Hereditary Amyloidosis with Recurrent Lung Infiltrates

BACKGROUND: Amyloidosis is a protein conformational disorder characterized by extracellular deposition of amyloid fibrils in extracellular tissue. Lung involvement is most commonly caused by secondary AL amyloidosis. The familial autosomal-dominant senile transthyretin (ATTR) disease manifests mainly as polyneuropathy and restrictive cardiomyopathy denoting the name familial amyloidotic polyneuropathy (FAP). Rarely, this form manifests with clinical and radiologically relevant respiratory tract symptoms and lung involvement.
CASE REPORT: A 51-year-old male former smoker presented with progressive lower-extremity weakness of several months’ duration. He was ultimately diagnosed with chronic demyelinating polyneuropathy and treated with intravenous immunoglobulin therapy. Subsequently, he was admitted with heart failure symptoms and pulmonary infiltrates and his echocardiogram showed a ‘myocardial speckled pattern’, prompting an endomyocardial biopsy, which showed transthyretin amyloid deposition. He was started on diflunisal. Additionally, serial radiographic imaging of his chest over 3 different admissions for cough, dyspnea, hypoxemia, and lethargy demonstrated recurrent pulmonary infiltrates. A fiberoptic bronchoscopy with trans-bronchial biopsies revealed amyloid deposition in the lung tissue.
CONCLUSIONS: The clinical presentation of recurrent or persistent pulmonary symptoms and fleeting infiltrates on imaging in a patient with familial amyloidotic polyneuropathy is not common; when present, it should raise the suspicion of respiratory tract involvement.

Keywords: Amyloid Neuropathies, Familial, Amyloidosis, Familial, Pulmonary Alveoli