title: Risk, predictors, and clinical characteristics of lymphoma development in primary Sjögren's syndrome.
abstract: OBJECTIVE
  To assess the risk and predictors of lymphoma development in a large cohort of patients with primary Sjögren's syndrome (pSS).
  
  
  METHODS
  Cox-regression analyses were used to study the predictive value of clinical and laboratory findings at pSS diagnosis, and Kaplan-Meier survival curves to compare survival probability between patients who developed lymphoma and the total cohort. Expected risk for lymphoma was calculated by comparison with the background population.
  
  
  RESULTS
  Eleven (4.5%) from 244 patients developed a non-Hodgkin lymphoma (NHL). Diffuse large B-cell and mucosa-associated lymphoid tissue lymphomas occurred at a similar frequency. Three (27.3%) patients died: 2 due to transformation from mucosa-associated lymphoid tissue to diffuse large B-cell. Purpura (HR 8.04, 95% confidence interval [CI] 2.33-27.67), parotidomegaly (HR 6.75, 95%CI 1.89-23.99), anemia (HR 3.43, 95%CI 1.04-11.35), leukopenia (HR 8.70, 95%CI 2.38-31.82), lymphocytopenia (HR 16.47, 95%CI 3.45-78.67), hypergammaglobulinemia (HR 4.06, 95%CI 1.06-15.58), low C3 (HR 36.65, 95%CI 10.65-126.18), and low C4 (HR 39.70, 95%CI 8.85-126.18) levels at pSS diagnosis were significant predictors of NHL development, but only hypocomplementemia and lymphocytopenia were independent risk factors. Hypocomplementemia was related to earlier development of NHL and higher mortality. The cumulative risk of developing lymphoma ranged from 3.4% in the first 5 years to 9.8% at 15 years. Standardized incidence ratio (95%CI) for NHL development was 15.6 (95%CI 8.7-28.2).
  
  
  CONCLUSIONS
  Patients with pSS have a 16-fold increased risk of developing lymphoma. This risk increases with time. Hypocomplementemia and lymphocytopenia at pSS diagnosis are the strongest predictors. Survival is clearly reduced in patients with hypocomplementemia. Indolent lymphomas tend to evolve over time toward a more aggressive histologic type.
authors.affiliation: Internal Medicine Department of Vall d'Hebron University Hospital, Barcelona, Spain. rsolans@vhebron.net
authors.forename: Roser
authors.initials: R
authors.lastname: Solans-Laqué
authors.forename: Andrés
authors.initials: A
authors.lastname: López-Hernandez
authors.forename: Josep Angel
authors.initials: JA
authors.lastname: Bosch-Gil
authors.forename: Andrés
authors.initials: A
authors.lastname: Palacios
authors.forename: Mercedes
authors.initials: M
authors.lastname: Campillo
authors.forename: Miquel
authors.initials: M
authors.lastname: Vilardell-Tarres
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D015994:Incidence; D008223:Lymphoma / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012306:Risk; D012307:Risk Factors; D012859:Sjogren's Syndrome / Q000150:complications* / Q000453:epidemiology; D015996:Survival Rate