Idiopathic lung fibrosis and anti myeloperoxidase glomerulonephritis: the tree that hides the forest.
BACKGROUND
Although anti-neutrophil cytoplasmic antibodies [ANCA] are frequently found in patients diagnosed with idiopathic pulmonary fibrosis [IPF], current guidance does not recommend serologic testing for vasculitis.


METHODS
A 71-year old Caucasian male, diagnosed with IPF three years earlier, presented with rapidly progressive glomerulonephritis. ANCA were found both in current and historical sera. A kidney biopsy sample was taken, which revealed a pauci-immune glomerulonephritis, but also areas of glomerular fibrosis, hence strongly suggesting unrecognized flares of an indolent vasculitis in his past. This made the diagnosis of "idiopathic" pulmonary fibrosis very unlikely.


CONCLUSIONS
As nephrologists, we argue that testing for ANCA should be performed on a systematic basis, at least in elderly patients, even in the absence of extra-pulmonary signs of vasculitis at presentation.
APHP, Hôpital Tenon, Urgences Néphrologiques et Transplantation Rénale, Hôpital Tenon, 4 rue de la Chine, 75020, Paris, France. marc.dechambrun@gmail.com.
Marc
M
Pineton de Chambrun
APHP, Hôpital d'Avicenne, Service de Pneumologie, Bobigny, France. hilario.nunes@aphp.fr.|Université Paris 13, Sorbonne Paris Cité, EA2363 "Réponses cellulaires et fonctionnelles à l'hypoxie", Paris, France. hilario.nunes@aphp.fr.
Hilario
H
Nunes
APHP, Hôpital Tenon, Anatomopathologie, Paris, France. isabelle.brocheriou@aphp.fr.|UPMC Sorbonne Université Paris 06, UMR S 1155, F-75020, Paris, France. isabelle.brocheriou@aphp.fr.
Isabelle
I
Brochériou
APHP, Hôpital Tenon, Urgences Néphrologiques et Transplantation Rénale, Hôpital Tenon, 4 rue de la Chine, 75020, Paris, France. alexandre.hertig@aphp.fr.|UPMC Sorbonne Université Paris 06, UMR S 1155, F-75020, Paris, France. alexandre.hertig@aphp.fr.
Alexandre
A
Hertig
D000368:Aged; D056648:Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis / Q000150:complications / Q000175:diagnosis* / Q000276:immunology; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000276:immunology; D003937:Diagnosis, Differential; D005921:Glomerulonephritis / Q000150:complications / Q000175:diagnosis* / Q000276:immunology; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000150:complications / Q000175:diagnosis* / Q000276:immunology; D008297:Male; D009195:Peroxidase / Q000276:immunology; D014057:Tomography, X-Ray Computed
D019268:Antibodies, Antineutrophil Cytoplasmic; D009195:Peroxidase