An algorithm to locate hrB- donors for individuals with sickle cell disease.

Many African Americans with sickle cell disease (SCD) develop alloantibodies to antigens in the Rh blood group system. Others have shown that from D- individuals, those lacking the high-incidence hrB antigen (> 98% prevalence) may be found among r'r African Americans. We describe an algorithm to locate units for African Americans with SCD and anti-hrB and -D. From 46,539 donations, 5136 listed African American as race. Our primary reference laboratory performed Rh phenotyping (D, C, c, E, e) for first-time donors and those not tested previously. Specimens typing r'r were sent to a secondary reference laboratory for hrB phenotyping after each donation. Hemoglobin S screening was performed. Of 24 donors (27 donations) who phenotyped r'r, seven donors,29.2 percent (nine donations) were hrB-. Two of seven who donated twice consistently tested hrB-. One of 24 donors initially tested hrB-, but hrB+ on repeat donation. The donor tested hrB- by a second reference laboratory. Reagents for phenotyping high-incidence antigens are often not readily available, requiring a specialized reference laboratory that adds cost and turnaround time. Our algorithm selected r'r African American donors most likely to lack hrB for further evaluation by a second reference laboratory. We felt this was the most judicious use of resources and provided the greatest opportunity to find compatible components for individuals with SCD and anti-hrB and -D.

Confirmation of positive antibody screens by solid-phase red cell adherence assay using a tube technique method with polyethylene glycol enhancement.

Our blood bank routinely screens donors for antibodies using a solid-phase red cell adherence (SPRCA) assay. Positive results are then confirmed using a tube technique with polyethylene glycol (PEG) enhancement due to reported higher specificity than with SPRCA. Over a 5-month period, 49,084 donor serum or plasma samples were tested using the SPRCA assay. Further identification of positive samples was performed using a PEG enhancement method. Testing was performed with strict adherence to the manufacturers' inserts. Of 49,084 samples, 313 (0.64%) were positive by the SPRCA assay. Of these, 99 (31.6%) samples remained positive when tested with PEG enhancement. The remaining 214 (68.4%) were negative, giving specificity for the SPRCA assay of 99.6 percent (48,985/ 49,199). We report a high specificity for antibody screening using the SPRCA assay. However, it is cost effective to perform a confirmatory tube test with PEG enhancement because 214 SPRCA assay samples were interpreted as having a negative antibody screen, thus allowing the release of valuable blood components for transfusion.

Hemolysis during leukocyte-reduction filtration of stored red blood cells.

Hemolysis has been reported in red blood cells (RBCs) that have undergone leukocyte-reduction filtration. This study investigated whether the age of RBCs or the filter type affected hemolysis. One hundred eighty units of RBCs (adenine-saline added) were leukocyte-reduced by filtration. At each of the 6 weeks of shelf life, 10 units were filtered with the "BPF4" filter, 10 units with the "Purecell RCQ" filter, and 10 units with the "Sepacell" filter. Filtration was performed with strict adherence to the manufacturers' directions. Pre- and post-filtration samples were assayed for plasma hemoglobin by measuring the plasma absorbances at 578 nm and 562 nm. The increase of plasma hemoglobin concentration following filtration was significantly greater (p < 0.05) in older units, compared to fresher units, when the Sepacell and BPF4 filters were used. For example, the increase of plasma hemoglobin at week 6 (83.47 mg/dl:Sepacell, 128.93 mg/dl BPF4) was significantly greater than at week 1 (7.07 mg/dl Sepacell, 4.77 mg/dl BPF4) (Sepacell: p=0.008; BPF4: p=0.006). For units stored 1, 2, 4, 5, or 6 weeks, the increase of plasma hemoglobin concentration post-filtration was significantly greater with the BPF4 filter, compared to the Purecell RCQ filter (p <0.045); for units stored 5 weeks, the increase in plasma hemoglobin concentration post-filtration was significantly greater with the BPF4 filter compared to the Sepacell filter (p = 0.009). Mean filtration times were significantly longer in older units compared to fresh units. This study shows that increased storage duration of RBCs (adenine-saline added) is attended by greater hemolysis during leukocyte-reduction filtration and by prolongation of the filtration time. In addition, the amount of hemolysis may be influenced by the type of filter.

Rapid preparation of small-volume autologous fibrinogen concentrate and its same day use in bleb leaks after glaucoma filtration surgery.

The authors evaluated small-volume preparation of autologous fibrin glue (AFG) and same day use in postglaucoma filtration surgery patients with Seidel positive bleb leaks and determined fibrinogen concentrations in autologous fibrinogen concentrates (AFCs) from 10 volunteers. Thirty milliliters of blood was centrifuged (5 min, 2400 x g); plasma was frozen (5 min-ethanol and ice), thawed (1-6 C, 30-60 min), and centrifuged (10 min, 5 C, 2800 x g); and the precipitate was transferred to a 1.0-ml tuberculosis syringe. Thrombin (1000 U) was dissolved (0.8 sterile water, 0.2 ml aminocaproic acid) and warmed (37 C). Average preparation time was 90 minutes. Alternating drops of AFC and thrombin were applied to bleb leaks until AFC clotted. Seidel testing with fluorescein determined success. AFC was prepared from 10 volunteers and fibrinogen was measured. AFG was initially successful with two (Seidel negative) eyes; one eye remained negative. AFG was unsuccessful in one briskly Seidel-positive leak. Mean +/- SD fibrinogen concentration in AFCs from the 10 volunteers was 2314 +/- 643 mg/dl (range 1608-3431 mg/dl). AFG may successfully close bleb leaks in outpatient settings. Brisk aqueous flow may impair effectiveness of AFG. Fibrinogen concentrations were comparable with previous reports.

Pulmonary alveolar proteinosis. A report of two cases with diagnostic features in bronchoalveolar lavage specimens.

BACKGROUND: Pulmonary alveolar proteinosis (PAP) is a rare condition that has been associated with myriad diseases and disorders. Alveolar spaces are progressively filled with a phospholipoproteinaceous material, presumably related to a derangement of surfactant production and/or catabolism. The cytologic features of PAP in bronchoalveolar lavage (BAL) sediments are unique, and recognition of these characteristics can help guide clinical intervention. CASES: A 47-year-old male with a history of progressive dyspnea and recent pneumonia presented with a five-lobe alveolar infiltrate and subsequently underwent bronchoscopic examination. A 31-year-old female with chronic myelogenous leukemia in blast transformation developed unresponsive pulmonary infiltrates necessitating bronchoscopy with lavage. Both BAL lavage fluid sediments contained a homogeneous, basophilic, granular material typical of PAP. The material was composed of extracellular, multilamellated bodies when viewed by electron microscopy. Both patients required repeated therapeutic whole lung lavage, and one died of the disease eight months after the diagnosis. CONCLUSION: Clinical presentation, grossly milky BAL fluid and fluid sediment with light microscopic findings of basophilic, periodic acid-Schiff-positive, granular debris with cholesterol crystals and a few alveolar macrophages suggest this process. The light microscopic findings can be confirmed by ultramicroscopic demonstration of extracellular multilamellated bodies. BAL with appropriate examination of the effluent sediment facilitates the diagnosis of PAP.

Fibrin sealant: an evaluation of methods of production and the role of the blood bank.

Blood banks can prepare fibrin sealant by several methods. Allogeneic components allow for banking of the fibrinogen concentrate for immediate use. Autologous components eliminate the risk of transfusion-transmitted disease to the recipient, but not necessarily to the preparer. Ethanol and ammonium sulfate precipitation of fibrinogen concentrate allow use of autologous blood and fast preparation (less than 90 minutes). Cryoprecipitation from liquid plasma is adequate, conserving fresh frozen plasma. Cryoprecipitation by the "freeze-thaw" method has been reported to have the highest fibrinogen yield (7840 mg/dL +/- 1800 mg/dL), whereas ammonium sulfate precipitation has been reported to have the highest bonding strength (41 g/cm2 10 minutes after thrombin addition). Cost, storage, preparation time, and transfusion-transmitted disease all play a role in choice of method.

Evaluation of CAPTURE CMV solid phase testing over the allowable shelf-life of red blood cells (adenine-saline added).

BACKGROUND: CAPTURE CMV (IMMUCOR Inc., Norcross, GA) is a solid-phase screening test used to detect IgM and IgG antibodies to cytomegalovirus (CMV). CAPTURE CMV is licensed for testing whole blood (WB) in citrate phosphate dextrose (CPD) preserved segments of units of red blood cells (RBC) only up to 7 days of storage. We determined if CAPTURE CMV could produce consistent results in CPD preserved WB segments from RBC adenine-saline added (ASA) for their 42 day shelf-life. METHODS: Ten CMV-seropositive and 10 CMV-seronegative RBC (ASA) tested by CAPTURE CMV during the first week of storage were studied. Segments were tested weekly for 6 weeks. RESULTS: All 10 units that initially tested as CMV-seropositive remained strongly seropositive. All 10 units initially CMV-seronegative, remained seronegative. CONCLUSION: CAPTURE CMV testing provides consistent results over the entire shelf-life of RBC (ASA).