TY - JOUR T1 - Platelet Microparticles: Making Blood a Bad Humor JF - The Journal of Rheumatology JO - J Rheumatol SP - 590 LP - 592 DO - 10.3899/jrheum.101359 VL - 38 IS - 4 AU - DAVID S. PISETSKY Y1 - 2011/04/01 UR - http://www.jrheum.org/content/38/4/590.abstract N2 - Ancient physicians based their practice of medicine on the humoral theory of disease. This theory posited that substances called humors make up the body and determine health and disease. When in balance, these humors — blood, yellow bile, black bile, and phlegm — caused health; out of balance, they caused disease. This theory also related humors to the 4 elements: earth, fire, water, and air. Of the humors, blood was unique in its content of all 4 elements.Now relegated to the realm of quaint and discredited ideas of the past, the humoral theory of disease nevertheless has elements of truth. Importantly, this theory recognized the importance of blood in disease pathogenesis and the diversity of bodily constituents that can influence disease. With scientific advance, earth, fire, water, and air have been replaced by cells, cytokines, chemokines, and prostanoids, among many others. The list of these substances is ever increasing, with disciplines of genomics, proteomics, metabolomics, and nucleomics filling the blood to the brim with noxious mediators. Reading today’s literature, we can be wistful about a time when physicians could understand disease with only 4 elements, in contrast to today’s 4 thousand or even 4 million.As an article in this issue of The Journal demonstrates, the blood of patients with connective tissue disease (CTD) has novel elements that can drive disease and serve as biomarkers to elucidate pathogenesis and assess disease activity1. Thus, using an enzyme-lined immunosorbent assay (ELISA), Oyabu, et al provide evidence that the blood of patients with CTD has increased levels of platelet-derived microparticles (PDMP) and that elevations of PDMP are related to Raynaud’s phenomenon (RP). This article is important in substantiating the value of solid-phase methods to detect particles and in delineating clinical associations.As shown in … Address correspondence to Dr. D.S. Pisetsky, 151G Durham VA Medical Center, 508 Fulton Street, Durham, NC 27705, USA. E-mail address: dpiset{at}acpub.duke.edu ER -