Abstract: Antiphospholipid Syndrome (AFS) is one of the current multidisciplinary problems of modern medicine and is being investigated as a unique example of autoimmune thrombotic vasculopathy. This syndrome was first described in the context of Systemic lupus erythematosus (TSA) and was referred to as anticardiolipin syndrome, later renamed antiphospholipid syndrome (AFS) by the same authors. There is an immunological predisposition to increased synthesis of antiphospholipid antibodies (AFL) and most of them have been detected in relatives of patients with AFS. The prevalence of AFS in the population is still unknown. It is possible that the synthesis of antiphospholipid antibodies (AFL) may be normal, but often low levels of antibodies are observed in the blood of a healthy person. According to various data, the rate of antibody cardiolipin (ACL) in the population varies from 0 to 14%, averaging 2-4%, with high titers detected in about 0.2% of donors.1 In Uzbekistan, systemic connective tissue is found in several people per year. The disease develops antibodies to the interaction with phospholipids - components of the cell membrane.