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Biomedical subjects

A Humpe

Publications and source records attributed to A Humpe.

At least 19 recordsLinked to original sources
PubMed2006

Successful autologous stem cell transplantation in a severely immunocompromised patient with relapsed AIDS-related B-cell lymphoma.

There is now evidence that the tolerability and response to systemic chemotherapy in HIV-infected patients with AIDS-related lymphoma (ARL) is significantly improved by highly active antiretroviral therapy. Here we report an severely immunocompromised AIDS patient with recurrent ARL who was successfully treated with autologous stem cell transplantation (ASCT). We also review the current literature of ASCT in HIV-infected patients.

Adult↗
PubMed2006

Proliferation-based T-cell selection for immunotherapy and graft-versus-host-disease prophylaxis in the context of bone marrow transplantation.

Graft-versus-host disease (GvHD) caused by alloreactive T cells within the graft is a major drawback of allogeneic BMT, but depletion of T cells leads to higher rates of relapse, opportunistic infections and graft failure. Therefore, selective removal of GvHD-inducing alloreactive T cells might be beneficial. We describe here the separation of alloresponsive T cells, based on carboxyfluorescein succimidyl ester labeling, in vitro allostimulation and FACS-sorting. In vivo effects of the separated cell populations were investigated in the context of allogeneic BMT in murine models: in vitro resting T cells were shown to survive in the allogeneic host and retain immunoreactivity against 'third-party' antigens. As demonstrated in two different transplantation models, elimination of proliferating cells significantly reduces GvHD but offers no advantages to using T-cell-depleted bone marrow alone concerning engraftment and tumor control. Transplanting T cells that proliferate in response to tumor antigens in vitro may narrow down the spectrum of antigens recognized by T cells and therefore reduce GvHD while maintaining graft-facilitating function and tumor control. Therefore, selecting tumor-reactive T cells on the basis of their proliferative response in vitro may be beneficial for the recipient, less time consuming than T-cell cloning and still reduce the extent of GvHD.

Animals↗
PubMed2005

Myelodysplastic syndrome of donor origin subsequent to successful treatment of myeloid/NK-cell precursor leukaemia with allogeneic PBSCT: two very rare conditions in one patient.

We report a 36-year-old male with myeloid/natural killer (NK)-cell precursor acute leukaemia with a complex aberrant karyotype, who was treated according to an acute-myeloid-leukaemia (AML) treatment protocol (idarubicine, cytarabine, and etoposide) followed by high-dose cytarabine consolidation and achieved complete remission. He underwent allogeneic matched unrelated donor (MUD) peripheral blood stem-cell transplantation (PBSCT) and remained in remission throughout his remaining life. Seven months posttransplantation, a myelodysplastic syndrome (MDS) with (20q-) of donor origin was diagnosed causing severe thrombocytopenia and finally leading to infection and death. This patient represents one of the few cases published achieving remission for a significant period of time after being diagnosed with myeloid/NK-cell precursor acute leukaemia, a very rare malignant disease. We conclude, despite the fatal outcome due to infection, that allogeneic PBSCT is a therapeutic option for patients with this entity. In addition, the development of a myelodysplastic syndrome of donor origin is extremely rare and only very few cases are published worldwide.

Acute Disease↗
PubMed2001

Prospective, randomized, sequential, crossover trial of large-volume vs. normal-volume leukapheresis procedures: effects on subpopulations of CD34(+) cells.

Some data exist on the influence of leukapheresis volume on the number of harvested peripheral blood hematopoietic progenitor cells (HPC), but less is known about the influence on the composition of HPC. We therefore performed a prospective, randomized crossover trial to evaluate the effect of large-volume (LVL) vs. normal-volume leukapheresis (NVL) on subpopulations of CD34(+) cells in the harvest product of 15 patients with breast cancer and 8 patients with non-Hodgkin's lymphoma. Patients were randomly assigned to start either with an LVL on day 1 followed by an NVL on day 2 or vice versa. The number of HPC, the extraction efficiency defined as difference between yield in the harvest and decrease in peripheral blood, and the relative proportion as well as the absolute numbers of CD34(+) cells coexpressing CD38, CD90, HLA-DR, CD117, CD7, CD19, CD41, or CD33 were evaluated. There was no significant difference with regard to the percentages of the subsets on comparison of LVL to NVL procedures. Only the absolute median number of CD34(+)HLA-DR(-) cells was significantly (P=0.02) higher in LVL harvests compared with the corresponding NVL components, which can be explained on the basis of the higher yield and the higher extraction efficiency in LVL compared with NVL. LVL results in a higher yield of CD34(+) cells and leads to an intra-apheresis recruitment of HPC but the relative composition of the harvested CD34(+) cells is not changed significantly. In addition, the amount of early, HLA-DR(-), hematopoietic HPC seems to be increased by an LVL.

Adult↗
PubMed2001

Successful transplantation and engraftment of peripheral blood stem cells after cryopreservation, positive and negative purging procedures, and a second cryopreservation cycle.

Transplantation of peripheral blood stem cells (PBSC), positively and/or negatively selected immediately after harvest, has become a widely applied therapeutic option in hematological or oncological patients. The following case of peripheral blood stem cell transplantation represents the first case of successful transplantation of PBSC, cryopreserved twice and purged after cryopreservation. PBSC were harvested in a 44-year-old female patient with a low-grade non-Hodgkin's lymphoma stage IV after mobilization with chemotherapy and G-CSF. A total number of 15.2 x 10(6) CD34+ cells/kg bodyweight was harvested with a 36.9% contamination of tumor cells coexpressing CD5 and CD20. After subsequent chemotherapy cycles and cyclophosphamide mobilization, only 0.77 x 10(6) CD34+ cells/kg bodyweight, not sufficient for transplantation, were achieved after positive selection. Therefore, 10.8 x 10(6) cryopreserved CD34+ cells/kg bodyweight were thawed and a positive selection was carried out with the BAXTER Isolex 300i machine. Before additional negative selection, the 0.77 x 10(6) positively selected CD34+ cells/kg bodyweight from the second mobilization were added. A total quantity of 4.4 x 10(6) CD34+ cells/kg bodyweight with a purity of 93.1% representing a recovery of 38% was obtained. Cells were again cryopreserved, stored and retransfused after conditioning the patient with TBI and high-dose cyclophosphamide. The patient engrafted with a WBC count > 1000/microliter on day eight and a platelet count > 20,000/microliter without transfusion support on day 12 post-transplantation. This case indicates that purging procedures can successfully be carried out with cryopreserved cell material and that purified CD34+ cells can be cryopreserved a second time before transplantation, without affecting their hematopoietic capacity.

Adult↗
PubMed2001

Filtration of methylene blue-photooxidized plasma: influence on coagulation and cellular contamination.

BACKGROUND: Virus inactivation of plasma can be achieved by photodynamic methods in the presence of phenothiazine dyes such as methylene blue (MB). Subsequent filtration may increase the efficacy of virus inactivation and reduce adverse effects of WBC contamination and MB. STUDY DESIGN AND METHODS: This study examined the effect of filtration with three different filters (MBF1, MBF2, and MBF3) on MB concentration, residual cells, coagulation factors, and activation measures of coagulation, fibrinolysis, and complement in MB-treated (1 microM/L) plasma units. RESULTS: Filtration reduced the concentration of MB by > or = 89 percent. WBCs were depleted by 92 percent (MBF1) and >99.9 percent (MBF2 and MBF3). Treatment with MB significantly decreased the coagulation potency from levels in untreated plasma, as measured by thromboplastin time ratio (112 +/- 18% vs. 95 +/- 11%), activated partial thromboplastin time (40 +/- 3 sec vs. 44 +/- 3 sec), thrombin time (16.9 +/- 1.1 sec vs. 18.6 +/- 1.5 sec), factor VIII (1.09 +/- 0.21 U/mL vs. 0.85 +/- 0.13 U/mL), and vWF (0.94 +/- 0.65 U/mL vs. 0.65 +/- 0.24 U/mL). Filtration did not further decrease these values, while factor XI (0.75 +/- 0.22 U/mL vs. 0.37 +/- 0.20 U/mL) and prekallikrein values decreased in MB plasma units filtered with the MBF3. In addition, activated factor XII (0.7 +/- 0.5 microg/L vs. 4.5 +/- 1.0 microg/L) increased. CONCLUSION: WBCs and MB can be eliminated from MB-treated plasma units by filtration. Differences in biocompatibility of the different filters, especially the influence on the contact phase of coagulation, must be taken into consideration.

Blood Coagulation↗
PubMed2000

Isolated meningeal chloroma (granulocytic sarcoma)--a case report and review of the literature.

Isolated chloromas (granulocytic sarcomas) are rare tumors, most of them progressing to acute myeloblastic leukemia within months. There are still no conclusive treatment strategies for this entity; however, early antileukemic chemotherapy seems to lower the probability of developing systemic disease and prolong survival. We report on a patient with isolated meningeal chloroma, primarily misdiagnosed as a high-grade Non-Hodgkin's lymphoma. Two cycles of antileukemic induction chemotherapy were administered, followed by local irradiation and intensified consolidation therapy with autologous stem cell transplantation. After 20 months, he is still in complete remission.

Adult↗
PubMed2000

A prospective, randomized, sequential crossover trial of large-volume versus normal-volume leukapheresis procedures: effects on serum electrolytes, platelet counts, and other coagulation measures.

BACKGROUND: LVL procedures with the administration of heparin as an additional anticoagulant are increasingly performed because of the potentially higher yield of autologous peripheral blood HPCs. A prospective, randomized crossover trial was performed to evaluate the influence of leukapheresis volume-that is, large versus normal-on serum electrolytes, platelet count, and other coagulation measures in 25 patients with breast cancer and 14 patients with non-Hodgkin's lymphoma. STUDY DESIGN AND METHODS: Patients were randomly assigned to start either with an LVL on Day 1 followed by a normal-volume leukapheresis (NVL) on Day 2 or vice versa. In LVL, heparin was administered in addition to ACD-A. Bleeding complications, transfusion support, whole-blood counts, and several coagulation measures as well as plasma heparin levels were evaluated. RESULTS: Although the duration, the infused amount of ACD-A, the flow rate, the drop in platelet count, and the drop in potassium were significantly greater in LVL, and although LVL patients also received heparin, there was no significant difference in clinical tolerance or bleeding complications. After LVL, patients exhibited a significantly longer activated partial thromboplastin time (APTT), with a median of 70 seconds (range, 44-100 sec), and a median anti-factor Xa activity of 0.69 IU per mL (range, 0.10-1.29 IU/mL). The value of the APTT after LVL correlated with anti-factor Xa activity (r = 0.37, p<0.05), but not with platelet count or heparin infusion rate. Markers for coagulation activation did not increase during NVL or LVL. CONCLUSION: LVL with heparin as an additional anticoagulant seems to be a safe procedure in patients with low preleukapheresis platelet counts. No activation of coagulation occurred after NVL or LVL procedures.

Adult↗
PubMed2000

Testing of individual blood donations for HCV RNA reduces the residual risk of transfusion-transmitted HCV infection.

BACKGROUND: To allow cost-effective RNA testing with NAT techniques, the national authorities of several countries have planned or already introduced tests of mixed specimens, that is, plasma pools. STUDY DESIGN AND METHODS: High-throughput extraction, amplification, and detection of HCV RNA from individual blood donations were optimized and validated. The feasibility of the method and the frequency of anti-HCV-negative, HCV RNA-positive donations were determined in a prospective study of 27,745 allogeneic and 792 autologous individual donations. RESULTS: The 50- and 95-percent detection limits of the method were determined at 44 IU per mL and 162 IU per mL, respectively (World Health Organization HCV reference material). When 201 HCV RNA-positive sera were taken as a reference, the sensitivity was 97.5 percent. The assay specificity was determined at 99.77 percent. During a 20-month period, two seronegative blood donors tested positive in HCV PCR. The viral load of these donations was 6 x 10(6) and 3 x 10(7) copies per mL, respectively. Thus, the yield of HCV RNA testing in this study was 7. 63 per 100,000 screened donations (95% CI, 1.25-22.07). In both PCR-positive donors, seroconversion was found in subsequent blood samples. CONCLUSION: This study compares the feasibility of single-donation HCV RNA screening, with the detection of a relatively high percentage of window-phase donations, to data reported from groups using HCV RNA testing of plasma pools. The relative yield of NAT of individual donations versus minipools should be directly investigated in the near future.

Blood Donors↗
PubMed2000

A cell-kinetic model of CD34+ cell mobilization and harvest: development of a predictive algorithm for CD34+ cell yield in PBPC collections.

BACKGROUND: Mobilization and homing of PBPCs are still poorly understood. Thus, a sufficient algorithm for the prediction of PBPC yield in apheresis procedures does not yet exist. STUDY DESIGN AND METHODS: The decline of CD34+ cells in the peripheral blood during apheresis and their simultaneous increase in the collection bag were determined in a prospective study of 18 consecutive apheresis procedures. A cell-kinetic, four-compartment model describing these changes was developed. Retrospective data from 136 apheresis procedures served to further improve this model. A predictive algorithm for the yield was developed that considered the sex, weight, and height of the patient, the number of CD34+ cells in peripheral blood before apheresis, the inlet flow, and the duration of the apheresis. The accuracy of this algorithm was evaluated by comparison of the predicted and the observed yields of CD34+ cells in 105 prospective autologous and 148 retrospective allogeneic apheresis procedures. RESULTS: The correlation between predicted and observed yields was good for the autologous and allogeneic groups with a correlation coefficient (r) of 0.8979 and 0.8311 (p<0.0001), respectively. The regression is described by the equations log (measured value [m]) = 1.0118 + 0.8595 x log (predicted value [p]) for the autologous and log (m) = 2.226 + 0.7559 x log (p) for the allogeneic group. The respective equations for the zero-point regression are log (m) = 1.014 x log (p) and log (m) = 1.026 x log (p). The probability that the measured value was 90 percent or more of the predicted value was 83.8 percent for the autologous and 90.5 percent for the allogeneic apheresis procedures. CONCLUSION: The predictive accuracy of the algorithm and the slope of the zero-point regression curve were higher for allogeneic than autologous PBPC collections. The predictive algorithm may be a useful tool in PBPC harvest, enabling the adaptation of the size of the apheresis to the needs of each patient.

Algorithms↗
PubMed2000

Hepatitis C virus transmission through quarantine fresh-frozen plasma.

In 1994, quarantine fresh-frozen plasma (Q-FFP) was introduced in Germany in order to reduce the risk of HIV and HCV transmission. In 1998, an acute HCV infection of a patient was reported to us. The look-back revealed that this patient had received two Q-FFP from a donor who had seroconverted for HCV in the meantime. Recipients of further plasma donations from this donor were identified. Back-up specimens of these donations were investigated in several laboratories. A total of 25 additional HCV-PCR positive plasma units had been transfused to 12 further patients. HCV infections were diagnosed in seven of these recipients, three patients had already been deceased. One of the remaining two recipients was already HCV positive prior to transfusion, in the other patient, no HCV infection was detectable. This patient had received three units of an "early" plasma donation , which was tested negative by PCR in one laboratory, but positive in the other. The subsequent, clinically infectious donation had the same discrepant PCR results. Thus, eight cases of HCV transmission were revealed and classified as "certain" with regard to causality, also due to an identical HCV genotype, i.e. 3e. Some of these infections would have been prevented by application of a different anti-HCV assay. The assay used in the respective plasmapheresis station was in-sensitive in this individual case for more than 400 days after the first PCR positive donation. This caused the release of the above mentioned infectious units. Upon re-testing the backups, three of four other anti-HCV assays revealed a positive result already 104 days after the first PCR-positive donation. The donor had increased ALAT levels (> 23 IU/L) at nine of 28 donations, two of these were higher than 2.5 times the upper normal limit, and two were higher than 68 IU/L, which is the cut-off value for male blood donors in Germany. The results of these (look-back) studies arouse several queries, i.e. differences in the diagnostic sensitivity between current anti-HCV and PCR tests, the accuracy of risk-estimates (especially when based on hemovigilance studies for Q-FFP), the value of ALAT testing, and currently practised release algorithms for Q-FFP.

Adult↗
PubMed1999

A dispermic chimerism in a 2-year-old Caucasian boy.

Detection of two different cell populations in a child is a rare event. The following case of a dispermic chimera was diagnosed before surgery due to problems in blood group determination. A 2-year-old phenotypically male child was admitted for correction of a penoscrotal hypospadia and unilateral cryptorchism. During presurgical laboratory investigation, difficulties in blood group determination occurred. Blood group typing was performed by the DiaMed-ID Micro Typing System and by FACS. Additionally, cytogenetic analysis of lymphocytes and analysis of DNA polymorphisms in different tissues were performed. Two populations of red blood cells were detected, O cells accounting for 75% and B cells for 25%. Analysis of DNA-PCR polymorphisms in lymphocytes, nails, and in cells of the oral mucous membrane demonstrated a chimerism, with two alleles inherited from the father and one from the mother. A cytogenetic analysis of cultured lymphocytes showed a mosaic 46, XY/46,XX. Surgery revealed a prostatic utricle grade III, also called pseudovagina; genitography confirmed a vagina. Bilateral gonad biopsy showed a testis on one side and an ovary on the other. This case of chimerism represents a true hermaphroditism that most probably developed by double fertilization of one or more egg nuclei by two sperms.

Blood Grouping and Crossmatching↗
PubMed1999

A prospective, randomized, sequential, crossover trial of large-volume versus normal-volume leukapheresis procedures: effect on progenitor cells and engraftment.

BACKGROUND: The influence of leukapheresis size on the number of harvested peripheral blood progenitor cells is still unclear. A prospective randomized crossover trial was thus performed, to evaluate the effect of large-volume leukapheresis (LVL) versus normal-volume leukapheresis (NVL) on progenitor cells and engraftment in 26 patients with breast cancer and 15 patients with non-Hodgkin's lymphoma who were eligible for peripheral blood progenitor cell transplantation. STUDY DESIGN AND METHODS: Patients were randomly assigned to undergo either LVL on Day 1 and on Day 2 or vice versa. The number of progenitor cells was evaluated in the harvest and before and after leukapheresis in the peripheral blood. RESULTS: The number of harvested CD34+ cells (4.8 x 10(6) vs. 3.4 x 10(6)/kg body weight, p < 0.001) and colony-forming units-granulocyte-macrophage (3.1 x 10(5) vs. 2.4 x 10(5)/kg body weight, p = 0.0026) was significantly higher for LVL procedures than for NVL procedures. The median extraction efficacy, defined as the difference between the yield in the harvest and the decrease in the total number of CD34+ cells in peripheral blood during leukapheresis, was significantly (p < 0.0001) higher for LVL than for NVL (2.6 x 10(8) and 8 x 10(7), respectively). In patients with breast cancer, the median amount of CD34+ cells in the harvest and the median extraction efficacy were higher for LVL than for NVL (p < 0.0001). This was not found for patients with non-Hodgkin's lymphoma. CONCLUSION: LVL results in a higher yield of CD34+ cells and colony-forming units-granulocyte-macrophage than NVL, but only in patients with breast cancer and with high numbers of CD34+ cells in the peripheral blood before leukapheresis.

Adult↗
PubMed1998

Quality and safety of platelet apheresis concentrates produced with a new leukocyte reduction system.

OBJECTIVES: Contaminating white blood cells (WBC) in apheresis platelet concentrates (PC) can cause a variety of adverse effects after platelet transfusion. To obtain PCs with low WBC contamination, a new leukoreduction system (LRS) utilizing 'fluidized particle bed' technology has recently been introduced. METHODS: We prospectively examined the effect of LRS apheresis on the donor, the quality of the resulting PCs (n = 120), and the platelet increment in the corresponding recipients. Conventionally prepared apheresis PCs served as control group (n = 27). Platelet glycoproteins were examined by flow cytometry. RESULTS: In LRS apheresis, we observed no serious adverse effects on the donors, but the postdonation absolute lymphocyte counts were reduced from 1,787 +/- 505/microliter to 1,405 +/- 383/microliter (p < 0.001). Comparable results were seen in non-LRS donors. The collection efficiency of the LRS procedures was 50.0 +/- 7.6%, resulting in a yield of 4.3 +/- 1.0 x 10(11) platelets/PC. In flow cytometry, platelet glycoproteins in LRS PCs were not elevated: mean fluorescence of CD62 (6 +/- 4) or CD63 (9 +/- 3) in comparison with non-LRS PCs (mean fluorescence of CD62: 7 +/- 4, CD63: 8 +/- 3). Median leukocyte contamination of the LRS PCs was 0.41 x 10(5) (range 0.07-8.5) WBCs/unit. In 43 recipients, the 24-hour corrected count increments after transfusion of LRS PCs (12,530 +/- 8,761) were essentially the same as those of 20 recipients of non-LRS PCs (13,133 +/- 9,812; p = 0.75). CONCLUSIONS: LRS apheresis appears to be a safe procedure, which produced effective PCs with few contaminating leukocytes. With new apheresis technology, filtration of PCs may become superfluous.

Antigens, Human Platelet↗
PubMed1997

Frequency and causes of refractoriness in multiply transfused patients.

The use of leukocyte-depleted blood components has become the standard therapy for multiply transfused patients during the past few years, as a measure to reduce the frequency of alloimmunization and refractoriness. We assessed frequency and causes of refractoriness, defined as a repeated 24-h post-transfusion platelet count below 20,000/microliters, in 145 consecutive patients who received three or more single-donor platelet concentrates during a 1-year period. Flow-cytometric detection of anti-platelet antibodies and a glycoprotein-specific ELISA were applied for the diagnosis of alloimmunization. Forty patients (27.6%) had at least one episode of refractoriness. In 25 of these 40 patients (62.5%), nonimmune factors (fever, sepsis, coagulopathy, splenomegaly) alone were the cause. In 15 refractory patients alloantibodies were detected. In seven patients (17.5%), alloimmunization alone caused an inadequate transfusion response, while in eight refractory patients (20.0%) alloimmunization and fever or sepsis were present. HLA antibodies were detected in 17 patients (11.7%); three patients (2%) had platelet-specific antibodies in addition to HLA antibodies; in two patients panreactive platelet antibodies were detectable. All 17 patients had a history of previous transfusions or pregnancy. We did not observe primary immunization in patients transfused exclusively with filtered (leukodepleted) blood products. Our data suggest that alloimmunization in patients with a negative risk history can be prevented by the exclusive use of leukodepleted blood components.

Antigens, Human Platelet↗
PubMed1997

Comparison of CD34+ cell numbers and colony growth before and after cryopreservation of peripheral blood progenitor and stem cell harvests: influence of prior chemotherapy.

BACKGROUND: Quantitative determination of hematopoietic progenitor cells is a major issue in peripheral blood progenitor and stem cell collection and transfusion, although the extent is still an object of discussion. STUDY DESIGN AND METHODS: In 116 leukapheresis collections from 42 patients, immunophenotyping for CD34+ cells, evaluation of in vitro proliferative capacity by a colony-forming unit-granulocyte-macrophage (CFU-GM) assay, and viability assessment by trypan blue exclusion were performed before and after storage in liquid nitrogen at -196 degrees C. RESULTS: Before storage, the median number of CD34+ cells was 1.46 x 10(6) (range, 0.01-54.05 x 10(6)) per kg of body weight (BW). There was no significant difference between precryopreservation and postcryopreservation numbers. The median number of CFU-GM was 2.25 x 10(5) (range, 0.02-157.49 x 10(5)) per kg of BW before cryopreservation and significantly (p < 0.001) lower, 0.83 x 10(5) (range, 0-220.36 x 10(5)) per kg of BW, after cryopreservation. The correlation coefficient of prestorage and poststorage values was 0.92. The median ratio of poststorage and prestorage values was 42.3 percent (0-304.8%). Male patients who underwent intense chemotherapy (> 5 cycles) showed a significantly lower ratio of postcryopreservation and precryopreservation CFU-GM values than other patients (p = 0.0047). A strong linear correlation was determined between the number of CD34+ cells per kg of BW and the number of CFU-GM per kg of BW before and after cryopreservation. A viability below 50 percent predicted a high loss of in vitro proliferative capacity, while a viability above 50 percent did not correlate with a high ratio of CFU-GM from after and before cryopreservation. CONCLUSION: A good correlation between the variables used for characterization of peripheral blood progenitor cells--the number of CD34+ cells and the number of CFU-GM--was observed. Viability assessment by trypan blue exclusion does not seem to be a substitute for assays evaluating in vitro proliferative capacity.

Adult↗
PubMed1997

[Quality control in producing thrombocytapheresis preparations with minimal leukocyte contamination].

Passenger white blood cells (WBC) in platelet concentrates (PC) produced by apheresis can cause a variety of adverse effects in recipients after platelet transfusion. With new technologies (LRS, leukocyte reduction system), the preparation of PC with a low WBC contamination is possible without consecutive filtration. In a prospective examination, we compared the effect of LRS apheresis on the donor, the quality of the resulting PC (n = 120), and the platelet increment in the corresponding recipients with conventionally prepared PC (n = 27). In LSR apheresis, no serious adverse effects on the donors were observed, but the post-donation absolute numbers of lymphocytes were reduced from 1,787 +/- 505/microliter to 1,402 +/- 383/microliter (p < 0.001). Comparable results were observed in non-LRS donors. The collection efficiency of the LRS procedures was 50.0 +/- 7.6%, resulting in a yield of 4.25 +/- 1.03 x 10(11) platelets/PC. Flow cytometric examination concerning the expression of platelet glycoproteins in LRS PC showed no elevation in mean fluorescence of CD 62 (6 +/- 4) or CD 63 (9 +/- 3) in comparison to non-LRS PC (mean fluorescence CD 62: 7 +/- 4, CD 63: 8 +/- 3). Median leukocyte contamination of the LRS PC was 0.41 x 10(5) (range 0.06-8.5 x 10(5)) WBC/unit. In 43 recipients, the 24-hour corrected count increments (CCI) after transfusion of LRS PC (12,530 +/- 8,761) showed no significant differences when compared with the CCI in 20 recipients of non-LRS PC (13,133 +/- 9,812, p = 0.75). LRS apheresis seems to be safe procedure, resulting in PC with low WBC contamination, which causes adequate CCI values after transfusion.

Adult↗