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L D Petz

Publications and source records attributed to L D Petz.

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

Platelet crossmatch tests using radiolabelled staphylococcal protein A or peroxidase anti-peroxidase in alloimmunized patients.

Refractoriness to random-donor platelets as a result of alloimmunization remains a major problem in long-term platelet transfusion therapy despite the use of HLA-matched platelets. We have therefore studied the use of two methods for detection of platelet associated IgG as platelet crossmatch tests for the selection of platelet donors. These methods use radiolabelled staphylococcal protein A (125I-SPA) and peroxidase anti-peroxidase (PAP), respectively. One hundred and ten crossmatch tests using 125I-SPA were performed retrospectively in 18 alloimmunized patients. The results indicated that the predictive value of a positive or a negative test was 87%; the sensitivity was 73% and the specificity was 95%. Results with the PAP test were similar. The HLA types were known for 48 donor-recipient pairs. With few exceptions, there was a correlation between the results of the platelet crossmatch tests and the effectiveness of platelet transfusion regardless of the degree of HLA match. These results indicate that platelet crossmatch tests may be valuable even when closely HLA matched donors are not available. A large-scale prospective study is warranted, particularly in highly immunized patients.

Anemia, Aplastic↗
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↗
PubMed1984

Increased IgG molecules bound to the surface of red blood cells of patients with sickle cell anemia.

We have used the complement-fixing antibody consumption ( CFAC ) test to detect small concentrations of IgG on red blood cells from patients with hemolytic anemias that are not thought to be caused by an immune mechanism. Although patients with hereditary spherocytosis, pyruvate kinase deficiency, and mechanical hemolytic anemias generally had normal concentrations of IgG bound to their red cells (less than 25 molecules IgG per red cell), we found that 39/62 (63%) patients with sickle cell anemia had elevated values. These 39 patients had a mean of 195 and a maximum of 890 molecules of IgG per red cell. None of the patients had been transfused within the previous 90 days, and some had never been transfused. Direct antiglobulin tests were positive in only two instances and autoantibodies were not found in the serum of any patient. However, eluates from the red cells of 6 of 23 patients demonstrated antibody activity against all of a panel of normal red cells by the indirect antiglobulin test. There was no correlation between the number of IgG molecules on patients' red cells and the severity of their anemia, the incidence of painful sickle cell crises, the reticulocyte count, or with blood transfusion history. We conclude that further study of immunohematologic abnormalities in patients with sickle cell anemia is warranted, especially in view of previous reports in this population of patients with red cell autoantibodies, autoimmune hemolytic anemia, hemolytic transfusion reactions without detectable alloantibodies, and an association of some episodes of pain crises with immunologically mediated red cell destruction.

Adolescent↗
PubMed1983

Autoimmune hemolytic anemia.

Nowhere in the management of patients with autoimmune hemolytic anemias is the communication between clinician and laboratory personnel more important than in regard to blood transfusion. A clinical decision that blood transfusion is necessary must be tempered by the knowledge that transfusion has a greater-than-usual risk in this setting, both because the autoantibody may cause a shortened red cell life-span of transfused red cells and because the autoantibody makes detection of red cell alloantibodies in the patient's serum more difficult. Nevertheless, when transfusion is indicated because of anemia of life-threatening severity, blood must be provided even when there is an incompatible crossmatch caused by the autoantibody. Improved methods for the typing of antibody-coated red blood cells have been described, and several eminently practical serologic techniques are now available for detection of alloantibodies even when the patient's autoantibody reacts with all donor cells. These methods include the warm autoabsorption and the differential absorption tests as well as tests for autoantibody specificity. Thus, it is no longer justifiable to omit a search for allo-antibodies in the serum of patients with autoimmune hemolytic anemia prior to blood transfusion, and the use of "least incompatible" units without more detailed compatibility testing should be considered obsolete.

Anemia, Hemolytic, Autoimmune↗
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

Cimetidine-induced hemolytic anemia: the fallacy of clinical associations.

Two patients developed hemolytic anemia while taking cimetidine. Neither patient was taking other drugs known to cause hemolytic anemia. In both, the hemolytic anemia resolved after the drug was stopped. In one patient, the direct antiglobulin (Coombs') test was strongly positive when the hemolytic anemia was recognized and became only weakly positive as the hemolysis subsided. However, serologic studies for antidrug antibodies yielded negative results in both patients; readministration of cimetidine for 55 days in patient 1 and for more than 24 months in patient 2 did not cause recurrence of hemolysis. We conclude that we cannot incriminate cimetidine as the cause of the hemolytic anemia in either of our patients. These findings emphasize that a temporal association of drug administration and hemolytic anemia is not proof of a cause-effect relationship and that reports of drug-related adverse hematologic effects must be interpreted with caution.

Adult↗
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

Detection of IgG sensitization of red cells with 125I staphylococcal protein A.

Most cases of immune hemolytic anemia are associated with a positive direct antiglobulin test. However, in some cases, the antiglobulin test is not sensitive enough to detect low levels of red-cell bound antibodies. This report describes a method using radiolabelled purified staphylococcal protein A which is capable of detecting IgG sensitization of red cells beyond the threshold of serologic techniques. It is less cumbersome than previously described methods and does not require antibody purification procedures. Its effectiveness was demonstrated for the detection of red-cell alloantibodies and in evaluation of patients with acquired hemolytic anemias associated with a negative direct antiglobulin test.

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↗