High Prevalence of Seropositivity to a Major Allergen of Anisakis simplex , Ani s 1, in Dyspeptic Patients

Abstract

Finding evidence of anisakidosis requires invasive methods. We have developed a serological assay based on the detection of an immunoglobulin E (IgE) specifically directed against Ani s 1 protein, a major parasite allergen of Anisakis simplex, which has shown a high level of accuracy in the diagnosis of anisakidosis. We used this tool to determine the prevalence of anti-Ani s 1 IgE in dyspeptic patients and to investigate if its seropositivity could be related to epidemiological factors other than raw fish consumption. A total of 174 dyspeptic patients who submitted to upper digestive tract endoscopy were studied. Specific IgE against Ani s 1 was determined by immunoblotting. Quantitative information on smoking, alcohol consumption, and fish consumption as well as a history of gastric surgery was recorded. Twenty-four (13.8%) patients were seropositive for Ani s 1 protein. The seroprevalence of anti-Ani s 1 IgE increased with age in patients who were less than 62 years old (P ‫؍‬ 0.047). Seropositivity to Ani s 1 was associated with the consumption of fish in vinegar (P < 0.001), raw fish (P ‫؍‬ 0.001), and smoked fish (P ‫؍‬ 0.007). There was no relationship between anti-Ani s 1 IgE seropositivity and the number of cigarettes smoked (P ‫؍‬ 0.098) or alcohol intake (P ‫؍‬ 0.179). Five patients had undergone previous gastric surgery, and three of those patients were seropositive for Ani s 1 (P ‫؍‬ 0.019). In multivariate analysis, the consumption of fish in vinegar (P ‫؍‬ 0.006), raw fish (P ‫؍‬ 0.017), and smoked fish (P ‫؍‬ 0.002) and a history of gastric surgery (P ‫؍‬ 0.005) were independent factors associated with anti-Ani s 1 IgE detection. In conclusion, at present, anisakidosis might frequently be underdiagnosed, and it might have a clinical role in patients with upper dyspeptic symptoms. Uncooked-fish ingestion and previous gastric surgery were associated with seropositivity for Ani s 1 protein.

Assessing the risk of an emerging zoonosis of worldwide concern: anisakiasis

“…Although symptomatic anisakiasis has been reported, asymptomatic intestinal anisakiasis5 or symptomless clinical presentation9 have also been observed. Toro et al 11. suggested that human anisakiasis might be underdiagnosed in Spain because only the most severe cases that required intervention are being diagnosed.…”

Utilidad de la anamnesis y de las técnicas inmunológicas en el diagnóstico de la anisakidosis en pacientes con abdomen agudo

“…La anisakidosis debe ser sospechada para poder realizar su diagnóstico (14,15,30) y, con toda probabilidad, está infradiagnosticada, pudiendo ser esta la causa de pacientes con síntomas dispépticos (31,32) o dolor abdominal leve (10,33). En nuestro estudio, una simple pregunta sobre la ingesta de pescado crudo ha sido muy útil, mostrando una elevada sensibilidad (98,08%) y VPN (98,39%), aunque su VPP ha sido menor (70,83%) probablemente debido al elevado consumo de pescado crudo en la población (34).…”

Seropositivity to a major allergen of Anisakis simplex, Ani s 1, in dyspeptic patients with Helicobacter pylori infection: histological and laboratory findings and clinical significance

“…A high prevalence of seropositivity to Ani s 1 has been reported in dyspeptic patients with Helicobacter pylori infection [11], but the clinical significance of this finding is unknown. It is possible that episodes of anisakiasis in combination with H. pylori infection may have been misdiagnosed, or that the findings may reflect previous exposure to the parasite without clinical relevance.…”