Combined immunodeficiencies

Combined immunodeficiencies is heading D81 of the tenth revision of the International Classification of Diseases, filed by the World Health Organization in Chapter III under the block of certain disorders involving the immune mechanism. The heading is subdivided into severe combined immunodeficiency with reticular dysgenesis, severe combined immunodeficiency with low T- and B-cell numbers, severe combined immunodeficiency with low or normal B-cell numbers, adenosine deaminase deficiency, Nezelof syndrome, purine nucleoside phosphorylase deficiency, major histocompatibility complex class I deficiency, major histocompatibility complex class II deficiency, other combined immunodeficiencies and an unspecified code. The classification excludes autosomal recessive agammaglobulinaemia of the Swiss type, which it places under D80.0 among the antibody defects.