Platelet-, leucocyte- and red cell-derived microparticles in stored whole blood, with and without leucofiltration, with and without ionising radiation.

BACKGROUND: Storage lesion, including microparticle formation, has been partially characterised in whole blood, but not in all combinations of pre-storage leucofiltration and/or irradiation. MATERIALS AND METHODS: Single-donor whole blood products were processed into four subunits: with and without leucofiltration, with and without X-irradiation (25 Gy). Platelet-, leucocyte-, and erythrocyte-derived microparticles and free haemoglobin were measured periodically throughout 42 days of storage. RESULTS: Pre-storage leucofiltration substantially reduced platelet- and leucocyte-derived microparticle counts throughout storage. Irradiation, in contrast, had no significant effect on microparticle counts. A gate for all microparticles showed a substantial time-dependent increase in unfiltered whole blood. A time-dependent increase in free haemoglobin was greatest in unfiltered, irradiated whole blood. DISCUSSION: This study indicates that leucofiltration can prevent the formation of leucocyte- and platelet-derived microparticles, and might reduce haemolysis in irradiated whole blood, either by removing factors that provoke haemolysis, or by selective retention of senescent or effete red cells most prone to haemolysis.

Hemolytic disease of the fetus and newborn with late-onset anemia due to anti-M: a case report and review of the Japanese literature.

Hemolytic disease of the fetus and newborn (HDFN) attributed to M/N-incompatibility varies from asymptomatic to lethally hydropic. Case reports are rare, and the clinical significance of anti-M is not completely understood. A challenging case of HDFN due to anti-M prompted an investigation of the Japanese literature, in order to characterize the clinical spectrum of M/N-incompatibility pregnancies in Japan and report results to English-language readers. Japanese reports of HDFN attributed to M/N incompatibility were compiled. Abstracted data include maternal antibody titers at delivery, fetal direct antiglobulin test, hemoglobin, total bilirubin, reticulocyte count at birth, and therapeutic interventions. We investigated characteristics of HDFN due to M/N-incompatible pregnancies in Japan after encountering a case of severe HDFN along with late-onset anemia in an infant born to a woman carrying IgG anti-M with a titer of 1. In total, thirty-three babies with HDFN due to anti-M and one due to anti-N have been reported in Japan since 1975. The median maternal antibody titer was 64 at delivery and was 16 or less in 10 of 34 women (29%). Five of 34 babies (15%) were stillborn or died as neonates. Twenty-one of 29 survivors (72%) had severe hemolytic anemia and/or hydrops fetalis. The reticulocyte count of neonates with anemia stayed below the reference interval. Sixteen (55%) developed late-onset anemia and 14 (48%) were transfused with M-negative RBCs. Significant positive correlation (P < .05) between the hemoglobin value and the reticulocyte count within 4 days of birth was obtained in 16 babies with anti-M HDFN. In the Japanese population, 21 of 34 cases of M/N-incompatible HDFN (72%) have manifested as severe hemolytic anemia and/or hydrops fetalis. Low reticulocyte count in neonates with late-onset anemia is consistent with suppressed erythropoiesis due to anti-M.

Peripheral blood progenitor cell collection by two programs for autologous and allogeneic transplantation.

BACKGROUND: In the Spectra apheresis instrument (Terumo BCT), both manual (Spectra-MNC) and automated (Spectra-Auto) programs have been widely used to collect peripheral blood progenitor cells (PBPCs). However, direct comparison of these programs remains extremely limited. STUDY DESIGN AND METHODS: We investigated 188 collections and products from autologous (patient) and allogeneic (donor) subjects and analyzed a subset of 89 allogeneic collections and products. Twenty-nine subjects who received apheresis for 2 consecutive days using both programs were also evaluated with a paired crossover comparison. RESULTS: The two programs processed similar volumes, but run time was longer with Spectra-Auto. Yield and efficiency of CD34+ cell collection were similar between these programs in the whole cohort, although white blood cell (WBC) and mononuclear cell (MNC) yields were higher with Spectra-MNC. In the allogeneic cohort, yield and efficiency of WBC collection were greater in Spectra-MNC. However, collected WBCs, MNCs, and CD34+ cells were similar between these programs in paired comparison. Regardless of program, preapheresis peripheral WBC, MNC, and CD34+ cell counts correlated with the number of cells collected. In contrast, preapheresis WBC counts in the whole cohort were negatively correlated with collection efficiencies of CD34+ cells in Spectra-MNC but not Spectra-Auto. The products collected using Spectra-MNC contained more contaminating platelets (PLTs) than Spectra-Auto, with a corresponding reduction in postdonation circulating PLTs. CONCLUSION: Spectra-MNC and Spectra-Auto showed distinct features that should be considered on a case-by-case basis. Similar investigations should be undertaken as new collection platforms are introduced.

Microparticle formation in apheresis platelets is not affected by three leukoreduction filters.

BACKGROUND: Microparticles in blood components might contribute to transfusion-related immunomodulation or other side effects. To elucidate the role of leukofiltration, we compared three commercially available filters for their effect on platelet (PLT)-derived (PDMP), leukocyte-derived (LDMP), and red blood cell-derived (RDMP) microparticle formation in apheresis PLTs. STUDY DESIGN AND METHODS: Apheresis PLTs from pairs of ABO-identical male donors were pooled and divided into four volumes. One volume was stored without filtration, whereas the other three were filtered with different devices. PDMPs, LDMPs, and RDMPs were measured by flow cytometry during 2 weeks of controlled-temperature (22°C) agitated storage. RESULTS: On average, PDMPs doubled over 5 days of storage, followed by a much steeper increase by which PDMPs on Day 14 were nearly 20 times higher than on Day 0. LDMP and RDMP counts were relatively stable over 14 days. Significant differences among filtered and nonfiltered products did not emerge. CONCLUSION: Although the conditions of this study showed no favorable or unfavorable effects of three different filters on microparticle formation, surveillance and investigation of unanticipated outcomes in other experimental and clinical circumstances should continue.

Fatal delayed hemolytic transfusion reaction associated with anti-Di(b) and anti-E.

We report the death of a 61-year-old Japanese man massively transfused during and after emergency aortic surgery. Postoperative on day 8, he died after cardiac arrest associated with hyperkalemia. Indirect antiglobulin testing demonstrated both anti-Di(b) and anti-E antibodies pre-transfusion, and elevation of their titers as the delayed hemolytic transfusion reaction evolved. Monocyte monolayer assay (induction of reactive monocytes) and flow cytometry (increase of IgG1 and/or IgG3) gave evidence of the clinical significance of both antibodies. Anti-Di(b) must be considered when an antibody to a high incidence antigen is found in Japanese and other Mongoloid populations.

CD34+ cell enumeration by flow cytometry: a comparison of systems and methodologies.

CONTEXT: An increasing number of medical centers can collect bone marrow, peripheral blood, or umbilical cord stem cells. Pathology laboratories should accommodate this trend, but investment in additional equipment may be impractical. OBJECTIVES: To compare CD34(+) cell counting results by using 2 widely available flow cytometry systems, with and without the use of a separate hematology analyzer (ie, single-platform versus dual-platform methodologies). DESIGN: Whole blood and peripheral blood stem cell (PBSC) samples were analyzed from 13 healthy allogeneic PBSC donors and 46 autologous PBSC donors with various malignancies. The Cytomics FC500 (Beckman Coulter, Fullerton, California) was compared with the FACSCalibur (BD Biosciences, San Jose, California). Dual-platform CD34(+) cell counting incorporated data from a KX-21 hematology analyzer (Sysmex, Kobe, Japan). RESULTS: Subtle differences in CD34(+) cell counting between 2 systems and 2 methods did not achieve statistical significance. CONCLUSION: Different systems and methods for CD34(+) cell enumeration, properly validated, can support care for patients undergoing transplants and provide meaningful data for multicenter studies or meta-analyses.

Increased detection of clinically significant antibodies and decreased incidence of delayed haemolytic transfusion reaction with the indirect antiglobulin test potentiated by polyethylene glycol compared to albumin: a Japanese study.

BACKGROUND: The indirect antiglobulin test (IAT) can be potentiated by agents such as polyethylene glycol (PEG-IAT) and albumin (Alb-IAT). PEG-IAT is generally regarded as superior to Alb-IAT for the detection of clinically significant red blood cell (RBC) antibodies. However, supporting data come from Caucasian-dominant populations. Non-Caucasian populations should be investigated as well. MATERIAL AND METHODS: In this single-centre, retrospective, sequential study, Alb-IAT was used from 1989 to 1996 (8 years) and PEG-IAT from 1997 to 2008 (12 years). Pre-transfusion RBC alloantibody detection rates and specificity, post-transfusion alloantibody production, and the incidence of delayed haemolytic transfusion reaction were assessed and compared for the two periods. RESULTS: Although overall RBC alloantibody detection rates were comparable, PEG-IAT more frequently detected clinically significant antibodies such as anti-E, anti-Fy(b), and anti-Jk(a), and less frequently detected insignificant antibodies such as anti-Le(b) and anti-P(1). New alloantibodies emerged comparably during the two periods. Delayed haemolytic transfusion reaction was less frequent during the PEG-IAT period (0.30% versus 0.12%, p<0.05). CONCLUSION: PEG-IAT was superior in the detection of clinically significant antibodies, reduced the detection of insignificant antibodies, and prevented delayed haemolytic transfusion reaction better than Alb-IAT among Japanese transfusion recipients in this retrospective survey of limited power.

Preventing platelet-derived microparticle formation--and possible side effects-with prestorage leukofiltration of whole blood.

CONTEXT: Platelet-derived microparticles (PDMPs) probably function in hemostasis, thrombosis, inflammation, and transfusion-related immunomodulation. OBJECTIVE: To compare PDMP levels of leukocyte-filtered and unfiltered whole blood during storage. DESIGN: Ten whole blood donations were collected and processed. Half of each collection was filtered, half remained unfiltered, and both halves were measured for red cell, white cell, and platelet (PLT) content before storage. Samples were drawn on days 0, 1, 2, 3, 5, 7, 14, 21, 28, and 35 and analyzed by flow cytometry. RESULTS: Leukocyte filtration lowered prestorage PDMP and PLT counts by an average of 72% and 99%, respectively. Prestorage PDMP counts were 123 +/- 51/microL in unfiltered whole blood supernatant versus 34 +/- 18/microL after filtration. Prestorage PLT counts were 190 +/- 49/microL in unfiltered whole blood supernatant versus 2 +/- 4/microL after filtration. Moreover, PDMP and PLT counts in filtered whole blood remained low throughout storage, typically below 100/microL. In contrast, unfiltered whole blood PDMP- and PLT-gated events increased approximately 2 log during storage, with the peak number of PLT-gated events tending to coincide with the peak number of PDMP-gated events (4 donors) or to come after the peak number of PDMP-gated events (6 donors). CONCLUSIONS: Leukocyte filtration of whole blood lowers prestorage PDMP and PLT counts. Platelet-derived microparticle and PLT counts remain low throughout 35 days of storage. In contrast, PDMP- and PLT-gated events increase significantly in unfiltered whole blood. The nature of PLT-gated events in stored blood warrants further investigation.