Т-хелперы
The cause of selective IgM deficiency remains unclear, although various mechanisms have been proposed, such as an increase in regulatory T cell functions, defective T helper cell functions and impaired terminal differentiation of B lymphocytes into IgM-secreting cells among others. In addition it was recently described that hypomorphic mutations in the B-cell receptor (BLNK &amp; BTK) lead to selective IgM deficiency.