The effect of processing method on the in vitro characteristics of red blood cell products

BACKGROUND AND OBJECTIVES

While the clinical impact of differences in red blood cell (RBC) component processing methods is unknown, there are concerns they may be confounding variables in studies such as the ongoing 'age of blood' investigations. Here, we compare the in vitro characteristics of red cell concentrates (RCCs) produced by several different processing methods.

MATERIALS AND METHODS

Nine processing methods were examined: three apheresis methods (Alyx, MCS+ and Trima), as well as leucoreduced whole blood-derived RCCs produced by buffy coat and whole blood filtration and non-leucoreduced RCCs. RCCs were stored in saline-adenine-glucose-mannitol or additive solutions (AS) 1 or 3 for 42 days, with quality tested on day 5 and day 42.

RESULTS

Many significant product differences were observed both early in and at the end of storage. Mean haemoglobin (Hb) ranged from 52 to 71 g/unit and mean Hct from 59·5 to 64·8%. Most RCC passed regulated quality control criteria according to Canadian Standards Association guidelines, although there were some failures relating to Hb content and residual WBC counts.

CONCLUSION

Processing method impacts RCC characteristics throughout storage; better understanding of these differences and reporting of processing method details is critical.

Screening of selected male blood donors for p24 antigen of human immunodeficiency virus type 1. The Transfusion Safety Study Group

BACKGROUND

The p24 antigen of human immunodeficiency virus type 1 (HIV-1) is sometimes detected before antibody (anti-HIV-1) is detectable in the serum of recently infected persons. This has led to the consideration of p24-antigen testing for routine screening of blood donors.

METHODS

To estimate how many HIV-infected seronegative donors would be identified if p24-antigen screening was introduced, we tested selected donations from a repository of 200,000 serum samples from voluntary donors that was established in late 1984 and early 1985. The 8597 serum samples selected for p24-antigen screening were chosen because their donors had demographic characteristics known to be associated with a high prevalence of seropositivity.

RESULTS

The prevalence of anti-HIV-1 antibodies in the 1984-1985 serum samples selected for p24-antigen screening was 1.54 percent--more than 100 times the 0.012 percent prevalence in present-day donations in the United States. The antigen was detected in 15 of 132 serum samples (11.4 percent) from donors who had already been confirmed as seropositive. No instance of confirmed positivity for p24 antigen was found among the 8465 seronegative serum samples.

CONCLUSIONS

These data indicate that the yield of screening for p24 antigen in volunteer donors to identify HIV-1 carriers would be negligible. We therefore recommend against routine screening with currently available p24-antigen assays.

Epidemiologic background of blood donors with antibody to human T-cell lymphotropic virus. Transfusion Safety Study Group

We interviewed 51 blood donors in four major US metropolitan areas subsequently found to have had antibodies to human T-cell lymphotropic virus (anti-HTLV) in late 1984-early 1985. Sixteen donors (31%) reported that they or a sexual contact had a history of blood transfusion. Twelve donors (24%) reported that they or a sexual contact used intravenous drugs. Ten donors (20%) were blacks born in the southeastern US. Four of the male donors (15%) reported homosexual contact. The most common characteristic was an association with Japan or the Caribbean basin (61%). These results show a broader variation of epidemiologic backgrounds than anticipated.

Current autologous transfusion practices. Implications for the future

A questionnaire was distributed to 509 AABB institutional members to evaluate current autologous transfusion practices. Results were returned from 47 blood centers, 108 transfusion services and 64 hospital blood banks (response rate 43%). Results indicate that not all eligible patients are allowed to donate due to unnecessarily strict eligibility criteria. Thirty percent of autologous units are not tested for infectious disease markers. Of those units tested and found positive for anti-HIV or HBsAg, 53 and 72% respectively, of the institutions provide the units to the intended recipient. Forty-seven percent of institutions perform an AHG crossmatch for autologous recipients. Sixty five percent of institutions permit "crossing-over" of autologous units for homologous use. Implications of these findings for the development of standards for autologous transfusion programs are discussed.

Automatic special case consultations in transfusion medicine

In the past, consultations in immunohematology were usually delivered only when there was a blood or component shortage, or when the time required for compatibility testing was prolonged due to the presence of a difficult recipient antibody problem. More recently, transfusion medicine physicians have increased their role as clinical consultants concerned about the appropriate indications for blood transfusion. This communication presents a way to begin a sound program of clinical transfusion medicine consultation. The program can fit with community-wide teaching efforts, community or hospital transfusion audits, and specific physician education programs. Automatic or unsolicited consultations appear to have been both accepted well and beneficial in large hospitals and in communities where they have been provided for more than 7 years.

A study of criteria for blood donor deferral

Donor deferral rates in regional blood centers vary from 5 to 24 per cent, reducing by more than 1,250,000 the number of units of volunteer blood available for transfusion in the nation each year. Those criteria for donor deferral which are intended to exclude donors likely to suffer a "donor reaction" are based partially on untested hypotheses and tradition. In a six-month prospective study, we adopted more liberal criteria for donor acceptance. During this period, donor reaction rates did not increase, and the deferral rate fell from 10 to 7 per cent. Our findings suggest that less restrictive criteria can be used for donor selection without compromising donor safety. If all blood centers reduced their deferral rates to 7 per cent, the nation's blood supply would be increased by more than 500,000 units annually.

Congenital neutropenia: studies of pathogenesis

Congenital neutropenia (CN) was diagnosed in a five-month-old boy. A variety of studies was performed to define the pathogenesis of his disease. Opsonic antineutrophil antibodies wre present in his serum. Transfused normal granulocytes circulated poorly. Incubation of the patient's serum with normal granulocytes failed to alter their metabolic or functional activity. The patient's marrow demonstrated increased numbers of colony-forming units (CFUs) in vitro compared with control marrow. The patient's parents had low marrow CFU activity. The patient's serum and peripheral lymphocytes failed to inhibit normal marrow CFU activity. The patient's marrow did inhibit CFU growth of an HLA-identical-sibling's marrow in coculture. Histocompatibility studies demonstrated the HLA-B12 antigen in this patient, a histocompatibility marker previously associated with CN. These studies suggest some cases of CN are associated with a genetically transmitted marrow factor capable of suppressing myelopoiesis in normal marrow.

ABO compatibility and platelet transfusions of alloimmunized thrombocytopenic patients

With data on 91 alloimmunized thrombocytopenic patients and 389 donor-recipient pairs matched or selectively mismatched for HLA antigens, it was observed that ABO incompatibility significantly reduced the effectiveness of platelet transfusions. The mean 24-hr recovery of platelets from histocompatible donors and from donors selectively mismatched for cross-reactive HLA antigens was decreased by approximately 23% if the donor typed for blood group A and/or B not found in the recipient. Thus, the reduction in platelet recovery associated with ABO incompatibility is not of a magnitude that would contraindicate transfusion of ABO-mismatched platelets.

Survival of transfused normal granulocytes in a patient with chronic granulomatous disease

A 5-year-old boy with chronic granulomatous disease (CGD) received four granulocyte transfusions from unrelated HLA-matched donors as part of therapy for a hepatic abscess. Survival studies of transfused granulocytes using the endotoxin-stimulated nitroblue tetrazolium (NBT) test on two occasions demonstrated 19.6% and 16.8% transfusion efficiency and a biphasic granulocyte disappearance curve. These curves were similar whether or not the patient had serum leukoagglutinins directed against donor granulocytes. Transfused granulocytes were present 24 hours after transfusion. Parallel studies demonstrated normal stimulated NBT activity of donor PMNs after overnight storage at 4 C. Kinetic studies of transfused granulocytes in the non-neutropenic recipient with CGD may be performed without radioactive labeling of granulocytes because of the distinctive metabolic abnormality of their cells compared with normal donor granulocytes.

Biological activities of tritiated endotoxins: correlation of the Limulus lysate assay with rabbit pyrogen and complement-activation assays for endotoxin

Tritiated endotoxins were prepared by three different methods. The biological activities of the tritiated endotoxins were determined by the Limulus amebocyte lysate assay, a rabbit pyrogen assay, and a complement-activation assay and were compared to native, unlabeled endotoxin. All three tritiated endotoxin preparations manifested adequate biological activity in each of the three assay systems, and all three assays ranked the biological activity of the different endotoxin preparations in the same order. Endotoxin tritiated by the Wilzbach procedure retained most of its biological activity and also had the highest specific radioactivity. The good correlation between the Limulus lysate, rabbit pyrogen, and complement-activation assays suggests that the same active site of the endotoxin molecule is identified by the three different assays.

Thrombocytopenia occurring during the administration of heparin. A prospective study in 52 patients

In a group of 52 patients receiving continuous intravenous heparin, 16 developed thrombocytopenia (platelets less than 100 000/mm3). Ten of the 16 patients who had thrombocytopenia had elevated titers of fibrinogen-fibrin degradation products, and five of these 10 patients also had a reduction in plasma fibrinogen. The abnormalities disappeared after the heparin preparation was discontinued. These occurrences could not be attributed to drugs other than heparin, to the dose of heparin administered, or to prior exposure to heparin. The mechanism by which the heparin preparation may induce these changes is not known.

Tritiation of endotoxin

Tritiated endotoxin was synthesized by three different methods: (1) sodium boro[3H]hydride reduction of native endotoxin; (2) sodium boro[3H]hydride reduction of endotoxin that had been oxidized previously with sodium metaperiodate; and (3) exposure of dry endotoxin to 3H2 gas. Sodium borohydride reduces aldehyde groups and sodium metaperiodate oxidizes vicinal glycol groups to aldehydes. Chromatographic analysis of the three tritiated endotoxins, using agarose, revealed that the biological activity associated with each labeled product appeared at the void volume, and in each case the biological activity coincided with a peak in radioactivity. The labeled product of the first method had a specific radioactivity of 0.18 mCi/g and a biological activity equal to that of native endotoxin. The labeled products of the second and third methods had specific activities of 2.1 mCi/g and 60.0 mCi/g, respectively, while their biological activities were one hundred-fold less than native endotoxin, as determined by the Limulus amebocyte lysate assay. These three labeled endotoxins are potentially ueled endotoxin.

Studies on the pathogenesis of fever. XX. Suppression and regeneration of pyrogen-producing capacity of exudate granulocytes

Suppression of the pyrogen-producing capacity of exudate granulocytes results from incubation of the cells in plasma, serum, or Ringer's solution. When transferred in this state and incubated in isotonic NaCl, the cells release much less pyrogen than untreated exudate cells. The suppressive effect is reversible and appears to involve the cellular uptake of calcium ions. In contrast, regeneration of pyrogen-producing capacity in depleted exudate cells occurs only when the cells are incubated in serum. The process resembles activation and requires the cellular synthesis of protein.