Concomitant Selective Antibody Deficiency in Pediatric Patients with Mannose-Binding Lectin Deficiency

Abstract

Mannose-binding lectin (MBL) deficiency is relatively common occurring in ∼7% of the general population. Most individuals with MBL deficiency are clinically unaffected due to protective antibody adaptive immunity, and therefore never present for evaluation of recurrent infections. We sought to identify associated immunologic abnormalities in patients with MBL deficiency that may have influenced their clinical presentation and resulted in referral for evaluation. Retrospective chart review of all patients found to have MBL deficiency at Cardinal Glennon Children's Medical Center at Saint Louis University between 2000 and 2009. Twenty-two patients, 40% of 55 patients with MBL deficiency, were found to have concomitant selective antibody deficiency (SAD). At initial evaluation Streptococcus pneumoniae antibody titers were frequently nonprotective in both groups of patients. After S. pneumoniae vaccination, MBL-deficient patients with SAD developed protective antibody titers to 44% ± 13% of S. pneumoniae sero...