An overview of several commonly used lymphoid tissues and tumor markers
The tumor components of lymphoid tissues are more complicated. Some of them are similar in morphology to other epithelial-derived tumors, the identification is difficult. Therefore, immunohistochemistry is more accurate in the identification of lymphoid tissue tumors. Lymphoma is a malignant tumor that originates in various lymphoid tissues and lymph nodes. According to the morphology and structure of tumor cells, they are divided into two major categories, Hodgkins disease (HD) and non-hodgkins lymphoma (NHL).
There are many antibodies for detecting lymphoma. There are more than one hundred kinds of antibodies for CD series. Here we list several commonly used antibodies in clinical practice, as follows:
1. Leucoyte common antigen (LCA)
This antibody is mainly used to detect normal white blood cells, i.e. lymphocytes (T.B), granulocytes, tissue cells and monocytes, and tumors derived therefrom. It is suitable for all kinds of slices without special treatment. The dilution is 1:200.
2. T cells
T lymphocytes divide and differentiate in the thymus to form T cells with various specific antigen receptors, so it is also called thymus-dependent cells. The number of T cells is the largest, and its function is multi-faceted. According to their functions, they can be divided into helper T cells, inhibit T cells and cytotoxic T cells.
The distribution of T lymphocytes in the lymph nodes is usually in the paracortical area. Therefore, after immunohistochemical staining, positive cells can be found in the paracortical area, and two antibodies are commonly used in clinical practice.
(1). T cells, CD45RO, clone is human WHL-1
The antibody can label almost all thymocytes and also detect CD4 and CD8 as well as resting T cell subsets of mature activated T cells and lymphoma cells derived therefrom. The antibody is suitable for various sections without any treatment methods. Good results are obtained with a dilution of 1:100.
(2). T cells, CD3, clone PS1
This antibody is used to detect normal and nascent T cells and has a high specificity for early T cells. Although its specificity is high, its sensitivity is not as good as that of antibody in above (1). In clinical application, both antibodies can be applied simultaneously to improve the accuracy of diagnosis. It does not require a variety of methods to deal with. The dilution is 1:100.
3. B cells, CD20, clone L26
B lymphocytes are different from T lymphocytes, and their differentiation and division are carried out in the embryonic liver and bone marrow. According to the experiment, B lymphocytes in the lymph nodes are mainly distributed in the follicular reaction center. It has been proved by experiments that the reaction center is the place where B cells are transformed in various periods, basically it takes four periods:
After the first stage, the mature small lymphocytes receive the antigen information and the volume gradually increases, and the surface of the cell nucleus has a depression or a groove-like fissure called a small cleaved cell. The cells continue to enlarge in the second phase, with a small amount of cytoplasm around the nucleus, namely the large cleaved cell. The nucleus gradually changes in the third phase and develops into a circular or elliptical shape. The cleave also disappears with the change. The nucleolus appears in the nucleus, the cytoplasm increases, and the synthesis of RNA and protein increases, this is small non-cleaved cell. In the fourth stage, the cells continue to enlarge, which is several times larger than the original small lymphocytes. In this stage, the nucleus is round or elliptical, showing nuclear division and abundant cytoplasm, which is called large non-cleaved cell. Because of the changes in B cells at different stages, different types of antibodies should be used for labeling.
In clinical applications, detecting lymphoma is not as detailed as studying lymphoma.
The antibody requires no special treatment and has a dilution of 1:100.
4. Bone marrow tissue cell antigen, clone Mac387
The coloration of the antibody can be divided into three major types, namely T, B lymphocyte shape and tissue cell shape. The antibody detects normal granulocytes, monocytes in blood and tissue cells in tissues and tumors derived therefrom.
The antibody does not require a special treatment and the dilution is 1:100.
CD29 antibody is mainly used for the differential diagnosis of labeled B cells, B cell lymphoma, B cell leukemia, etc., and antigen retrieval should be performed when labeling.