Coagulation factor activity in platelet concentrates stored under different condtions was investigated. At both 22 C and 4 C, coagulation factors, II, VII, IX, X, XI, and XII and fibrinogen were well maintained up to 72 hours. Factor V activity declined slightly in platelet concentrates stored at 4 C (to 78% at 72 hours), but fell to 47 per cent activity in platelets stored at 22 C. Factor VIII activity declined to approximately 68 per cent of normal activity by 72 hours at both 22 C and 4 C. Agitation did not make a difference in levels of coagulation factors. While the decline in Factor V was clearly more pronounced in platelet concentrates than in platelet-poor plasma from the same units, the decline in Factor VIII was decreased by the presence of platelets. Platelet concentrates are a source of coagulation factor activity which should be considered in a component program.

Blood Coagulation Factors↗

PubMedDate not supplied

Size distribution measurements of microaggregates in stored blood.

Microaggregates in various blood preparations were studied, before and after filtration, using an optical scattering (laser) technique which measures number density and size of aggregates in flowing blood. These measurements were comparable to screen filtration pressures. In all blood units, storage increased aggregates in the 20 to 170-microns range. Whole blood and red blood cells were comparable, while removal of leukocytes and platelets by an inverted spin technique essentially prevented formation of aggregates in all size ranges. Platelet-depleted units of whole blood also reduced aggregates. Removal of cryoprecipitate did not significantly affect aggregate size distribution; however, blood modified by both platelet and cryoprecipitate removal reduced aggregates. Commercially available microfilters reduced aggregates initially, but some increase ("shedding") occurred with continued use. The optical scattering technique did not require the dilution or red blood cell lysis needed in other techniques. Therefore, this method has potential for aggregate detection in in vivo flowing blood.

Blood Platelets↗

PubMedDate not supplied

Lack of adverse effect of transportation on room temperature stored platelet concentrates.

The ability of platelet concentrates stored at room temperature to withstand transportation after removal from the rotator and ideal temperature environment was studied by reinfusing autologous 51Cr-labeled platelets obtained from normal volunteers. Periods of up to 6 hours off the rotator and not under temperature control did not result in a significant change in platelet viability. Platelets transported up to 12 hours after 24 hours of storage and then placed on a rotator for the remainder of the 72-hour storage interval also showed expected recovery and survival. Thus, room temperature stored platelets may be used even when transportation for up to 6 hours is required before the concentrates are transfused.

Blood Platelets↗

PubMedDate not supplied

Extension of platelet concentrate storage.

Extension of the storage time of platelet concentrates in a satellite bag which is part of a new blood bag system was studied by reinfusing autologous 51Cr-labeled platelets into normal volunteers, and measuring postinfusion platelet counts and bleeding times in patients requiring platelet transfusions. This satellite bag, made of polyvinylchloride plasticized with a new agent, was found to protect platelet concentrates against fall of pH better than other containers studied. This protection was felt to be due to the greater gas permeability of the new plastic. Mean in vivo recovery and half-life (greater than 31% and 3.3 days, respectively) of autologous reinfused platelets were satisfactory following 5 days of storage. Following 7 days of storage, mean recovery was 41 percent and half-life was 2.8 days. Peripheral platelet count increments in patients following platelet transfusions with concentrates stored 4 to 7 days in the new plastic were comparable to increments following transfusion of platelets stored 2 to 3 days in the other plastics studied. Bleeding times shortened in three of four patients receiving platelet concentrates stored from 4 to 6 days in the new plastic. Platelet concentrates stored in the new bag at 20 to 24 degrees C with flat-bed or elliptical agitation could be transfused for up to 5 days following phlebotomy with acceptable clinical results. The new plastic container is promising for storage of platelet concentrates for up to 7 days. Due to the higher pH of 50-ml platelet concentrates stored in bags made with the new plastic, the concentrates were superior at any storage interval to those stored in bags made of the other plastics studied.

Blood Coagulation Tests↗

PubMedDate not supplied

The effect of obstruction of bag surface on platelet concentrate pH.

Platelet concentrates stored in bags (made of a plastic film incorporating a new plasticizer) on flat-bed agitators for up to 5 days were found to have accelerated pH decline when the surface of the bag was obstructed with added labels and an invoice on the non-labeled side. Without the over-labeling and invoice, only one of 20 concentrates had a pH below 6.0, even at very high concentrations of platelets. Blood banks experiencing problems with pH decline in the platelet concentrates being stored up to 5 days should consider eliminating surface obstruction on the bag.

Blood Glucose↗

PubMedDate not supplied

Concentration of platelet units into small volumes.

To determine the best procedure for concentrating platelets in a smaller volume after storage, we studied platelet loss after concentration at various centrifugation g forces for various times. In vitro studies demonstrated the need to let platelets sit for 1 hour prior to resuspension by gentle kneading. 500 X g gave unacceptable results. Losses were minimal at 1500 X g for 7 minutes, 2000 X g for 10 minutes and 5000 X g for 6 minutes. Reinfusion of 51 Cr-labeled platelets into normal volunteers after concentration at both 2000 X g for 10 minutes and 5000 X g for 6 minutes showed normal viability. Numbers and viability of platelets stored up to 5 days in 50 ml plasma and then concentrated in 10 ml plasma after centrifugation at 1500 X g for 7 minutes, 2000 X g for 10 minutes or 5000 X g for 6 minutes should be clinically acceptable.

Blood Platelets↗

PubMedDate not supplied

A pilot study of surrogate tests to prevent transmission of acquired immune deficiency syndrome by transfusion.

Because of reports that acquired immune deficiency syndrome (AIDS) might be transmissible by blood transfusion, we studied potential surrogate tests that could be used for screening donors. Male donors at one volunteer blood center and two plasma centers were screened for total lymphocyte count, OKT3, OKT4, OKT8, OKT11, LEU-7, LEU-M2, antibodies to hepatitis B core (anti-HBc), cytomegalovirus (CMV), and herpes and circulating immune complexes. Total lymphocyte counts and the OKT11 were significantly lower in one plasma center. No significant differences were found for the other lymphocyte or monocyte tests. Low T4/T8 ratios, found in 20 percent of donors, did not correlate with other abnormalities. A small percentage (3.3%) of volunteer donors, 15.4 percent at one plasma center and 20.8 percent at a second plasma center, and 38.5 percent of the male homosexual donors were positive for anti-HBc (significant when comparing the male homosexuals to the volunteers at p = 0.032). Positive CMV and herpes titers were similar in the groups. Circulating immune complex levels greater than two standard deviations above the mean were found in 20 percent of the volunteer donors, 7.7 percent at one plasma center and 8.3 percent at the second plasma center, and none in the male homosexual population. Pearson product moment correlations showed reasonably good agreement among the lymphocyte tests. However, the anti-HBc, CMV, and herpes antibodies and circulating immune complex levels did not correlate with any of the other tests. Surrogate tests for AIDS are nonspecific and unlikely to be helpful in screening blood donor units.

Acquired Immunodeficiency Syndrome↗

PubMedDate not supplied

Iron supplementation for menstruating female blood donors.

Depletion of body iron stores is a major factor limiting regular blood donations by menstruating females. To determine if regular iron supplementation would solve this problem, we conducted a double-blind study in which menstruating female donors were randomly placed into one of three groups: one taking 39 mg elemental iron, a second taking 39 mg of iron plus 75 mg vitamin C, and a third taking 100 mg vitamin C daily. The women were requested to donate every 8 weeks for at least 1 year. Blood samples were taken on each donation for measurements of hemoglobin, total iron binding capacity (TIBC), and ferritin. In the two groups taking iron supplements hemoglobin and ferritin increased from baseline values and the TIBC decreased. The vitamin C control group showed decreases from baseline for hemoglobin and ferritin and increases in TIBC. Differences between groups taking iron supplements and the group not taking supplements were highly significant. Drop-out from the study was due to various causes; however, iron intolerance was uncommon. Minimal daily iron supplementation was beneficial in maintaining body iron stores and hemoglobin levels in menstruating females on a schedule of blood donation as often as every 8 weeks.

Adolescent↗

PubMedDate not supplied

Lymphocytaplasmapheresis in Devic's syndrome.

A pregnant 26-year-old woman with Devic's syndrome manifesting as paraplegia and visual loss was treated with multiple courses of lymphocytaplasmapheresis. Clinical improvement was temporally related to the lymphocytaplasmapheresis. She relapsed when treatment was stopped and improved with reinstitution of therapy. Thereafter, further treatments were not required and she delivered a normal infant.

Adult↗

PubMedDate not supplied

Use of radioisotopically-labeled platelets to determine the survival properties of stored platelets. An overview of the present status.

Explore the source record for details and available documents.

Blood Platelets↗

PubMedDate not supplied

Efficacy of plasma exchange in severe idiopathic rapidly progressive glomerulonephritis. A report of ten cases.

The vast majority of patients with idiopathic rapidly progressive glomerulonephritis (RPGN) develop irreversible renal failure within weeks to months. We report a retrospective study of 10 patients with idiopathic RPGN who were treated with plasma exchange in addition to steroids and immunosuppression. Renal biopsies were obtained in nine patients. RPGN without immune complexes was present in four, immune complex disease in four, and anti-glomerular basement membrane disease in two. Renal function did not recover in those patients with anti-glomerular basement membrane disease. In contrast, seven of eight patients without auto-antibodies to basement membranes responded to therapy, and four did not need dialysis for two years or more. The sustained improvement in renal function in these seven patients suggests the need for evaluation of plasma exchange as an adjunct to steroids and immunosuppression in a prospective, controlled study in RPGN.

Acute Disease↗

PubMedDate not supplied

Extension of platelet concentrate storage to 7 days in second-generation bags.

Platelet concentrates stored for 7 days in 50 ml of plasma in both thin film and enlarged variations of the standard 5-day CLX plastic bags were evaluated for pH maintenance and in vivo viability by two laboratories working independently. 51Cr-labeled platelets were reinfused into normal volunteers at the end of storage and recovery and half-life calculated. The pH was maintained well; less than 10 percent of units fell below 6.0 at 7 days. Mean 7-day recovery for both laboratories was 43.6 +/- 11.6 percent in the thin-film bag and 45.4 +/- 8.52 percent in the enlarged bag, compared with 43.6 +/- 8.8 percent at 5 days in the 5-day plastic licensed bag. After 7 days storage the half-life was 3.6 +/- 0.9 days in the thin-film bag and 3.7 +/- 0.6 days in the enlarged bag, compared with 3.6 +/- 0.5 days in the previously licensed CLX plastic bag after 5 days. Thus, platelet viability was maintained well at 7 days of storage in both of the container variations that allowed increased gas exchange.

Blood Platelets↗