11 Summary Despite the fact that anemia is one of the most striking clinical features of visceral leishmaniasis (kala-azar), the factors involved in the pathogenesis are not fully understood. The cause of anemia seen in these patients is often multifactorial including sequestration and destruction of the erythrocytes in the enlarged spleen, hemophagocytosis and alterations in erythrocyte membra...

Sheep erythrocytes sensitized by incubation with the heat-labile enterotoxin (LT) of Escherichia coli are hemolyzed in the presence of anti-LT antiserum and complement. The Microtiter (Cooke Laboratory Products) technique was used to titrate anti-LT antibody in serum by this immune hemolysis reaction. Immune hemolysis was inhibited by preexposure of the anti-LT antiserum to soluble LT before ad...

The method of passive immune hemolysis of Evans and Evans (Infect. Immun. 16:604-609, 1977) for detection of heat-labile enterotoxin produced by enterotoxigenic Escherichia coli was modified. A total of 373 strains of E. coli were tested by this method using materials obtained by treating the cells with polymyxin B and rabbit antiserum against cholera enterotoxin, purified by affinity gel colum...

In most cases, immune-mediated hemolysis occurs extravascularly and is associated with IgG antibodies on the surface of red cells. Rare syndromes include IgG antibodies that cause direct intravascular hemolysis, such as paroxysmal cold hemoglobinuria. Also rare are extravascular hemolytic syndromes caused by IgM polyclonal or monoclonal antibodies that demonstrate red cell agglutination at 3 de...

The role of the C' 1 system in the hemolysis of PNHE has been emphasized recently by the demonstration in this laboratory that PNHE lysis and classical C'-dependent immune lysis have similar cation requirements and pH optima (2, 3). In addition, the enhancing effects of C'la, C'1 esterase, and C'l activators upon PNHE hemolysis suggested that the early steps of C'activation ultimately leading t...

The capsular polysaccharide of Hemophilus influenzae type b, polyribosyl ribitol phosphate (PRP), is released from growing organisms during human infection and can be found in body fluids. It binds to untreated erythrocytes. Many patients with invasive infections with this organism develop significant hemolysis, but the mechanism has been unclear. We have found that PRP binds to human erythrocy...

Chronic lymphocytic leukemia is frequently associated with immune disturbances. The relationship between chronic lymphocytic leukemia and autoimmune cytopenias, particularly autoimmune hemolytic anemia and immune thrombocytopenia, is well established. The responsible mechanisms, particularly the role of leukemic cells in orchestrating the production of polyclonal autoantibodies, are increasingl...

Animals cope with seasonal variation in environmental factors by adjustments of physiology and life history. When seasonal variation is partly predictable, such adjustments can be based on a genetic component or be phenotypically flexible. Animals have to allocate limited resources over different demands, including immune function. Accordingly, immune traits could change seasonally, and such ch...

Hemolysis most commonly occurs following bone marrow transplant when there is "minor" ABO blood group incompatibility between donor and recipient. The hemolysis has been attributed to destruction of the patient's incompatible erythrocytes by donor-derived anti-A and/or anti-B antibody produced from "passenger" immunocompetent donor lymphocytes. Extraordinary transfusion requirements of group O ...