title: Goodpasture's syndrome with absence of circulating anti-glomerular basement membrane antibodies: a case report.
abstract: BACKGROUND
  Goodpasture's syndrome, a rare disease, is an organ-specific autoimmune disease mediated by anti-glomerular basement membrane antibodies. Its pathology is characterized by crescentic glomerulonephritis with linear immunofluorescent staining for immunoglobulin G on the glomerular basement membrane. Although rare, a few cases with absence of circulating anti-glomerular membrane antibodies have been described.
  
  
  METHODS
  The objective of this clinical case report is to describe and discuss a case of a 27-year-old white man who was hospitalized with a 1-year history of weight loss and a 1-month history of hemoptysis, with aggravation  the day before, having developed dyspnea and cough in the previous 24 hours. An analytical study showed normocytic normochromic anemia with a hemoglobin level of 7.2 g/dL and leukocytosis with normal renal function and coagulation times. A blood transfusion was performed without complications. Chest computed tomography revealed a reticulonodular infiltrate of both lungs. Bronchoscopy showed no apparent lesions. Sputum cultures, rapid urine antigens for Legionella pneumophila and Streptococcus pneumoniae, studies for Influenza, virologic markers and serologic studies for autoimmunity were all negative. At the end of the tenth day his general state deteriorated with fatigue, hematuria, and in 3 days he developed aggravation of renal function with recurrent hemoptysis and anemia. Immunosuppression with daily prednisolone 1 g administered intravenously was initiated. An urgent bronchoscopy showed no lesions. A kidney biopsy showed fibrinoid necrosis and cellular crescents. Immunofluorescence revealed a linear immunoglobulin G deposition compatible with Goodpasture's syndrome. Immunosuppressive therapy with daily cyclophosphamide 120 mg orally was added. Subsequently he was transferred to a referral center at which 21 sessions of plasmapheresis and four sessions of hemodialysis were performed with good response; he currently has no need of hemodialysis.
  
  
  CONCLUSIONS
  The absence of circulating anti-glomerular basement membrane antibodies in Goodpasture's syndrome adds complexity to the diagnosis creating an unusual setting in a rare disease. In our case a kidney biopsy was essential for diagnosis and clinical approach. Studies have shown that early aggressive therapy leads to an improved prognosis. Physicians should consider tissue diagnoses such as bronchoscopy and kidney biopsy in pulmonary renal syndrome.
authors.affiliation: Internal Medicine Department Guimarães, Centro Hospitalar do Alto Ave Rua dos Cutileiros Creixomil, 4810, Guimarães, Portugal. ruifernandes_2001@hotmail.com.
authors.forename: Rui
authors.initials: R
authors.lastname: Fernandes
authors.affiliation: Internal Medicine Department Guimarães, Centro Hospitalar do Alto Ave Rua dos Cutileiros Creixomil, 4810, Guimarães, Portugal.
authors.forename: Sara
authors.initials: S
authors.lastname: Freitas
authors.affiliation: Internal Medicine Department Guimarães, Centro Hospitalar do Alto Ave Rua dos Cutileiros Creixomil, 4810, Guimarães, Portugal.|Life and Health Science Research Institute (ICVS) School of Health Science, University of Minho, Braga, Portugal.
authors.forename: Pedro
authors.initials: P
authors.lastname: Cunha
authors.affiliation: Internal Medicine Department Guimarães, Centro Hospitalar do Alto Ave Rua dos Cutileiros Creixomil, 4810, Guimarães, Portugal.
authors.forename: Gloria
authors.initials: G
authors.lastname: Alves
authors.affiliation: Internal Medicine Department Guimarães, Centro Hospitalar do Alto Ave Rua dos Cutileiros Creixomil, 4810, Guimarães, Portugal.|Life and Health Science Research Institute (ICVS) School of Health Science, University of Minho, Braga, Portugal.
authors.forename: Jorge
authors.initials: J
authors.lastname: Cotter
mesh_terms: D000328:Adult; D019867:Anti-Glomerular Basement Membrane Disease / Q000175:diagnosis* / Q000188:drug therapy; D003520:Cyclophosphamide / Q000627:therapeutic use; D003937:Diagnosis, Differential; D005455:Fluorescent Antibody Technique; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D008297:Male
chemical_list: D007166:Immunosuppressive Agents; D003520:Cyclophosphamide
keywords: Anti-GBM antibodies; Case report; GBM; Glomerular basement membrane; Glomerulonephritis; Goodpasture’s syndrome; Rapidly progressive glomerulonephritis; Renal failure