title: Synergism between prior Anisakis simplex infections and intake of NSAIDs, on the risk of upper digestive bleeding: a case-control study.
abstract: BACKGROUND
  The aim of this study was to investigate the relationship between prior Anisakis infections and upper gastrointestinal bleeding (UGIB), and its interaction with non-steroidal anti-inflammatory drug (NSAID) intake.
  
  
  RESULTS
  We conducted a hospital-based case-control study covering 215 UGIB cases and 650 controls. Odds ratios (ORs) with their confidence intervals (95% CIs) were calculated, as well as the ratio of the combined effects to the sum of the separate effects of Anisakis allergic sensitization and NSAIDs intake. Prior Anisakis infections were revealed by the presence of anti-Anisakis IgE antibodies specific to the recombinant Ani s 1 and Ani s 7 allergens used as the targets in indirect ELISA. Prior Anisakis infections (OR 1.74 [95% CI: 1.10 to 2.75]) and the intake of NSAIDs (OR 6.63 [95% CI: 4.21 to 10.43]) increased the risk of bleeding. Simultaneous NSAIDs intake and Anisakis allergic sensitization increased the risk of UGIB 14-fold (OR=14.46 [95% CI: 6.08 to 34.40]). This interaction was additive, with a synergistic index of 3.01 (95% CI: 1.18-7.71).
  
  
  CONCLUSIONS
  Prior Anisakis infection is an independent risk factor for UGIB, and the joint effect with NSAIDs is 3 times higher than the sum of their individual effects.
authors: Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Santiago de Compostela, Santiago de Compostela, Spain.
authors: Florencio M
authors: FM
authors: Ubeira
authors: Ana M
authors: AM
authors: Anadón
authors: Angel
authors: A
authors: Salgado
authors: Alfonso
authors: A
authors: Carvajal
authors: Sara
authors: S
authors: Ortega
authors: Carmelo
authors: C
authors: Aguirre
authors: María José
authors: MJ
authors: López-Goikoetxea
authors: Luisa
authors: L
authors: Ibanez
authors: Adolfo
authors: A
authors: Figueiras
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D017129:Anisakiasis / Q000150:complications* / Q000276:immunology; D017163:Anisakis / Q000276:immunology / Q000472:pathogenicity*; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage* / Q000009:adverse effects*; D000909:Antibodies, Helminth / Q000097:blood; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000139:chemically induced*; D006801:Humans; D006967:Hypersensitivity / Q000150:complications* / Q000276:immunology; D007073:Immunoglobulin E / Q000097:blood; D008297:Male; D008875:Middle Aged
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000909:Antibodies, Helminth; D007073:Immunoglobulin E