RESUMEN
ObjectiveTo investigate the clinical and pathological features of patients with anti-glomerular basement membrane(GBM) disease lacking linear IgG deposition along GBM on renal biopsy.Method Ninety-three patients with anti-GBM disease were collected in our hospital from 1991 to 2008,with 40 patients presenting negative linear IgG deposition along GBM on renal biopsy by direct immunofluorescence(group A) and 53 patients presenting classical linear IgG deposition along GBM(group B).The clinical manifestation,pathological presentation and prognosis were compared between two groups.Results Between two groups,there were no significant differences in gender,age,hemoptysis,oliguria or anuria,gross hematuria,proteinuria,anemia,ANCA positivity,level of circulating anti-GBM antibodies,the percentage of crescent formation in glomeruli and patient outcomes(P＞0.05).Patients in group A were diagnosed significantly later than patients in group B(68 d vs 36 d,P=0.013) and serum creatinine was significantly lower at diagnosis(716.0 μmol/L vs 896.8 μmol/L,P=0.027).Direct immunofluorescence was performed on the paraffin-embedded renal sections from four patients in group A,and all of them revealed positive linear IgG deposition along GBM.Conclusions Patients with circulating anti-GBM antibodies but withont IgG deposition along GBM present slower progress of renal injury,but same clinical,pathological and prognostic features as those with classical anti-GBM disease.Serum anti-GBM antibodies should be prescribed earlier to the suspected patients,and the diagnosed patients should be treated with plasmapheresis and extensive immunosuppression to improve prognosis.