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

Abstract

BackgroundMyeloperoxidase 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).MethodsWe 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.ResultsThe 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.ConclusionsMPO-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.

Mortality and survival in idiopathic pulmonary fibrosis: a systematic review and meta-analysis

“…Similar trend was found for the 5-year CSRs (patients taking antifibrotics: 51.4% [95% CI, 44.1-58.7; I 2 = 97.9%] vs. those taking non-antifibrotics: 43.9% [95% CI, 39.9-47.8; I 2 =93.4%]) (P=0.084). In addition, there were no significant associations between various diagnostic criteria and CSRs, and those associations remained consistent after exclusion of 16 studies [27,32,39,40,43,49,50,52,55,66,68,71,74,85,86,88] in which patients received antifibrotics (Table 4).…”

ANCA-associated vasculitis in idiopathic pulmonary fibrosis

“…Combination therapy with corticosteroids and cyclophosphamide is the mainstay of remission induction treatment for severe MPA. One study that compared the prognosis of the UIP pattern in MPO-ANCA nephritis patients with the prognosis of IPF patients found no significant difference in the median survival time [16] …”

“…One study that compared the prognosis of the UIP pattern in MPO-ANCA nephritis patients with the prognosis of IPF patients found no significant difference in the median survival time. [16] The pathophysiological mechanisms underlying the association between ANCA vasculitis and pulmonary fibrosis remain poorly understood. It remains unclear whether this association represents 2 distinct diseases with potential pathophysiological links or manifestations of the same disorder.…”

Myeloperoxidase and associated lung disease: Review of the latest developments

“…Treatment for MPO‐positive AAV‐ILD is predominantly the standard therapy for systemic vasculitis, including systemic corticosteroids, cyclophosphamide, rituximab, mycophenolate mofetil, azathioprine and, to a lesser extent, methotrexate (due to its side effect of pulmonary fibrosis) 22 . However, good evidence for these treatments is lacking, and the prognosis of AAV‐ILD is not improved with immunosuppression 23,24 . There are no comparative studies looking at efficacy of anti‐fibrosing agents in AAV‐ILD, though there are small reports of improvement in survival predominantly for those with a usual interstitial pneumonia (UIP) pattern 25 …”

“…Based on this, clinicians from the Mayo Clinic have suggested treating nonspecific interstitial pneumonia pattern patients with immunosuppression, but for those with a UIP pattern without associated systemic vasculitis, to avoid immunosuppressive therapy and take a watch‐and‐wait approach, similar to the usual treatment paradigms for IPF 7 . This finding was not seen in other studies 23,24 . Of note, in the Mayo Clinic cohort, the classification of patients based on ILD subtype was based on radiology, 7 but Baqir et al 33 have demonstrated that though radiology may not identify UIP pattern, histopathology on biopsy subsequently demonstrated predominant UIP pattern in a non‐AAV MPO‐ANCA ILD cohort.…”