Inherited immunodeficiency syndromes

General features

Splenectomy is rarely performed in patients with inherited immunodeficiency syndromes but, since deaths may occur in early life due to infection, spleens from such individuals may be seen at post-mortem examination. In those syndromes associated with less severe immunodeficiency, splenectomy may occasionally be performed incidentally during intra-abdominal surgery or the spleen may require removal following trauma, just as in any other individual. Therefore, it is useful to have an understanding of the pathological changes likely to be present due to underlying immunodeficiency. See Singer (1998) and Janeway et al. (1999) for overviews of clinico-pathological and immunological aspects of these conditions.

In general, red pulp cords and sinusoids are anatomically and functionally normal. In combined immune deficiency due to defective production of the T and B lymphoid cell lineages from early precursor cells, absence of the PALS and B cell follicles will be seen. Small B lymphocytes, plasma cells and CD8-positive T cells will also be absent from red pulp cords but this may only be detectable by immunohistochemistry. Immunodeficiency syndromes associated with this pattern of splenic lymphoid hypoplasia present as severe combined immunodeficiency (SCID) syndromes and have heterogeneous underlying genetic defects, such as cytokine receptor γ-chain deficiency in X-linked SCID.

Inherited immunodeficiency states predominantly affecting T cells

Selective depletion of T cells in the PALS and cords accompanies pure T cell deficiency such as that in DiGeorge's syndrome.