A. Humpe

Frequency and causes of refractoriness in multiply transfused patients

Abstract 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/μl, 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.

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 × 10(6) (range, 0.01–54.05 × 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 × 10(5) (range, 0.02–157.49 × 10(5)) per kg of BW before cryopreservation and significantly (p < 0.001) lower, 0.83 × 10(5) (range, 0–220.36 × 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.

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.

Flow cytometric detection of platelet‐reactive antibodies and application in platelet crossmatching

Background: Alloimmunization against HLA or platelet antigens can cause refractoriness to platelet transfusions in multiply transfused patients. Crossmatching of platelet concentrates is effective in overcoming this problem.

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.

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

Abstract 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, 0 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.

A prospective, randomized, sequential crossover trial oflarge‐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‐Hodgkins lymphoma.

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.

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/μl to 1,405±383/μl (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 × 1011 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 × 105 (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.

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‐Hodgkins 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. J. Clin. Apheresis. 16:109–113, 2001.