This study evaluates the clinical/immunological features and outcomes of 91 patients with the diagnosis of transient hypogammaglobulinemia of infancy(THI). Mean age at diagnosis was 8.4±5.2 months. IgG levels normalized at 30.6±11.88 months. Sixty three patients (69.3%) resolved in their first 3 years of life and 28 patients (30.7%) thereafter. In the univariate analysis, presence of atopy, occ...