title: Absence of up-regulation for a proliferation-inducing ligand in Sjögren's sialadenitis lesions.
abstract: OBJECTIVE
  To determine whether a proliferation-inducing ligand (APRIL) has a role in the survival of plasma cells infiltrating salivary glands from SS patients.
  
  
  METHODS
  We performed immunological staining for APRIL in minor salivary glands from SS with a pair of antibodies specifically recognizing APRIL-producing cells and secreted APRIL.
  
  
  RESULTS
  Despite high leucocyte infiltration, APRIL-producing cells, identified as neutrophils, were rare in SS salivary glands. Keratinocytes from the adjacent oral epithelium also produced APRIL, but we never detected significant levels of secreted APRIL in SS salivary glands. We obtained similar results with B-cell lymphomas associated with SS. In fact, there was no significant difference in APRIL production and the level of secreted APRIL in these pathological samples compared with normal corresponding tissues.
  
  
  CONCLUSIONS
  The combined observation that APRIL production is not up-regulated in lesions from SS patients, and that secreted APRIL is not retained in these lesions, indicates that plasma cells frequently present in SS lesions may not rely on APRIL for survival, as they do in other rheumatic diseases.
authors.affiliation: Laboratory of Oral Histopathology, Division of Stomatology, Faculty of Medicine, Department of Pathology-Immunology, Geneva, Switzerland.
authors.forename: Tommaso
authors.initials: T
authors.lastname: Lombardi
authors.forename: Solange
authors.initials: S
authors.lastname: Moll
authors.forename: Pierre
authors.initials: P
authors.lastname: Youinou
authors.forename: Jacques-Olivier
authors.initials: JO
authors.lastname: Pers
authors.forename: Alexander
authors.initials: A
authors.lastname: Tzankov
authors.forename: Cem
authors.initials: C
authors.lastname: Gabay
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Santiago-Raber
authors.forename: Carlo
authors.initials: C
authors.lastname: Chizzolini
authors.forename: Bertrand
authors.initials: B
authors.lastname: Huard
mesh_terms: D000328:Adult; D000368:Aged; D001707:Biopsy, Needle; D049109:Cell Proliferation; D002470:Cell Survival; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D010950:Plasma Cells / Q000166:cytology / Q000378:metabolism*; D012470:Salivary Glands, Minor / Q000473:pathology; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D012793:Sialadenitis / Q000150:complications / Q000378:metabolism* / Q000473:pathology; D012859:Sjogren's Syndrome / Q000150:complications / Q000378:metabolism* / Q000473:pathology; D053300:Tumor Necrosis Factor Ligand Superfamily Member 13 / Q000235:genetics* / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D053300:Tumor Necrosis Factor Ligand Superfamily Member 13