This disorder is characterized by diffuse alveolar hemorrhage and glomerulonephritis. Although other disorders share similar clinical symptoms, particularly hemoptysis (SLE, Wegeners granulomatosis, vasculitis, Behcet's syndrome, mitral stenosis), this disorder differs in that it is an autoimmune disease in which end organ damage results secondary to autoantibodies directed against the pulmonary alveolar and renal glomerular basement membranes. Goodpastures syndrome should be suspected when there is radiographic evidence of pulmonary infiltrates, hemoptysis, and anemia along with evidence of glomerulonephritis or renal failure. Two studies useful to determine if pulmonary infiltrates noted on chest radiograph are consistent with pulmonary hemorrhage include the DLCO and bronchoalveolar lavage. With pulmonary hemorrhage, the DLCO will be elevated and hemosiderin-laden macrophages will be present in bronchoalveolar lavage. This disorder most commonly affects young adult males although persons of any sex or age may be affected.
The pulmonary symptoms, mainly hemoptysis, usually precede gross renal involvement. Therefore, if the diagnosis is suspected and there is no evidence of renal failure, microscopic examination of a urine sample may be fruitful because more than 90% of patients will have microscopic hematuria when the serum BUN and creatinine values are within normal limits. Symptoms of this disease are usually limited to the pulmonary and renal systems, and hypertension is usually not a symptom of renal failure associated with this disorder.
Patients with diffuse pulmonary hemorrhage should be subjected to multiple studies to help narrow the above-mentioned differential diagnosis. Recommended studies include the following: anti-glomerular basement membrane (GBM) assays, antinuclear antibody (ANA) assay, serum cryoglobulins, serum complement studies (CH50), anti-neutrophilic cytoplasmic antibody (C-ANCA) assays, coagulation studies (PT and PTT), renal function studies (serum BUN and creatinine), and a urinalysis with microscopic examination. Elevated levels of anti-glomerular basement membrane may provide the diagnosis. The titer of anti-GBM does not correlate with the severity of disease. Once the diagnosis is established, renal biopsy should be performed to determine the level of renal involvement.
Therapy is controversial; however, the literature suggests that plasmapheresis or plasma exchange improves outcome drastically. Plasmapheresis is followed by immunosuppressive therapy with corticosteroids and cyclophosphamide until anti-GBM is no longer detected (usually 9 to 12 months). Following remission, regular follow-ups should be conducted as relapses may occur.
Prior to plasmapheresis, this disorder was progressive and fatal. Currently, plasma exchange may decrease anti-GBM levels and allow for complete remission although relapses may occur. It is important to establish the diagnosis and institute therapy as soon as possible as the preservation of renal function depends on the level of impairment prior to the institution of therapy. In patients with severe renal failure, hemodialysis may be necessary to support the patient.