title: [Sclerosing mesenteritis: can it be a IgG4 dysimmune disease?].
abstract: OBJECTIVE
  Mesenteric panniculitis (MP), sclerotic mesenteritis (SM) and mesenteric lipodystrophy (ML) are the three histopathological forms of a rare inflammatory mesenteric disease. The pathogenesis is unknown until now. Hypothesis of a dysimmune disorder is advocated. Our purpose was to find histological basis to assert this hypothesis.
  
  
  METHODS
  All patients with a diagnosis of inflammatory mesenteric disease made in Beaujon hospital were selected. A histological study and a systematic immunostaining with IgG4, CD3 and CD8 antibodies were performed for each patient with paraffin block available. Dysimmune features were defined by: a plasma cells component >30 %, an eosinophilic polynuclears component >10 %, a rate TCD8/CD3 >30 % and IgG4+ plasma cells >30/high power field (x400). Cases were classified in 3 forms on the basis of the predominant component: MP (lymphoid/plasma cell infiltrate), SM (fibrosis), ML (fat necrosis).
  
  
  RESULTS
  Thirteen patients (7 men, 6 women) were selected, with a mean age of 57 years (21-80 years); a paraffin block was available for 10 patients. The clinical and histological presentations were heterogeneous: a mesenteric mass was the most frequent mode of revelation (6/13 patients) and all histological forms were present (3 MP, 5 SM and 5 ML). Nine patients had surgical biopsy, 2 had a trephine biopsy and 2 a resection. Standard histological analysis showed numerous eosinophils (> or =10 %) and plasma cells (>30 %) in respectively 3 (23 %) and 6 (46 %) of the 13 cases. The immunohistochemistry (performed in 10 patients) showed numerous TCD8+ in 80 % of the cases and numerous IgG4+ plasma cells in only 31 % of the cases (4 cases) (IgG4+ >30/x400).
  
  
  CONCLUSIONS
  Our results demonstrate that inflammatory mesenteric diseases are heterogeneous: high components of plasma cells, eosinophils and TCD8+ lymphocytes were found respectively in 46, 23 and 80 % of cases; eosinophils were observed exclusively in sclerotic forms. Only 31 % of cases encompass numerous IgG4+ plasma cells, suggesting a pathogenesis different than hyper-IgG4 diseases.
authors.affiliation: Service d'anatomie-pathologique, hôpital Beaujon, AP-HP, 92118 Clichy cedex, France.
authors.forename: Hicham
authors.initials: H
authors.lastname: Belghiti
authors.forename: Dominique
authors.initials: D
authors.lastname: Cazals-Hatem
authors.forename: Anne
authors.initials: A
authors.lastname: Couvelard
authors.forename: Nathalie
authors.initials: N
authors.lastname: Guedj
authors.forename: Pierre
authors.initials: P
authors.lastname: Bedossa
mesh_terms: D000273:Adipose Tissue / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000906:Antibodies / Q000097:blood; D001706:Biopsy; D017252:CD3 Complex / Q000032:analysis / Q000276:immunology; D016827:CD8 Antigens / Q000276:immunology; D005260:Female; D005355:Fibrosis / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007150:Immunohistochemistry; D008214:Lymphocytes / Q000276:immunology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D015436:Panniculitis, Peritoneal / Q000276:immunology* / Q000473:pathology* / Q000601:surgery; D010950:Plasma Cells / Q000276:immunology / Q000473:pathology; D012189:Retrospective Studies
chemical_list: D000906:Antibodies; D017252:CD3 Complex; D016827:CD8 Antigens; D007074:Immunoglobulin G