstitial pneumonia patients.

Current perspective of progressive-fibrosing interstitial lung disease

Interstitial lung disease (ILD) is a parenchymal lung disease and restrictive disorder that presents as diffuse infiltrative shadows. The initial diagnosis of ILD is important because management strategies depend on the disease pathogenesis. Connective-tissue disease (CTD)-associated ILD including rheumatoid arthritis (RA), systemic sclerosis (SSc) requires a thorough evaluation of chronic respiratory symptoms such as non-productive cough and exertional dyspnea, as well as physical findings. Moreover, myeloperoxidase-positive anti-neutrophilic cytoplasmic antibody (MPO-ANCA)-associated vasculitis with ILD also shows disease progression. In CTD-associated ILD, the first-line treatment is anti-inflammatory drugs such as prednisolone or immunosuppressants. In hypersensitivity pneumonitis (HP), detailed environmental history-taking is crucial. Therefore, systematic standardized questionnaires are needed. However, the causative antigens are often not identified in daily clinical practice. When an antigen is identified or suspected, the first action is avoidance. If antigen avoidance does not contribute to clinical improvement, anti-inflammatory drugs such as prednisolone might be introduced. Regarding sarcoidosis, while most patients do not require treatment for lung involvement, some need anti-inflammatory drugs or immunosuppressants. Additionally, steroid treatment should be considered for the critical status of extrapulmonary sarcoidosis including cardiac, neurogenic and ocular sarcoidosis. Once starting treatment for ILD, multi-dimensional approaches are applied, including symptom tracking, chest imaging, pulmonary function test (PFT), and 6-min walking test. Recently, the concept of progressive-fibrosing interstitial lung disease (PF-ILD) has been proposed as a new disease entity. The definition of PF-ILD includes symptom progression, PFT decline, and extension of chest high-resolution computed tomography (HRCT) findings. This mini-review describes the background, definition, clinical characteristics, management, and challenges of PF-ILD.

Anti-Inflammatory and/or Anti-Fibrotic Treatment of MPO-ANCA-Positive Interstitial Lung Disease: A Short Review

The presence of a lung lesion is common in microscopic polyangiitis (MPA), and interstitial lung disease (ILD) can lead to a poor prognosis. Although myeloperoxidase antineutrophil cytoplasmic antibodies (MPO-ANCA) are often present in patients with MPA, patients with ILD and MPO-ANCA positivity but without other manifestations of systemic vasculitis have also been reported. Therefore, the possible association between MPO-ANCA, MPA, and idiopathic ILD remains unclear. This problematic matter has influenced the treatment strategy of MPO-ANCA-positive ILD patients without systemic vasculitis. Clinicians should undertake treatment with careful consideration of the four major causes of death in MPO-ANCA-positive ILD: acute exacerbation of ILD, progressive lung fibrosis, infectious comorbidities, and diffuse alveolar hemorrhage. Further, clinicians need to carefully judge whether inflammation or fibrosis is the dominant condition with reference to the patient’s clinical domain and radiopathological lung features. Recently, anti-fibrotic agents such as nintedanib and pirfenidone were shown to be effective in treating various etiologies associated with ILD and have thus led to the widening of treatment options. In this review, the clinical characteristics, radiopathology, prognosis, and therapeutic options in patients with MPO-ANCA-positive ILD are summarized using limited information from previous studies.

ANCA-associated vasculitis in idiopathic pulmonary fibrosis: A case report and brief review of the literature

RATIONALE

Idiopathic pulmonary fibrosis (IPF) is a progressive disease with poor prognosis. Patients with IPF represent a heterogeneous population with several described clinical phenotypes. More recently, the development of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis in IPF patients, with an incidence higher than that in the general population, has drawn attention.

PATIENT CONCERNS

A 64-year-old woman previously diagnosed with IPF presented to the emergency department with hemoptysis and hypoxemic respiratory failure.

DIAGNOSES

High-resolution chest computed tomography revealed bilateral ground-glass opacities associated with areas of consolidation superimposed on the patient's fibrotic background pattern. Diffuse alveolar hemorrhage was confirmed by the presence of hemorrhagic bronchoalveolar lavage fluid. Hematological and biochemical investigations revealed an inflammatory syndrome, moderate anemia, and rapidly progressive glomerulonephritis. Serological analysis revealed perinuclear antineutrophil cytoplasmic antibody positivity and high levels of antimyeloperoxidase antibodies antibodies. The patient underwent kidney biopsy, which revealed necrotizing glomerulonephritis. Clinical and laboratory findings were diagnostic of microscopic polyangiitis with lung and renal involvement.

INTERVENTIONS

Cyclophosphamide in combination with methylprednisolone was administered as remission induction therapy. The maintenance therapy consisted of mycophenolate mofetil and prednisone.

OUTCOMES

The patient achieved clinical, radiological, and serological remission within six weeks of treatment.

LESSONS

The association between IPF and ANCA-associated vasculitis may represent a distinct clinical phenotype. Autoimmune testing for ANCAs should be considered part of the diagnostic work-up and follow-up of patients with IPF because of the clinical and therapeutic implications of developing vasculitis in an already vulnerable patient.

Antineutrophil cytoplasmic antibody-associated interstitial lung disease: a review

Over the past three decades, an increasing number of publications have reported the association between interstitial lung disease (ILD) and anti-neutrophil cytoplasmic antibody (ANCA) or ANCA-associated vasculitis (AAV). With this increased awareness, we have reviewed the literature to date and provide an update in this narrative review. The vast majority of cases of ILD have been shown to be in the setting of positive anti-myeloperoxidase antibody and can be present in up to 45% of patients of microscopic polyangiitis, though cases of ILD associated with proteinase 3 ANCA have rarely been reported. Pulmonary fibrosis and ANCA positivity can occur with or without systemic involvement. The pathogenetic mechanisms establishing the relationship between ANCA and the development of pulmonary fibrosis remain unclear. Histologic and radiographic features of ANCA-ILD most commonly reveal usual interstitial pneumonia or non-specific interstitial pneumonia patterns, though other atypical features such as bronchiolitis have been described. ILD in the setting of AAV has been associated with worse outcomes, and thus early identification and treatment in these patients is appropriate. We advocate that ANCA antibody testing be performed as a baseline evaluation in patients presenting with idiopathic interstitial pneumonia. Suggested treatment of ANCA-ILD includes immunosuppression and/or antifibrotic agents, though supporting data and clinical trials to substantiate use of these therapies are needed.

Interstitial Lung Disease in Antineutrophil Cytoplasmic Antibody-Associated Vasculitis Patients: Comparison With Idiopathic Pulmonary Fibrosis

BACKGROUND/OBJECTIVE

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) may involve the kidney, respiratory tract, skin, or central and peripheral nervous system. Reports of interstitial lung disease (ILD) in AAV (AAV-ILD) have been increasing.

METHODS

We reviewed the medical records of all patients with AAV-ILD between January 1, 2007, and December 31, 2017, and compared their pulmonary involvement to patients with idiopathic pulmonary fibrosis (IPF).

RESULTS

We identified 24 patients with AAV-ILD: 14 with microscopic polyangiitis, 8 with granulomatosis with polyangiitis, and 2 with eosinophilic granulomatosis with polyangiitis. Perinuclear or myeloperoxidase ANCA was present in 16 cases (66.7%), whereas cytoplasmic or proteinase 3 ANCA was positive in 8 (33.3%). Usual interstitial pneumonia (UIP) was seen in 11 (45.8%), probable UIP in 1 (4.2%), indeterminate UIP in 2 (8.3%), and an alternate diagnosis in 10 (41.7%), and was further characterized as chronic hypersensitivity pneumonitis-like pattern seen in 6 (25%), nonspecific interstitial pneumonia-like pattern in 3 (12.5%), and cryptogenic organizing pneumonia-like pattern in 1 (4.2%). Forced vital capacity and diffusing capacity declined over time in patients with AAV-ILD. When compared with the IPF cohort, patients with AAV-ILD had intermediate survival and speed of lung function decline (3-year survival in AAV-ILD group was 94% vs 69% in IPF).

CONCLUSIONS

Antineutrophil cytoplasmic antibody-associated vasculitis ILD is a progressive and potentially fatal condition. Although most cases in the literature are associated with p-ANCA and positive myeloperoxidase, we found that a third of patients had c-ANCA or granulomatosis with polyangiitis. Our cohort adds experience in this rare manifestation of AAV.

Prognostic value of radiological findings indeterminate for UIP pattern and anterior upper lobe honeycomb-like lesion in chronic fibrosing interstitial lung disease associated with MPO-ANCA

Background

Myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA) is often positive in patients with interstitial lung disease (ILD), which is also often present in patients with microscopic polyangiitis (MPA). A possible association between MPO-ANCA, MPA, and idiopathic ILD remains unclear. The objective of this study was to determine whether high-resolution computed tomography (HRCT) classification based on recent idiopathic pulmonary fibrosis guideline and specific CT findings can obtain new knowledge of prognostic factors in all MPO-ANCA-positive patients with ILD including both idiopathic ILD and MPA-ILD.

Methods

We analyzed 101 consecutive MPO-ANCA-positive patients with respiratory disease. We assessed the diagnostic accuracy of CT findings, HRCT pattern, and specific radiological signs. Prognostic predictors were determined using Cox regression models.

Results

Subjects with chronic ILD included 22 patients with MPA-ILD and 39 patients with ILD but without MPA. A quarter of the patients were radiological indeterminate for usual interstitial pneumonia (UIP) pattern, which resulted in a better prognosis than that for UIP pattern. “Increased attenuation around honeycomb and traction bronchiectasis” and “anterior upper lobe honeycomb-like lesion” were found to be highly frequent radiological findings (39% and 30%, respectively). In addition, the latter finding was a significant negative prognostic factor.

Conclusions

Radiological indeterminate for UIP was a useful HRCT classification in MPO-ANCA-positive patients with ILD. In addition, anterior upper lobe honeycomb-like lesion was found to be specific radiological finding that was a significant prognostic factor. The present results might aid in the assessment of appropriate strategies of diagnosis in these patients.

2020 guide for the diagnosis and treatment of interstitial lung disease associated with connective tissue disease

The prognosis of patients with connective tissue disease (CTD) has improved significantly in recent years, but interstitial lung disease (ILD) associated with connective tissue disease (CTD-ILD) remains a refractory condition, which is a leading cause of mortality. Because it is an important prognostic factor, many observational and interventional studies have been conducted to date. However, CTD is a heterogeneous group of conditions, which makes the clinical course, treatment responses, and prognosis of CTD-ILD extremely diverse. To summarize the current understanding and unsolved questions, the Japanese Respiratory Society and the Japan College of Rheumatology collaborated to publish the world's first guide focusing on CTD-ILD, based on the evidence and expert consensus of pulmonologists and rheumatologists, along with radiologists, pathologists, and dermatologists. The task force members proposed a total of 27 items, including 7 for general topics, 9 for disease-specific topics, 3 for complications, 4 for pharmacologic treatments, and 4 for non-pharmacologic therapies, with teams of 2-4 authors and reviewers for each item to prepare a consensus statement based on a systematic literature review. Subsequently, public opinions were collected from members of both societies, and a critical review was conducted by external reviewers. Finally, the task force finalized the guide upon discussion and consensus generation. This guide is expected to contribute to the standardization of CTD-ILD medical care and is also useful as a tool for promoting future research by clarifying unresolved issues.

Myeloperoxidase and associated lung disease: Review of the latest developments

Myeloperoxidase (MPO) anti-neutrophil cytoplasmic antibodies (ANCA) are often detected in association with a variety of lung pathologies, the most common being interstitial lung disease (ILD). A growing cohort of patients are being diagnosed with MPO-ANCA in the context of ILD without ANCA-associated vasculitis. Clinically and radiologically, there is little to differentiate this cohort from MPO-ANCA-negative ILD patients; however, the pathophysiology is likely different and different treatments are likely required. We present here a brief summary of the proposed pathophysiology of MPO-ANCA-positive ILD, and a more detailed review of the latest evidence on management, including monitoring for development of ANCA-associated vasculitis, immunosuppression, anti-fibrotics, and novel agents that have yet to be trialled in human experiments.

Interstitial Lung Disease and Diffuse Alveolar Hemorrhage, the Two Key Pulmonary Manifestations in Microscopic Polyangiitis

Microscopic polyangiitis (MPA) is an antineutrophil cytoplasmic antibody (ANCA)‒associated necrotizing vasculitis, which mainly affects small vessels in various organs, especially the lungs. The two key pulmonary manifestations, interstitial lung disease (ILD) and diffuse alveolar hemorrhage (DAH), increase the morbidity and death rate of patients with MPA. ILD is more common in MPA than in other ANCA-associated vasculitis subsets and is primarily associated with myeloperoxidase-ANCA. Unlike alveolar hemorrhage due to pulmonary capillaritis, ILD can initially manifest as isolated pulmonary fibrosis. Of note, its most frequent radiographic pattern is the usual interstitial pneumonia pattern, similar to the characteristic pattern seen in idiopathic pulmonary fibrosis. In this review we present the pathogenesis, clinical manifestations, and radiographic and histopathologic features of ILD and DAH in MPA. We also briefly summarize the outcome and therapeutic options for the two conditions.

Antithrombin III as predictive indicator of survival in idiopathic pulmonary fibrosis (IPF) patients treated with nintedanib: a preliminary study

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease often managed with nintedanib, a tyrosine kinase inhibitor targeting several profibrotic pathways. Although clotting processes are involved in wound healing and repair in the lung, there are no data on the role of antithrombin III (ATIII) in IPF patients treated with nintedanib. A previous proteomic analysis of serum of IPF patients before and after 1 year of nintedanib treatment showed differential protein expression of ATIII.

AIMS

Here we used quantitative methods to evaluate differential ATIII concentrations in IPF patients before and after 1 year of nintedanib treatment and to assess the potential of ATIII as a prognostic biomarker in IPF patients.

METHODS

Serum levels of ATIII were measured by enzyme-linked immunosorbent assay in 14 IPF patients before and after 1 year of nintedanib treatment.

RESULTS

A statistically significant inverse correlation was found between serum ATIII concentrations and pulmonary function test parameters in all patients at baseline and follow up. Baseline serum ATIII and bronchoalveolar lavage (BAL) neutrophils proved to be reliable predictors of poor prognosis. A baseline ATIII threshold of 126.5 μg/mL discriminated survivors from non-survivors.

CONCLUSIONS

After 12 months of antifibrotic treatment, IPF patients with high serum ATIII concentrations and high BAL neutrophil percentages had a poor prognosis and increased survival risk. The results of this preliminary study suggest that ATIII has potential as a biomarker of IPF severity and in predicting response to nintedanib therapy. As a marker, ATIII showed several advantages over BAL neutrophil percentage.

Interstitial Lung Disease and Anti-Myeloperoxidase Antibodies: Not a Simple Association

Anti-neutrophil cytoplasmic antibodies (ANCA), mainly anti-myeloperoxidase (MPO) antibodies, have been frequently identified in patients with idiopathic pulmonary fibrosis (IPF). However, their role remains unclear, and only 7–23% of these patients develops clinically overt vasculitis. We aimed to investigate the clinical, serological, and radiological features and prognosis of anti-MPO-positive interstitial lung disease (ILD) patients. Fifty-eight consecutive patients firstly referred for idiopathic interstitial pneumonia and showing serological positivity of anti-MPO antibodies were retrospectively enrolled. For each patient, clinical data, lung function testing, chest high-resolution computed tomography (HRCT) pattern, and survival were recorded. Thirteen patients developed a rheumatic disease during a median follow-up of 39 months. Usual interstitial pneumonia (UIP) was the most frequent ILD pattern, significantly influencing the patients’ survival. In fact, while the 52-week survival of the overall population was 71.4 ± 7.5%, significantly higher than IPF, survivals of anti-MPO patients with UIP pattern and IPF were similar. Forced vital capacity and diffusion lung capacity for CO significantly declined in 37.7 and 41.5% of cases, respectively, while disease progression at chest HRCT was observed in 45.2%. A careful clinical history and evaluation should always be performed in ILD patients with anti-MPO antibodies to quickly identify patients who are developing a systemic rheumatic disease.

Risk of progression of idiopathic pulmonary fibrosis to connective tissue disease: a long-term observational study in 527 patients

OBJECTIVE

Connective tissue disease (CTD) might occur during the course of idiopathic pulmonary fibrosis (IPF). Clinical factors associated with CTD development in IPF patients have still not been identified. We investigated which antibodies have a significant association with the development of CTD during the clinical course of IPF.

METHODS

We retrospectively reviewed the records of 527 patients with a first diagnosis of IPF between January 2007 and March 2014 and investigated the time to CTD development after IPF diagnosis in these patients.

RESULTS

CTD developed in 15 patients at a median of 2.1 years (range 1.2-4.8) after IPF diagnosis. All patients had anti-neutrophil cytoplasmic antibodies (ANCA) or autoantibodies that met the serology criteria for interstitial pneumonia with autoimmune features (IPAF). Survival duration for IPF patients with progression to CTD was 5.3 (3.8, 6.7) years, which was significantly longer than for IPF patients without progression to CTD [2.9 (1.7, 4.8), p = 0.001]. Independent risk factors for CTD development in IPF patients included female gender [adjusted hazard ratio (HR) 5.319, p = 0.0082], titer of rheumatoid factor (RF; adjusted HR, 1.006; p = 0.022), titer of anti-citrullinated protein antibody (ACPA; adjusted HR, 1.009; p = 0.0011), and titer of myeloperoxidase (MPO)-ANCA (adjusted HR, 1.02; p < 0.0001).

CONCLUSION

Progression to CTD is uncommon in IPF patients. However, a significant number of IPF patients with high titers of RF, ACPA, or MPO-ANCA progressed to CTD. RF, ACPA, and MPO-ANCA might be significantly associated with CTD development in IPF patients. Key Points • A significant number of IPF patients with high titers of RF, ACPA, or MPO-ANCA progressed to CTD. • IPF/UIP with high titers of RF, ACPA, or MPO-ANCA might be the initial clinical manifestation of CTD. • RF, ACPA, and MPO-ANCA may be significantly associated with the development of pulmonary fibrosis in patients with CTD.

Clinical features and long-term outcomes of interstitial lung disease with anti-neutrophil cytoplasmic antibody

Background

Patients with interstitial lung disease (ILD) are occasionally positive for anti-neutrophil cytoplasmic antibodies (ANCAs). Differences between ILDs secondary to microscopic polyangiitis (MPA) and isolated ANCA-positive idiopathic interstitial pneumonia (IIP) remain unclear. The aim of this study was to explore the differences in clinical features and outcomes between MPA-associated ILDs and isolated ANCA-positive IIPs.

Methods

We reviewed 1338 ILDs patients with available ANCA results and retrospectively analysed 80 patients who were ANCA-positive. MPA-associated ILDs (MPA-ILDs group) and isolated ANCA-positive IIPs (ANCA-IIPs group) were compared.

Results

Among 80 patients with ANCA-positive ILDs, 31 (38.75%) had MPA-ILDs, and 49 (61.25%) had isolated ANCA-positive IIPs. Compared with ANCA-IIPs group, patients in MPA-ILDs group had a higher proportion of fever (p = 0.006) and higher neutrophil count (p = 0.011), erythrocyte sedimentation rate (ESR) (p < 0.001) and C-reactive protein (CRP) (p = 0.005). Multivariable analysis showed that ESR level was an independent risk factor for mortality in all 80 ANCA-positive ILDs patients (HR 1.028, p = 0.001). Survival in MPA-ILDs group was lower than that in ANCA-IIPs group, and further stratified analysis revealed that ANCA-IIPs patients with elevated ESR or CRP had a worse prognosis than those with normal inflammation markers, with 5-year cumulative survival rates of 60.00%, 86.90% and 100.00% in MPA-ILDs and ANCA-IIPs with and without elevated inflammation markers, respectively.

Conclusions

Among patients with ANCA-positive ILDs, the prognoses of ANCA-IIPs with normal inflammation markers, ANCA-IIPs with elevated inflammation markers and MPA-ILDs were sequentially poorer. Therefore, stratified treatment should be considered in the management of ILDs patients positive for ANCAs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01451-4.

Clinical implications of ANCA positivity in idiopathic pulmonary fibrosis patients

The diagnostic process of idiopathic interstitial pneumonias (IIPs) is complex and the underlying mechanisms that participate in these diseases still need to be fully understood. In 2015, the European Respiratory Society/American Thoracic Society Task Force on Undifferentiated Forms of Connective Tissue Disease-Associated Interstitial Lung Disease introduced the term “interstitial pneumonia with autoimmune features” (IPAF) to identify subjects with IIP and features suggesting background autoimmunity but not characterisable connective tissue disease (CTD) [1]. The need for a proper clinical, serological and morphological assessment of IIP was highlighted to identify potential subjects with IPAF and CTD-ILD. However, the measurement of anti-neutrophil cytoplasmic antibodies (ANCAs) is not included in the definition of IPAF and ANCA serological testing is only recommended in idiopathic pulmonary fibrosis (IPF) when a clinical suspicion of vasculitis exists [2]. As current research evaluates the prognostic relevance of autoimmune features in IIP, the clinical importance of ANCA positivity still needs to be determined.

ANCA positivity is uncommon in North American IPF patients. However, women with IPF who areMPO-positive have a considerable risk for developing clinical manifestations of vasculitis.http://bit.ly/2RlsQNP

Management of ANCA associated vasculitis

Anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis (AAV) is a small to medium vessel vasculitis associated with excess morbidity and mortality. This review explores how management of AAV has evolved over the past two decades with pivotal randomized controlled trials shaping the management of induction and maintenance of remission. Contemporary AAV care is characterized by approaches that minimize the cumulative exposure to cyclophosphamide and glucocorticoids, increasingly use rituximab for remission induction and maintenance, and consider therapies with less toxicity (for example, methotrexate, mycophenolate mofetil) for manifestations of AAV that do not threaten organ function or survival. Simultaneously, improvements in outcomes, such as renal and overall survival, have been observed. Additional trials and observational studies evaluating the comparative effectiveness of agents for AAV in various patient subgroups are needed. Prospective studies are necessary to assess the effect of psychosocial interventions on patient reported outcomes in AAV. Despite the expanding array of treatments for AAV, little guidance on how to personalize AAV care is available to physicians.

Prognosis of pulmonary fibrosis presenting with a usual interstitial pneumonia pattern on computed tomography in patients with myeloperoxidase anti-neutrophil cytoplasmic antibody-related nephritis: a retrospective single-center study

Background

Myeloperoxidase anti-neutrophil cytoplasmic antibody-related nephritis (MPO-ANCA nephritis) is occasionally accompanied by lung abnormalities such as pulmonary fibrosis. However, the clinical features of pulmonary fibrosis in patients with MPO-ANCA nephritis have not been well documented. This study was performed to compare the prognosis of a usual interstitial pneumonia (UIP) pattern of lung fibrosis in patients with MPO-ANCA nephritis with the prognosis of idiopathic pulmonary fibrosis (IPF).

Methods

We retrospectively reviewed the medical records of 126 patients with MPO-ANCA nephritis and identified 31 with a UIP pattern of lung fibrosis on high-resolution or thin-slice computed tomography (CT). We compared the characteristics and prognosis of these patients with those of 32 patients with IPF. In 18 patients from both groups, we assessed and compared the decline in lung volume over time using three-dimensional (3D) CT images reconstructed from thin-section CT data.

Results

The numbers of male and female patients were nearly equal among patients with MPO-ANCA nephritis exhibiting a UIP pattern; in contrast, significant male dominancy was observed among patients with IPF (p = 0.0021). Significantly fewer smokers were present among the patients with MPO-ANCA nephritis with a UIP pattern than among those with IPF (p = 0.0062). There was no significant difference in the median survival time between patients with MPO-ANCA nephritis with a UIP pattern (50.8 months) and IPF (55.8 months; p = 0.65). All patients with IPF in this cohort received antifibrotic therapy (pirfenidone or nintedanib). Almost half of the deaths that occurred in patients with MPO-ANCA nephritis with a UIP pattern were caused by non-respiratory-related events, whereas most deaths in patients with IPF were caused by respiratory failure such as acute exacerbation. In the 3D CT lung volume analyses, the rate of decline in lung volume was equivalent in both groups.

Conclusions

MPO-ANCA nephritis with a UIP pattern on CT may have an unfavorable prognosis equivalent to that of IPF with a UIP pattern treated with antifibrotic agents.

Autoantibodies in interstitial lung diseases

The role of autoantibody testing for patients with interstitial lung disease is an evolving area. Recent guidelines recommend routine anti-nuclear antibodies, rheumatoid factor, and anti-citrullinated cyclic peptide antibody testing for patients undergoing diagnostic evaluation for interstitial lung disease, with further autoantibody testing reserved for selected cases guided by rheumatological features. Even this approach may miss patients with clinically significant autoantibodies when interstitial lung disease is the dominant or first manifestation of autoimmune disease. We retrospectively performed autoimmune serology in a clinically well characterised cohort of interstitial lung disease patients. Using stored serum, additional testing was performed to ensure all patients had complete autoantibody profiles including anti-nuclear antibodies, extractable nuclear antigen antibodies, double-stranded DNA antibodies, rheumatoid factor, anti-citrullinated cyclic peptide antibodies, anti-neutrophil cytoplasmic antibodies, and myositis antibodies. Eighty patients with interstitial lung disease, and available stored serum, were assessed. Mean age at interstitial lung disease diagnosis was 65.2 years and 42 patients were male. Positive autoimmune serology was found in 56 of 80 (70.0%) patients; the most common positive result was anti-nuclear antibodies (n=34; 42.5%). Myositis antibodies were detected in 13 of 80 (16.2%) patients. Four (5%) patients had elevated anti-citrullinated cyclic peptide antibodies, and two (2.5%) patients had detectable myeloperoxidase antibodies. Eleven (13.7%) patients with negative anti-nuclear antibodies had other significant disease associated autoantibodies. An extended panel of autoantibody testing may detect cases of connective tissue disease associated interstitial lung disease, regardless of clinical or radiological subtype, and prior to extra-pulmonary manifestations of systemic autoimmunity.

Prevalence and Clinical Significance of Antineutrophil Cytoplasmic Antibodies in North American Patients With Idiopathic Pulmonary Fibrosis

BACKGROUND

Antineutrophil cytoplasmic antibodies (ANCAs) have been reported to occur in 7% to 10% of patients with idiopathic pulmonary fibrosis (IPF), but their clinical relevance remains unclear. The aim of this study was to estimate the prevalence of ANCAs in a North American population with IPF and evaluate their clinical significance.

METHODS

This was a retrospective study of two independent cohorts of patients diagnosed with IPF at the University of California San Francisco (discovery cohort) and the University of Chicago (replication cohort). Myeloperoxidase (MPO) and proteinase 3 (PR3) ANCAs were measured in all patients. Prevalence and associations of ANCAs with clinical characteristics and transplant-free survival were evaluated.

RESULTS

A total of 14 of 353 (4.0%; 95% CI, 2.2-6.5) and 20 of 392 (5.1%; 95% CI, 3.1-7.8) patients with IPF were positive for ANCAs at the time of diagnosis in the discovery and replication cohorts, respectively. Among those positive for MPO antibodies, two of six (33%) in the discovery cohort and three of 12 (25%) in the replication cohort developed vasculitis. None of the patients who were PR3-positive developed vasculitis. Patients who were ANCA-positive were more likely to be women than patients who were ANCA-negative, and were more likely to have some ground-glass opacities on CT scan. In the combined cohort of 745 patients, median transplant-free survival was not significantly different in patients who were ANCA-positive vs ANCA-negative (P = .57).

CONCLUSIONS

ANCA positivity is uncommon in North American patients with IPF and not associated with baseline disease severity or transplant-free survival; however, a significant proportion of patients who are MPO-positive with IPF develop clinical vasculitis.

Systematic review and meta-analysis of clinical significance of autoantibodies for idiopathic pulmonary fibrosis

OBJECTIVE

To clarify clinical significance of the sole presence of autoantibodies for idiopathic pulmonary fibrosis (IPF) without any other symptoms or signs suggestive of autoimmune disease.

DESIGN

Systematic review and meta-analysis DATA SOURCES: Medline, EMBASE, Science Citation Index Expanded and Google Scholar were searched from 1 January 2002 through 12 February 2019.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Primary studies addressing all-cause mortality and the development of a defined autoimmune disease for IPF with autoantibodies were included for the review.

DATA EXTRACTION AND SYNTHESIS

Two reviewers extracted relevant data and assessed risk of bias independently. Meta-analysis was conducted using a random-effects model if three or more studies reported the same outcome for a certain autoantibody. The quality of evidence was assessed by the Grades of Recommendation, Assessment, Development and Evaluation system.

RESULTS

Out of 4603 records retrieved nine studies were included in this review. All studies contained some risk of bias. Based on pooled data myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA) was significantly associated with microscopic polyangiitis incidence with risk ratio (RR) of 20.2 (95% CI: 7.22 to 56.4) and antinuclear antibody (ANA) was also significantly associated with the development of connective tissue diseases with RR of 7.11 (p=0.001) (10 cases in 157 patients with ANA) in one study. However, there was no significant association of autoantibodies with all-cause mortality aside from MPO-ANCA and proteinase 3-ANCA in one study each. MPO-ANCA was not demonstrated to be associated with all-cause mortality by meta-analysis. The quality of evidence was deemed as either low or very low.

CONCLUSIONS

The presence of autoantibodies such as MPO-ANCA and ANA was demonstrated to be associated with the development of some autoimmune diseases for patients with IPF although there was no difference of all-cause mortality. However, the results should be interpreted with caution due to low evidence level.

PROSPERO REGISTRATION NUMBER

CRD42017077336.

Clinical features and prognosis of microscopic polyangiitis with usual interstitial pneumonia compared with idiopathic pulmonary fibrosis

INTRODUCTION

Pulmonary involvement in microscopic polyangiitis (MPA) is common, little is known about the clinical features of MPA with interstitial pneumonia (MPA-IP).

OBJECTIVES

This study aimed to explore the prevalence of microscopic polyangiitis associated usual interstitial pneumonia (UIP)(MPA-UIP) and compare its clinical features and prognosis with those of MPA-non-UIP and idiopathic pulmonary fibrosis (IPF).

METHODS

A total of 73 patients with MPA-IP were identified and divided into MPA-UIP patients and MPA-non-UIP patients. The clinical characteristics and survival of MPA-UIP patients were analysed and compared with those of MPA-non-UIP patients and 68 patients with IPF.

RESULTS

The results showed that 34/73 (47%) MPA-IP patients were classified as MPA-UIP patients. Compared with MPA-non-UIP patients, MPA-UIP patients tend to have longer duration of symptoms prior to diagnosis and usually have pulmonary involvement as the initial presentation. However, they were less likely to have proteinuria and/or hematuria. Compared with IPF patients, MPA-UIP patients usually had multisystem damage, positive anti-neutrophil cytoplasmic autoantibodies and elevated levels of nonspecific inflammatory markers. MPA-UIP death was concentrated mainly in the first 3 months after diagnosis and resulted in a higher early mortality compared with IPF.

CONCLUSION

UIP is the most frequent type of MPA-IP. These patients tend to have longer duration of symptoms prior to diagnosis and usually have pulmonary involvement as the first presentation. However, they are less likely to have proteinuria and/or hematuria. MPA patients with UIP can be differentiated from IPF patients through comprehensive analysis of clinical and laboratory findings.

Interstitial Lung Disease and Other Pulmonary Manifestations in Connective Tissue Diseases

Lung involvement in connective tissue diseases is associated with substantial morbidity and mortality, most commonly in the form of interstitial lung disease, and can occur in any of these disorders. Patterns of interstitial lung disease in patients with connective tissue disease are similar to those seen in idiopathic interstitial pneumonias, such as idiopathic pulmonary fibrosis. It may be difficult to distinguish between the 2 ailments, particularly when interstitial lung disease presents before extrapulmonary manifestations of the underlying connective tissue disease. There are important clinical implications in achieving this distinction. Given the complexities inherent in the management of these patients, a multidisciplinary evaluation is needed to optimize the diagnostic process and management strategies. The aim of this article was to summarize an approach to diagnosis and management based on the opinion of experts on this topic.

Antineutrophil cytoplasmic antibody-positive familial Mediterranean fever and hyperthyroidism: A case report

RATIONALE

Familial Mediterranean fever (FMF) is a genetic autoinflammatory disorder characterized by serositis and recurrent fever. Previous reports identified patients with antineutrophil cytoplasmic antibody (ANCA)-positive FMF, but vasculitis symptoms were not reported.

PATIENT CONCERNS

We report the case of a 44-year-old man with numbness. He had a history of 3 episodes of pleurisy and was being treated with propylthiouracil for hyperthyroidism. Because he was ANCA-positive, we suspected drug-induced ANCA-associated vasculitis and propylthiouracil was discontinued. However, his numbness was not ameliorated, and he again developed high fever with pleurisy.

DIAGNOSIS

Diagnosis of FMF was finally made, and genetic analysis revealed compound heterozygous mutations in exon 2 of the familial Mediterranean fever gene (L110P/E148Q).

INTERVENTIONS

The patient was treated with 0.5 mg/day of colchicine.

OUTCOMES

His numbness improved, and fever has not recurred.

LESSONS

Appearance of ANCA and development of vasculitis should be considered in a clinical course of FMF with hyperthyroidism.

Combined pulmonary fibrosis and emphysema with myeloperoxidase-antineutrophil cytoplasmic antibody positivity that resolved upon smoking cessation

Myeloperoxidase antineutrophil cytoplasmic autoantibody (MPO-ANCA) is well-known as a serological marker for small-vessel vasculitis. However, when a smoker with interstitial lung disease (ILD) exhibits serum ANCA positivity without systemic vasculitis, diagnosis is a matter of debate; the relationship between smoking and ANCA is unknown. We report a case of combined pulmonary fibrosis and emphysema (CPFE) with elevated MPO-ANCA. Surgical lung biopsy showed emphysema and fibrotic interstitial pneumonia without vasculitis. The MPO-ANCA level decreased after smoking cessation, and no vasculitis or progression was observed during 3 years of follow-up. This suggested that smoking cessation was related to normalization of MPO-ANCA and corresponding disease activity.

Clinical significance of myeloperoxidase-anti-neutrophil cytoplasmic antibody in idiopathic interstitial pneumonias

Objective

Although a possible association among myeloperoxidase-anti-neutrophil cytoplasmic antibody (MPO-ANCA), microscopic polyangiitis (MPA), and idiopathic pulmonary fibrosis (IPF) has been suggested, the clinical significance of MPO-ANCA in idiopathic interstitial pneumonias (IIPs), including IPF and non-IPF, remains unclear. We aimed to investigate the frequency of MPO-ANCA positivity, as well as MPA incidence and risk factors for development in patients initially diagnosed with IIP.

Methods

We retrospectively analysed 305 consecutive patients who were initially diagnosed as IIP and had MPO-ANCA results available.

Results

Of the 305 patients, 26 (8.5%) were MPO-ANCA-positive. Baseline characteristics were similar between the MPO-ANCA-positive and -negative patients. The cumulative 5-year MPA incidence was 24.3% in the MPO-ANCA-positive patients and 0% in the -negative patients (P < 0.0001). MPO-ANCA was positive in 15 of 133 (11.3%) patients initially diagnosed with IPF and in 11 of 172 (6.3%) patients initially diagnosed with non-IPF (P = 0.56), with cumulative 5-year MPA incidence of 6.2% and 1.0%, respectively (P = 0.10). Multivariate analysis revealed that UIP pattern on HRCT (HR = 3.20, P < 0.01) and no treatment for IIP (HR = 3.52, P < 0.01) were independently associated with MPA development in MPO-ANCA-positive patients.

Conclusion

MPO-ANCA positivity was uncommon, but was associated with subsequent MPA development in patients initially diagnosed with IIP, including both IPF and non-IPF cases. The study suggested that attention should be paid to MPA development in MPO-ANCA-positive IIP patients with UIP pattern on HRCT and those without treatment for IIP.

Autoimmune liver disease-related autoantibodies in patients with biliary atresia

AIM

To investigate the prevalence and clinical significance of autoimmune liver disease (ALD)-related autoantibodies in patients with biliary atresia (BA).

METHODS

Sera of 124 BA patients and 140 age-matched non-BA controls were assayed for detection of the following autoantibodies: ALD profile and specific anti-nuclear antibodies (ANAs), by line-blot assay; ANA and anti-neutrophil cytoplasmic antibody (ANCA), by indirect immunofluorescence assay; specific ANCAs and anti-M2-3E, by enzyme linked immunosorbent assay. Associations of these autoantibodies with the clinical features of BA (i.e., cytomegalovirus infection, degree of liver fibrosis, and short-term prognosis of Kasai procedure) were evaluated by Spearman’s correlation coefficient.

RESULTS

The overall positive rate of serum autoantibodies in preoperative BA patients was 56.5%. ALD profile assay showed that the positive reaction to primary biliary cholangitis-related autoantibodies in BA patients was higher than that to autoimmune hepatitis-related autoantibodies. Among these autoantibodies, anti-BPO was detected more frequently in the BA patients than in the controls (14.8% vs 2.2%, P < 0.05). Accordingly, 32 (25.8%) of the 124 BA patients also showed a high positive reaction for anti-M2-3E. By comparison, the controls had a remarkably lower frequency of anti-M2-3E (P < 0.05), with 6/92 (8.6%) of patients with other liver diseases and 2/48 (4.2%) of healthy controls. The prevalence of ANA in BA patients was 11.3%, which was higher than that in disease controls (3.3%, P < 0.05), but the reactivity to specific ANAs was only 8.2%. The prevalence of ANCAs (ANCA or specific ANCAs) in BA patients was also remarkably higher than that in the healthy controls (37.9% vs 6.3%, P < 0.05), but showed no difference from that in patients with other cholestasis. ANCA positivity was closely associated with the occurrence of postoperative cholangitis (r = 0.61, P < 0.05), whereas none of the autoantibodies showed a correlation to cytomegalovirus infection or the stages of liver fibrosis.

CONCLUSION

High prevalence of autoantibodies in the BA developmental process strongly reveals the autoimmune-mediated pathogenesis. Serological ANCA positivity may be a useful predictive biomarker of postoperative cholangitis.

Pulmonary Involvement in Antineutrophil Cytoplasmic Antibodies (ANCA)-associated Vasculitis: The Influence of ANCA Subtype

OBJECTIVE

To describe pulmonary involvement at time of diagnosis in antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV), as defined by computed tomography (CT).

METHODS

Patients with thoracic CT performed on or after the onset of AAV (n = 140; 75 women; granulomatosis with polyangiitis, n = 79; microscopic polyangiitis MPA, n = 61) followed at a tertiary referral center vasculitis clinic were studied. Radiological patterns of pulmonary involvement were evaluated from the CT studies using a predefined protocol, and compared to proteinase 3 (PR3)-ANCA and myeloperoxidase (MPO)-ANCA specificity.

RESULTS

Of the patients, 77% had an abnormal thoracic CT study. The most common abnormality was nodular disease (24%), of which the majority were peribronchial nodules, followed by bronchiectasis and pleural effusion (19%, each), pulmonary hemorrhage and lymph node enlargement (14%, each), emphysema (13%), and cavitating lesions (11%). Central airways disease and a nodular pattern of pulmonary involvement were more common in PR3-ANCA-positive patients (p < 0.05). Usual interstitial pneumonitis (UIP) and bronchiectasis were more prevalent in MPO-ANCA-positive patients (p < 0.05). Alveolar hemorrhage, pleural effusion, lymph node enlargement, and pulmonary venous congestion were more frequent in MPO-ANCA-positive patients.

CONCLUSION

Pulmonary involvement is frequent and among 140 patients with AAV who underwent a thoracic CT study, almost 80% have pulmonary abnormalities on thoracic CT. Central airway disease occurs exclusively among patients with PR3-ANCA while UIP were mainly seen in those with MPO-ANCA. These findings may have important implications for the investigation, management, and pathogenesis of AAV.

Interstital lung disease in ANCA vasculitis

Anti-neutrophil cytoplasmic antibodies (ANCA) vasculitides are immune-mediated disorders that primarily affect small blood vessels of the airway and kidneys. Lung involvement, one of the hallmarks of microscopic polyangiitis and granulomatosis with polyangiitis, is associated with increased mortality and morbidity. In recent years, several retrospective series and case reports have described the association of interstitial lung disease (ILD) and ANCA vasculitis, particularly those positive for ANCA specific for myeloperoxidase. In the majority of these patients pulmonary fibrosis occurs concurrently or predates the diagnosis of ANCA vasculitis. More importantly, these studies have shown that ILD has an adverse impact on the long-term prognosis of ANCA vasculitis. This review focuses on the main clinical and radiologic features of pulmonary fibrosis associated with anti-neutrophil cytoplasmic antibodies. Major histopathology features, prognosis and therapeutic options are summarized.

Idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis is a fibrosing interstitial pneumonia associated with the radiological and/or histological pattern of usual interstitial pneumonia. Its aetiology is unknown, but probably comprises the action of endogenous and exogenous micro-environmental factors in subjects with genetic predisposition. Its diagnosis is based on the presence of characteristic findings of high-resolution computed tomography scans and pulmonary biopsies in absence of interstitial lung diseases of other aetiologies. Its clinical evolution is variable, although the mean survival rate is 2-5 years as of its clinical presentation. Patients with idiopathic pulmonary fibrosis may present complications and comorbidities which modify the disease's clinical course and prognosis. In the mild-moderate disease, the treatment consists of the administration of anti-fibrotic drugs. In severe disease, the best therapeutic option is pulmonary transplantation. In this paper we review the diagnostic and therapeutic aspects of the disease.

Myeloperoxidase Anti-Neutrophil Cytoplasmic Antibody-Positive Interstitial Pneumonia Associated with Granulomatosis with Polyangiitis Diagnosed by Surgical Lung Biopsy

Granulomatosis with polyangiitis (GPA) is a rare systemic vasculitis that often involves the lung. However, interstitial pneumonia (IP) is rarely seen in GPA patients. We herein report 3 cases of IP associated with GPA diagnosed by surgical lung biopsy. High-resolution CT showed uniform subpleural reticular opacity with traction bronchiectasis. Biopsies from all 3 patients revealed neutrophilic capillaritis, microabscesses with giant cells, and coexisting histological findings of usual IP pattern or fibrosing nonspecific IP pattern. All 3 patients had elevated levels of serum myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA), but not proteinase 3-ANCA. We diagnosed GPA and treated with corticosteroid and cyclophosphamide. Follow-up CT showed improvement of the lesions in all patients. Surgical lung biopsy specimens which revealed GPA enabled us to conduct the most suitable therapy. This report indicates the importance of surgical lung biopsy for differentiating idiopathic IPs from GPA-associated IP and suggests a relationship between MPO-ANCA and IP in GPA.