Prevalence of atopic symptoms among blood donor carriers of mannose-binding lectin variant alleles.

Mannose-binding lectin (MBL) is a C-type soluble collectin involved in the innate immune response. Carriers of MBL gene variant alleles (MBLva) have decreased plasma concentrations of MBL and increased susceptibility to bacterial and viral infections. The aim of the present study is to test the hypothesis that carriers of MBLva could have a different frequency of atopic symptoms as compared to wild-type carriers. A total of 385 consecutively enrolled Caucasian blood donors were studied. Blood specimens underwent genomic analysis and genotyping for MBLva by polymerase chain reaction (PCR). MBLva carrier status was associated with a reduced frequency of allergic rhinitis (OR 0.41 [95\% CI 0.2 to 0.8], chi2 = 6.98, p =.008). No relationship was found between MBLva carrier status and asthma or atopic skin symptoms. MBLva might be one of the host-related genetic factors involved in atopic disorders, namely allergic rhinitis.