INTRODUCTION: Airway-centred interstitial fibrosis (ACIF) is a relatively new pattern of lung injury described by Churg et al. (1) but has not yet been added to the list of Idiopathic Interstitial Pneumonias. We present a case of a non-smoking Hutterite woman with Common Variable Immunodeficiency (CVID) and ACIF. ACIF has not yet been described in association with CVID.
CASE PRESENTATION: A 52-year-old woman living in a Hutterite community in Alberta, Canada presented with a 2-year history of persistent non-productive cough, wheeze and dyspnea. She had a history of recurrent, radiographically-proven bacterial pneumonias that resolved with antibiotics. She was a lifetime non-smoker and was taking no medications. Apart from subjective worsening around household cleaners including bleach and Pinesol, she had no other exposures. Her symptoms did not improve with bronchodilators or inhaled corticosteroids. High resolution computed tomography scan revealed a pattern of tree-in-bud nodularity and no honeycombing. Pulmonary function testing showed normal spirometry with reduced DLCO. Bronchoalveolar lavage (BAL) revealed 20% polymorphonuclear cells, 1% eosinophils, 3% lymphocytes, 76% macrophages. Pertinent laboratory investigations revealed a negative antinuclear antigen (ANA), IgA 0.66 g/L (0.75-4.55 g/L), IgG 5.63 g/L (6.8 - 18 g/L) and IgM <0.21 g/L (0.5 - 3g/L). Flow cytometry showed no evidence of a B-cell lymphoproliferative disorder. She was diagnosed with common variable immunodeficiency (CVID) and treated with monthly injections of intravenous immunoglobulins (IVIG). Precipitin analysis was not performed due to the CVID. Open lung biopsy revealed prominent bronchiolar fibrosis around isolated bronchi with marked bronchiolar metaplasia which appeared to link up. Only sparse chronic inflammation was present and no granulomata were identified. A diagnosis of ACIF was made. There was no improvement in symptoms or spirometry with 8 weeks of prednisone 50 mg/d. She has remained dyspneic but clinically stable since 2008.
DISCUSSION: Airway-centred interstitial fibrosis (ACIF) is one of several patterns of lung injury predominantly involving airways described in recent years. Others include centrilobular fibrosis, idiopathic bronchiolocentric interstitial pneumonia and peribronchial metaplasia (2). It is unclear whether ACIF represents a distinct disease process or a manifestation of an environmental exposure. In our case, our patient had no prolonged contact with substances known to cause hypersensitivity pneumonitis (HP). Also, lack of granulomas, minimal inflammation on histology and the paucity of lymphocytes on BAL argue against a diagnosis of HP. ACIF following exposure to cleaning products, however, has been reported previously (3). Interstitial lung disease is known to occur in up to 25% of patients with CVID. Granulomatous-lymphocytic interstitial lung disease (GL-ILD) is a term used for lymphoid hyperplasia, follicular bronchiolitis and LIP and is seen in CVID but the absence of granulomas and paucity of lymphocytes in our case makes this diagnosis unlikely. ACIF has not previously been reported in association with CVID. CVID may be unrelated to the diagnosis of ACIF in our patient. Alternatively, CVID may have contributed to the development of ACIF due to immune dysregulation which might provide clues to the pathogenesis of this relatively new pattern of lung injury.
CONCLUSIONS: As ACIF becomes better understood we will hopefully learn the pathogenesis of ACIF, whether there is an association between CVID and ACIF and whether ACIF should be added to the list of Idiopathic Interstitial Pneumonias.
Reference #1 Churg A et al. Airway-centred interstitial fibrosis. A distinct form of aggressive diffuse lung disease. Am J Surg Pathol 2004; 28: 62-68.
Reference #2 Cordeiro CR. Airway involvement in Interstitial lung disease. Curr Opin Pulm Med 2006; 12: 337-341
Reference #3 Serrano M et al. Airway centred interstitial fibrosis associated with exposure to fumes from cleaning products. Arch broncopneumol 2006; 42 (10): 557 - 559.
DISCLOSURE: The following authors have nothing to disclose: Tara Lohmann, John Chan, Margaret Kelly
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