Autoimmune hemolytic anemia (AIHA) is caused by hemolysis induced by the reaction of autoantibodies with red blood cells. Events that lead to AIHA include extravascular hemolysis caused by phagocytosis of erythrocyte-bound IgG in the spleen (hemolytic mechanism), activation of polyclonal B cells, reactions induced by molecular mimicry of exogenous antigens, breakdown of immune tolerance, and abnormal cytokine expression. Evans syndrome is diagnosed by the simultaneous presence of AIHA, which is detected using a direct antiglobulin test (DAT), and immune (idiopathic) thrombocytopenic purpura (ITP) in the absence of an underlying etiology. This syndrome is characterized by hemolytic anemia, thrombocytopenia, and the production of either antibodies, or complement, or both that attack RBCs and platelets.
The impact factor of journal provides quantitative assessment tool for grading, evaluating, sorting and comparing journals of similar kind. It reflects the average number of citations to recent articles published in science and social science journals in a particular year or period, and is frequently used as a proxy for the relative importance of a journal within its field. It is first devised by Eugene Garfield, the founder of the Institute for Scientific Information.The impact factor of a journal is evaluated by dividing the number of current year citations to the source items published in that journal during the previous two years.
Last date updated on September, 2014