Exposure of cryptantigens on red blood cell membranes in patients with acquired immune deficiency syndrome or AIDS-related complex.

Patients with acquired immune deficiency syndrome (AIDS) or AIDS-related complex (ARC) are subject to recurrent and severe infections due to organisms known to cause red blood cell membrane modifications. These red cell modifications include the exposure of novel carbohydrate cryptantigens that can react with naturally occurring antibodies and potentially result in hemolysis. We examined the frequency of cryptantigen exposure on the surface of red cells from AIDS/ARC patients. Blood samples from 108 patients with AIDS/ARC and from 65 non-AIDS/ARC patients were tested for most common forms of cryptantigens. The lectin Arachis hypogaea agglutinated red cells from 7% (8/108) of the AIDS/ARC patients and 3% (2/65) of non-AIDS/ARC patients, indicating the presence of T, Tk, or Th cryptantigen exposure. One sample from an AIDS patient with E. coli sepsis had T activation with polyagglutinable red cells. None of the samples showed evidence of exposed Tn or acquired B antigens. These results show that red cell cryptantigen exposure does occur in AIDS patients with a prevalence similar to that previously reported in patients with sepsis or malignancy. For this reason, and because polyagglutination has been associated with in vivo hemolysis, cryptantigen exposure should be considered in the differential diagnosis in AIDS patients with suspected immune hemolysis; it can be tested for by performing a minor crossmatch with ABO compatible serum.

Prospects for control of hepatitis B virus infection: implications of childhood vaccination and long-term protection.

Hepatitis B vaccine has been recommended for high-risk individuals in the United States for more than a decade. This targeted strategy, however, has failed to control hepatitis B virus (HBV) infection. Universal immunization is being considered as an alternative approach, in particular the inclusion of hepatitis B vaccine with routine childhood vaccinations. Data presented herein demonstrate a high degree of efficacy for hepatitis vaccine with hepatitis B immune globulin in preventing perinatal HBV infection in newborns. Immune response to vaccine was dependent in part on the dose administered, with some enhancement of response if the infant was older at the time of initial injection or if the booster dose was given later. Long-term follow-up showed persistence of vaccine-induced antibody for 5 to 10 years in 90% of immunized infants and adults. Only 3% to 5% of these high-risk individuals had serologic evidence of an HBV infection. None of the infections had been symptomatic and none resulted in a chronic HBV carrier state. Thus, immune responses and efficacy of hepatitis B vaccine in infants were excellent, and immunity and protection against clinically significant HBV infection persisted for at least 5 to 10 years, features essential to success of a program of universal childhood immunization against HBV.

Laboratory hemostatic abnormalities in massively transfused patients given red blood cells and crystalloid.

Most of the literature on massive transfusion concerns whole blood replacement, whereas clinically, packed red blood cells are commonly given. To determine when hemostatic abnormalities occur in patients resuscitated primarily with packed red blood cells and crystalloid, the cases of 39 consecutive patients who were transfused with 10 or more red blood cell units of any kind within 24 hours were reviewed. After transfusion with 20 or more units of red blood cell products of any kind (packed red blood cells, cell-saver units, or whole blood), 75% (3 of 4) of patients had platelet counts less than 50 x 10(9)/L, compared to 0 of 29 patients given less than 20 units (P less than 0.001). After transfusion of 12 units of relatively plasma-free red blood cell products (packed red blood cells or cell-saver units), 100% (8 of 8) of patients had prothrombin time prolonged by more than 1.5 times mid-range of normal, compared to 36% (5 of 14) of patients given less than 12 units (P = 0.012). These data confirm that patients massively transfused with red blood cells of any kind develop significant thrombocytopenia after 20 units. Importantly, probably clinically significant prothrombin time and partial thromboplastin time prolongations occurred consistently after transfusion of 12 units of relatively plasma-free red blood cells in unselected patients at an urban trauma hospital. These data suggest that coagulation factor replacement is necessary in patients who receive 12 or more units of packed red blood cells or cell-saver blood, and platelet replacement is necessary in patients who receive 20 or more units of any red blood cell product. A prospective study is needed to determine whether the expected abnormal clinical bleeding indeed occurs in patients with such laboratory coagulation abnormalities and to determine when plasma transfusion is indicated in patients massively transfused with red blood cells.

Simplified method for recovery of autologous red blood cells from transfused patients.

Separation of autologous and transfused red blood cells from recently transfused patients is necessary for the proper identification of any red blood cell alloantibody or autoantibody. We compared two methods of separation: the standard technic of microhematocrit centrifugation with phthalate ester solution, and a simplified method of microhematocrit centrifugation without the use of esters. Autologous red blood cells were concentrated in the top layer of the capillary tube by both methods. Separation efficacy was comparable, as determined by blood group antigen reactivity. Good separation was achieved only in samples drawn three or more days post transfusion. Microhematocrit centrifugation without the use of phthalate esters is a simple method for the recovery of autologous red blood cells from recently transfused patients that can be performed by any standard clinical laboratory.

Lack of increased bleeding after liver biopsy in patients with mild hemostatic abnormalities.

Prophylactic transfusions of fresh frozen plasma and platelets are sometimes given to patients with mild elevations in prothrombin time (PT) and partial thromboplastin time (PTT) and mild thrombocytopenia before percutaneous liver biopsy. To determine whether PTs and PTTs 1.1-1.5 times midrange normal levels and platelet counts 50-99 x 10(9)/L are associated with increased bleeding complications, hospital records of all patients who underwent percutaneous liver biopsy during 56 consecutive months (n = 291) were reviewed. Complete information was available for 177 inpatient procedures (155 standard, 22 fine needle). Overall, the frequency of bleeding complications in patients with platelet counts greater than or equal to 50 X 10(9)/L was 3.4% (6 of 175), with no significant difference between patients with mild hemostatic abnormalities and patients with normal parameters. These data suggest that prophylactic transfusions may not be necessary. One factor was highly associated with bleeding complications: a patient diagnosis of malignancy, 14% (7 of 50) compared with 0.8% (1 of 127) among other patients (P less than 0.001). These patients should be monitored closely after biopsy.

Factors associated with successful autologous blood donation for elective surgery.

Not all donors can donate the number of autologous blood units requested by their physicians before surgery, and donors are more frequently unsuccessful as more units are requested. Therefore, 368 autologous blood donors who were requested to donate 4 or more units during the 6-week period before surgery at one community blood center were studied. More men were able to donate 4 units with no deferrals for anemia than were women (86% [181 of 211] compared to 42% [48 of 115], P less than 0.001). Greater success also was observed among donors with an initial hemoglobin level greater than 125 g/L (12.5 g/dL), those with higher weight, and those with more advanced age. Multiple logistic regression analysis showed that only higher initial hemoglobin levels (odds ratio, 3.3 per 10 g/L [1 g/dL] increment) and male sex (odds ratio, 2.7) were independent predictors of successful donation of 4 or more units.

Agglutination of an EDTA blood sample caused by an EDTA-dependent panagglutinin.

A novel example of an EDTA-dependent panagglutinin is described. A blood sample drawn into EDTA for a routine hematologic workup demonstrated strong agglutination due to EDTA-dependent panagglutinins. Previous examples have been detected because of discrepant ABO results. This is the first report of an EDTA-dependent panagglutinin that caused agglutination in the EDTA sample collection tube and a false positive direct antiglobulin test.

Physician recommendation as the key factor in patients' decisions to participate in preoperative autologous blood donation programs: Preoperative Autologous Blood Donation Study Group.

To determine whether the physician or patient had initiated the discussion regarding preoperative autologous blood donation (PABD) and to assess the relative importance of the physician's recommendation in patients' decision to donate, responses were obtained from 254 of 409 patients (62%) who had donated preoperatively during the 3 study months. Nearly all (96%) strongly agreed they would donate again for themselves and nearly all (94%) strongly agreed they would recommend PABD to others. Patients initiated the discussion about PABD 23% of the time, while 71% indicated strong surgeon input. The remaining respondents said their surgeon had "mentioned it, but said it was up to me." The importance of avoiding transfusion reactions was rated significantly greater among those whose surgeons had initiated the discussion, as was the relative weight of the surgeon's recommendation. The desire to alleviate the blood shortage was rated much less important among patients who had initiated the discussion themselves.

Underutilization of autologous blood donation among eligible elective surgical patients.

In January 1983, blood banks encouraged the use of autologous blood for transfusion in elective surgical patients due to the advent of transfusion-associated AIDS. Since autologous blood does not transmit hepatitis and other viruses and does not cause alloimmunization, it should be utilized whenever possible. To determine whether patients eligible to predeposit autologous blood before elective operation were actually doing so, we studied patients at three hospitals between January 1 and June 30, 1985. Patients considered eligible for autologous predeposit blood donation were adults with preoperative hemoglobin levels of 11 g/dl or more who underwent elective surgical procedures for which blood transfusion was anticipated. Excluded were patients undergoing cardiovascular, intracranial, or renal transplant procedures. Of eligible patients, only 11 percent (32 of 278) predeposited blood; of these, 81 percent (26 of 32) were transfused with only autologous blood. Among eligible patients who did not predeposit blood, all could have benefited from predepositing because transfusion was likely for the procedure. Of those who did not predeposit, 33 percent (83 of 246) received homologous blood and therefore would have benefited from autologous donation. We conclude that autologous donations are underutilized for medically eligible patients undergoing elective operation.

Effectiveness of transfusion audits and practice guidelines.

To seek evidence of the effectiveness of transfusion audits and practice guidelines in improving transfusion practice, transfusion audit literature was reviewed. The inherent limitation of this approach is that investigators are more likely to report success and less likely to report unsuccessful experiences. Measures of success included decrease in units transfused, decrease in inappropriate units transfused, or increase in appropriate transfusion practice. Side benefits of audits included continuous improvement in practice guidelines, improvement in technologists' education, opportunities for consultation, and identification of areas for further research. Most successful programs had a common thread: individual education of the ordering physician by the transfusion medicine physician. In addition, for most successful programs, audits occurred in a timely manner, either before transfusion or during the 24 hours or weekend after the transfusion. In conclusion, several reports provide corroborating evidence to suggest that transfusion audits can improve transfusion practice if performed in a timely manner and if individual education of ordering physicians is provided by transfusion medicine physicians.

Audit and education in transfusion medicine.

Because transfusions carry risks to the patient and because inappropriate transfusions are costly, interest in audits and effective education in transfusion medicine has increased over the last decade. Audits identify areas of practice that can be improved by follow-up education of the physicians who prescribe the transfusions. Successful educational approaches to follow-up on problems identified by audit include 30-min one-on-one meetings with surgeons, traditional scheduled teaching conferences, daily clinical rounds on transfused patients, prospective review of blood transfusions and installation of transfusion practice algorithms in the operating room. Other than identifying inappropriate transfusions, audit and education have also been used successfully to improve bedside blood administration practices, decrease unnecessary crossmatches and reduce outdating of donor blood. Multi-institutional audits play a useful benchmarking role. In summary, audit followed by targeted education can improve practices in transfusion medicine.

Lack of increased bleeding after paracentesis and thoracentesis in patients with mild coagulation abnormalities.

To determine whether untreated mild coagulopathy in patients with no evidence of clinical bleeding is associated with an increased risk of hemorrhage after paracentesis or thoracentesis, retrospective examination was conducted of 608 consecutive procedures for which prothrombin time (PT), partial thromboplastin time (PTT), platelet (Plt) counts, and preprocedure and postprocedure hemoglobin concentrations were available. There was no increased bleeding in patients with mild to moderate coagulopathy (defined as PT or PTT up to twice the midpoint normal range or pit count of 50 to 99 x 10(3) per microL [50-99 x 10(9)/L]). However, patients with markedly elevated serum creatinine levels (6.0 to 14.0 mg/dL [530-1240 mumol/L]) had a significantly greater average hemoglobin loss (-0.82 +/- 1.3 g/dL [-8 +/- 13 g/L], n = 11) than patients with normal serum creatinine levels (-0.12 +/- 0.88 g/dL [-1 +/- 9 g/L], n = 450) (p = 0.011). Overall, the frequency of bleeding complications requiring red cell transfusions was very low: 0.2 percent of events. The most common diagnosis for patients who had paracentesis was alcoholic liver disease (72%); for those having thoracentesis, it was infection (37%). It can be concluded that, for these patients, prophylactic plasma or platelet transfusions are not necessary. Patients with markedly elevated serum creatinine deserve close postprocedure observation.

Occlusive impedance plethysmography. A noninvasive method of diagnosis of proximal deep vein thrombosis.

The purpose of this study was to assess and confirm the accuracy of impedance plethysmography (IPG) by the occlusive cuff method, in detecting proximal (popliteal, femoral and iliac) deep vein thrombosis in patients with symptomatic limbs. In 27 patients 30 consecutive limbs were studied with concurrent venography and IPG. The IPG result was normal in 9 of 9 limbs which were normal on venography, and abnormal in 15 of 16 limbs which showed venographic evidence of proximal deep vein thrombosis (DVT). An abnormal IPG strongly suggests proximal DVT (predictive value 0.88). A normal IPG virtually rules out proximal DVT (predictive value 1.0).

Use of preserved autologous red blood cells to absorb warm autoantibodies from the serum of patients receiving blood transfusion therapy.

This paper describes two practical methods for the preservation of pretransfusion patient red blood cells for antigen typing and autoabsorption during a course of transfusion therapy. Blood samples from patients who had serum warm autoantibodies and a positive direct antiglobulin test were collected, the serum frozen, and the red cell aliquots separately preserved by PVP-methanol or formaldehyde fixation. After storage and recovery, the IgG antibodies were dissociated and the cells used for absorption of the warm autoantibodies. The preserved red cells removed the warm autoantibodies as effectively as fresh red blood cells from the same patient. Preservation of autologous red cells prior to the onset of transfusion therapy provides an extension of the autoabsorption procedure and a simple alternative to differential absorption.

The variability of transfusion practice in coronary artery bypass surgery. Transfusion Medicine Academic Award Group.

We audited 540 patients undergoing elective first-time coronary artery bypass grafts at 18 institutions. The purposes of the study were to describe the variability in transfusions among institutions and to determine factors that may account for variability. Mean homologous red blood cell use per patient was 2.9(+/- 0.1) U (institutional range, 0.4 to 6.3 U). One hundred seventy-seven patients (32%) received plasma (institutional range, 0% to 97%), and 119 (22%) received platelets (institutional range, 0% to 80%). After controlling for patient and surgical practice variables, transfusion practice factors still accounted for variation in red blood cell transfusions. Variation in patients receiving plasma and platelet transfusions among institutions was determined in part by prophylactic transfusions. We conclude that blood component usage for coronary artery bypass grafts differs widely among institutions. The variability in use of these components is accounted for in part by unnecessary transfusions in otherwise routine, uncomplicated coronary artery bypass graft procedures.

Return of autologous blood donors as homologous blood donors.

Autologous blood donors (ABDs) have been reported to have favorable attitudes toward returning as homologous blood donors (HBDs), but the frequency of return has not been well documented. ABDs eligible by history to be HBDs were followed at one blood center: 255 donating for elective surgery and 234 donating during pregnancy were followed for an average of 18 months and 20 months, respectively, from time of eligibility after surgery or postpartum. Male ABDs had a higher rate of return as HBDs, as 34 percent (21/62) returned to donate an average of 3 units, whereas 13 percent (56/427) of female ABDs returned as HBDs to donate an average of 2 units. Although a history of donation was associated with a higher rate of return (30%, 34/113), 11 percent (43/376) of ABDs with no history as HBDs returned to donate homologous units, despite having been recruited less frequently than prior HBDs. Overall, all male ABDs and female ABDs with an HBD history returned most frequently. The extra effort required for an autologous donor program may result in the recruitment of new donors into the HBD pool.

Oxygen-induced marrow red cell hypoplasia leading to transfusion in sickle painful crisis.

The benefit of oxygen (O2) therapy in non-hypoxic sickle cell patients in painful crisis is uncertain. We report a case of a non-hypoxic sickle cell patient in painful crisis who developed marrow red cell hypoplasia requiring transfusion support after O2 therapy. The uncertain benefits of O2 use in such cases must be weighed against the serious and underrecognized risks of transfusion. In patients who develop O2-induced marrow red cell hypoplasia, cessation of O2 therapy may reverse the anemia and obviate the need for transfusion.