Objective: Anisakis simplex parasite causes anisakidosis, a disease that often mimics other gastrointestinal diseases such as peritonitis, appendicitis, Crohn's disease, ulcer, etc. Patients with digestive haemorrhage caused by ulcers, varices or Mallory syndrome were analysed for antibodies to the worm A. simplex.
Methods: Antibody detection was carried out by enzyme-linked immunosorbent assay (ELISA) and immunoblot using crude extracts of antigen and excretory/secretory products. Total immunoglobulin (Ig), IgG, IgM, IgA and IgE were studied.
Results: Eighty-seven patients were studied. The following prevalence rates were found with crude antigen: total Ig 30% (95% confidence interval 21-40), with values for IgG, IgM, IgA and IgE of 22 (CI 14-31), 17 (CI 10-26), 37 (CI 27-47) and 12% (CI 6-20), respectively. Twenty-four positive sera for total Ig response and crude products were selected for determination of specific antibodies with excretory/secretory antigens. We obtained 8, 13, 3 and 16 positive cases for total Ig, IgG, IgM and IgA respectively. The percentages of positivity within the varices and Mallory groups of patients were higher although differences were not significant (35 and 50% respectively). In a healthy population, the prevalence for total Ig is much lower (6%). Twenty-five positive sera for total Ig response were tested by means of immunoblot analysis against crude larval antigen. Concerning total Ig antibody response, 12 of the sera showed an immuno-recognition pattern concordant with the human anisakidosis reference serum (E17). Specific IgG bands were visualized in 30 sera; specific IgM and IgA in 6 and 12, respectively. Different clinical variables of these patients were studied: leucocytes, eosinophils, haemoglobin, prothrombin activity, thromboplastin time, fibrinogen, platelets and erythrocyte sedimentation rate. There were a few significant differences: for total Ig in prothrombin activity and platelets, and for IgM in eosinophils.
Conclusions: The prevalence of detectable antibodies against A. simplex is higher in patients with digestive haemorrhage than in the healthy population.