ABSENT T LYMPHOCYTES: WHAT IS ABSENT T LYMPHOCYTES?
Definition: What is "Absent T lymphocytes"?
Absent t lymphocytes definition: The deficiency or absence of T lymphocytes is a rare immuno-deficiency condition which is characterized by the lack of CD8(+) T lymphocytes & the absence or depression of the function of the T cell. A mutation of the gene for ZAP-70 (tyrosine kinase which has notable effects on indicating through the T cell receptor) has been associated with this syndrome. T cells are cells that belong to a cluster of white blood cells which are known as the lymphocytes. These lymphocytes are responsible in cell-mediated immunity. They are distinguished from the other types of lymphocytes (the NK cells & the B cells) through the presence of a specific receptor on the surface of these cells. This receptor is called as T cell receptor or the TCR. The T abbreviation in T cell refers to thymus which is the primary organ in the development of the T cell.
No experiment or exact studies have proven the cause of absent T lymphocytes. To date, it is still a mystery how this defect happens. It is believed, however, that the errors or defects occur during the development of the fetus.
The Office of Rare Diseases has categorized absent t lymphocytes as a very rare form of disorder. This denotes that the condition does not affect more than 20,000 American individuals.
Use of Cytotoxic T Cells
The cytotoxic T cells are the ones that are responsible in the combat of tumor cells & those cells that have been infected viruses. They are also implicated in rejection of transplants. The CD8 (+) T cells are named such because they express glycoprotein (CD8) at their shell. When these cells interact with the helper T cells, they can be converted into regulatory T cells that could hamper autoimmune diseases such as experimental autoimmune encephalomyelitis. The absence of CD8 (+) T cells (or when they cease to function) would automatically make an individual vulnerable to severe & life-threatening diseases (most of them caused by viral infections). This is so because the immune system fails to function at the normal level. Not only is the body exposed to viruses when this disorder occurs, it is also now vulnerable to bacterial infections in varying degrees. If the precursor cells for T cells (also known as stem cells) are deficient in the human bone marrow, the unique source of B & T lymphocytes are damaged or eliminated.