B-lymphocytes carrying IgM, in the blood
Normally, the relative amount of B-lymphocytes carrying IgM in adults is 3-10%, the absolute amount is 0.07-0.17x109 / l.
B-lymphocytes carrying IgM, - cells of humoral immunity, responsible for the synthesis of AT.They are formed in the red bone marrow and accumulate mainly in the peripheral lymphoid organs. Peripheral blood contains only 3-10% of their total number. After the binding of Ar to the surface IgM receptors of B lymphocytes, the latter are activated and prepared for DNA synthesis and fission. Growth factors( IL-4) are required to proliferate B-lymphocytes, and IL-5 and IL-6( factors determining the differentiation of B-lymphocytes) to form immunoglobulin-producing plasma cells.
The ratio of populations in a common B-lymphocyte pool is important in assessing humoral immunity. The violation of the ratio is characteristic for insufficiency of humoral immunity.
An increase in the number of B-lymphocytes with IgM receptors is characteristic of the acute phase of the inflammatory process. If the increase in B-lymphocytes with IgM receptors in the acute period of the disease is not detected, this indicates a lack of humoral immunity associated with a violation of the synthesis of IgM.The number of B-lymphocytes with IgM receptors increases earlier than the increase in IgM concentration in the blood, so this indicator can be used for the early diagnosis of infectious diseases. Myeloma, synthesizing IgM, is characterized by a predominance of B-lymphocytes with IgM receptors in the blood. With lymphocytic leukemia, the determination of the number of B-lymphocytes with IgM receptors in the blood makes it possible to clarify the localization of the B-lymphocyte maturation block. Absence or a small amount of B-lymphocytes with IgM receptors indicates that the block occurred at the level of pre-B lymphocytes. Diseases and conditions that result in a change in the number of B-lymphocytes carrying IgM are shown in the table.
Table Diseases and conditions leading to a change in the number of B-lymphocytes carrying IgM
Table Diseases and conditions leading to a change in the number of B lymphocytes,carrying IgM