RESUMO
A 66-year-old Asian woman presented with severe kidney injury, microscopic haematuria and subnephrotic range proteinuria with elevated serum anti-glomerular basement membrane (anti-GBM) titre. She had a history of renal cell carcinoma. Renal biopsy revealed dual pathology with immunofluorescence showing 3+ linear glomerular IgG staining and 3+ IgA mesangial staining. Cellular crescents were present on light microscopy and electron microscopy revealed increased mesangial matrix. She was treated with plasma exchange and immunosuppression and remained in stage 4 chronic kidney disease. This case describes the coexistence of anti-GBM disease and IgA nephropathy, a phenomenon not well described in the literature. The report also explores the association of malignancy and glomerulonephritis as well as the role of genetics and the utility of human leukocyte antigen (HLA) typing in risk stratification.
Assuntos
Doença Antimembrana Basal Glomerular , Carcinoma de Células Renais , Glomerulonefrite por IGA , Neoplasias Renais , Idoso , Doença Antimembrana Basal Glomerular/complicações , Doença Antimembrana Basal Glomerular/diagnóstico , Autoanticorpos , Carcinoma de Células Renais/complicações , Feminino , Membrana Basal Glomerular , Glomerulonefrite por IGA/complicações , Glomerulonefrite por IGA/diagnóstico , Humanos , Neoplasias Renais/complicaçõesRESUMO
BACKGROUND: Treponema pallidum specific serology generally remains reactive for life. Therefore, the diagnosis of syphilis reinfection relies on clinical assessment and nontreponemal (reagin) serologic testing. The prozone phenomenon can lead to a falsely nonreactive rapid plasma reagin (RPR) assay result. METHODS: We report a case of secondary syphilis in a HIV infected patient with a previous history of syphilis infection, where a falsely nonreactive RPR assay was associated with a delayed diagnosis of reinfection and infectious syphilis. The prozone phenomenon was detected in several of the patient's serum samples collected around this time. We subsequently undertook a prospective evaluation for the prozone phenomenon in 3222 consecutive sera, which were assayed using the RPR assay for clinical purposes over a 10-month period. RESULTS: The overall rate of the prozone phenomenon was 2 out of 3222 samples (0.06%; 95% confidence interval (CI): 0.02-0.22%) and the rate per reactive sample was 2 out of 397 (0.5%; 95% CI: 0.14-1.81%). CONCLUSION: Clinicians should request RPR testing at dilutions of sera when syphilis is suspected clinically and the RPR assay is nonreactive.