Incidence of myeloperoxidase anti-neutrophil cytoplasmic antibody positivity and microscopic polyangitis in the course of idiopathic pulmonary fibrosis.

Pulmonary fibrosis is a manifestation of microscopic polyangitis (MPA), and often precedes the detection of MPA. The prevalence and sequence of myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA) and MPA in patients initially diagnosed with idiopathic pulmonary fibrosis (IPF) have not been precisely elucidated. We enrolled 61 consecutive patients with IPF and measured the MPO-ANCA titers at initial presentation and during the follow-up period. Clinical, radiologic and histologic features of MPO-ANCA-positive cases were examined. Of 61 patients, 3 (4.9%) had positive MPO-ANCA titers at the initial presentation of IPF. During the disease course, MPO-ANCA-positive conversion occurred in 6 patients and the prevalence of ANCA increased to 14.8%. Among the nine patients positive for MPO-ANCA, two patients developed MPA during follow-up. Histologic features of MPO-ANCA-positive pulmonary fibrosis were compatible with the usual interstitial pneumonia pattern in which alveolar hemorrhage and capillaritis were not observed. The patients with MPO-ANCA-positive conversion showed increased percentages of bronchoalveolar lavage eosinophils and more frequent complication of pulmonary emphysema compared to those with MPO-ANCA-negative IPF. The findings of the present study demonstrated that patients with an initial diagnosis of IPF occasionally acquire MPO-ANCA, which develops to MPA during the disease course of IPF. The presence of pulmonary eosinophilia and low attenuation areas on computed tomography scans might be predictive of MPO-ANCA positive conversion.

Ando M ，Miyazaki E ，Ishii T ，Mukai Y ，Yamasue M ，Fujisaki H ，Ito T ，Nureki S ，Kumamoto T ... -  《-》

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.

Watanabe T ，Minezawa T ，Hasegawa M ，Goto Y ，Okamura T ，Sakakibara Y ，Niwa Y ，Kato A ，Hayashi M ，Isogai S ，Kondo M ，Yamamoto N ，Hashimoto N ，Imaizumi K ... -  《BMC Pulmonary Medicine》

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

Myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA) is occasionally positive in patients with usual interstitial pneumonia (UIP). However, the differences from idiopathic pulmonary fibrosis (IPF/UIP) have not been well documented. We aimed to clarify the clinical, radiological and pathological features of UIP associated with MPO-ANCA (ANCA/UIP). We retrospectively reviewed the medical records of 12 consecutive ANCA/UIP patients not manifesting microscopic polyangiitis and 108 IPF/UIP patients with no autoantibodies, both diagnosed by surgical lung biopsy. There was no significant difference in clinical background, laboratory results and pulmonary function tests between ANCA/UIP patients and IPF/UIP patients except for the percentage of bronchoalveolar lavage neutrophils. HRCT showed subpleural reticulation in both groups. Increased attenuation around honeycombing and cysts was significantly observed in ANCA/UIP. Pathologically, ANCA/UIP had more prominent inflammatory cell infiltration, lymphoid follicles with germinal centres and cellular bronchiolitis. During the disease course, three of 12 patients (25%) developed microscopic polyangiitis. Immunosuppressive treatment tended to be more effective in ANCA/UIP patients, and the survival time in ANCA/UIP patients tended to be longer than those with IPF/UIP. ANCA/UIP may be distinguishable from IPF/UIP with a combination of HRCT findings of increased attenuation around honeycombing and cysts and some of the characteristic pathological findings. In contrast to IPF/UIP, immunosuppressive treatment could be a therapeutic option for ANCA/UIP.

Hosoda C ，Baba T ，Hagiwara E ，Ito H ，Matsuo N ，Kitamura H ，Iwasawa T ，Okudela K ，Takemura T ，Ogura T ... -  《-》

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

Hozumi H ，Oyama Y ，Yasui H ，Suzuki Y ，Kono M ，Karayama M ，Furuhashi K ，Enomoto N ，Fujisawa T ，Inui N ，Nakamura Y ，Suda T ... -  《PLoS One》

Antineutrophil cytoplasmic antibody-positive conversion and microscopic polyangiitis development in patients with idiopathic pulmonary fibrosis.

Kagiyama N ，Takayanagi N ，Kanauchi T ，Ishiguro T ，Yanagisawa T ，Sugita Y ... -  《-》