Histopathologic abnormalities of the lymphoreticular tissues in organic cation transporter 2 deficiency: evidence for impaired B cell maturation.

Immunohistology of lymphoreticular tissues of a fatal case of organic cation transporter 2 deficiency revealed inhibited proliferation with increased apoptosis in the germinal centers, resulting in "burned out" follicles. This is indicative of impaired antigen driven B cell affinity maturation. Defective humoral immune response might explain the recurrent infections in untreated organic cation transporter 2 deficiency.