[IgG4-Related Disease: A rare cause of severe interstitial lung disease]

The intrathoracic manifestations of IgG4-related disease include a range of conditions and severity, and can on occasion cause acute respiratory failure as reported in the case described here.

A 69-year-old male former smoker, was admitted to our hospital with dyspnea, fever, cough, fatigue, and a 3-month history of weight loss. He received high flow oxygen therapy and non-invasive ventilation for severe respiratory failure. Chest computed tomography revealed multifocal condensations and ground glass opacities, accompanied by thickening of the perilymphatic interstitium, mediastinal lymphadenopathy and bilateral pleural effusion. Elevated serum concentrations of IgG4 suggested an IgG4-Related Disease. He developed renal failure and underwent a renal biopsy. Histopathological analysis of which supported the diagnosis by showing dense lymphocytic infiltrate with a count of IgG4+ cells/hpf higher than 60, and storiform fibrosis - a swirling, "cartwheel" pattern of fibrosis which may have a patchy distribution. The patient responded well to steroid therapy.

Although respiratory symptoms are usually mild in IgG4-relatd disease, thoracic features can evolve into acute respiratory failure with few extra thoracic manifestations.