FIBROTIC PROTEASE 3 ANCA-ASSOCIATED VASCULITIS

Abstract

SESSION TITLE: Fellows Diffuse Lung Disease Posters SESSION TYPE: Fellow Case Report Posters PRESENTED ON: October 18-21, 2020 INTRODUCTION: Interstitial lung disease (ILD) associated with anti-neutrophil cytoplasmic antibody (ANCA) vasculitis (AAV) is rare disease The most common reported association is myeloperoxidase autoantibodies (MPO-ANCA) and usual interstitial pneumonia (UIP) [1,2] This case represents a unique instance of protease 3 (PR3-ANCA) associated vasculitis with non-specific interstitial pneumonitis (NSIP) CASE PRESENTATION: A 57-year-old female smoker with a past medical history of COPD presented with worsening dyspnea for 3 weeks accompanied by mild hemoptysis and generalized fatigability On presentation, her oxygen saturation 88% on non-rebreather Physical exam was significant for decreased air entry bilaterally with crackles but was otherwise unremarkable Due to persistent hypoxia patient was intubated Arterial blood gas was pH 7 44, pCO2 38 3, and pO2 50 CBC showed no leukocytosis and platelets within normal limits Comprehensive metabolic panel was all within normal limits Procalcitonin 0 09 ng/ml, CRP 94 mg/l normal Urinalysis Viral respiratory panel including COVID-19 were all negative CT chest showed bilateral interstitial thickening, homogeneous ground-glass opacities, and traction bronchiectasis She was started on ceftriaxone and azithromycin for community-acquired pneumonia Infectious workup including sputum culture, blood culture, urine culture, were negative Connective tissue disease and AAV workup were done to address the fibrotic changes identified on CT chest The patient was positive for homogeneous ANA 1:320 and PR3-ANCA 219-AU/ml Bronchoscopy with BAL performed showed no diffuse alveolar hemorrhage Cell count with differential from BAL was 45% neutrophils 54% macrophage 1% eosinophils 0% lymphocytes, GMS stain, bacterial, viral and fungal cultures were negative Patient was started on pulse does steroid and 60 mg prednisone and rituximab thereafter Over the following 5 days the patient’s oxygen requirement gradually decreased to 3L nasal cannula DISCUSSION: Reports of ILD in AAV have been increasing [4] Microscopic Polyangiitis (MPA) with UIP is the most common type of AAV associated ILD [3] NSIP associated with PR3-ANCA vasculitis is extremely rare, our patient had positive P-ANCA with positive anti-PR3 and negative anti-MPO, with no other manifestations of AVV Previous literatures showes the evidence of ILD usually precedes the appearance of systemic vasculitis [2, 3,5] The pathogenesis of ILD in AAV remains poorly understood The presence of anti-MPO or anti-PR3 contributing directly to the generalized pulmonary tissue injury resulting in subsequent fibrosis is most likely the pathogenesis in our patient [1] Regardless, treatment remains induction with steroids followed by an immunosuppressive agent CONCLUSIONS: It is important that physicians remain aware of this clinical association and the presence of ILD should be considered in all patients with AAV Reference #1: Comarmond C, Crestani B, Tazi A, et al Pulmonary fibrosis in antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis: A series of 49 patients and review of the literature Med (United States) 2014;93(24):340–9 Reference #2: Kishore N, Gupta N, Dhar A, Abrari A, Rath P Interstitial lung disease with usual interstitial pneumonia pattern preceding the presentation of ANCA-associated vasculitis by 4 years: coincidence or correlation? Breathe 2018;14(3):e105–10 Reference #3: Katsumata Y, Kawaguchi Y, Yamanaka H 26448696 2015;1147(Ild):51–6 Arulkumaran N, Periselneris N, Gaskin G, et al Interstitial lung disease and ANCA-associated vasculitis: a retrospective observational cohort study Rheumatology (Oxford) 2011;50(11):2035–43 DISCLOSURES: No relevant relationships by Mohammed Megri, source=Web Response no disclosure on file for Scott Morehead;No relevant relationships by Michael Morris, source=Web Response