Hyperimmunoglobulin M syndrome

Hyperimmunoglobulin M syndrome is a heterogeneous group of several types of antibody primary immunodeficiencies, the most common type of them is type 1.

Hyperimmunoglobulin M syndrome, type 1
This type (Hyper-IgM immunodeficiency X-linked, HIGM1, XHIM, OMIM: 308230) represents X-linked immunodeficiency caused by a mutation in the antigenic ligand gene CD40 (CD40LG, localization Xq26). This ligand is essential for the interaction of T and B cells before the onset of isotype switching from IgM production to other classes of immunoglobulins. Studies have shown that T-lymphocytes are defective, as carrier B-lymphocytes (heterozygous women) are properly stimulated even with a small number of non-defective T-lymphocytes.

The clinical picture
Manifestation involves high levels of IgM and the absence of other immunoglobulin classes (IgG, IgA). In addition to antibody deficiency, there is also a cellular deficit - due to defective T-lymphocytes and autoimmune neutropenia (tendency to develop autoimmune diseases). Manifestations include susceptibility to various bacterial and viral infections, including opportunistic infections (for example, diarrhea caused by Cryptosporidium parvum is typical).

Other types
Other types of IgM hyperimmunoglobulinemia syndrome are mentioned on a separate page.

Related articles

 * Protilátky
 * Primární imunodeficience
 * Brutonova agamaglobulinemie