Evidence supporting the use of: Dialyzable Leukocyte Extract
For the body system: Thymus
Synopsis
Source of validity: Scientific
Rating (out of 5): 2
Dialyzable Leukocyte Extract (DLE), also known as transfer factor, has been investigated for its immunomodulatory properties since the 1950s. It is a low-molecular-weight fraction obtained from leukocytes, and its primary proposed mechanism of action is the modulation of cell-mediated immunity. The thymus plays a central role in the development and maturation of T lymphocytes, which are key components of cell-mediated immunity. Several small clinical studies and in vitro experiments, primarily from Latin America and Eastern Europe, suggest that DLE can enhance T-cell responses and may be beneficial in conditions involving immune dysregulation, such as chronic infections and certain immunodeficiencies. However, the overall quality of evidence is low, with most studies being uncontrolled, open-label, or lacking rigorous methodology. There is limited direct evidence linking DLE specifically to the support or restoration of thymic function in humans. Most claims are extrapolated from its general effects on the immune system. Regulatory bodies such as the FDA have not approved DLE for any indication, and its use remains investigational in most countries. In summary, while there is some scientific rationale and preliminary research supporting its immunomodulatory effect (and thus a connection to the thymus), robust clinical evidence is lacking, and further high-quality studies are needed to confirm its efficacy and safety in supporting the thymus or related immune functions.