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G Garratty

Publications and source records attributed to G Garratty.

At least 73 records · Page 4Linked to original sources
PubMed1993

Predicting hemolytic disease of the newborn: a comparison of the monocyte monolayer assay and the chemiluminescence test.

The ability of the monocyte monolayer assay (MMA) and the chemiluminescence test (CLT) to predict the clinical significance of alloantibodies associated with hemolytic disease of the newborn (HDN) was assessed by the use of 22 well-characterized antisera--predominantly anti-D--from alloimmunized pregnant women. Seventeen sera were obtained before delivery from women whose infants were antigen positive for the antibody specificities identified in the maternal serum. With testing of these 17 sera by MMA, 10 results were in agreement with the presence or absence of HDN, but there were 5 false-positive and 2 false-negative results. With the CLT, 16 results were in agreement with the presence or absence of HDN, and there was 1 false-negative result. Five sera were obtained from women whose infants were antigen negative for the antibody specificities identified in the maternal serum. The CLT and the MMA were both subject to false-positive results with these sera. These results suggest that the CLT may be more valuable than the MMA as a noninvasive test for predicting the clinical significance of alloantibodies in HDN.

Erythroblastosis, Fetal↗
PubMed1993

Monocyte monolayer assay as a predictor of severity of hemolytic disease of the fetus and newborn.

The monocyte monolayer assay (MMA), an in vitro model of in vivo antibody-mediated red blood cell destruction, was previously reported to predict the severity of hemolytic disease of the fetus and newborn accurately when only Rh antibodies and antigen-positive babies were studied. We studied 33 women whose serum contained antibodies with the potential to cause erythroblastosis fetalis; 7 of the 33 women had antibodies other than Rh. None of the babies of the ten women who had consistently negative test results required intrauterine or neonatal transfusions. False-positive MMA results were sometimes found when the fetus was antigen negative. Although the predictive value of a negative MMA was 100%, the efficiency of the MMA was no better than that of the antibody titer. Because of the lack of advantage of the MMA as well as the time and expense it requires, we cannot recommend the general clinical application of this test at this time.

Antibodies↗
PubMed1993

The effect of methyldopa and procainamide on suppressor cell activity in relation to red cell autoantibody production.

Kirtland et al (1980) suggested that methyldopa caused the production of red cell (RBC) autoantibodies by causing a persistent increase in lymphocyte cyclic AMP, which inhibited suppressor T cell function, leading to unregulated autoantibody production in some patients. They showed that significantly higher lymphocyte cyclic AMP concentrations were generated by lymphocytes from healthy donors after adding methyldopa, and by lymphocytes from patients who were receiving methyldopa compared to lymphocytes from healthy donors without methyldopa present. They also showed that methyldopa affected suppressor cell activity. We measured the effect of methyldopa and procainamide on suppressor cell activity, using a similar approach to Kirtland et al (1980). Suppressor cell activity was measured by measuring the amount of IgG, produced in vitro, by B cells following mitogen stimulation preceded by a 24 h incubation period. We found no significant increase in the amount of IgG generated by normal donor lymphocytes, when methyldopa or procainamide was present during the preincubation period. This is in contrast to the findings of Kirtland et al (1980). We also measured the amount of IgG generated in vitro by mitogen-stimulated lymphocytes from patients (with and without positive direct antiglobulin tests) taking methyldopa and compared this to the amount of IgG generated by lymphocytes from normal donors and patients (with and without positive direct antiglobulin tests). The results were similar for each group. This does not agree with the findings of Kirtland et al (1980) who found that lymphocytes from patients taking methyldopa produced more IgG in vitro than lymphocytes from normal donors. Our results do not support the hypothesis that methyldopa and procainamide induce autoantibodies by affecting suppressor cell function.

Autoantibodies↗
PubMed1993

Problems associated with compatibility testing for patients with autoimmune hemolytic anemia.

Two major areas where problems are encountered when performing compatibility testing for AIHA patients are ABO/Rh typing and crossmatching blood for transfusion. ABO/Rh typing is usually not a problem with warm type AIHA (WAIHA), but sometimes false positive Rh typing results may occur with reagents containing potentiators (eg, albumin). Approaches to overcoming this problem include using reagents not having potentiators, or removing IgG from RBCs (eg, using chloroquine) before typing. Major problems are encountered when typing patients with cold agglutinin syndrome (CAS). These can usually be resolved by using RBCs that have been washed at 37 degrees C, and testing the serum with A, B and O cells at 37 degrees C using the "prewarm" technique. When crossmatching blood for patients with CAS, all tests should be carried out with saline or LISS-suspende RBCs, strictly at 37 degrees C; albumin or enzyme techniques should be avoided. If sera from WAIHA are reacting with all RBCs, the presence of underlying alloantibodies must be excluded by performing absorption studies with with autologous, or homologous RBCs. If alloantibodies are present, they should be identified, and "antigen negative" blood crossmatched. If alloantibodies are not present, and if time allows, the less important autoantibody specificity may be studies. If specificity is shown (eg, auto anti-e) and appropriate donors (eg, e negative) are available, with relative ease, then it is preferable to use this blood. If the appropriate compatible donors are rare [eg, Rhnull, LW-, U-, Kp (b-)], they should not be used for AIHA but should be reserved for patients with alloantibodies.(ABSTRACT TRUNCATED AT 250 WORDS)

ABO Blood-Group System↗
PubMed1993

Autoimmune hemolytic anemia after Kawasaki disease in a child.

A 2-year-old male presented with upper respiratory tract infection symptoms, continuous high fever, extensive truncal rash with desquamation, lymphadenopathy, subconjunctival hemorrhage, and oral stomatitis. He was diagnosed with Kawasaki disease and did well on aspirin. Approximately 8 weeks after initial presentation he had evidence of severe immune hemolysis. At that time a direct antiglobulin test was microscopically positive; it became strongly positive (3 + IgG, w + C3) 2 weeks later. The serology was unusual in that a warm IgG autoantibody and a low titer high thermal range cold antibody of unusual specificity (anti-Ena or anti-Pr) were present. We were uncertain as to which antibody caused the hemolysis, or whether they worked synergistically. The hemolysis resolved following treatment with high dose prednisone.

Anemia, Hemolytic, Autoimmune↗
PubMed1993

Rapid enzymatic analysis for human immunodeficiency virus type 1 DNA in clinical specimens.

A clinical procedure for rapid detection of human immunodeficiency virus type 1 (HIV-1) by DNA amplification is demonstrated. The rapid procedure reduces handling requirements and amplification time and eliminates use of radioactivity for the detection of the amplification product. Total leukocyte lysates are the amplification substrates. Two conserved regions in the HIV-1 genome are amplified by 45 cycles of a two-temperature thermal cycle and the amplification products are detected by ultraviolet light after electrophoresis on agarose gels. Twenty-four specimens clinically diagnosed by detection of antibody (IgG) to HIV-1 were confirmed by the rapid DNA amplification procedure. In a blind study, 56 samples positive for HIV-1 DNA were detected in 503 individuals by the current classical polymerase chain reaction method; the same 56 positive samples were also detected by the rapid amplification protocol. No false-positive or false-negative results were obtained. The turnaround time for analysis has been reduced to < 24 h without compromising test results.

Base Sequence↗
PubMed1992

Selection of platelets for refractory patients by HLA matching and prospective crossmatching.

A multi-site clinical study compared platelets chosen for refractory patients by prospective platelet crossmatching using stored donor platelets and HLA-based selection. Seventy-three patients who were refractory to random-donor platelets received two plateletpheresis components, one chosen by HLA-based criteria and the other by crossmatching. Patients were carefully evaluated to exclude nonimmune factors that could adversely affect transfusion results. Each of the five study sites used a crossmatch procedure with which it had experience. Results from this study indicate the following: 1) The overall rate of successful transfusion was similar when an HLA-based method of donor selection that includes all grades of matching and mismatching was compared to a crossmatch-based method of donor selection. 2) HLA-based selection that restricts recipients to grade A and BU matches was superior to a selection method based upon crossmatching alone. Donor selection based on HLA matching (grades A or BU) was also superior to selection based on any degree of HLA mismatching (grades BX, C, or D). 3) Selection of donors based on HLA-cross-reactive groups (defined by in vitro serologic crossreactivity) was no more successful than that based on grade C and D mismatches and was no more successful than selection by crossmatching alone. 4) Lymphocytotoxic and platelet antibodies were not detected in many of the enrolled patients, even though patients demonstrating nonimmune factors were eliminated from the study. It can be concluded that HLA-compatible (grades A and BU) platelets provide optimal support for refractory patients, but that crossmatch-selected platelets are acceptable as an alternative component.

Adult↗
PubMed1991

A fatal case of ceftriaxone (Rocephin)-induced hemolytic anemia associated with intravascular immune hemolysis.

Fatal hemolytic anemia developed in a 52-year-old woman who was treated with a cephalosporin, ceftriaxone. The patient's red cells (RBCs) were coated with C3, but no RBC-bound IgG, IgA, or IgM was detected. Her serum contained an antibody that did not react with cephalosporin-coated RBCs but reacted strongly with RBCs in vitro when her serum was added to drug and RBCs. This is the first case of immune hemolytic anemia associated with ceftriaxone, the first case of fatal cephalosporin-induced hemolytic anemia, and the second case in which a cephalosporin antibody showed in vitro and in vivo characteristics usually thought to be associated with the so-called immune complex mechanism.

Anemia, Hemolytic↗
PubMed1991

Effect of cell-bound proteins on the in vivo survival of circulating blood cells.

Normal circulating red blood cells (RBCs) and platelets have been shown to have small amounts of IgG on their membranes. The cell-bound IgG may be cytophilic (IgG nonspecifically adsorbed from the plasma) and/or IgG autoantibody. It has been suggested that most of the RBC-bound IgG is on older RBCs and is an autoantibody directed against senescent cell antigen (SCA). The accumulation of this RBC-bound IgG leads to Fc-dependent removal of senescent RBCs by macrophages in the reticuloendothelial system. RBCs also have complement components on their membrane; it is not clear how this accumulates on RBCs and whether it has a physiologic function. This small amount of nonpathogenic RBC-bound IgG is not detected by the antiglobulin test. It is still unclear whether the major difference between pathogenic and nonpathogenic IgG autoantibodies is qualitative, quantitative, or both. Seemingly healthy blood donors (1 in 1,000 donors) and patients without hemolytic anemia (up to 8% of patients) have increased amounts (greater than 200 molecules/RBC) of RBC-bound IgG and complement that is detected by the antiglobulin test. This RBC-bound IgG has been shown to be an IgG autoantibody directed against blood group antigens, and/or IgG anti-idiotype, and/or IgG nonspecifically adsorbed onto the RBC membrane when plasma IgG levels are high. Most patients with autoimmune hemolytic anemia (AIHA) have RBC-bound IgG and/or complement detectable by the antiglobulin test. Most of the RBC-bound IgG is of the IgG1 subclass, whether one examines the RBCs of healthy blood donors or hospitalized patients with and without AIHA. Although the quantity of RBC-bound IgG is generally higher in patients with AIHA, there is no clear correlation with the quantity of RBC-bound IgG and the rate of in vivo RBC destruction. There is some recent evidence that the SCA autoantibody may at times be pathogenic and cause autoimmune disease.

Anemia, Hemolytic↗
PubMed1990

Flow cytometry: its applications to immunohaematology.

Flow cytometry, using fluorescent probes, has only recently been applied to practical aspects of immunohaematology. It has been used for the detection and quantitation of cell-bound immunoglobulins and complement, minor cell populations, cellular antigens, and platelet and granulocyte antibodies. Practical applications of detecting minor cell populations have been successful in determining the extent of fetal maternal haemorrhage; determining the survival of transfused RBCs (small and large volumes); demonstrating RBC chimaerism (e.g. following bone marrow transplantation) and RBC mosaicism (e.g. demonstration of the McLeod phenotype carrier status). A large variety of cellular antigens have been demonstrated on RBCs, platelets and white cells using flow cytometry. Quantitation of RBC antigens by flow cytometry has been found to be much more objective and accurate than the routinely used serological approaches for establishing zygosity in paternity studies. Flow cytometry has been found to be a sensitive, objective and reproducible method for detecting platelet auto-and alloantibodies, and has also been used to detect granulocyte antibodies. More recently, it has been used to detect antibodies to monocytes and lymphocytes. As flow cytometers become more commonly available, many of these applications may become routine in clinical pathology laboratories.

Antigens, Surface↗