Red blood cell survival studies in patients with anti-Cha, anti-Yka, anti-Ge, and anti-Vel

High-titer, low-avidity (HTLA) antibodies and antigens: a review

Antibodies that react to HTLA characteristics cause difficulties in serologic testing because of the weak reactions they produce in the indirect antiglobulin test. Those specificities that are more frequently encountered (anti-Yka, -McCa, -Kna, -Ch) are directed toward antigens of high incidence in both the white and black populations. They have not been shown to cause significant destruction of transfused antigen-positive red cells. The antibodies create problems in serologic tests because the reactions they produce interfere with the identification of reactions due to other, clinically significant antibodies.

An infant girl with severe autoimmune hemolytic anemia: apparent anti-Vel specificity

Autoantibodies directed against the common red-cell antigen Vel are unusual, with only 2 previous cases reported. This report describes an infant girl with steroid-resistant autoimmune hemolytic anemia whose serum contained an antibody with apparent specificity for Vel antigen. Transfusion with Vel-positive cells resulted in a massive hemolytic transfusion reaction. Survival of labelled Vel-negative cells was normal up to 8 h following transfusion, and no transfusion reaction followed subsequent use of Vel-negative cells. There was no evidence of a collagen vascular disease, an immunodeficiency syndrome, or a malignancy. Although rare, anti-Vel should be considered in unexplained autoimmune hemolytic anemia.

Adverse transfusion reactions associated with a precipitating anti-C4 antibody of anti-Rodgers specificity

A patient suffering from chronic hepatitis exhibited severe transfusion reactions after administration of fresh frozen plasma and a plasma fraction: PPSB (prothrombin complex concentrate). 1 month before these reactions, she received fresh frozen plasma during plasma exchange therapy. The patient's serum obtained 1 week and 6 months after the second reaction gave a precipitation arc against PPSB preparations when examined by double-diffusion technique in agarose gel. An antibody of IgG class present in these sera reacted with a purified preparation of the fourth complement component (C4). This was demonstrated by various experiments (protein A radioimmunoassay and passive hemagglutination) using purified C4 as antigen. The antibody had a limited specificity and reacted only with C4 of Rodgers specificity. Phenotype determination of the patient's C4 group showed that she was Chido positive and Rodgers negative. Her HLA group was A1, Aw30; B8,-; DR3,-. The patient had neither detectable anti-IgA nor other anti-immunoglobulin antibodies. She had not received blood or plasma transfusion before her hepatitis. The coexistence of a precipitating anti-C4 antibody and adverse transfusion reactions to plasma fractions containing large amounts of C4 indicates that in the absence of antibodies of other specificities, this antibody can be considered as the cause of the transfusion reaction.

Clinical evaluation of a 51Cr-labeled red blood cell survival test for in vivo blood compatibility testing

Modified red blood cell survival studies with use of 51Cr were performed in three groups of subjects. Group 1 consisted of normal subjects who were given labeled autologous blood, group 2 were subjects in need of blood transfusions and given labeled ABO and Rh crossmatch-compatible blood, and group 3 were patients in need of blood transfusion but in whom problems arose in finding compatible blood. The results of the studies suggest that for patients with blood compatibility problems, normal red blood cell survival values at 1 hour do not exclude the possibility of severe hemolysis 24 hours later. Thus, if a 1-hour test result is normal, the procedure should be extended routinely to 24 hours. Moreover, the test can be used to evaluate the clinical importance of antibodies. We showed that anti-Yka and anti-Lan were clinically significant, but high-titer, low-avidity antibodies, anti-Kna, anti-I, and anti-HI were clinically insignificant in the cases studied. This finding emphasizes the importance of an in vivo test for the final compatibility evaluation in complicated blood replacement problems.

Successful transfusion results using Rg(a+) blood in four patients with anti-Rga

4 patients with anti-Rga successfully transfused in 1979 and 1980 with Rg(a+) donor units are herein reported since the literature lacks information on transfusion results in patients with this alloantibody. The transfusions of both Rg(a+) whole blood and packed red blood cell units caused no discernible immediate or delayed transfusion reactions. Clinically, predicted hematocrit increases were attained and sustained and the laboratory findings showed no evidences of shortened survivals of donors' red blood cells.

Autoimmune hemolytic anemia associated with autoanti-Ge

The first reported example of autoimmune hemolytic anemia due to an autoanti-Gerbich is described. The patient's red blood cells exhibited a strongly positive direct antiglobulin test with both IgG and complement antiglobulin reagents. The serum contained a potent antibody which produced agglutination of red blood cells as well as a positive indirect antiglobulin test. Treatment of the serum with 2-mercaptoethanol demonstrated that the antibody contained both IgG and IgM components. The serum antibody and the antibody eluted from the patient's red blood cells had anti-Gerbich specificity. The patient's cells typed as Gerbich-positive with saline-agglutinating anti-Gerbich sera. Of great interest was the fact that the patient's mother also has acquired immune hemolytic anemia, but the IgG antibody in her serum and eluted from her red blood cells had anti-pdl specificity.

Survival studies of 51Cr Ch(a+) red blood cells in a patient with anti-Cha, and massive transfusion of incompatible blood

Survival studies of 51Cr, Ch(a+) red blood cells in a patient with anti-Cha, showed normal survival time in the observation period of 6 days. Successive massive transfusion of Ch(a+) blood was performed without any complication. A very strong secondary immune response to the Ch antigen was observed.