PAROXYSMAL NOCTURNAL HEMOGLOBINURIA AND GLYCOSYL PHOSPHATIDYLINOSITOL ANCHORED PROTEINS THAT REGULATE COMPLEMENT.

The article focuses on Paroxysmal nocturnal hemogiobinuria (PNH). PNH is a rare but informative disease that appears to arise as a result of a somatic mutation involving the pluripotent hematopoietic stem cell. As a consequence, the peripheral blood elements are affected by a pathophysiological process that results in an entire family of cell surface proteins being deficient. The proteins that are deficient in PNH share the common biochemical feature of being linked to the membrane by a glycosyl phosphatidylinositol (GPI) moiety. The GPI linked proteins are functionally diverse, but some are important regulators of complement, and the greater sensitivity of PNH erythrocytes to the lytic action of complement is causally related to their deficiency.