The marker "CD18 Expression (LAD 1)" on a Leukocyte Adhesion Deficiency (CD15s, CD18) panel from Quest Diagnostics is a crucial test for diagnosing Leukocyte Adhesion Deficiency Type 1 (LAD-1), a rare genetic disorder. In this condition, CD18, a protein that is part of a complex necessary for white blood cells (leukocytes) to adhere to and migrate through blood vessel walls during an immune response, is either missing or malfunctioning. CD18 expression is vital because it facilitates the process by which white blood cells exit the bloodstream to reach sites of infection, inflammation, or injury. In individuals with LAD-1, the defective or deficient expression of CD18 results in the inability of leukocytes to adhere properly, leading to a severe impairment in the body's immune defense mechanism. This can result in recurrent, severe infections from an early age because the white blood cells cannot reach the sites where they are needed to fight off pathogens. The diagnosis is made by assessing the expression levels of CD18 on the surface of leukocytes using flow cytometry, a technique that analyzes the properties of cells in a fluid as they pass through a laser. If CD18 levels are significantly reduced or absent, it confirms a diagnosis of LAD-1. Treatment options are primarily supportive and include managing infections through the use of antibiotics and, in severe cases, may involve hematopoietic stem cell transplantation to correct the underlying defect in leukocyte function. It’s important for the management and treatment plans to be closely monitored by healthcare providers, as the condition can significantly impact the overall quality of life and health outcomes.
CD18 EXPRESSION (LAD 1)
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