Clinical and serological data on 1435 Italian thalassemia major patients were collected during a cooperative study involving 19 centers in 10 regions. The main findings were as follows: 18 percent of the patients were under 6 years of age, 63 percent between 6 and 15, and 19 percent over 15. Forty-one percent had undergone splenectomy. Sixty-two percent of the patients were maintained at pretransfusion hemoglobin levels higher than 10 g per dl, 36 percent between 8 and 10 g per dl, and 2 percent below 8 g per dl. Overall, 5.2 percent of the patients had clinically significant red cell alloantibodies (136 alloantibodies in 74 patients). One-half of the immunized patients had more than one and one-fourth had more than two alloantibodies. The specificities of the 136 alloantibodies were almost exclusively confined to the common antigens of the Rh, Kell, Kidd, and Duffy systems, in that decreasing order of frequency. The antibody screening procedure, using a low-ionic-strength solution antiglobulin test against a three-red-cell panel and the patient's own red cells (autocontrol) with a serum to cell ratio of 100 to 1 was shown to be an adequate technique for red cell antibody detection.
White cell (WBC) reduction, red cell (RBC) recovery, and filtration time were determined in 1-day-old standard and buffy coat-depleted RBCs filtered in the laboratory through six commercial filters for WBC reduction. Residual WBCs were counted with a Bürker chamber (BC), with a Nageotte chamber (NC), and by flow cytometry (FC). Results show that BC counts were 0 in several cases in which WBCs were detected with NC and FC, which indicated that the traditional BC method is too insensitive in use with currently available filters. Calibration curves performed by FC and with NC with samples containing known concentrations of WBCs from 1000 to 1 per microL showed that both FC and NC detected, on average, 67 percent of WBCs present in the samples (efficiency). However, the efficiency of FC showed small variability (61-70%) at different WBC levels, whereas the variability with NC was large (39-91%). This greater variability prevented the correction of NC counts by using a single factor and indicated difficulty in NC standardization. Therefore, because our main aim was to compare different filters rather than to define absolute levels of WBC contamination, uncorrected FC and NC counts were chosen to be reported. True WBC counts per unit should not exceed values that can be obtained by dividing uncorrected counts by the lowest efficiencies (61% for FC and 39% for NC). Uncorrected NC and FC counts were below 2 x 10(6) per unit in all units processed through three of the filters and below 5 x 10(6) per unit in all units processed through the other three.(ABSTRACT TRUNCATED AT 250 WORDS)
The effectiveness of a new filter (RC100) for the preparation of white cell-depleted red cells (RBCs) at the bedside was evaluated in vitro and in vivo using three RBC products: standard RBC concentrate (CPDA units), RBCs suspended in saline-adenine-glucose-mannitol additive solution after the removal of plasma (SAGM units), and RBCs suspended in SAGM after the removal of plasma and buffy coat (SAGM-BC units). Median RBC recovery was at least 92 percent when 2 units were administered through one filter; median values for residual white cells and platelets were less than or equal to 20 x 10(6) and less than or equal to 2.5 x 10(9) per 2 units, respectively. The in vivo study was carried out in 80 multiply transfused patients with thalassemia, 35 of whom had experienced frequent nonhemolytic transfusion reactions when given standard or buffy coat-free RBCs. During the 6-month study, each patient was given two transfusions of each type of RBC product One febrile nonhemolytic transfusion reaction occurred in each of two patients receiving SAGM-BC units, but in no other case. If the flow rate is not reduced, the median transfusion time is 35 minutes per CPDA unit and 15 minutes per SAGM and SAGM-BC unit. It is concluded that the transfusion of RBCs through the RC100 is a simple and effective procedure to administer white cell-depleted RBCs prepared at the bedside.
Although placental blood has recently become a new source of hematopoietic progenitors for marrow replacement, limited attention has been given to systems suitable to ensure the short-term and long-term quality of placental blood units used for transplantation. In this article, we describe a quality system for placental blood banking developed in accord with ISO 9002 norms at Milano Cord Blood Bank. The quality system is the organizational structure, procedures, processes, and resources needed to implement quality management. ISO 9002 is a model for quality assurance in production, installation, and servicing, which includes a number of clauses providing guidance for the implementation of the quality system. The quality system was started by the bank medical director with step 1: the general quality plan, which included (a) the written description of mission, objectives, technical and organizational policies, and staff organization chart of the placental blood bank, (b) the definition and acquisition of adequate financial, human, and structural resources, (c) the appointment of a quality system head independent from the production laboratory and reporting directly to the medical director. Tasks of the quality system head were (a) to identify the placental blood banking process together with the placental blood bank personnel, (b) to implement a documentation plan finalized at the production and maintenance of (i) the quality manual, which provides a summary on how the bank operates with a quality system in compliance with the ISO 9002 clauses, (ii) the general procedures (or quality system procedures), which provide more detail on selected clauses, including at least those prescribed by the ISO 9002 standard, (iii) the operative procedures (or process procedures), which describe in detail the process of placental blood banking and how technical activities must be performed, (iv) the work instructions, which provide stepwise descriptions of individual activities, (v) records/forms for data collection and storage, (c) to identify quality indicators, (d) to start a regular internal audit, (e) to report audit results to the medical director for review. This was followed by step 2: the job descriptions, staff training, and qualification; step 3: the documentation plan; step 4: the internal audit plan; step 5: the launch of the quality system, and step 6: the assessment by an external team from an accredited third-party organization and final certification for compliance to ISO 9002. The quality system, which must be maintained and undergo external audit at regular intervals so that certification is confirmed, ensures the high probability that placental blood units provided to clinicians conform regularly to predefined levels of quality.
Standard packed red cell (PRC) units can be depleted of leukocytes and platelets if they are transfused through a blood administration set in which the usual 170-mu filter has been replaced by a leukocyte removal filter (Sepacell R-500). During a 6-month period, 1550 PRC units were transfused through this filter in 611 transfusions to 80 multitransfused patients with thalassemia who had had a patient reaction rate (PRR) of 63 percent and a transfusion reaction rate (TRR) of 13 percent when given standard PRC or buffy-coat-depleted PRC. When given filtered PRC, PRR and TRR became 3.7 percent and 0.5 percent, respectively. The effectiveness of the filter was also evaluated in vitro. By filtering 2 standard PRC units through the same filter, median values (and ranges) for red cell recovery and for residual leukocytes and platelets were 87 percent (83-92), 6.1 X 10(6) (0-100), and 2.7 X 10(9) (0.6-9.7), respectively. Although refinements are needed to improve standardization of the filter and to increase red cell recovery (which is low when 1 unit is filtered through one filter) and blood administration rate, the ability to provide leukocyte-free red cells prepared at the bedside for virtually all recipients appears to be a realistic goal.
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