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Biomedical subjects

E A Steane

Publications and source records attributed to E A Steane.

At least 19 recordsLinked to original sources
PubMed1994

Safety of the blood supply. Surrogate testing and transmission of hepatitis C in patients after massive transfusion.

OBJECTIVE: To define a risk profile for post-transfusion hepatitis C in patients receiving massive transfusion. SUMMARY BACKGROUND DATA: Hepatitis C accounts for more than 90% of post-transfusion hepatitis. METHODS: Two-hundred twenty-one of 8,765 consecutive trauma admissions to a Level I trauma center received more than 20 units of erythrocytes. Sixty-nine survivors had positive viral serologic tests at least 1 year after transfusion. Surrogate testing for hepatitis C using alanine aminotransferase (ALT) levels and antibodies to hepatitis B core antigen (Core) began in October 1986 and January 1987, respectively. Donor blood for group 1 (pre-ALT/Core) was transfused before surrogate screening was introduced. Donor blood for group 2 (post-ALT/Core) was transfused after surrogate screening. RESULTS: Sixty-nine patients received blood products from 4,987 donors (mean, 72.3 units of exposure). No patient tested positive for antibodies to hepatitis B surface antigen, human immunodeficiency virus, or human T-lymphotrophic virus type 1. However 23.2% tested positive for hepatitis C virus (HCV) as measured by a second-generation enzyme immunoassay (HCV 2.0) and a recombinant immunoblot assay (RIBA), and 21.7% tested positive by HCV 1.0. Antibodies to Core were found in 8.7% of patients. The risk for post-transfusion hepatitis C per unit of exposure is estimated to be 1.52% group 1 (pre-ALT/Core) and 0.239% for group 2 (post-ALT/Core). CONCLUSIONS: The introduction of ALT/Core donor screening by a blood bank reduced the incidence of post-transfusion hepatitis C by 84%. The risk for post-transfusion hepatitis C depends on units of exposure, screening techniques, and prevalence of hepatitis C in the donor population. In our community, the risk for post-transfusion hepatitis C is less than 0.2% per unit of exposure. The population of massively transfused patients may serve as our effective resource for monitoring the safety of the blood supply.

Adult↗
PubMed1982

Therapeutic plasma exchange in the immune hemolytic anemias and immunologic thrombocytopenic purpura.

Thus, plasma exchange appears to have a potential but limited role in the care of antibody mediated injury of red cells or platelets. Its clearest indication appears to be in those uncommon instances of warm antibody mediated hemolysis with a highly fulminant course where the classical therapeutic measures do not have adequate time for effect. Similarly, such therapy appears to have significant potential in cases of acute immunologic thrombocytopenic purpura where some clinical contraindication to steroids, immunosuppressive agents or splenectomy exists. Acute ITP of pregnancy may provide another important setting for such a therapeutic approach. Finally, plasma exchange has been shown to provide temporary clinical stability in cases of chronic cold agglutinin disease.

Acute Disease↗
PubMed1980

Evaluation of methods for quantitating erythrocyte antibodies and description of a new method using horseradish peroxidase-labelled antiglobulin.

Concentrates of anti-D and rabbit anti-human globulin (AHG) prepared by standard elution and ammonium sulphate precipitation methods were labelled with 125I and 131I and horseradish peroxidase (HRP), respectively. The number of anti-D molecules attached per rbc ranged from 12,500 to 21,300 for the various phenotypes studied and the label of D-negative rbc never exceeded 3.4% of these values. With 131I-AHG the uptake by control D-negative cells averaged 13% of the uptake by D-positive cells. It was also found that the average ratio of AHG molecules reacting with each IgG molecule was between 2.6 and 3.3 in free solution regardless of the label but was between 3.4 and 7.5 on rbc and ghosts with 131I-AHG and 3 or lower with HRP-AHG. A colorimetric procedure for quantitating IgG antibodies on rbc ghosts is described using HRP-labelled-AHG and o-dianisidine as the hydrogen donor. The method is very sensitive and useful for the detection of coating antibodies but cannot be used for precise quantitation because about 50% of the IgG molecules on rbc are lost in preparing the ghosts. An AutoAnalyzer method for estimating the number of antibodies attached to red cells is briefly described. Direct measurements of numbers of antigens receptors with radiolabeled specific antibodies gave the most reproducible results. Labelled rabbit AHG was not as good because the ratio of AHG to IgG varied. The AutoAnalyzer method may prove useful because of its convenience.

Antibodies↗
PubMed1975

Use of horseradish peroxidase-labelled antiglobulin for the colorimetric quantitation of erythrocyte antibodies.

Horseradish peroxidase (HRP)-labelled antiglobulin has been used extensively as a histochemical marker. In the method described the stable reaction product formed by using 3,3'-diaminobenzidine (DAB) as the hydrogen donor in the peroxidase reaction was dissolved in a fluoro alcohol, 1,1,1,3,3,3-hexafluoroisopropanol (HPF). Reproducible standardisation curves resulted with HRP. Based on these observations a colorimetric assay procedure was developed to quantitate the amount of antibody coating red cells. This was achieved by treating the coated red blood cells with HRP-labelled rabbit antihuman IgG followed by hypotonic lysis separating the ghosts for colour development with the DAB reagent, solubilisation in HFP, and reading at 450 nm. Preliminary estimates of the number of anti-D molecules on Rhesus positive red cells were found to approximate the results reported using radioiodinated antibodies. The smallest number of anti-D molecules detected was 350 per red cell. Qualitative studies indicate that this procedure can be applied to other blood group systems.

3,3'-Diaminobenzidine↗