PubMed Health⌕ Search

Biomedical subjects

D R Branch

Publications and source records attributed to D R Branch.

At least 55 records · Page 3Linked to original sources
PubMed1985

The red cell antigens A, B, D, U, Ge, Jk3 and Yta are not detected on human granulocytes.

We report the inability to detect the following red blood cell antigens on human granulocytes: A, B, D, U, Gerbich (Ge), JkaJkb (Jk3) and Cartwright (Yta). To study each antigen, granulocytes were purified on density gradients, fixed in glutaraldehyde, and the uptake of specific antisera measured using two direct immunological techniques: 125I-staphylococcal protein A (125I-SPA) binding and avidin-biotin-complex (ABC) immunoperoxidase staining. Glutaraldehyde fixation was shown not to affect the antigenicity when the antisera were tested using red blood cells. Using three anti-A, three anti-B and three anti-A,B antisera, our 125I-SPA results of 47 tests with granulocytes from group A individuals and 39 tests with granulocytes from group B individuals indicate that A or B antigens are not expressed on human granulocytes. Tests using ABC were also negative with 37 and 36 granulocytes from group A or B individuals, respectively. In addition, no positive results using 125I-SPA were obtained with granulocytes from individuals having antigen positive red cells when tested with two anti-D (number of tests performed (n = 22), three anti-Ge (n = 22), three anti-U (n = 20), two anti-Jk3 (n = 17), and three anti-Yta (n = 25); control anti-NA1 or -NB1 antisera were invariably positive. Also, using these antisera, no positive results were obtained by ABC except with one anti-Yta antiserum which was positive with one of seven granulocytes tested. This anti-Yta was also positive with three of 10 granulocytes by 125I-SPA. This activity was shown to be due to a granulocyte-specific antibody; adsorption of the antiserum with human granulocytes removed all activity against granulocytes but did not reduce the activity against red cells. Thus, our results are in agreement with recent reports which demonstrated the absence of the A, B and D antigens on human granulocytes. However, we have been unable to confirm previous reports which indicated the presence of the U, Ge and Jk3 antigens on human granulocytes. Also, we have been unable to detect the Yta antigen on human granulocytes.

ABO Blood-Group System↗
PubMed1984

In vitro determination of red cell alloantibody significance using an assay of monocyte-macrophage interaction with sensitized erythrocytes.

One hundred and forty-eight red cell alloantibodies, of specificities generally considered to be of clinical significance, were studied in vitro for their ability to induce phagocytosis of sensitized red cells by allogeneic mononuclear phagocytes. Results indicate that only 53% of the alloantibodies studied mediated significant phagocytosis in vitro. The percentages for each blood group system were as follows: Kell, 73%; Jka, 32%; Jkb, 67%; D, 75%; E, 60%; Fya, 62%; Yta, 25%; Ge, 22%; and Vel, 25%. Significant phagocytosis was independent of the strength of the indirect antiglobulin test. The percentage of anti-Jka and anti-Fya mediating significant phagocytosis was increased when fresh complement was added during the sensitization procedure and/or red cells homozygous for the antigen in question were used. The in vivo clinical significance or lack of significance was documented for nine alloantibodies; five caused haemolysis and four did not. Those causing in vivo haemolysis mediated in vitro phagocytosis by monocyte-macrophages whereas the antibodies that did not result in haemolysis showed no increased in vitro phagocytosis. Autologous monocytes were more reliable than random allogeneic monocytes in that phagocytosis was increased over that obtained using allogeneic monocyte-macrophages with two of four alloantibodies having documented clinical significance. The use of target red cells homozygous for the antigen in question, the addition of fresh complement in the antibody sensitization procedure, and use of autologous and allogeneic monocyte-macrophages appear necessary for optimal results. Since 47% of those alloantibodies generally considered to be clinically significant failed to mediate phagocytosis in vitro, the monocyte-macrophage assay should not be considered a predictive assay of a given alloantibody's in vivo significance or lack of significance until more extensive correlation of these assays with in vivo red blood cell survival is obtained.

Antibody Specificity↗
PubMed1984

Two distinct categories of warm autoantibody reactivity with age-fractionated red cells.

Using age-fractionated erythrocytes, warm autoantibodies can be classified into two distinct categories, depending on their reactivity with reticulocyte-enriched (younger) or reticulocyte-poor (older) red cell fractions. The strength of the direct antiglobulin test (DAT) on the age-fractionated red cells of 24 patients indicated that 19 (79%) had an IgG warm autoantibody that reacted preferentially with older red blood cells. In 7 of these 19 patients (37%), the DAT was negative using reticulocyte-enriched red cell fractions. We have termed this preferential reactivity of warm autoantibodies with older red cells as type I. Five of the 24 patients studied (21%) had an IgG warm autoantibody that demonstrated no preference for young or older red cells. We have termed this pattern of warm autoantibody reactivity as type II. All 5 patients having type II warm autoantibodies had severe anemia. In contrast, 6 of 19 patients having type I warm autoantibody did not have clinical evidence of anemia when tested, and 11 of the 19 had only slight to moderate anemia. Additionally, our results using type I warm autoantibody raise questions regarding the blood group specificity of warm autoantibodies. The antigen recognized by type I warm autoantibody may be a cryptantigen. Rh specificity or relative Rh specificity, often associated with warm autoantibodies, may simply be a coincidental finding.

Anemia, Hemolytic, Autoimmune↗
PubMed1983

Discrepant in vitro versus in vivo interaction of M-positive donor red cells with IgG1 anti-M.

Following massive transfusion and a suspected sepsis, a patient produced a potent, high titer IgG1 anti-M alloantibody reactive at 37 degrees C with an indirect antiglobulin test [IAT] titer using anti-IgG of 1:512 versus MM red blood cells (RBC). During pretransfusion tests, the antibody was strongly reactive with M+ RBC using IAT, however, transfused M+ RBC remained in circulation and demonstrated normal red cell survival. The direct antiglobulin test remained negative and no antibody activity was detectable in eluates prepared at various times from red cells obtained from the patient post transfusion. There was no direct agglutination of red cells obtained from the patient post transfusion with autologous serum, even at 4 degrees C. However, these samples contained donor M+ RBC as determined by tests using various examples of human and rabbit anti-M antisera. The extraordinary findings of transfused M+ RBC, highly incompatible pretransfusion using IAT, coexisting with potent warm reactive anti-M antibody without evidence of in vivo antibody-antigen interaction represents an unusual discrepancy. Although the explanation for these findings remains unclear, it may indicate antigen modification of donor red cells in vivo.

Binding Sites, Antibody↗
PubMed1983

Erythrocyte age-fractionation using a Percoll-Renografin density gradient: application to autologous red cell antigen determinations in recently transfused patients.

A rapid technic for the age-fractionation of human erythrocytes into reticulocyte-enriched (young) red blood cells and reticulocyte-poor (old) red blood cells using an isopycnic density gradient centrifugation through Percoll-Renografin was evaluated for use in autologous red blood cell antigen determinations in multiply-transfused patients. The fractionation was demonstrated by statistically significant density-related changes in pyruvate kinase and acetylcholinesterase activities (P = 0.002 and 0.042, respectively) and by the distribution of reticulocytes on the gradient (P less than 0.005). With initial reticulocyte counts of less than or equal to 1.5%, reticulocyte counts up to 78% were achieved (means = 25%; n = 31). When starting with reticulocyte counts greater than 5%, samples containing up to 98% reticulocytes were obtained (means = 64%; n = 7). The technic requires less than two hours, uses isotonic media, and is nontoxic to red blood cells. Volumes of red blood cells up to 10 mL can be fractionated at one time and the gradient medium is stable when refrigerated at 4 degrees C. Red blood cell typing was performed in six patients who had received from 4-29 units of blood within a 12-hour period. Within 72 hours posttransfusion, typing of the reticulocyte enriched fraction correctly identified the patient's red blood cell antigens with all 16 antisera tested. This technic for typing reticulocyte-enriched samples is of importance for confirmation of antibody specificity in determining whether an antibody is an alloantibody or autoantibody, and in the selection of donor blood for transfusion to patients having autoimmune hemolytic anemia.

Blood Grouping and Crossmatching↗
PubMed1983

Disulfide bonds are a requirement for Kell and Cartwright (Yta) blood group antigen integrity.

We have investigated the effect of dithiothreitol (DTT) upon the Kell blood group system and other red cell antigens. All Kell blood group antigens studied (K, k, Kpa, Kpb, Jsa, Jsb and Ku) as well as the Cartwright (Yta) antigen were completely denatured after treatment with DTT. The Gerbich antigen was substantially weakened but not completely denatured. The Jsa and Jsb antigens appear to have an exquisite sensitivity to treatment with DTT and can be completely denatured using very low concentrations (less than or equal to 2 mM) whereas other Kell system antigens require much higher concentrations of DTT for their denaturation (100-200 mM). Of 38 other blood group antigens investigated, only the Yta antigen was completely denatured using 200 mM DTT. Furthermore, the Yta antigen was denatured within the same concentration range as Kell and one can speculate that this indicates some biochemical relationship between these two blood group systems. From our results, we conclude that: (1) at least two distinct disulfide (S-S) bonds are required for maintenance of the Kell blood group antigen system; (2) Jsa and Jsb antigens are distinctly different from other Kell system antigens based upon sensitivity to treatment with DTT; these antigens may be located on a different antigenic domain; and (3) the Yta antigen requires at least one disulfide bond for its maintenance of antigen integrity. Although the Gerbich antigen was not completely denatured, results indicate that disulfide bonds may also be important structural determinants for these antigens.

Blood Group Antigens↗
PubMed1983

Reticuloendothelial cell function in alpha-methyldopa-induced hemolytic anemia.

2 patients having alpha-methyldopa-induced hemolytic anemia were followed sequentially using an in vitro assay of autologous monocyte-macrophage activity to determine if their reticuloendothelial system (RES) function was abnormal and thus could be related to the mechanism of lysis. RES function was evaluated while the patients were actively hemolyzing and during remission, following discontinuance of the drug. The results indicated that RES activity is normal in patients having hemolytic anemia due to alpha-methyldopa administration. Also, following cessation of drug therapy, the patients' IgG-coated red cells interacted significantly for a prolonged period (4-5 months) with autologous or normal allogeneic monocyte-macrophages. This was associated with a concurrent reticulocytosis and indicates a persistent low-level hemolytic phase throughout this period, even though hemoglobin and hematocrit values remained within the normal ranges. Although levels of IgG sensitizing the patients' red cells were essentially constant during the hemolytic phase and when the patients were in complete remission, significant monocyte-macrophage activity was only evident during the hemolytic period. In an attempt to explain this phenomenon, it is postulated that hemolysis in patients receiving alpha-methyldopa is related to the interaction of drug with red cell membrane proteins which results in a variably expressed 'altered' antigen which is recognized by 'autoantibody'. The proper expression of the Fc portion of the immunoglobin molecule to result in specific recognition by receptors on monocyte-macrophages depends upon the extent of the antigen alteration by alpha-methyldopa. If the drug does not result in appropriate antigen alteration, then, although 'autoantibody' may still bind to the red blood cell, its Fc region is not readily recognized by monocyte-macrophages and little or no erythrophagocytosis occurs.

Aged↗
PubMed1983

Evaluation of reticuloendothelial function in autoimmune hemolytic anemia using an in vitro assay of monocyte-macrophage interaction with erythrocytes.

We have used an in vitro assay of monocyte-RBC interaction to study the correlation of in vitro monocyte activity with in vivo lysis in patients with autoimmune hemolytic anemia (AIHA). All of 16 patients with a positive direct antiglobulin test (DAT) (0.5 + to 4+) and clinical evidence of hemolysis showed elevated association (ARBC) and phagocytic (PRBC) indices. Of 6 patients studied with a positive DAT (0.5+ to 4+) without clinical evidence of hemolysis, none showed elevated PRBC while 2 showed slightly elevated ARBC. Thus, when using a PRBC index, our assay distinguished between hemolysing and non-hemolysing patients independent of the degree of red cell sensitization as determined by the DAT. In addition, we have studied 6 patients with a positive DAT following alpha-methyldopa therapy. Two of these patients were hemolysing, 4 were not. Again, our assay correlated with in vivo lysis. Finally, we have studied red cells from 11 patients with DAT-negative acquired hemolytic anemia. Seven of these patients showed elevated ARBC and PRBC indices, indicating a possible immune etiology involving extravascular lysis in some DAT-negative acquired hemolytic anemias.

Anemia, Hemolytic, Autoimmune↗
PubMed1982

A new reagent (ZZAP) having multiple applications in immunohematology.

A reagent (ZZAP) containing a mixture of 0.1 M dithiothreitol (DTT) plus 0.1% cysteine-activated papain was found to dissociate IgG immunoglobulin from red blood cells (RBC) of patients having a positive direct antiglobulin test (DAT) although this could not be achieved with either chemical alone. In all 67 patients tested, ZZAP treatment of IgG sensitized RBC reduced the strength of the DAT, and in all 52 instances tested, this allowed for accurate Rh phenotyping using slide/rapid tube typing reagents. This included five examples in which spontaneous agglutination that occurred in saline or 6% albumin was eliminated by ZZAP. Thus, all red blood cell typing for Rh-Hr antigens was accomplished using slide/rapid tube reagents making unnecessary the use of saline reactive or chemically modified antisera. Kidd antigen typing is also possible after ZZAP treatment of IgG sensitized RBC. In regard to warm autoabsorption tests, ZZAP treatment of 14 RC samples having a positive DAT proved preferable to heat elution technics since equal or greater amounts of IgG were removed by ZZAP and little or no hemolysis resulted. ZZAP has no effect on ABH, Rh or Kidd antigens but denatures Duffy, MNSs and all Kell antigens tested (K:1-K:7, K:11-K:14, K:18, K:19). This should prove valuable in certain investigations of multiple alloantibodies and, moreover, may allow for better characterization of Kell antigens.

Blood Grouping and Crossmatching↗
PubMed1982

A new elution procedure using chloroform, a nonflammable organic solvent.

A new method for eluting red cell antibodies using chloroform has been shown to be effective. The method is similar to ether and xylene techniques but can be completed within 10 min after adequate cell washing. Comparison studies using ether, xylene and chloroform showed that antibodies eluted by chloroform yielded equivalent titration scores. Antibodies within the Ss blood group system were easily eluted using chloroform but not using ether. Also, the chloroform method yielded informative eluates when prepared from red cells of patients with warm antibody autoimmune hemolytic anemia, drug-induced immune hemolytic anemia, hemolytic disease of the newborn caused by ABO or Rh fetal maternal incompatibility, or from patients having a positive direct antiglobulin test as a result of alloantibodies stimulated by recent transfusion ("delayed transfusion reaction'). The advantages of chloroform elution are: (1) chloroform is nonflammable; (2) the eluate is readily obtained from the top layer after centrifugation; (3) no residual solvent remains in the eluate, and (4) the method is rapid.

Anemia, Hemolytic↗
PubMed1982

An enzyme basis for blood type A intermediate status.

The blood type A is known to be subclassified as A1, A2, and A1-A2 intermediate (Aint), depending upon red cell agglutinability with anti-A1 and anti-H lectins. Approximately 80% of the blood group H-sites remained unglycosylated in type Aint erythrocyte membranes. Plasma from Aint individuals contains a special blood group GalNAc transferase (UDP-GalNAc:2'-fucosylgalactoside-alpha-3-N-acetylgalactosaminyl transferase), which is different from the enzyme in A1 plasma and the enzyme in A2 plasma. A1-enzyme has strong affinity to UDP-GalNAc and 2'-fucosyllactose, A2-enzyme has low affinity to both substrates, and Aint-enzyme has strong affinity to UDP-GalNAc and very low affinity to 2'-fucosyllactose, which is a soluble analog of the H-substances. The low degree of glycosylation of the blood group H-sites due to the low affinity of Aint-enzyme with the H-substances can account for the lower A activity and higher H activity in Aint red cells than in A1 red cells. The blood group A allele can be subdivided into three common alleles, A1, A2, and Aint, each controlling the formation of different types of blood group GalNAc transferases.

ABO Blood-Group System↗
PubMed1979

Allergic reaction to transfused cephalothin antibody.

Antibodies to cephalothin sodium (Keflin) can be transferred passively via whole blood transfusion. In one case a mild allergic-type reaction was initiated in a patient who was receiving cephalothin therapy. This case is differentiated from a penicillin-caused allergic reaction. All patients that demonstrate allergic-type transfusion reactions should give drug histories. Investigation of passive transfer of antibodies to these drugs might be of benefit in any evaluation made.

Aged↗
PubMedDate not supplied

Detection of complement (c3d) coated cells in a newborn due to maternal anti-i.

A case of a positive direct antiglobulin test on a newborn's cord red blood cells caused by maternal anti-i is reported. The direct antiglobulin test was moderately positive using polyspecific antiglobulin reagent and monospecific anti-C3d, but negative using monospecific anti-IgG. The infant showed no clinical signs of hemolytic disease of the newborn.

Blood Group Antigens↗
PubMedDate not supplied

Fetal death due to extreme maternal Rh immune augmentation.

A 19-year-old woman who denied previous transfusion or pregnancy delivered a stillborn RhO(D)-positive male fetus at 38 weeks' gestation. IgG antibodies with the specificities anti-Rh0(D), anti-rh"(E), anti-Jka, and anti-Yta were eluted from the fetal red blood cells. In the maternal serum, the antiglobulin titer of anti-Rh0(D) was 1:20,000 and the saline (IgM) titer was 1:1,024. Amniocentesis findings at 36 weeks had suggested only mild, if any, fetal hemolysis, but the stillborn infant showed signs of severe hemolytic disease with cardiac failure. This case appears to represent an unusual augmented immune response to fetal red blood cell antigens.

Adult↗
PubMedDate not supplied

Anti-M causing delayed hemolytic transfusion reaction.

A 52-year-old gravida 1, para 1 woman with M- red cells experienced a delayed hemolytic transfusion reaction and exhibited an anti-M antibody following the infusion of four units of M+ red cells. Measurements of erythrocyte survival using 51Cr-labeled donor M+ and M- red cells and in vitro studies of monocyte-macrophage phagocytosis of sensitized reagent red cells implicate anti-M in the pathogenesis of hemolysis.

Chromium Radioisotopes↗