title: ANCA vasculitis in a patient with Alport syndrome: a difficult diagnosis but a treatable disease!
abstract: BACKGROUND
  Alport syndrome and ANCA-associated vasculitis are both rare diseases. The co-existence of these two conditions has never been reported. There is no obvious pathogenic link between these two glomerular diseases. The management of this case highlights the importance of a systematic approach when investigating the unexpected unfavourable evolution of a known glomerulopathy.
  
  
  METHODS
  A-17 year old caucasian boy with a genetically proven X-linked Alport syndrome presented with progressive dyspnea, fatigue and pallor. His blood tests showed a severe anemia (Hb 6.9 g/dl) with acute worsening of kidney function (serum creatinine, normal 9 months earlier, was now 3.6 mg/dl). Microscopic hematuria and proteinuria also worsened. He soon developed signs of alveolar hemorrhage. Serological tests showed the presence of perinuclear ANCA with anti MPO specificity. Kidney biopsy showed a necrotizing and crescentic glomerulonephritis. Pulses of methylprednisolone were given in combination with plasmapheresis. The patient further received 6 pulses of cyclophosphamide, followed by maintenance oral azathioprine. During the 15-months follow up he remained well with serum creatinine back to normal, and some residual proteinuria and hematuria ascribed to Alport syndrome.
  
  
  CONCLUSIONS
  We report a young patient with the coexistence of Alport syndrome and ANCA associated vasculitis. Clinicians should be aware of the possibility of a second acquired disease in a patient with a known kidney disease, genetic in this case. This coexistence is very rare, but should be considered even if both diseases are rare, if the evolution is atypical for the single (known) primary disease. The diagnosis of the added vasculitis prompted in our case the initiation of immunosuppressive drugs, with a favourable outcome.
authors.affiliation: Division of Nephrology, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Brussels, Belgium.
authors.forename: Valentine
authors.initials: V
authors.lastname: Gillion
authors.affiliation: Division of Nephrology, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Brussels, Belgium. michel.jadoul@uclouvain.be.
authors.forename: Michel
authors.initials: M
authors.lastname: Jadoul
authors.affiliation: Division of Pathology, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Brussels, Belgium.
authors.forename: Selda
authors.initials: S
authors.lastname: Aydin
authors.affiliation: Division of Pediatric Nephrology, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Brussels, Belgium.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Godefroid
mesh_terms: D000293:Adolescent; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage; D056648:Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis / Q000150:complications / Q000175:diagnosis* / Q000628:therapy*; D001379:Azathioprine / Q000008:administration & dosage; D003131:Combined Modality Therapy / Q000379:methods; D003520:Cyclophosphamide / Q000008:administration & dosage; D003937:Diagnosis, Differential; D003951:Diagnostic Errors / Q000517:prevention & control*; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage; D008297:Male; D008775:Methylprednisolone / Q000008:administration & dosage; D009394:Nephritis, Hereditary / Q000150:complications / Q000175:diagnosis* / Q000628:therapy*; D010956:Plasmapheresis / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D000893:Anti-Inflammatory Agents; D007166:Immunosuppressive Agents; D003520:Cyclophosphamide; D001379:Azathioprine; D008775:Methylprednisolone
keywords: ANCA-associated vasculitis; Alport syndrome; Glomerulonephritis