Rare disease characterized by intra-alveolar hemorrhage and glomerulonephritis.
Etiology and Pathogenesis
- A cytotoxic antibody against glomerular and alveolar basement
membrane is responsible for the injury.
- By activating complement, the antibody causes damage to
glomerular and alveolar basement membrane.
- A respiratory viral infection is believed to initiate production of the antibody.
- Antigenic similarity between kidney and lung basement membrane
accounts for the clinical picture.
Pathology
Clinical Features
- Pulmonary complaints consist of hemoptysis and dyspnea.
- Hematuria, proteinuria, red cell casts and renal failure are results of glomerulonephritis.
- Iron deficiency anemia results from pulmonary hemorrhage.
- Diffuse bilateral alveolar infiltrates in chest x-ray.
- Hypoxemia and restrictive defect of PFT's.
- Leniar deposition of
IgG and complement
along glomerular and alveolocapillary basement membranes, characteristic of type II
reaction in lung and kidney biopsies.
- EM
- Antiglomerular basement membrane antibody can be detected in
serum.
Therapy
- Steroid in high doses controls pulmonary hemorrhage.
- Nephrectomy with dialysis is necessary in some patients.
- Combination of plasmapheresis and immunosuppressive therapy
provides the best results.
