Antiphospholipid syndrome (APS) is an autoimmune disorder in which the body makes antibodies to its own phospholipids or plasma proteins. This causes abnormal blood clots to develop frequently. Researchers at the Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, in Mexico City, studied the mechanism behind the clot development in 434 individuals. They found that individuals with antiphospholipid syndrome have significantly more annexin 2 antibiodies than people without the disorder. The authors suggest that these antibodies contribute to the development of clots in people with APS. The research was published in the June 1, 2006, issue of Blood.