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

Abstract

Previous studies have demonstrated a high prevalence of seropositivity to the Ani s 1 protein in dyspeptic patients with Helicobacter pylori infection, but it is not known whether this represents episodes of anisakiasis misdiagnosis or previous exposure to the parasite without clinical relevance. To investigate the clinical significance of seropositivity to the Ani s 1 protein, a cohort study was performed with 87 consecutive dyspeptic patients who were treated for H. pylori infection. Fourteen (16.5%) patients were seropositive for the Ani s 1 protein, which was associated with the consumption of uncooked fish (p 0.0002). There were no differences in histological findings between subjects seropositive or seronegative for Ani s 1, but seropositive patients had increased eosinophil and basophil leukocyte counts (p < 0.05). Anti-Ani s 1 IgE was associated with a lack of improvement in the group of patients with non-ulcer dyspepsia after successful eradication of H. pylori (p 0.016). Thus, in at least a subset of patients with H. pylori infection, seropositivity to Ani s 1 could have clinical relevance. In addition, these data highlight that only anisakiasis associated with severe allergic or gastric symptoms is currently being diagnosed.

Analysis of Ani s 7 and Ani s 1 allergens as biomarkers of sensitization and allergy severity in human anisakiasis

“…When these type of clinical features are associated to IgE-mediated symptoms, patients suffer a gastro-allergic anisakiasis 7 , 17 , 18 . Anisakis simplex sensitization has been also considered as a triggering and/or worsening factor of other diseases such as urticaria/angioedema and dyspepsia 13 , 19 , 20 .…”

Anisakis simplex: from Obscure Infectious Worm to Inducer of Immune Hypersensitivity

“…This recognition of multiple allergens from a given biological source is now a common finding, such as with grass pollens (272). Ani s 1 is now known to occur in different isoforms (247) and has been found to be highly resistant to heat (boiling for 30-and 10-min intervals) by both Spanish and Japanese research groups, respectively (29,47,48,247,264). It is not yet known to which family of proteins it belongs because, although it showed certain similarities in amino acid sequence (30 to 40% identity) to Kunitz-type serine protease inhibitors, it lacks appropriate inhibitory activity (247).…”

“…Curiously, Cuellar et al have shown by enzymelinked immunosorbent assay (ELISA) that IL-4-like molecules are present in L3 ES products and crude extracts from A. simplex (67). Among dyspeptic patients with Helicobacter pylori infection, for instance, those seropositive to A. simplex presented with increased eosinophil and basophil counts as determined histologically (264).…”

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).…”