INTRODUCTION:Amyloidosis can be a localized or a systemic process. The prognosis of the disease ranges from a few months when it is secondary to plasma cell dyscrasias to many years when it is familial. The most common causes of death are heart disease (intractable heart failure) and renal disease. We report what we believe to be the first documented case of systemic amyloidosis contributing to end stage emphysema leading to lung transplantation.
CASE PRESENTATION:A 35 year old African-American male with a diagnosis of emphysema was referred to our institution for lung transplant evaluation. His past history was significant for hypertension, and smoking marijuana for 10-15 years; he had no history of tobacco abuse. Pulmonary function tests showed a severe obstructive ventilatory defect with hyperinflation and air trapping. Alpha-1 antitrypsin level was normal. Pre-transplant cardiac workup showed a normal ejection fraction with moderately increased left ventricular wall thickness, normal coronaries, and mildly elevated pulmonary capillary wedge pressure (18 mmHg) and pulmonary artery pressures (40/15/28). The rest of the pre-transplant evaluation was negative. He underwent lung transplantation shortly thereafter. He developed multiple complications, including Clostridium difficile colitis requiring a total colectomy; pneumonia secondary to Herpes simplex, Enterococcus faecalis, and Aspergillus; thrombocytopenia; chronic diffuse intravascular coagulation; renal failure due to acute tubular necrosis and contrast administration. The patient expired two months after transplantation secondary to worsening sepsis and renal failure. The autopsy revealed systemic amyloidosis involving the heart, kidneys, bowel, spleen, pancreas and adrenal glands. Reexamination of the explanted lungs with Congo Red stains revealed diffuse amyloid deposition.
DISCUSSIONS:Severe emphysema at such an early age with extensive amyloid deposition, no significant tobacco exposure and a normal alpha-1 antitrypsin level suggests amyloidosis could be a contributing factor. Amyloidosis has been associated with pulmonary nodules, pleural effusions, and infiltration of the alveolar septal walls leading to restrictive lung disease from diffuse protein accumulation. However, the association between amyloid deposition in the lung and the development of emphysema has never been described. There are two possible mechanisms that could explain this phenomenon. Studies in murine models with amyloidosis have shown an increase in inflammatory cells, oxygen radical accumulation, and increased elastase-like activity leading to emphysema1. Another possible mechanism could be amyloid deposition in the terminal or respiratory bronchioles leading to bronchoconstriction and air trapping with subsequent emphysematous changes. In addition, this condition was likely the predisposing factor for the multiple postoperative complications and ultimate death. Except for subtle findings on this patient’s echocardiogram and cardiac catheterization, there were no obvious preoperative signs of amyloidosis.
CONCLUSION:We present a case of end-stage emphysema in a young man who was found to have systemic amyloidosis after undergoing lung transplantation. This may be the first reported case where extensive pulmonary amyloid deposits present as end stage emphysema. There are animal studies that could suggest such an association.
DISCLOSURE:Alvaro Visbal, No Financial Disclosure Information; No Product/Research Disclosure Information