Follow-up of pediatric patients with recurrent infection and mild serologic immune abnormalities

Background: Children with recurrent infections significant enough to warrant referral to an immunologist frequently have mild abnormalities of the humoral immune system. Parents of these children are generally reassured that their child will outgrow the clinical problems that prompted their referral. Objective: This is a retrospective study with the objective being to evaluate changes in immune measurements and clinical status of children with recurrent infections followed in an immunology clinic. Methods: Forty-two patients (mean age 60 months) previously evaluated for recurrent infections were re-evaluated after at least 12 months (mean 37 months). Initial evaluation studies included quantitative immunoglobulins in all patients and IgG subclass determinations and pre-and postvaccination pneumococcal polysaccharide antibody titers in a subpopulation of patients. Results: Patients were assigned to one of two categories: those with initial laboratory abnormalities (27 patients) and those with normal initial studies (15 patients). Among the patients with initial abnormalities, partial IgA deficiency was most commonly seen (20/27). It persisted in 15. Only 6/27 patients had studies that were completely normal on follow-up. Among patients with no initial abnormality, 9/15 developed a partial deficiency of at least one immunoglobulin isotype or IgG subclass. Eighty-six percent of the patients were clinically improved at the time of their last follow-up visit regardless of their laboratory values. Conclusions: A high proportion of children with recurrent infection have persistent, partial immunoglobulin deficiencies lasting in some cases for years. Despite this finding almost all patients demonstrate clinical improvement with time.