Deficiency of humoral immunity in cartilage-hair hypoplasia

Objective: Cartilage-hair hypoplasia (CHH), a metaphyseal chondrodysplasia, is usually associated with impaired cellular immunity. This study evaluate s tumor al immunity in patients with CHH. Methods: The concentrations of immunoglobulins G, A, and M (IgG, IgA, and I gM) and Ige subclasses were studied in 20 patients. Data for 5 additional p atients with recurrent infections were retrospectively reviewed. Results: Seven of the prospectively evaluated patients (35%) had defective humoral immunity. Three patients had IgA deficiency. Four patients had IgG2 deficiency, accompanied by Ig A deficiency, IgG4 deficiency, or both in 3 patients. IgG4 was low in most patients. Increased infections were usually associated with supranormal Ige and IgG1 and subnormal IgA, IgG2, or IgG4 c oncentrations. One retrospectively reviewed patient had severe hypogammaglo bulinemia, and 3 had multiple IgG subclass deficiencies. Conclusions: Humoral immunity is impaired in CHH and contributes to the inc reased susceptibility to infections.