<prompt> Macrophage activation syndrome characterized by all exceptActivation of CD 8 T cellsLow levels of plasma ferretinPresence of cytokine stormIt is the other name for hemophagocy  <response>: Hemophagocv_c Lymphohis_ocvtosiso Hemophagocytic lymphohis_ocytosis HLH is a reactive condition marked by cytopenias and signs andsymptoms of systemic inflammation related to macrophage activation. For this reason, it is alsosometimes referred to as macrophage activation syndrome. Pathogenesis The common feature of all forms of HLH is systemic activation of macrophages and CD8 cytotoxic T Cells, The activated macrophages phagocytose blood cell progenitors in the marrow and formed elements inthe peripheral issues, while the stew of mediators released from macrophages and lymphocytesSuppress hematopoietic and produce symptoms of systemic inflammation. These effects lead to cytopenias and a shock-like picture sometimes referred to as cytokine storm orThe systemic inflammatory response syndrome. Familial forms of HLH are associated with several different mutations, all of which impact the ability ofCytotoxic T cells and NK to properly form or deploy cytotoxic granules, The most common trigger for HLH is an infection, particularly with Epstein-Barr virus EBV.Clinical Featureso Most patients present with an acute febrile illness associated with splenomegaly and hepatomegaly,o Hemophagocytosis is usually seen on bone marrow examination, but is neither sufficient nor required toMake the diagnosis. Laboratory studies typically reveal anaemia, thrombocytopenia, and very high levels of plasma functional andSoluble IL-2 receptor, both indicative of severe inflammation, as well as elevated liver function tests andTriglyceride levels, both related to hepatesises.o Coagulation studies may show evidence of disseminated intravascular coagulation. If untreated, this A picture can progress rapidly to multiorgan failure, shock, and death.Treatment Involves the use of immunosuppressive drugs and mild chemotherapy.Parents with germline mutations that cause HLH or who have the persistent resistant disease are candidates for hematopoietic stem cell transplantation.Without treatment, the prognosis is grim, particularly in those with familial forms of the disease, who typically survive for less than 2 months. 