Reactivity of IgE in fish-allergic patients to fish muscle collagen

ABSTRACTBackground: In addition to parvalbumin, the well- known major allergen in fish, collagen was recently identified as a new allergen in the muscle of bigeye tuna and in the skin of several species of fish. The aim of the present study was to evaluate fish muscle colla- gens for their reactivity with IgE in fish-allergic patients and antigenic cross-reactivity.Methods: Collagen was purified from the white muscle of five species of fish (Japanese eel, alfonsin, mackerel, skipjack and bigeye tuna) by acid extraction and salt precipitation, whereas parvalbumin was purified from bigeye tuna by gel filtration and reverse- phase HPLC. The IgE reactivities to collagen and parvalbumin were examined by ELISA, whereas antigenic cross-reactivity among fish muscle collagens was investigated by ELISA inhibition experiments.Results: When 15 sera from fish-allergic patients were subjected to ELISA using bigeye tuna collagen and parvalbumin, 10 sera reacted only to parvalbumin, two reacted only to collagen, two reacted to both collagen and parvalbumin and one reacted to neither collagen nor parvalbumin. The sera containing specific IgE to bigeye tuna collagen also reacted to collagens from the other four species of fish. In the ELISA inhibition experiments, bigeye tuna collagen inhibited the binding of IgE not only to bigeye tuna collagen, but also to that from the other four species of fish, suggesting cross-reactivity among the collagens from five species of fish.Conclusions: These results demonstrate that some Japanese fish-allergic patients have specific IgE to fish muscle collagen and that fish muscle collagen is a cross-reactive allergen among various species of fish

Mutation Analysis of 2009 Pandemic Influenza A(H1N1) Viruses Collected in Japan during the Peak Phase of the Pandemic

BACKGROUND: Pandemic influenza A(H1N1) virus infection quickly circulated worldwide in 2009. In Japan, the first case was reported in May 2009, one month after its outbreak in Mexico. Thereafter, A(H1N1) infection spread widely throughout the country. It is of great importance to profile and understand the situation regarding viral mutations and their circulation in Japan to accumulate a knowledge base and to prepare clinical response platforms before a second pandemic (pdm) wave emerges. METHODOLOGY: A total of 253 swab samples were collected from patients with influenza-like illness in the Osaka, Tokyo, and Chiba areas both in May 2009 and between October 2009 and January 2010. We analyzed partial sequences of the hemagglutinin (HA) and neuraminidase (NA) genes of the 2009 pdm influenza virus in the collected clinical samples. By phylogenetic analysis, we identified major variants of the 2009 pdm influenza virus and critical mutations associated with severe cases, including drug-resistance mutations. RESULTS AND CONCLUSIONS: Our sequence analysis has revealed that both HA-S220T and NA-N248D are major non-synonymous mutations that clearly discriminate the 2009 pdm influenza viruses identified in the very early phase (May 2009) from those found in the peak phase (October 2009 to January 2010) in Japan. By phylogenetic analysis, we found 14 micro-clades within the viruses collected during the peak phase. Among them, 12 were new micro-clades, while two were previously reported. Oseltamivir resistance-related mutations, i.e., NA-H275Y and NA-N295S, were also detected in sporadic cases in Osaka and Tokyo

Elucidation of IgE-binding epitopes of Ani s 1: The major Anisakis simplex allergen

Ani s 1, the major allergen of Anisakis simplex, is expected to be a useful antigen in allergen-specific immunotherapy of Anisakis allergy. To avoid side-effects such as anaphylactic shock in immunotherapy, it is desirable to use not native allergens bu