Generalized urticaria induced by the Na-ASP-2 hookworm vaccine: implications for the development of vaccines against helminths.

BACKGROUND: Necator americanus Ancylostoma-secreted protein 2 (Na-ASP-2) is secreted by infective hookworm larvae on entry into human hosts. Vaccination of laboratory animals with recombinant Na-ASP-2 provides significant protection against challenge infections. In endemic areas antibodies to Na-ASP-2 are associated with reduced risk of heavy N americanus infections. OBJECTIVE: To assess the safety and immunogenicity of recombinant Na-ASP-2 adjuvanted with Alhydrogel in healthy Brazilian adults previously infected with N americanus. METHODS: Participants were randomized to receive Na-ASP-2 or hepatitis B vaccine. Major IgG and IgE epitopes of the Na-ASP-2 molecule were mapped by using sera from these same subjects. Seroepidemiologic studies in adults and children residing in hookworm-endemic areas were conducted to assess the prevalence of IgE responses to Na-ASP-2. RESULTS: Vaccination with a single dose of Na-ASP-2 resulted in generalized urticarial reactions in several volunteers. These reactions were associated with pre-existing Na-ASP-2-specific IgE likely induced by previous hookworm infection. Surveys revealed that a significant proportion of the population in hookworm-endemic areas had increased levels of IgE to Na-ASP-2. Epitope mapping demonstrated sites on the Na-ASP-2 molecule that are uniquely or jointly recognized by IgG and IgE antibodies. CONCLUSION: Infection with N americanus induces increased levels of total and specific IgE to Na-ASP-2 that result in generalized urticaria on vaccination with recombinant Na-ASP-2. These data advance knowledge of vaccine development for helminths given their propensity to induce strong T(H)2 responses. Study data highlight the important differences between the immune responses to natural helminth infection and to vaccination with a recombinant helminth antigen.

Geriatric assessment of a giant splenic artery aneurysm accidentally diagnosed.

Giant splenic artery aneurysms (GSAAs) larger than 8 cm in diameter have rarely been reported, particularly in older people. They are clinically important lesions, often asymptomatic and related to an increased risk of complications such as abrupt rupture, requiring emergency surgical treatment. Comprehensive geriatric assessment (CGA), originally developed for multidimensional clinical evaluation in several geriatric settings, was recently proposed as a fundamental preoperative aid for treatment planning of older patients undergoing elective surgery and preventing adverse post-operative outcomes. We present the first case of an asymptomatic 9-cm partially thrombosed GSAA, accidentally diagnosed during abdominal ultrasound in a 63-year-old woman from the Apulia region in Southern Italy. She successfully underwent aneurysmectomy, highlighting the usefulness of CGA in elective surgical patients.