title: Serum levels of beta2-microglobulin and free light chains of immunoglobulins are associated with systemic disease activity in primary Sjögren's syndrome. Data at enrollment in the prospective ASSESS cohort.
abstract: OBJECTIVE
  To analyze the clinical and immunological characteristics at enrollment in a large prospective cohort of patients with primary Sjögren's syndrome (pSS) and to investigate the association between serum BAFF, beta2-microglobulin and free light chains of immunoglobulins and systemic disease activity at enrollment.
  
  
  METHODS
  Three hundred and ninety five patients with pSS according to American-European Consensus Criteria were included from fifteen centers of Rheumatology and Internal Medicine in the "Assessment of Systemic Signs and Evolution of Sjögren's Syndrome" (ASSESS) 5-year prospective cohort. At enrollment, serum markers were assessed as well as activity of the disease measured with the EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI).
  
  
  RESULTS
  Patient median age was 58 (25(th)-75(th): 51-67) and median disease duration was 5 (2-9) years. Median ESSDAI at enrollment was 2 (0-7) with 30.9% of patients having features of systemic involvement. Patients with elevated BAFF, beta2-microglobulin and kappa, lambda FLCS had higher ESSDAI scores at enrollment (4 [2]-[11] vs 2 [0-7], P = 0.03; 4 [1]-[11] vs 2 [0-7], P< 0.0001); 4 [2]-[10] vs 2 [0-6.6], P< 0.0001 and 4 [2-8.2] vs 2 [0-7.0], P = 0.02, respectively). In multivariate analysis, increased beta2-microglobulin, kappa and lambda FLCs were associated with a higher ESSDAI score. Median BAFF and beta2-microglobulin were higher in the 16 patients with history of lymphoma (1173.3(873.1-3665.5) vs 898.9 (715.9-1187.2) pg/ml, P = 0.01 and 2.6 (2.2-2.9) vs 2.1 (1.8-2.6) mg/l, P = 0.04, respectively).
  
  
  CONCLUSIONS
  In pSS, higher levels of beta2-microglobulin and free light chains of immunoglobulins are associated with increased systemic disease activity.
authors.affiliation: Rheumatology Centre National de Référence des Maladies Auto-Immunes Rares, Institut National de la Santé et de la Recherche Médicale UMRS_1109, Fédération de Médecine Translationnelle de Strasbourg, Strasbourg University Hospital, Université de Strasbourg, Strasbourg, France. jacques-eric.gottenberg@chru-strasbourg.fr
authors.forename: Jacques-Eric
authors.initials: JE
authors.lastname: Gottenberg
authors.forename: Raphaèle
authors.initials: R
authors.lastname: Seror
authors.forename: Corinne
authors.initials: C
authors.lastname: Miceli-Richard
authors.forename: Joelle
authors.initials: J
authors.lastname: Benessiano
authors.forename: Valerie
authors.initials: V
authors.lastname: Devauchelle-Pensec
authors.forename: Philippe
authors.initials: P
authors.lastname: Dieude
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Dubost
authors.forename: Anne-Laure
authors.initials: AL
authors.lastname: Fauchais
authors.forename: Vincent
authors.initials: V
authors.lastname: Goeb
authors.forename: Eric
authors.initials: E
authors.lastname: Hachulla
authors.forename: Pierre Yves
authors.initials: PY
authors.lastname: Hatron
authors.forename: Claire
authors.initials: C
authors.lastname: Larroche
authors.forename: Véronique
authors.initials: V
authors.lastname: Le Guern
authors.forename: Jacques
authors.initials: J
authors.lastname: Morel
authors.forename: Aleth
authors.initials: A
authors.lastname: Perdriger
authors.forename: Xavier
authors.initials: X
authors.lastname: Puéchal
authors.forename: Stephanie
authors.initials: S
authors.lastname: Rist
authors.forename: Alain
authors.initials: A
authors.lastname: Saraux
authors.forename: Damien
authors.initials: D
authors.lastname: Sene
authors.forename: Jean
authors.initials: J
authors.lastname: Sibilia
authors.forename: Olivier
authors.initials: O
authors.lastname: Vittecoq
authors.forename: Gaétane
authors.initials: G
authors.lastname: Nocturne
authors.forename: Philippe
authors.initials: P
authors.lastname: Ravaud
authors.forename: Xavier
authors.initials: X
authors.lastname: Mariette
mesh_terms: D000368:Aged; D053264:B-Cell Activating Factor / Q000097:blood; D005260:Female; D006801:Humans; D007147:Immunoglobulin Light Chains / Q000097:blood*; D008223:Lymphoma / Q000097:blood; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012720:Severity of Illness Index; D012859:Sjogren's Syndrome / Q000097:blood* / Q000473:pathology; D001613:beta 2-Microglobulin / Q000097:blood*
chemical_list: D053264:B-Cell Activating Factor; D007147:Immunoglobulin Light Chains; C505719:TNFSF13B protein, human; D001613:beta 2-Microglobulin