Pulmonary Vasculitides: A Radiological Review Emphasizing Parenchymal HRCT Features

Vasculitides represent a heterogeneous group of immune-mediated disorders, characterized by a systemic inflammatory destructive process of the blood vessels resulting either in ischemia or hemorrhage. The organ involved and vessel size influence the pattern of presentation of the pathology. The lung is commonly involved in systemic vasculitides, with heterogeneous clinical, radiological, and histopathological presentations. Primary vasculitides most commonly associated with lung parenchymal involvement include small-vessel antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitides, such as granulomatosis with polyangiitis (GPA), eosinophilic granulomatosis with polyangiitis (EGPA), and microscopic polyangiitis (MPA). Several studies have reported cases of interstitial lung diseases (ILDs) associated with systemic vasculitis, particularly those positive for ANCA associated vasculitis/vasculitidis: AAV. We have selected from our case series different radiological features of pulmonary vasculitis (i.e., solitary or multiple nodules, cavitary lesions, nodules with centrilobular or peribronchial distribution, airspace consolidations, “crazy paving” appearance, interstitial disease), including cases with interstitial lung alterations. Therefore, the aim of this review is to describe the typical clinical manifestations of vasculitides and their main radiologic features (especially AAV).

Thoracic involvement and imaging patterns in IgG4-related disease

ObjectiveImmunoglobulin G4-related disease (IgG4-RD) is a rare orphan disease. Lung, pleura, pericardium, mediastinum, aorta and lymph node involvement has been reported with variable frequency and mostly in Asian studies. The objective of this study was to describe thoracic involvement assessed by high-resolution thoracic computed tomography (CT) in Caucasian patients with IgG4-RD.MethodsThoracic CT scans before treatment were retrospectively collected through the French case registry of IgG4-RD and a single tertiary referral centre. CT scans were reviewed by two experts in thoracic imagery blinded from clinical data.Results48 IgG4-RD patients with thoracic involvement were analysed. All had American College of Rheumatology/European League Against Rheumatism classification scores ≥20 and comprehensive diagnostic criteria for IgG4-RD. CT scan findings showed heterogeneous lesions. Seven patterns were observed: peribronchovascular involvement (56%), lymph node enlargement (31%), nodular disease (25%), interstitial disease (25%), ground-glass opacities (10%), pleural disease (8%) and retromediastinal fibrosis (4%). In 37% of cases two or more patterns were associated. Asthma was significantly associated with peribronchovascular involvement (p=0.04). Among eight patients evaluated by CT scan before and after treatments, only two patients with interstitial disease displayed no improvement.ConclusionThoracic involvement of IgG4-RD is heterogeneous and likely underestimated. The main thoracic CT scan patterns are peribronchovascular thickening and thoracic lymph nodes.

Atypical histological abnormalities in an adult patient with nephronophthisis harboring NPHP1 deletion: a case report

Background Nephronophthisis (NPHP) is a chronic tubular interstitial disorder that exhibits an autosomal recessive genetic form and causes progressive renal failure in children. Patients with NPHP rarely show urinary abnormalities, edema, or hypertension. Thus, NPHP is often detected only when renal failure becomes advanced. NPHP can be divided into three types based on the age of end-stage renal failure, i.e., infant type (approximately 5 years old), juvenile type (approximately 13–14 years old), and adolescent type (approximately 19 years old). Here, we report a case of NPHP diagnosed by genetic analysis at 26 years of age with atypical histological abnormalities. Case presentation A 26-year-old woman showed no growth disorders or urinary abnormalities in annual school physical examinations. However, at a check-up at 26 years old, she exhibited renal dysfunction (eGFR 26 mL/min/1.73 m2). Urine tests indicated low specific gravity of urine, but not proteinuria or microscopic hematuria. Urinary β2-microglobulin was high (805 μg/L), and renal biopsy was performed for definitive diagnosis. Histological findings showed no significant findings in glomeruli. However, moderate fibrosis was observed in the interstitial area, and moderate atrophy was observed in the tubules. There were no significant findings in immunofluorescence analysis, and no electron dense deposits were detected by electron microscopy. Although cyst-like expansion of the tubules was unclear, tubular atrophy was dominantly found in the distal tubule by cytokeratin 7 staining. Genetic analysis of the NPHP1 gene showed complete deletion of this gene, leading to a definitive diagnosis of NPHP. Conclusions NPHP is not merely a pediatric disease and is relatively high incidence in patients with adult onset end-stage of renal disease. In this case, typical histological abnormalities, such as cyst-like expansion of the tubular lesion, were not observed, and diagnosis was achieved by genetic analysis of the NPHP1 gene, which is responsible for the onset of NPHP. In patients with renal failure with tubular interstitial disease dominantly in the distal tubules, it is necessary to discriminate NPHP, even in adult cases.

Tubular and interstitial disease

Tubulointerstitial diseases refer to a group of disorders in which inflammatory cell infiltrates within the kidney interstitium and/or tubular epithelium are seen on kidney biopsy. These disorders constitute an important group of kidney diseases with varying prevalences and presentations due to a number of causes. It is difficult to estimate the worldwide incidence of tubular and interstitial disease as it is a histological diagnosis and biopsy rates vary substantially around the world. Increasing incidence of tubulointerstitial nephritis has been related to polypharmacy, particularly in the older population. Tubulointerstitial nephritis may present acutely as an immunologically mediated hypersensitivity reaction to an inciting agent—typically a drug or infection—or chronically as a part of a disease process leading to chronic interstitial fibrosis and tubular atrophy. Allergic interstitial nephritis, analgesic nephropathy, nephrotoxic metals, hyperuricemia, Balkan nephropathy, Mesoamerican nephropathy, aristolochic acid nephropathy, and other rare causes of tubulointerstitial nephritis are covered in this section. Isolated defects of tubular function, tubular disorder-related nephropathies, and electrolyte derangements also constitute important aspects of tubulointerstitial diseases.

Short follow-up of multisystem inflammatory syndrome after covid19 infection in children: case report

Background: covid19 infection, in children compared to adults, often occurs in a pauci and/or asymptomatic manner, but in some cases, a multisystem inflammatory syndrome (MIS) may occur in the 4-6 weeks following the infection. There are few data on the features of MIS after the clinical recovery phase, therefore we have described three cases of children with post-covid19 infection syndrome. Case presentation: out of the three cases described, in two children the onset clinical symptoms were similar to Kawasaki syndrome, while in the other neurological impairment was prevalent. In none of the three there were gastrointestinal symptoms, while the signs of interstitial disease were constant on lung ultrasound. In all of them, there was an increase in the inflammatory markers, high levels of ferritin, lymphocytopenia and thrombocytopenia only in one case. The lipid profile at onset was characterized by an increase in triglyceride levels. In all cases the course was benign with resolution of the symptoms upon admission within 4-5 days. After 1 month from the clinical recovery phase, the patients showed normalization of cytokines, inflammatory markers and triglyceride levels, while the total cholesterol value increased. Covid19 infection leads to an acute phase response with increase of the triglyceride in addition to inflammatory markers and the signs of interstitial disease on lung ultrasound. Conclusions: the inflammatory markers and lung involvement normalize over 30 days, while an initial increase of the triglyceride - and later in total cholesterol - suggest a direct relationship between triglyceride and inflammatory markers at the beginning, and between total cholesterol and host immune response during the follow-up.

Imaging of pulmonary sequelae described in viral pandemics prior to SARS-CoV-2 as a prediction model

Knowledge of lung sequelae after coronavirus disease 2019 (COVID-19) is still limited given the short follow-up time. In this work, publications with a follow-up of radiological findings once the infection caused by other previously described viruses that have the lung as their target organ and that cause probably similar changes are reviewed, including the coronaviruses that cause Severe Acute Respiratory Syndrome (SARS-CoV) and Middle East respiratory syndrome (MERS-CoV), and influenza A-subtype H1N1 virus. Lung damage caused by these viruses leads to slow-resolution interstitial disease, with variable correlation with respiratory function tests. The greater extension of the sequelae has been associated with an older age and a greater severity of the infectious clinical picture. However, the pulmonary imaging findings and their long-term functional impact are still unknown.

Higher Accuracy of Lung Ultrasound over Chest X-ray for Early Diagnosis of COVID-19 Pneumonia

Background: The COVID-19 pandemic rapidly strained healthcare systems worldwide. The reference standard for diagnosis is a positive reverse transcription polymerase chain reaction (RT-PCR) test, but results are not immediate and sensibility is variable. Aim: To evaluate the diagnostic accuracy of lung ultrasound compared to chest X-ray for COVID-19 pneumonia. Design and Setting: A retrospective analysis of symptomatic patients admitted into one primary care centre in Spain between March and September 2020. Method: Patients’ chest X-rays and lung ultrasounds were categorized as normal or pathologic. RT-PCR confirmed COVID-19 infection. Pathologic lung ultrasound images were further categorized as showing either local or diffuse interstitial disease. McNemar and Fisher tests were used to compare diagnostic accuracy. Results: Most of the 212 patients presented fever at admission, either as a standalone symptom (37.74% of patients) or together with others (72.17% of patients). The positive predictive value of the lung ultrasound was 90% for the diffuse interstitial pattern and 46.92% for local pattern. The lung ultrasound had a significantly higher sensitivity (82.75%) (p < 0.001), but lower specificity (71%) than the chest X-ray (54.02% and 86%, respectively) (p = 0.008) for identifying interstitial lung disease. Moreover, sensitivity of the lung ultrasound for severe interstitial disease was 100%, and was significantly higher than the chest X-ray (58.33%) (p = 0.002). Conclusion: The lung ultrasound is more accurate than the chest X-ray for identifying patients with COVID-19 pneumonia and it is especially useful for those presenting diffuse interstitial disease.