Microscopic polyangiitis associated with sinobronchial syndrome

A rare case of atypical ANCA-associated vasculitis without crescents overlapping with invasive pulmonary aspergillosis, successfully treated to remission with intravenous immunoglobulin therapy

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is life-threatening without treatment, but aggressive immunosuppression increases the risk of exacerbating a coexisting infection. Finding the balance between efficacy and safety of immunosuppression is challenging. We describe a 74-year-old man who was diagnosed with AAV following the aggravation of chronic pulmonary aspergillosis that required an aggressive antifungal agent. The laboratory data on admission demonstrated severe kidney failure requiring hemodialysis. Due to the active infection, we chose intravenous immunoglobulin (IVIg) as a low-risk initial treatment, which remarkably improved renal dysfunction (serum creatinine; 16.7 mg/dL-3.7 mg/dL) and systemic inflammation. Renal biopsy that was performed after renal recovery revealed atypical ANCA-associated nephritis without cellular crescents but with massive arteritis with multiple vascular sizes and diffuse interstitial inflammation. Despite these active AAV findings, adding plasma exchange therapy (PE) and low-dose steroids were sufficient to induce remission. The main pathogenesis of severe renal impairment was probably the reduction of blood flow, resulting from occlusions of small arteries by inflammatory cell infiltration and vascular endothelial injury due to AAV. Combination treatment with antifungal agents, IVIg, PE, and low-dose steroid treatment led to complete resolution of vasculitis. The specific histological findings and the good response to treatments suggest that pulmonary aspergillosis might trigger vasculitis through induction of ANCA antigen expression. IVIg could be an important option especially for cases of AAV associated with pulmonary aspergillosis.

Clinical implication of chronic paranasal sinusitis for the classification of microscopic polyangiitis

BACKGROUND

Chronic paranasal sinusitis (CPS) has been known as a surrogate marker for granulomatosis with polyangiitis (GPA). We investigated whether CPS at diagnosis may have an influence on the classification and outcomes of microscopic polyangiitis (MPA).

METHODS

We retrospectively reviewed the medical records of 106 immunosuppressive drug-naïve patients with MPA. We compared variables at diagnosis of MPA patients with CPS with either MPA patients without CPS or 29 GPA patients with CPS. We applied the algorithm for antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) proposed by the European Medicine Agency to 22 MPA patients with CPS and reclassify them. Death, relapse and end-stage renal disease were assessed as the poor outcomes.

RESULTS

Except for ENT manifestations, only pulmonary manifestation was more frequently observed in MPA patients with CPS than those without (77.3% vs 47.6%). No proteinase 3-ANCA was detected in all MPA patients with CPS. Meanwhile, general (63.6% vs 27.6%) and renal manifestations (81.8% vs 44.8%) more often developed in MPA patients with CPS than GPA patients with CPS. Of 22 MPA patients with CPS, 21 patients underwent biopsies. When CPS was not considered as a surrogate marker for GPA, all patients with CPS were reclassified as MPA. Ground glass opacity and reticulation on high-resolution computed tomography and renal vasculitis were helpful clues supporting the classification of MPA in patients with CPS. CPS at diagnosis was not associated with the outcomes of MPA.

CONCLUSION

CPS might not be a sufficient surrogate marker for GPA in the classification of AAV.

Prevalence and Responsiveness to Treatment of Lung Abnormalities on Chest Computed Tomography in Patients With Microscopic Polyangiitis: A Multicenter, Longitudinal, Retrospective Study of One Hundred Fifty Consecutive Hospital-Based Japanese Patients

OBJECTIVE

To determine the prevalence of lung abnormalities on chest computed tomography (CT) in patients with microscopic polyangiitis (MPA), to assess the responsiveness of such abnormalities to initial treatment, and to assess associations between these abnormalities and patient and disease characteristics and mortality.

METHODS

We retrospectively identified 167 consecutive hospital-based patients with MPA in 3 hospitals in Japan. We longitudinally collected clinical information for 150 of these patients, for whom CT images obtained before treatment were available. We then determined the presence of 22 imaging components of lung abnormalities in these patients.

RESULTS

The vast majority of patients (97%) had at least 1 lung abnormality on chest CT images, including interstitial lung lesions (66%), airway lesions (66%), pleural lesions (53%), and emphysematous lesions (37%). In multivariate analyses, ground-glass opacity was associated with the Birmingham Vasculitis Activity Score, whereas 3 of 4 airway lesions were associated with myeloperoxidase-antineutrophil cytoplasmic antibodies. Latent class analysis identified a distinct group of patients with airway-predominant lung lesions. Airway lesions such as bronchiolitis and bronchovascular bundle thickening were among the components that showed improvement within 3 months of the initial treatment. An idiopathic pulmonary fibrosis pattern was the only chest CT variable that was independently associated with shorter survival.

CONCLUSION

Abnormalities in a wide range of anatomic areas, including the whole airway, can be identified in the lungs of patients with MPA before treatment. The prevalence, clustering patterns, and responsiveness to treatment of individual lung abnormalities provide groundwork for informing future studies to understand the pathophysiology of MPA.

A case of sinobronchial syndrome complicated with myeloperoxidase antineutrophil cytoplasmic antibody associated vasculitis: review of the literature

We report a case of long-standing sinobronchial syndrome complicated by microscopic polyangiitis (MPA) during the clinical course. The patient showed a mild elevation of myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA) 17 months prior to the diagnosis of MPA. Subsequently, her MPO-ANCA level gradually became more elevated, and finally her MPO-ANCA level peaked when purpura appeared. Histologic examination of the skin biopsy was consistent with leukocytoclastic vasculitis. Based on the pathological and clinical findings, a diagnosis of MPA was made. Corticosteroid therapy finally led to a remission of MPA with normalized MPO-ANCA titers.

Development of microscopic polyangiitis in patients with chronic airway disease

Microscopic polyangiitis (MPA) is a rare systemic vasculitis syndrome, which is often accompanied by positive myeloperoxidase-specific antineutrophil cytoplasmic antibody (MPO-ANCA). While pulmonary involvement of MPA consists mainly of diffuse alveolar hemorrhage and interstitial pneumonia, bronchiectasis has been reported as a pulmonary lesion in association with MPA. To investigate the clinical features of patients with MPA, focusing on the presence or the absence of preceding chronic airway diseases (CAD), we conducted a retrospective observational study of 26 patients in the last 13 years at Saga University Hospital. The clinical records and radiologic chest examinations were reviewed retrospectively. Pulmonary manifestations were alveolar hemorrhage in 3 patients (12%) and interstitial pneumonia in 5 (19%). Bronchiectasis, defined by the findings of chest radiograph and computed tomography, was found in 9 patients (35%). Four patients (15%) with bronchiectasis and one patient (4%) with chronic bronchitis had experienced chronic bronchial suppuration prior to the onset of MPA. Ten patients were classified as having chronic airway disease (CAD) before the onset of MPA. MPO-ANCA tended to be lower in the CAD group than in the non-CAD group. None of the patients in the CAD group had pulmonary hemorrhage or interstitial pneumonia. Only one patient (10%) in the CAD group died within 90 days of the onset of MPA, while 7 (43.8%) of the non-CAD group died. Our study suggests that MPA may result in part from CAD and that the clinical course of MPA with CAD may be different from MPA without CAD.

Microscopic polyangiitis associated with diffuse panbronchiolitis

There are several case reports of systemic vasculitis associated with chronic suppurative lung diseases. We describe a 46-year-old female, previously diagnosed as having diffuse panbronchiolitis (DPB), presenting with hemosputum and dyspnea. Her serum titer of MPO-ANCA was positive together with a high titer of BPI-ANCA. Chest X-ray and chest CT scan showed pulmonary hemorrhage, and the renal biopsy specimen revealed necrotizing, crescentic glomerulonephritis. She was diagnosed as having ANCA-associated vasculitis, and more specifically, microscopic polyangiitis accompanied by DPB. She was treated with methylprednisolone pulse therapy, followed by intravenous cyclophosphamide. This case suggested a possible association with chronic bacterial infection, which may play a role in the pathogenesis of ANCA-associated vasculitis.