Category: IHC-Antibodies

CD4 is a glycoprotein expressed on the surface of immune cells, such as T-helper cells, monocytes, macrophages, and dendritic cells. Most of mature T-cell lymphomas and chronic T-lymphocytic leukemias are CD4 positive. Antibody CD4 plays an important role in classification of lymphocytes in inflammatory lesions and malignant lymphomas.

CD10 (CALLA, neprilysin) is a zinc-dependent metalloprotease enzyme that degrades various bioactive peptides and plays a functional role by modulating cellular responses to peptide substrates. CD10 is a membranous marker with extensive expression in normal tissues. It is reported to be critical for use in diagnosis and subclassification of leukemias (B lymphoblastic leukemia, mixed phenotype acute leukemia, etc.) and lymphomas (follicular lymphoma, Burkitt lymphoma, diffuse large B cell lymphoma, angioimmunoblastic T cell lymphoma, etc.).

Anti-CD10 is found in 60-70% of hepatocellular carcinoma (distinct canalicular pattern), in about 90% of renal cell carcinoma (clear cell and papillary types, but less chromophobic type), in 50-70% of urothelial carcinoma (particularly high grade), and in 60-73% of prostate carcinoma (particularly high grade and aggressive).

Keratins are cytoplasmic intermediate filament proteins expressed by epithelial cells. Cytokeratin 5 is a type II keratin. This antibody detects metastatic carcinoma in the pleura, epithelial mesothelioma, almost all squamous cell carcinomas, half of transitional carcinomas, many undifferentiated large cell carcinomas and undifferentiated large cell carcinomas. A cocktail of CK5, its corresponding partner CK14 and p63 is useful to detect the basal-likephenotype of breast carcinoma and to differentiate normal and prostate cancer.

CD23 is a type II transmembrane glycoprotein involved in B cell activation, B cell growth and regulation of IgE levels. Expression is found on mature B cells, activated macrophages, eosinophils, follicular dendritic cells and thrombocytes. Antibody CD23 may be helpful in detection of B cell chronic lymphocytic leukemia (CLL), follicular dendritic cell tumors, mediastinal large B cell lymphoma and mantle cell lymphoma.

CDX2, also known as caudal-related homeodomain protein 2, is a transcription factor expressed in intestine, but not in stomach and esophagus. CDX2 may play an important role in proliferation and differentiation of intestinal epithelial cells. Antibody CDX2 may be useful in detection of colorectal carcinoma with reduced or absent expression. On the other hand CDX2 is expressed in gastric intestinal metaplasia, dysplasia and carcinoma, as well as in acute myeloid leukemia.

Keratins are cytoplasmic intermediate filament proteins expressed by epithelial cells. Cytokeratin 7 is a type II keratin that is found in most ductal and glandular epithelia including the urinary tract, lung, breast and female genital tract. There is no expression in most gastrointestinal epithelia, prostate, hepatocyte and squamous epithelia, as well as in colon, prostate and squamous carcinomas. Restricted distribution of CK7 makes this antibody a useful marker in a panel with antibody Cytokeratin 20.

c-Myc is a transcription factor required for cell cycle progression and cell proliferation. Burkitt lymphoma is almost uniformly associated with chromosomal translocations involving c-Myc gene. Additionally, oncogene c-Myc is involved in tumorigenesis of multiple cancers, including breast, liver, pancreas and prostate cancer. [1-5]

Chromogranin A is a member of the granin family of neuroendocrine secretory proteins and is located in secretory vesicles of neurons and endocrine cells. It regulates function of secretory granula, is involved in hormone processing and secretion, and is disassembled to biologically active peptides.
Chromogranin A is the most important and most common granin in neuroendocrine tumors. Antibody Chromogranin A is the single most specific marker for such tumors including anterior pituitary, gastrointestinal tract, pancreas, thyroid and lung as well as neuronal tumors and merkel cell carcinomas. Co-expression of chromogranin A and neuron specific enolase (NSE) is common in neuroendocrine neoplasms.

CD56, also known as neural cell adhesion molecule (NCAM), is a part of the immunoglobulin superfamily of adhesion molecules and mediates homophilic interactions through its extracellular region. It is used as a marker fordetection of T-LGL (T-Large Granular Lymphocyte) lymphoproliferative disorders and NK cells. CD56 is also known as a marker of neural lineage due to its discovery site. For example, astrocytoma, neuroblastoma or small cell carcinoma of lung are CD56-positive. [1-6]

CD8 is a transmembrane glycoprotein and co-receptor that functions together with T cell receptor (TCR) in adaptive immune response. CD8 is mainly expressed on cytotoxic T cells as well as natural killer cells, cortical thymocytes and dendritic cells. Furthermore, CD8 is expressed in T cell LGL leukemia and together with CD4 in some T lymphoblastic lymphoma.CD8 can be detected in colorectal carcinoma and ovarian, renal, hepatocellular and esophageal tumors.

CD34 is a single-pass type I transmembrane glycoprotein and functions as a cell to cell adhesion factor. It is expressed on endothelial cells, hematopoietic progenitor cells, fibroblasts and other stromal components. The protein is thought to mediate the stem cell attachment to the bone marrow, ECM or stromal cells. CD34 is a known marker for quantifying and purifying hematopoietic progenitor cells. In identification of tumors with endothelial or lymphoid differentiation CD34 plays a useful role. It also supports in detection of gastrointestinal stromal tumors.

Calretinin is a calcium binding protein abundantly expressed in neurons. Outside the nervous system, calretinin is found in mesothelial cells, steroid producing cells, testicular Sertoli cells, rete testis, ovarian surface epithelium, some neuroendocrine cells, breast glands, eccrine sweat glands, hair follicular cells, thymic epithelial cells, endometrial stromal cells and fat cells.