Allergic and immunologic parameters in patients with Fanconi's anemia.

BACKGROUND: Fanconi's anemia (FA) is a rare recessive chromosomal instability disorder, characterized by progressive bone marrow failure and congenital defects. Patients with FA present with recurrent infections, particularly those of the respiratory tract. OBJECTIVE: The aim of the present study was to evaluate whether patients with FA have altered antibody-mediated immune responses. METHODS: A group of 12 patients with FA, 5-32 years old (6 males) was studied. Serum levels of IgG, IgM, IgA and IgG subclasses, isohemagglutinin titers and specific IgG antibodies to poliovirus and measles were determined using standard methods. Immediate skin tests to common inhalant allergens were performed, and total and specific serum IgE was quantitated using a fluoroenzymatic assay (Uni-CAP, Pharmacia). Antipneumococcal antibodies were measured by ELISA before and 4-8 weeks after immunization with pneumococcal vaccine (Pneumo 23, Pasteur Mérieux Connaught). Responses to serotypes 1, 3, 5, 6B, 9V and 14, which are the most prevalent in our country, were studied. RESULTS: Ten patients had elevated IgE levels in sera, and 7 of them had detectable specific IgE and positive immediate skin tests. An inadequate response to pneumococcal vaccination was found in 2 of the 12 patients. Isohemagglutinin titers and levels of IgG, IgM, IgA and IgG subclasses and antipoliovirus and antimeasles antibodies were within the normal limits for age in all patients. Two patients had undetectable IgG4 levels (below 5 mg/dl). CONCLUSIONS: The results indicate that a proportion of patients with FA (2/12) in our study had inadequate responses to pneumococcal vaccination. No other significant abnormalities of the immune system were found in these patients.