Comparison of characteristics of muscle magnetic resonance imaging findings in patients with antineutrophilic cytoplasmic antibody-associated vasculitis and polyarteritis nodosa

AIM

This study aimed to analyze the muscle magnetic resonance imaging (MRI) findings of patients with antineutrophilic cytoplasmic antibody-associated vasculitis (AAV) and polyarteritis nodosa (PAN) presenting with clinical symptoms in the extremities.

METHODS

Retrospective analysis was conducted on short tau inversion recovery MRI findings, with a focus on intramuscular vessels displaying abnormal perivascular signals, in 22 and eight patients with AAV and PAN, respectively. The number per unit area (4 cm2) and diameter of abnormal vessels on muscle MRI were compared between patients with AAV and those with PAN. Cut-off values, clinical sensitivity, and specificity for these indices were calculated from the receiver operating characteristic curves to distinguish between AAV and PAN, and the relationship between the indices and clinical findings in AAV was analyzed.

RESULTS

The number of abnormal vessels per unit area was significantly higher in AAV compared to PAN (p < .05). Additionally, the diameter of the abnormal vessels was significantly higher in PAN than in AAV (p < .05). The presence of >6.44 abnormal vessels per unit area or ≤3.61 mm diameter of abnormal vessels was able to predict AAV (sensitivity, 0.955; specificity, 0.625). AAV patients with peripheral neuropathy exhibited a significantly higher number of abnormal vessels per unit area than those without peripheral neuropathy (p < .05).

CONCLUSIONS

Muscle MRI can detect small- to medium-vessel vasculitis and be a valuable tool for distinguishing between patients with AAV and PAN experiencing clinical symptoms in the extremities.

Nailfold videocapillaroscopy in antineutrophil cytoplasmic antibody-associated vasculitis

OBJECTIVE

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of illnesses that cause inflammation and alterations to small vessels in the body. Some of the most common and detrimental manifestations, including alveolar hemorrhage and glomerulonephritis, are caused by this capillary inflammation. We sought to clarify whether patients with AAV would have abnormal nailfold capillaries when evaluated with nailfold videocapillaroscopy.

METHODS

Patients with a current diagnosis of AAV and a control group were identified for enrollment. Nailfold videocapillaroscopy images were used for a semiquantitative analysis on capillary density, morphology, dilation, and microhemorrhage after review by 2 rheumatologists. Disease characteristics, occurrence of recent disease flare, and presence of ANCA were recorded.

RESULTS

Thirty-three patients with a diagnosis of AAV and 21 controls were recruited. The AAV group had a median age of 59 and 17 (52%) were women. Granulomatosis with polyangiitis was the most common diagnosis (19 [58%]), followed by eosinophilic granulomatosis with polyangiitis (7 [21%]) and microscopic polyangiitis (7 [21%]). Twenty-seven patients (82%) had positive ANCA tests. After assessment of capillary density, dilation, morphology, microhemorrhages, and disorganization, there were no statistically significant differences between the 2 groups.

CONCLUSION

There was no evidence of differences in nailfold capillaroscopy abnormalities between those diagnosed with AAV and the control group. While this cohort was relatively small, we did not find a high enough prevalence or specific phenotype of capillary abnormalities that could aid in diagnosis or prognostication of these diseases in the clinical setting.

ANCA-associated vasculitis with abdominal aortic aneurysm : Case report and literature review

INTRODUCTION

ANCA-associated vasculitis is an autoimmune disease that usually involves the small vessel walls. It is difficult to find the presence of ANCA-associated vasculitis in the great arteries, especially the thoracic and abdominal aorta.

METHODS

This is an 86-year-old Chinese man with ANCA-associated vasculitis and abdominal aortic aneurysm who presented with epigastric pain. Considering his age and physical condition, the patient was treated with methylprednisolone and mycophenolate mofetil instead of surgery.

RESULTS

The patient's epigastric pain symptoms were relieved after 2 months of conservative treatment. Imaging at follow-up 2 years later showed signs of aneurysm enlargement because of irregular medication.

CONCLUSIONS

Patients with ANCA-associated vasculitis combined with aortic aneurysm often require surgical management. But for patients with stable disease and poor physical conditions, conservative treatment is also an effective treatment method, which can bring benefits to the patient's survival.

Association between computed tomography-assessed sarcopenia and mortality in patients with anti-neutrophil cytoplasmic antibody-associated vasculitis

AIM

Sarcopenia is frequently observed in patients with autoimmune rheumatic diseases; however, its relationship with patient outcomes has not been well understood. This study evaluated the influence of sarcopenia, especially muscle quality, on outcomes of antineutrophil cytoplasmic antibody-associated vasculitis (AAV).

METHODS

Records of patients with AAV at the Severance Hospital with computed tomography (CT) images taken at initial disease diagnosis were retrospectively reviewed. For measures of sarcopenia, normal attenuation muscle area (NAMA), low attenuation muscle area (LAMA), intramuscular adipose tissue (IMAT), and total abdominal muscle area (TAMA) in the axial muscles of the middle third lumbar vertebra level were calculated. Correlations between NAMA, LAMA, IMAT, and baseline patient characteristics, as well as the association between the NAMA/TAMA ratio and clinical outcomes were assessed.

RESULTS

A total of 136 patients with CT images at AAV diagnosis were identified. Correlation analyses revealed that age, female sex, total cholesterol, and alanine aminotransferase were significantly associated with NAMA. LAMA was associated with age, body mass index (BMI), five-factor score (FFS), and C-reactive protein, and a relationship between IMAT and age and BMI was observed. During the follow up of 31.2 months, 23 (16.9%) patients died, and Cox-proportional hazard analysis demonstrated that a NAMA/TAMA ≤0.46 (odds ratio [OR] 10.247, p < .001), female sex (OR 0.206, p = .006), dyslipidemia (OR 3.143, p = .027), creatinine (OR 1.342, p = .012), and FFS (OR 1.775, p = .046), were independently associated with patient mortality.

CONCLUSION

A higher rate of mortality was observed in patients with AAV with NAMA/TAMA ≤0.46, indicating that careful monitoring is required in these patients.

Image findings of anti-neutrophil cytoplasmic antibody-associated vasculitis involving the skull base

AIM

To investigate computed tomography (CT) and magnetic resonance imaging (MRI) features of skull bases involving anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV).

MATERIALS AND METHODS

A retrospective review was undertaken to identify an institutional historical cohort of 17 patients with confirmed AAV who underwent CT or MRI and had skull base involvement between 2002 and 2021. Two radiologists reviewed the extent and features of the lesions, bone changes, and other MRI findings.

RESULTS

A total of 17 patients (12 men; mean age ± standard deviation, 46.5 ± 17.1 years) were selected. AAV presented as infiltrative lesions with involvement at various sites. Most cases involved the paranasal sinuses (PNS; 88%, 15/17), nasopharynx (88%, 15/17), pterygopalatine fossa (82%, 14/17), and parapharyngeal space (82%, 14/17), frequently accompanied by mucosal irregularity of the PNS and nasopharynx (71%, 12/17). Central skull base and temporal bone involvement were seen in 53% (9/17) and 38% (6/16) of cases, respectively. On T1-weighted imaging (WI) and T2WI MRI, all lesions (15/15) showed predominant signal iso-intensity to grey matter.

CONCLUSIONS

Although radiological findings of AAV are non-specific and skull base involvement is less common, AAV may be considered if infiltrative lesions predominantly involving the PNS, nasopharynx, pterygopalatine fossa, and parapharyngeal space with combined bone changes of skull base are seen.

Evaluation of body composition using computed tomography in patients with anti-neutrophil cytoplasmic antibody-associated vasculitis

BACKGROUND/AIMS

Measures of body composition, including visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and skeletal muscle area (SMA), are considered important prognostic factors in chronic diseases. The association of these measures with auto-inflammatory disorders, such as anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV), remains unclear. We investigated the clinical significance of VAT, SAT, and SMA in patients with AAV.

METHODS

Patients with AAV subjected to chest computed tomography (CT), abdominal CT, or positron emission tomography-CT on diagnosis of AAV were evaluated. Quantitative assessment of VAT, SAT, and SMA was performed at the third lumbar vertebral level and computed by summing the pixel attenuation for tissue-specific Hounsfield units in the corresponding region. Associations of VAT, SAT, and SMA with clinical and laboratory data and clinical outcome measures were evaluated.

RESULTS

Of the 117 patients, 61 (52.1%) were classified as having microscopic polyangiitis, 28 (23.9%) as granulomatosis with polyangiitis, and 28 (23.9%) as eosinophilic granulomatosis with polyangiitis. VAT significantly correlated with age, weight, body mass index (BMI), and Birmingham Vasculitis Activity Score, whereas SAT correlated with weight, BMI, and creatinine levels. A significant association was found between SMA and age, height, weight, BMI, and the Five-Factor Score. Cox proportional hazards analysis showed that creatinine levels (odds ratio [OR], 1.346; 95% confidence interval [CI], 1.034 to 1.753; p = 0.027) and high VAT (OR, 7.137; 95% CI, 1.343-37.946; p = 0.021) were independently associated with all-cause mortality during follow-up.

CONCLUSION

Evaluation of VAT using CT is useful for estimating disease activity and all-cause mortality in patients with AAV.

Hypertrophic spinal pachymeningitis caused by ANCA-associated vasculitis revealed by 18F-FDG PET/CT: A case report

RATIONALE

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) can involve the central nervous system in estimatedly 15% of patients. Hypertrophic pachymeningitis causes inflammatory hypertrophy of the cranial or spinal dura mater and patients present with various neurological deficits. ANCA-associated hypertrophic spinal pachymeningitis has rarely been reported in literature. We report a case of AAV presenting with hypertrophic spinal pachymeningitis detected by 18F-FDG PET/CT.

PATIENT CONCERNS

A 66-year-old woman diagnosed with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis developed back pain, bilateral lower limb weakness, dysuria, and dysporia 1 month ago.

DIAGNOSIS

Contrast-enhanced MRI showed thickening and enhancement of the dura mater in the thoracic cord. Intraspinal hypermetabolism in the corresponding region was observed on 18F-FDG PET/CT. The patient was finally diagnosed with ANCA-associated hypertrophic spinal pachymeningitis.

INTERVENTIONS

The patient was treated with a higher dose of prednisone and cyclophosphamide.

OUTCOMES

After 2-week treatment, the patient's neurological symptoms improved rapidly and laboratory findings were ameliorated. A repeated contrast-enhanced MRI showed partial improvement of the disease in the thoracic cord.

LESSONS

18F-FDG PET/CT and contrast-enhanced MRI can aid in the clinical diagnosis and surveillance in AAV-associated hypertrophic spinal pachymeningitis and potentially facilitate early recognition and intervention to prevent irreversible neurological impairment.

Pathological and Radiological Correlation in Prolonged Myeloperoxidase Anti-neutrophil Cytoplasmic Antibody-related Diffuse Alveolar Hemosiderosis

A 60-year-old woman with a 20-year history of myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA)-associated vasculitis visited our hospital due to productive cough and a low-grade fever for several weeks. Thoracic computed tomography demonstrated scattered tiny nodules, patchy consolidation, ground glass opacities, and thickening interlobular septa. On video-assisted thoracic surgery, those abnormalities were found to correspond to the accumulation of hemosiderin-laden alveolar macrophages (AMs) in the alveolar spaces and alveolar septa due to MPO-ANCA vasculitis. The radiological findings persisted for a further two years, indicating the possibility of persistent vasculitis in the lung or evidence of incomplete clearance of hemosiderin-laden AMs.

Utility of lung ultrasound in ANCA-associated vasculitis with lung involvement

Introduction

Granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) are forms of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). AAV most commonly affects the upper and lower respiratory tract as well as the kidneys. The first symptoms are often nonspecific, requiring careful differential diagnosis with infections and malignancies.

Materials and methods

We analyzed the clinical and radiological data of 38 patients (20 females and 18 males) diagnosed with ANCA-associated vasculitis. Lung involvement was observed in 29 cases. Lung ultrasound (LUS) was performed on 21 patients from the study group and compared to chest CT. For 7 patients the examination was conducted repeatedly.

Results

In total, 35 LUS and CT examinations were performed, revealing the following lesions: nodules, infiltrates with and without features of disintegration, caves (n = 17), diffuse alveolar hemorrhage (n = 3), and features of interstitial lung disease (ILD) with pulmonary fibrosis (PF) (n = 11). In 2 cases LUS and CT were negative. In 4 cases LUS was negative, despite a positive CT result.

Conclusions

Both in CT and LUS, images of pulmonary lesions were consistent though highly variable. Therefore, further studies are required for a larger group of patients.

Aortitis caused by antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis: a case-based review

Antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) is a systemic necrotizing small vessel vasculitis primarily affecting elderly patients. Neutrophil apoptosis and release of pro-inflammatory mediators promote small vessel inflammation and hence multi-organ disease. It rarely affects larger vessels with extremely rare aortic involvement. Diagnosis is made based on clinical presentation, tissue biopsy of affected organ, as well as immunofluorescence and ELISA assays for ANCA. Management includes immunosuppression (e.g., glucocorticoids, cyclophosphamide and rituximab) and supportive therapy. We present a rare case of a younger patient with AAV involving the aorta. The patient's diagnosis was supported by clinical presentation, systemic organ involvement, strongly positive c-ANCA, and skin as well as aortic tissue biopsy results. After failing multiple immunosuppressants, he responded well to rituximab with improved symptoms, inflammatory markers, and imaging findings. Based on our literature review, we were only able to find ten cases of ANCA-related vasculitis involving the aorta. This is the first reported case of successful treatment of AAV-related aortitis using rituximab. Our case report and literature review provide insight into treatment of severe cases of AAV with aortic involvement.

Comparison of Radiological and Histological Findings of Lung Parenchyma in Patients with Antineutrophil Cytoplasmic Antibody-Associated Vasculitis

PURPOSE

The present study investigated chest computed tomography (CT) patterns and lung histological features, as well as the consistency between radiological and histological features among patients with microscopic polyangiitis (MPA), granulomatosis with polyangiitis (GPA), and eosinophilic GPA (EGPA).

MATERIALS AND METHODS

The medical records of 74 antineutrophil cytoplasmic antibody-associated vasculitis (AAV) patients with radiological lung parenchymal lesions were reviewed along with the histological results for 28 of them. Chest CT patterns were divided according 12 items mostly suggested by radiologists and histological features were divided according to necrotising granuloma, necrotising vasculitis, eosinophilic infiltration, and hemosiderin laden macrophages as defined by a pathologist.

RESULTS

The mean age was 57.1 years (22 men). The most common clinical manifestation other than lung manifestation was renal manifestation (62.2%), and the most common chest CT pattern was lung involvement of vasculitis (35.1%). In MPA patients, the major histological features were hemosiderin-laden macrophages in the alveolar space and vasculitis. In GPA patients, the major histological features were necrotizing vasculitis and necrotizing granuloma, while in EGPA patients, the major histological feature was only necrotising vasculitis. The consistency rate in GPA patients was the highest (100%), followed by that in MPA patients (66.7%) and EGPA patients (50.0%).

CONCLUSION

When lung involvement of AAV is suspected on chest CT, lung biopsy should be recommended for the proper classification of AAV, due to the discordance rate between radiological and histological findings in MPA and EGPA patients, but not GPA patients.

Anti-neutrophil Cytoplasmic Antibody-associated Vasculitis Complicated by Periaortitis and Cranial Hypertrophic Pachymeningitis: A Report of an Autopsy Case

Anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) is a systemic inflammatory disorder categorized as small-vessel vasculitis. We herein report an elderly Japanese man with AAV (granulomatosis with polyangiitis affecting the eyes, nose, lungs, and kidneys) who also showed periaortitis at the diagnosis and developed cranial hypertrophic pachymeningitis (HP) during steroid maintenance therapy. His consciousness disturbance caused by HP improved after steroid pulse therapy, but he died of aspiration pneumonia. Autopsy findings showed giant cells in the thickened pachymeninges and obsolete inflammatory lesions in the aortic adventitia and renal tubulointerstitium. This is the first case of AAV complicated by periaortitis and cranial HP.

18F-fluoro-deoxy-glucose positron emission tomography combined with computed tomography can reliably rule-out infection and cancer in patients with anti-neutrophil cytoplasmic antibody-associated vasculitis suspected of disease relapse

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of autoimmune diseases characterized by systemic inflammation in small- to medium-sized blood vessels. Although immunosuppressive therapy has greatly improved the prognosis for these patients, there are still significant comorbidities, such as cancer and infection, associated with AAV. These comorbidities are often indistinguishable from an underlying AAV disease relapse, and create a clinical conundrum, as these conditions are normally contraindications for immunosuppressive treatment. Thus, it is important to be able to rule out these comorbidities before initiation of immunosuppressive treatment. We examined F-fluoro-deoxy-glucose positron emission tomography combined with computed tomography (FDG-PET/CT)'s value in ruling out cancer or infection in patients with AAV.Data were obtained retrospectively for a clinically based cohort of AAV patients who underwent FDG-PET/CT during 2009 to 2014 owing to a suspicion of cancer, infection, or both cancer and infection indistinguishable from disease relapse. FDG-PET/CT conclusions were compared to the final diagnoses after follow-up analysis (mean 43 months).A total of 19 patients were included who underwent a total of 26 scans. The results of FDG-PET/CT outcome compared to final diagnosis were: 9 true positives, 3 false positives, 13 true negatives, and 1 false negative. The diagnostic probabilities for FDG-PET/CT with respect to overall comorbidity (i.e., cancer or infection) were: sensitivity 90% ( 95% confidence interval [CI] 60%-98%), specificity 81% ( 95% CI 57%-93%), positive predictive value 75% (95% CI 47%-91%), negative predictive value 93% (95% CI 68%-99%), and accuracy 84% (95% CI 66%-94%).FDG-PET/CT had a high negative predictive value and ruled out the comorbidities correctly in all but one case of urinary tract infection, a well-known limitation. Our study showed FGD-PET/CT's promise as an effective tool for ruling out cancer or infection in patients with AAV albeit in a limited population.

Thinking beyond the mass: ANCA-associated vasculitis mimicking a pancreatic malignancy

Isolated pancreatic involvement is a rare initial presentation in patients with ANCA-associated vasculitis. We report a patient with a suspected malignant pancreatic mass, referred to our hospital for pancreaticoduodenectomy. However, the pancreatic mass proved to be the initial manifestation of ANCA-associated vasculitis.

Positron emission tomography scanning in anti-neutrophil cytoplasmic antibodies-associated vasculitis

Tools for evaluation of disease activity in patients with anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) include scoring clinical manifestations, determination of biochemical parameters of inflammation, and obtaining tissue biopsies. These tools, however, are sometimes inconclusive. 2-deoxy-2-[F]-fluoro-D-glucose (FDG) positron emission tomography (PET) scans are commonly used to detect inflammatory or malignant lesions. Our objective is to explore the ability of PET scanning to assess the extent of disease activity in patients with AAV.Consecutive PET scans made between December 2006 and March 2014 in Maastricht (MUMC) and between July 2008 and June 2013 in Brussels (EUH) to assess disease activity in patients with AAV were retrospectively included. Scans were re-examined and quantitatively scored using maximum standard uptake values (SUVmax). PET findings were compared with C-reactive protein (CRP) and ANCA positivity at the time of scanning.Forty-four scans were performed in 33 patients during a period of suspected active disease. All but 2 scans showed PET-positive sites, most commonly the nasopharynx (n = 22) and the lung (n = 22). Forty-one clinically occult lesions were found, including the thyroid gland (n = 4 patients), aorta (n = 8), and bone marrow (n = 7). The amount of hotspots, but not the highest observed SUVmax value, was higher if CRP levels were elevated. Seventeen follow-up scans were made in 13 patients and showed decreased SUVmax values.FDG PET scans in AAV patients with active disease show positive findings in multiple sites of the body even when biochemical parameters are inconclusive, including sites clinically unsuspected and difficult to assess otherwise.

Computed tomography angiography in the diagnosis of ANCA-associated small- and medium-vessel vasculitis

Polyarteritis nodosa (PAN) is a systemic necrotizing vasculitis that typically occurs without detectable antineutrophil cytoplasmic antibody. It leads to aneurysm formation by affecting muscular arteries, usually those of medium size but also occasionally those of small size. Kidney involvement is common, leading to reduced glomerular filtration rate, hypertension, rupture of renal arterial aneurysms causing perinephric hematomas, and renal infarctions in those with severe vasculitis. Similar to PAN, microscopic polyangiitis (MPA) leads to aneurysm formation; however, MPA usually is associated with antineutrophil cytoplasmic antibody, and glomerulonephritis is a more common feature of MPA. Although kidney biopsy may show classic vascular changes in both PAN and MPA, this procedure is not without risk of significant bleeding due to aneurysm rupture. We present 2 cases of renal aneurysms that were diagnosed as MPA using computed tomography angiography (CTA), allowing implementation of appropriate immunosuppressive therapy. Follow-up CTA after treatment showed resolution of all previously observed abnormalities. CTA is a useful alternative to kidney biopsy in establishing both the extent of disease in renal aneurysms and allowing for tracking of disease progression and response to therapy.

Detection of asymptomatic aortic involvement in ANCA-associated vasculitis using FDG PET/CT

Large vessel involvement in ANCA-associated vasculitis is very rare. We report here on the case of two patients with ANCA-associated vasculitis and asymptomatic aortic arch involvement diagnosed using FDG-PET/CT. Because aortic involvement in ANCA-associated vasculitis is a potentially life-threatening condition, its early detection can be crucial. FDG-PET/CT may also provide new insights into large vessel involvement as part of the spectrum of ANCA-associated vasculitis.

What to do when you suspect your patient suffers from pulmonary vasculitis?

Making a diagnosis of pulmonary vasculitis is challenging. The most common cause of pulmonary vasculitis is small vessel anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis. Pulmonary involvement in other forms of vasculitis such as large vessel vasculitis is rare. Since correct and timely diagnosis is pivotal to start (immunosuppressive) therapy to avoid vasculitic damage, a complete patient history should be obtained and a physical examination performed. Initial laboratory evaluation should include inflammation markers, renal and liver function tests, and the determination of ANCA. New developments in ANCA testing result in tests with excellent predictive value for the diagnosis of AAV-related pulmonary vasculitis. Consequently, ANCA should be tested with these tests of the so-called second (capture ELISA) or third (anchor ELISA) generation. In patients who are ANCA negative, a simple algorithm is presented based on laboratory evaluation of autoantibodies and 18F-FDG-PET-CT scanning. Such an algorithm may be useful for accelerating the diagnostic process needed to make a diagnosis of pulmonary vasculitis, or alternatively, to quickly exclude such a diagnosis.