Defective synthesis of the sialyl Lewis antigen results in immunodeficiency (leukocyte adhesion deficiency type 2). During treatment with pyrimethamine, leukocyte and platelet counts should be monitored weekly. Dendritic cells (DCs) are a heterogeneous leukocyte (white blood cell) population. The response is also dependent on the genetic makeup of the human leukocyte antigen genes. The vincristine molecule inhibits leukocyte production and maturation. Human leukocyte antigen associations may even be at work. I and II are also called human leukocyte antigen (HLA). Human leukocyte antigen DR (especially DR3) appears to play a role. Peripheral eosinophilia can be seen in differential leukocyte count. Primary neutrophilia can additionally be a result of leukocyte adhesion deficiency. RU28362 (a specific type II receptor agonist) to adrenalectomized animals induced changes in leukocyte distribution. Types of leukocyte adhesion deficiency include LAD1, LAD2, and LAD3. Prevention of degradation of human polymorphonuclear leukocyte proteins by diisopropylfluorophosphate. Vasculitis is primarily caused by leukocyte migration and resultant damage. Although leukocyte telomeres shorten with age, sperm telomeres lengthen with age.