Clinical features and outcome of patients with both ANCA and anti-GBM antibodies.
BACKGROUND
Patients have been described who have both anti-neutrophil cytoplasm antibodies (ANCA) and anti-glomerular basement membrane (GBM) antibodies. We have attempted to define the true prevalence of such "double positive" patients, and describe in detail their clinical features and outcome.


METHODS
We have reviewed all serologic assays performed between 1990 and 2000 in a single institution, and the case notes of patients having sera positive for both ANCA and anti-GBM antibodies. During this time 20,392 sera were initially tested for ANCA, and 4808 sera tested for anti-GBM antibodies.


RESULTS
Five percent of all ANCA-positive serum samples were also positive for anti-GBM antibodies, and 32% of all anti-GBM positive samples had detectable ANCA. Of 27 patients with both antibodies, 82% had anti-myeloperoxidase specific P-ANCA. Pulmonary hemorrhage occurred in 44%. Renal biopsy showed extensive glomerular cellular crescents in most patients. Patient and renal survival rates were 52% and 26%, respectively, at one year. Sixty-eight percent of patients were dialysis-dependent at presentation, and none of these recovered renal function, despite immunosuppression with or without plasma exchange.


CONCLUSIONS
Serologic evidence of double positivity for both ANCA and anti-GBM antibodies is common in patients with either antibody. In our study these patients have a poor prognosis when presenting with severe disease and initially behave more like anti-GBM disease than vasculitis. Recovery from severe renal failure is rare.
Renal Section, Faculty of Medicine, Imperial College London, Hammersmith Hospital, United Kingdom. j.levy@imperial.ac.uk
Jeremy B
JB
Levy
Tarig
T
Hammad
Anne
A
Coulthart
Tammy
T
Dougan
Charles D
CD
Pusey
D019867:Anti-Glomerular Basement Membrane Disease / Q000276:immunology* / Q000401:mortality*; D000906:Antibodies / Q000097:blood*; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood*; D001323:Autoantibodies; D003404:Creatinine / Q000097:blood; D006801:Humans; D007676:Kidney Failure, Chronic / Q000276:immunology / Q000401:mortality; D011379:Prognosis; D016036:Seroepidemiologic Studies; D012720:Severity of Illness Index; D015996:Survival Rate
D000906:Antibodies; D019268:Antibodies, Antineutrophil Cytoplasmic; D001323:Autoantibodies; C051951:antiglomerular basement membrane antibody; D003404:Creatinine