Safety of donating multiple products in a single apheresis collection: Are we expecting too much?

"Normal values" for the lymphocyte cytokinesis-block micronucleus cytome parameters: Repeatability and reproducibility in a healthy reference population

The micronucleus test in peripheral blood lymphocytes is the most widely validated technique to evaluate the DNA damage and chromosomal instability in human populations. The test is largely applied in monitoring environmental and occupational exposure to genotoxic agents. It was also proposed as a biomarker of risk/susceptibility for cancer and other degenerative diseases. The availability of "normal values" in healthy populations is a main requisite for the assay application in human biomonitoring. Age and gender-related ranges of micronucleated binucleated cells (MNBN) baseline values were established in a group of 103 healthy platelet donors (50 males and 53 females) not recently exposed to genotoxic agents and characterized for demographic, lifestyle and dietary factors. Repeatability of the test by the same scorer was evaluated. Reproducibility was estimated through analysis of repeated blood samples. High correlation between the results of the three blood samplings in two separate scoring sessions of MNBN/1000BN (R² values were 0.83, 0.74 and 0.68; P < 0.0001) and PI values (R² values were 0.69, 0.62 and 0.65; P < 0.0001) was detected. High consistency among the values obtained in three different samplings in the same individual was observed (Intraclass Correlation Coefficient (ICC) = 0.905, (95% CI = 0.868-0.933, P < 0.0001) The range of "normal" values predicted on the basis of the results of the present study appears to be sufficiently narrow to warrant application of the assay in the comparison of data obtained from groups of exposed or susceptible subjects, supporting its use in preventive programs. The large inter-individual variability predicted by the model used in the present study hampers a clinical application of the assay at individual level. The method applied in the present study represents a generally applicable model to derive "normal values" in any population, as an essential step before starting a biomonitoring study.

Comparative Analysis of Various Aspects of Plateletpheresis on the Fenwal Amicus and Fresenius COM.TEC Cell Separator Instruments

OBJECTIVE

To compare the Fenwal Amicus and the Fresenius COM.TEC apheresis instruments regarding donor peripheral blood parameters, operational variables of the instruments, and quality control parameters of the product obtained.

METHODS

We performed 100 platelet collections from 100 voluntary donors using the 2 studied devices. We measured platelet count using an automated analyzer and analyzed the activation statuses using a flow cytometer.

RESULTS

The median time needed to perform the procedures was significantly longer with the COM.TEC. However, the product we obtained using the Amicus instrument showed higher degrees of platelet-activation. All products we obtained with both instruments had white blood cell counts of less than 5 × 10(6) per bag. We observed no statistical difference regarding collection efficiency and collection rates between the devices.

CONCLUSION

Both instruments collected platelets efficiently, with minimal donor discomfort. Compared with the COM.TEC instrument, the Amicus reached the platelet target yield more quickly; however, it displayed an increase in platelet activation.

Effect of thrombocytapheresis on blood rheology in healthy donors: role of nitric oxide

Platelet transfusions are increasingly being used to treat thrombocytopenic conditions. Because of anticoagulation, changes in blood composition and extracorporeal circulation, donor apheresis may cause alterations in hemorheology. This study aimed at investigating the effects of thrombocytapheresis on donor blood rheology. The effect of nitric oxide (NO) on donor red blood cell (RBC) deformability after thrombocytapheresis was also studied. Platelets were collected by a Haemonetics MCS 3p cell seperator. Blood samples were obtained before and 15 min after thrombocytapheresis. RBC deformability and aggregation were measured using an ektacytometer, whole blood viscosity (WBV) was determined with a cone-plate rotational viscometer. Donor RBCs were shown to be less deformable at all stress levels except 0.30 Pa after thrombocytapheresis and NO donor sodium nitroprusside (SNP, 10(-6) M) reversed the reduced deformability caused by thrombocytapheresis. It was observed that donor apheresis induces a decrement in RBC aggregation and WBV measured at standard hematocrit (Hct). No significant alterations were observed in WBV values determined at native Hct values. Thrombocytapheresis also resulted in a decrement in fibrinogen, total protein, cholesterol and albumin levels whereas Hct was found to be increased and serum glucose, triglyceride, hemoglobin levels unaltered after apheresis. These results suggest that, thrombocytapheresis causes alterations in hemorheological parameters and hence in the perfusion of the microvasculature of the donors and NO appears to have a protective effect on the impairment observed in RBC deformability.

Comparison of Plateletpheresis on the Fenwal Amicus and Fresenius Com.Tec Cell Separators

SUMMARY: BACKGROUND: A variety of apheresis devices are now available on the market for plateletapheresis. We compared two apheresis instruments (Fenwal Amicus and Fresenius COM.TEC) with regard to processing time, platelet (PLT) yield and efficiency, and white blood cell (WBC) content. MATERIAL AND METHODS: Donors undergoing plateletpheresis were randomly separated into two groups (either the Amicus or the COM.TEC cell separator). RESULTS: In the pre-apheresis setting, 32 plateletpheresis procedures performed with each instrument revealed no significant differences in donors' sex, age, weight, height and total blood volume between the two groups. However, the pre-apheresis PLT count was higher with the COM.TEC than with the Amicus (198 × 10(3)/μl vs. 223 × 10(3)/μl; p = 0.035). The blood volume processed to reach a target PLT yield of ≥3.3 × 10(11) was higher in the COM.TEC compared to the Amicus (3,481 vs. 2,850 ml; p < 0.001). The median separation time was also significantly longer in the COM.TEC than in the Amicus (61 vs. 44 min; p < 0.001). 91 and 88% of the PLT products collected with the Amicus and the COM.TEC, respectively, had a PLT count of >3.3 × 10(11) (p = 0.325). All products obtained with both instruments had WBC counts lower than 5 ↔ 10(6), as required. There was no statistical difference with regard to collection efficiency between the devices (55 ± 15 vs. 57 ± 15%; p = 0.477). However, the collection rate was significantly higher with the Amicus compared to the COM.TEC instrument (0.077 ± 0.012 × 10(11) vs. 0.057 ± 0.008 × 10(11) PLT/min; p < 0.001). CONCLUSION: Both instruments collected platelets efficiently. Additionally, consistent leukoreduction was obtained with both instruments; however, compared with the COM.TEC instrument, the Amicus reached the PLT target yield more quickly.

What’s happening: An overview of potential adverse reactions associated with apheresis technology

The current status of potential adverse reactions associated with the use of apheresis technology is reviewed, focussing on three main areas: adverse events related to component collection, progenitor cells collection and therapeutic apheresis. Based on available information it is believed that apheresis technologies are safe and increasingly used in transfusion medicine, including in auto-transfusion and different types of therapy. Occasionally, however, for various donor/patient and operational reasons, mild or moderate adverse reactions do occur. The majority of these reactions are related to vascular access and anticoagulants used, which can be mostly eliminated with calcium/magnesium administration. The reactions associated with therapeutic apheresis are more frequent (6.75%) than the multi-components and stem cell collections. Most of these reactions are generally mild and only 0.89% has been classified as severe. A national registry of donor adverse reactions as well as a planned haemovigilance system may prove helpful in identifying the potential causes which might be associated with either to donor/donation and/or with a particular technology or procedure.