A primary immunodeficiency disorder associated with absence of lymphoid germinal centers

In this article we describe three infants who suffered from a disorder characterized by splenomegaly, anemia, and severe infections beginning during the first months of life. Immunologic studies revealed agammaglobulinemia. However, normal numbers of lymphocytes and lymphocyte subsets were present in peripheral blood, and lymphocyte proliferation in responses to mitogenic stimulation in vitro was normal. Histologic and immunohistologic studies performed in one of the patients revealed lack of secondary follicles and follicular dendritic cells in lymphoid tissues and absence of plasma cells in the intestinal lamina propria. Similar findings have been observed in the hyper-IgM syndrome. However, these patients can be distinguished from currently recognized genetic variants of hyper-IgM syndrome on the basis of their clinical and histologic features, together with information obtained from DNA sequence analysis. Thus, their condition is likely to represent a novel form of primary immune deficiency with features of hyper-IgM syndrome.