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Biomedical subjects

R J Davey

Publications and source records attributed to R J Davey.

At least 37 records · Page 2Linked to original sources
PubMed1991

Changes in lymphocyte subpopulations as a result of cardiopulmonary bypass. The effect of blood transfusion.

Cardiopulmonary bypass is associated with postoperative humoral and cellular immune changes. Postoperative decrease in T helper (CD4), T suppressor (CD8), and B lymphocyte counts; decrease or reversal of the CD4/CD8 ratio; and poor in vitro response to mitogens have also been observed. Similar changes in lymphocyte number and function have also been noted in patients receiving transfusions. To determine whether observed changes after cardiopulmonary bypass are related to the bypass itself or to associated blood transfusions, we conducted a study of lymphocyte subsets in transfused and nontransfused patients. A flow cytometric analysis of seven lymphocyte subpopulations was conducted in 18 patients undergoing bypass, eight of whom did not receive a transfusion. The transfused group comprised recipients of both homologous (n = 8) and autologous (n = 2) blood. Total lymphocytes and lymphocytes with markers for CD3 (pan-T cells), CD4, and CD8 decreased significantly postoperatively independent of transfusion. B lymphocytes decreased postoperatively in both the autologous transfusion and no transfusion groups. However, this trend was not seen in patients receiving homologous blood, and three of these patients had evidence of T cell activation, suggestive of an immune response to homologous transfusion. Bypass produces significant changes in selected lymphocyte subsets. Furthermore, simultaneous homologous blood transfusion may specifically elicit an immune response in some patients undergoing cardiopulmonary bypass.

Adult↗
PubMed1990

Prevalence of thyroid abnormalities in patients with dermatitis herpetiformis and in control subjects with HLA-B8/-DR3.

PURPOSE: The prevalence of thyroid dysfunction as measured by the presence of overt thyroid disease, abnormal results of thyroid function tests, or antithyroid antibodies was compared in patients with dermatitis herpetiformis (DH) and a normal control group who had the HLA-B8/-DR3 haplotype. PATIENTS AND METHODS: The study population consisted of 56 patients with DH and 26 control subjects with the HLA-B8/-DR3 haplotype. All were examined for thyroid function abnormalities and thyroid autoantibodies. RESULTS: Patients with DH had a statistically significant increase in the prevalence of abnormal thyroid function test results and autoantibodies: 32% versus 4% for controls (Z = 2.01, p less than 0.02). In patients with DH, hypothyroidism was the most common thyroid abnormality (12 of 56) followed by hyperthyroidism (four of 56). Two patients had normal thyroid function test results with thyroid autoantibodies. Risk factors for thyroid abnormalities in patients with DH were increasing age (chi 2 = 6.55, p less than 0.02, significant) and the presence of thyroid microsomal antibodies. The HLA-B8/-DR3 haplotype was not a risk factor for thyroid abnormalities. CONCLUSION: The findings suggest that thyroid disease is independently associated with DH. Examination of patients with DH should include thyroid function tests along with assays for antithyroid antibodies.

Adult↗
PubMed1990

In vivo traffic of indium-111-oxine labeled human lymphocytes collected by automated apheresis.

The in vivo traffic patterns of autologous lymphocytes were studied in five normal human volunteers using lymphocytes obtained by automated apheresis, separated on Ficoll-Hypaque gradients, and labeled ex vivo with 111In-oxine. Final lymphocyte infusions contained 1.8-3.1 X 10(9) cells and 270-390 microCi (9.99-14.43 MBq) 111In, or 11-17 microCi (0.41-0.63 MBq) per 10(8) lymphocytes. Gamma imaging showed transient lung uptake and significant retention of radioactivity in the liver and spleen. Progressive uptake of activity in normal, nonpalpable axillary and inguinal lymph nodes was seen from 24 to 96 hr. Accumulation of radioactivity also was demonstrated at the forearm skin test site, as well as in its associated epitrochlear and axillary lymph nodes, in a subject who had been tested for delayed hypersensitivity with tetanus toxoid. Indium-111-oxine labeled human lymphocytes may provide a useful tool for future studies of normal and abnormal lymphocyte traffic.

Blood Component Removal↗
PubMed1988

The uses of radiolabeled red cells in transfusion medicine.

The ability to radiolabel and follow the red cell in vivo has been of great value to the clinician and the investigator. An understanding of the advantages and disadvantages of the three nuclides used in transfusion medicine--51Cr, 99mTc, and 111In--allows the selection of the appropriate nuclide for the task at hand. For red cell life-span studies and for red cell survivals extending over one hour, 51Cr is the label of choice. The most accurate method for determining the zero-time (100% survival) point for a life span or survival study is to ascertain the RCM of the subject using autologous red cells labeled with another nuclide, preferably 99mTc. RCM studies done independently from a 51Cr survival should be performed using 111In labeled red cells. Red cell survivals are most often used to determine transfusion compatibility or to evaluate blood storage systems. There are important differences in the conduct and interpretation of red cell survivals for these two purposes. Although other promising methods for evaluating the in vivo survival of red cells are under investigation, it is likely that the radiotracers now available will continue to play a primary role in performing these studies in the future.

Blood Transfusion↗
PubMed1988

A new specificity, SH7 (Bw75), defined by antisera produced by planned immunization.

SH7 specificity was defined by a group of antisera developed in Shanghai, China by planned immunization. SH7 antibody is cross-reactive with B5 and B15, as demonstrated by the serological reaction patterns obtained during planned immunization. Using 9th and 10th International Histocompatibility Workshop sera, we were able to confirm SH7, TS-1 and B15Kemp as identical specificities. They are equivalent to BW62S and B15Short-Thai. In view of the cross-reaction patterns obtained during planned immunization, SH7 appears to belong to the B5, B15, B35 and Bw70 cross-reactive groups.

Epitopes↗
PubMed1988

The effect of the plasticizer di-2-ethylhexyl phthalate on the survival of stored RBCs.

Recent in vitro studies have shown that di-2-ethylhexyl-phthalate (DEHP) inhibits the deterioration of RBCs during refrigerated storage in containers that use this compound as a plasticizer. The experiments described in this report were designed to assess whether this in vitro protective effect of DEHP would result in a prolonged in vivo survival of RBCs infused into normal human recipients. Whole blood collected from ten normal donors was stored for 35 days in citrate-phosphate-dextrose-adenine (CPDA-1) anticoagulant contained in polyvinylchloride (PVC) bags plasticized with DEHP or a trimellitate compound that is known to have low leachability. Aliquots of RBCs from each container were then labeled with chromium-51 and were reinfused into the original donors. For blood stored in DEHP-plasticized PVC bags, 24% more red cells survived in vivo 24 hours after reinfusion than was observed when the blood had been stored in trimellitate-plasticized bags (P less than .001). Whole blood stored in glass bottles showed a similar improvement in in vivo survival when DEHP was added in weekly increments to mimic the accumulation of this plasticizer seen during storage in plastic containers. Survival of packed red cells stored in the presence of DEHP increased by 14% compared with storage in trimellitate-plasticized bags (P less than .05). In agreement with previous studies, hemolysis and microvesicle formation were also reduced in the presence of DEHP. These results suggest that proposed new storage systems lacking DEHP should be carefully evaluated to determine whether adequate post-transfusion survival of RBCs may be achieved.

Blood Preservation↗
PubMed1987

Massive acute hemolysis secondary to Clostridium perfringens sepsis in a recently transfused oncology patient with multiple alloantibodies.

Sepsis with clostridia species is seen infrequently in oncology patients, and the massive acute intravascular hemolysis known to be associated with these organisms is rare. The urgency of making the diagnosis of clostridial sepsis is imperative since the course is rapidly fatal if untreated. We describe a patient with metastatic adenocarcinoma of the pancreas, known to have recent transfusions as well as multiple red cell alloantibodies, who developed massive nonimmunologic hemolysis associated with Clostridium perfringens sepsis. Because the hemolysis of C. perfringens sepsis can mimic that of a severe delayed hemolytic transfusion reaction, care must be taken to differentiate these conditions, especially in view of the frequency of transfusion in these patients as well as their predisposition to develop disseminated infections.

ABO Blood-Group System↗
PubMed1987

Stimulation of antibody following 51chromium survival studies.

The survival of red blood cells (RBCs) radiolabeled with 51Chromium (51Cr) is a reliable method for predicting transfusion compatibility. Approximately 1.0 ml of 51Cr tagged RBCs is infused into the patient and samples are drawn at predetermined intervals post infusion to determine RBC survival. Red cells used for the study are usually incompatible with the patient's antibody. This antigenic rechallenge may stimulate further antibody production, which could contribute to accelerated destruction of RBCs during subsequent incompatible transfusions. To study this question, blood samples were collected from six patients with a single atypical alloantibody, seven to nine months after 51Cr RBC survival studies had been performed in an unrelated protocol. Blood had not been transfused in the interim. The samples were tested in parallel with pre-survival samples for change in antibody titer and score. In addition, RBCs used for the 51Cr survival study, sensitized in vitro with pre- and post-survival serum, were tested by the monocyte monolayer assay (MMA). Serum antibody titers showed a significant increase (> 2 dilutions) in two of six patients and antibody score was significantly increased (> 10) in three of six patients. One of the two negative MMAs became weakly positive. This study suggests that 51Cr survival tests using small volumes of RBCs can stimulate significant increases in antibody in some patients, a factor that must be considered in performing these tests and in planning subsequent transfusions.

Journal Article↗
PubMed1987

Cold autoimmune hemolytic anemia with auto-anti-AI specificity: 51chromium survival studies.

A 65-year-old woman was found to have severe autoimmune hemolytic anemia. The patient was group A1, Rho(D) positive. The direct antiglobulin test was strongly positive with anti-C3 and negative with anti- IgG. The serum contained two distinct IgM antibodies, auto-anti-I and auto-anti-AI. Both were reactive at 22 degrees C. However, the anti-AI also was reactive in saline and in albumin at 37 degrees C. An eluate revealed anti-AI and a weak anti-I. Sequential 51Chromium survival studies were done with group OI and AI red cells. The group OI red cells survived normally (97% at 24 hours) while the group A1I red cells were removed in a "two-component" pattern characteristic of IgM complement-fixing antibodies (62% survival at one hour, 49% at 24 hours). Based on these observations, the patient was subsequently transfused without incidence with six group O units of washed red cells prior to splenectomy. Although auto-anti-AI has been previously reported, this is the first case to demonstrate the use of 51Cr survival studies to determine its clinical significance.

Journal Article↗
PubMed1980

Intraoperative hemolysis. The initial manifestation of glucose-6-phosphate dehydrogenase deficiency.

Unexpected intraoperative hemolysis suggestive of a hemolytic transfusion reaction was the initial clinical manifestation of Mediterranean type glucose-6-phosphate dehydrogenase (G-6-PD) deficiency in a 50-year-old Indian man. There was no evidence for immune mediated hemolysis since no unexpected RBC antibodies were found, and results of the direct antiglobulin test remained negative. Analysis of preoperative blood specimens demonstrated complete absence of G-6-PD activity. No etiologic agent clearly associated with G-6-PD hemolysis could be identified. Testing for G-6-PD deficiency should be considered when unexpected hemolysis occurs intraoperatively.

Glucosephosphate Dehydrogenase Deficiency↗
PubMed1980

Delayed hemolytic transfusion reaction presenting as sickle-cell crisis.

Eighteen patients with sickle-cell disease underwent partial exchange transfusion. Three developed delayed hemolytic reactions, with selective disappearance of transfused cells. All reactions occurred within 6 days of transfusion, and patients presented with the clinical features of painful crises. The two most severe reactions were associated with antibodies to Jka. These patients developed fever, arthritis, and a clinical course suggesting serum sickness. In both patients, other alloantibodies had previously been seen. A fourth patient developed multiple alloantibodies, accelerated destruction of tranfused cells, but milder illness. Such reactions may be commoner than in appreciated and should be suspected when patients have recurrent or severe sickle crises after transfusion. Blood that is nonimmunogenic in antigen systems frequently associated with delayed hemolytic reactions (Rh, Kell, Duffy, and Kidd) is preferred for sickle-cell patients who lack these antigens, especially if these patients have previously demonstrated capability to form erythrocyte alloantibodies.

Adolescent↗
PubMed1979

Incompatibility in vitro and in vivo demonstrated only with saline-suspended red cells.

An unusual IgG complement-binding antibody was observed in a 64-year-old man prior to surgery. This antibody was detectable by the indirect antiglobulin test when the red cells were suspended in saline, but not when they were suspended in acid citrate dextrose or albumin solutions. Positive reactions were obtained with the patient's own red cells and with the cells of all donors tested. In vivo chromium survival studies showed that donor cells and patient cells, when suspended in saline, had 1-hour survivals of 32 and 46%, respectively. In contrast, donor and patient cells suspended in ACD solution had 1-hour survivals of 77 and 93%, respectively. We concluded that this phenomenon may casue accelerated destruction of saline-suspended cells and should be suspected whenever in vitro incompatibility is noted with red cells suspended in saline.

ABO Blood-Group System↗
PubMed1978

Partial exchange transfusion as treatment for hemoglobin SC disease in pregnancy.

Serious infarctions and embolic events can complicate the course of pregnant patients with hemoglobin SC disease. In two cases, partial exchange transfusion preceded recovery in severely ill pregnant women with hemoglobin SC disease. There seem to be pathophysiological correlations for the observed clinical findings, and there are potential beneficial effects of partial exchange transfusion. Based on our experience, partial exchange transfusion should be considered as a means of reversing the often fatal complications attending hemoglobin SC disease and pregnancy. The exchange should be of sufficient volume to ensure a postexchange level of hemoglobin A of at least 30%.

Adult↗
PubMed1976

Acute coagulopathy following infusion of prothrombin complex concentrate.

An acute coagulopathy developed in a 49 year old woman with severe liver disease after she received an infusion of prothrombin complex concentrate. The concentrate used in the infusion was subsequently studied by observing the effect of the concentrate on the partial thromboplastin times of various plasmas. The evidence suggests that activated coagulation factors, including activated factor X, were present in the concentrate, and probably played a role in initiating the acute change in the patient's coagulation status. Mechanisms whereby liver disease predisposes toward the development of such a coagulopathy are discussed. It would appear that prothrombin complex concentrates should be used in patients with liver disease only with utmost caution.

Alcoholism↗