title: Tertiary Lymphoid Organs in Takayasu Arteritis.
abstract: OBJECTIVE
  The role of B cells in the pathogenesis of Takayasu arteritis (TA) is controversial. We aimed to study the presence of tertiary lymphoid organs (TLOs) in the aortic wall of TA patients.
  
  
  METHODS
  Hematoxylin and eosin-stained sections from aorta specimens from patients with TA were screened for TLOs. The presence of B cell aggregates (CD20), follicular dendritic cells (FDCs, CD21), and high endothelial venules (HEVs, PNAd) was investigated by immunohistochemistry. Immune cells from the adventitial layer of one patient were characterized by flow cytometry. Demographic, medical history, laboratory, imaging, treatment, and follow-up data were extracted from medical records.
  
  
  RESULTS
  Aorta specimens from Bentall procedures were available from seven patients (5 females, aged 22-57 years) with TA. Surgical treatment was performed at TA diagnosis (n = 4) or at a median of 108 months (84-156) after TA diagnosis. Disease was active at surgery in four patients according to NIH score. B cell aggregates-TLOs containing HEVs were observed in the adventitia of all but one patient. Of note, ectopic follicles containing CD21(+) FDCs were found in all patients (4/4) with increased aortic (18)F-fluoro-deoxyglucose (FDG) uptake before surgery but were absent in all but one patients (2/3) with no FDG uptake. In addition, flow cytometry analysis confirmed the accumulation of memory/germinal center-like B cells in the adventitial layer and showed the presence of antigen-experienced T follicular helper cells.
  
  
  CONCLUSIONS
  Ectopic lymphoid neogenesis displaying functional features can be found in the aortic wall of a subset of patients with active TA. The function of these local B cell clusters on the pathogenesis of TA remains to be elucidated.
authors.affiliation: INSERM U1148, Université Paris Diderot, PRES Sorbonne Paris Cité , Paris , France.
authors.forename: Marc
authors.initials: M
authors.lastname: Clement
authors.affiliation: Département de Médecine Interne, Hôpital Bichat, Assistance Publique Hôpitaux de Paris, Université Paris Diderot, PRES Sorbonne Paris Cité , Paris , France.
authors.forename: Adrien
authors.initials: A
authors.lastname: Galy
authors.affiliation: Département de Pathologie, Hôpital Européen Georges Pompidou, Assistance Publique Hôpitaux de Paris, Université Paris Descartes, PRES Sorbonne Paris Cité , Paris , France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Bruneval
authors.affiliation: INSERM U1148, Université Paris Diderot, PRES Sorbonne Paris Cité , Paris , France.
authors.forename: Marion
authors.initials: M
authors.lastname: Morvan
authors.affiliation: INSERM U1148, Université Paris Diderot, PRES Sorbonne Paris Cité, Paris, France; Département de Médecine Nucléaire, Hôpital Bichat, Assistance Publique Hôpitaux de Paris, Université Paris Diderot, PRES Sorbonne Paris Cité, Paris, France.
authors.forename: Fabien
authors.initials: F
authors.lastname: Hyafil
authors.affiliation: Département de Médecine Nucléaire, Hôpital Bichat, Assistance Publique Hôpitaux de Paris, Université Paris Diderot, PRES Sorbonne Paris Cité , Paris , France.
authors.forename: Khadija
authors.initials: K
authors.lastname: Benali
authors.affiliation: Département de Radiologie, Hôpital Bichat, Assistance Publique Hôpitaux de Paris, Université Paris Diderot, PRES Sorbonne Paris Cité , Paris , France.
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Pasi
authors.affiliation: Département de Pathologie, Hôpital Bichat, Assistance Publique Hôpitaux de Paris, Université Paris Diderot, PRES Sorbonne Paris Cité , Paris , France.
authors.forename: Lydia
authors.initials: L
authors.lastname: Deschamps
authors.affiliation: Département de Chirurgie Vasculaire, Hôpital Bichat, Assistance Publique Hôpitaux de Paris, Université Paris Diderot, PRES Sorbonne Paris Cité , Paris , France.
authors.forename: Quentin
authors.initials: Q
authors.lastname: Pellenc
authors.affiliation: Département de Médecine Interne, Hôpital Bichat, Assistance Publique Hôpitaux de Paris, Université Paris Diderot, PRES Sorbonne Paris Cité, Paris, France; INSERM U1149, Laboratoire d'excellence INFLAMEX, Université Paris Diderot, PRES Sorbonne Paris Cité, Paris, France; Département Hospitalo-Universitaire FIRE (Fibrosis, Inflammation and Remodelling in Renal and Respiratory Diseases), Université Paris Diderot, PRES Sorbonne Paris Cité, Paris, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Papo
authors.affiliation: INSERM U1148, Université Paris Diderot, PRES Sorbonne Paris Cité, Paris, France; Département Hospitalo-Universitaire FIRE (Fibrosis, Inflammation and Remodelling in Renal and Respiratory Diseases), Université Paris Diderot, PRES Sorbonne Paris Cité, Paris, France.
authors.forename: Antonino
authors.initials: A
authors.lastname: Nicoletti
authors.affiliation: Département de Médecine Interne, Hôpital Bichat, Assistance Publique Hôpitaux de Paris, Université Paris Diderot, PRES Sorbonne Paris Cité, Paris, France; INSERM U1149, Laboratoire d'excellence INFLAMEX, Université Paris Diderot, PRES Sorbonne Paris Cité, Paris, France; Département Hospitalo-Universitaire FIRE (Fibrosis, Inflammation and Remodelling in Renal and Respiratory Diseases), Université Paris Diderot, PRES Sorbonne Paris Cité, Paris, France.
authors.forename: Karim
authors.initials: K
authors.lastname: Sacre
keywords: B cells; Takayasu arteritis; immunopathogenesis; tertiary lymphoid organs