Therapeutic plasma apheresis: Expertise and indications.

Therapeutic apheresis is an extracorporeal treatment that is capable of removing pathogenic blood components from patients that causes morbidity. In this review an overview is given of the types of indications for which therapeutic plasma exchange is effective. Furthermore, practical and effective topics, as well as complications will be discussed.

A method for red blood cell biotinylation in a closed system.

BACKGROUND: Several circumstances require the accurate measurement of red blood cell (RBC) survival and clearance, such as determination of posttransfusion recovery of stored RBCs to investigate the effect of new additive solutions. To this end, biotin as a marker of RBCs to track donor RBCs in the blood of the recipient has been used in many studies. However, so far only experimental, nonvalidated, biotin-labeled red cell concentrates (RCCs) are transfused. The goal of this study was to produce a standardized biotin-labeled RCC product in a fast, simple, and sterile manner that can be used for clinical research and for the evaluation of new blood products according to Good Practice Guidelines (GPG) for blood establishments. STUDY DESIGN AND METHODS: RCC fractions were labeled with two different concentrations of biotinylation reagent in a closed system, to prevent bacterial contamination of the end product. Using flow cytometry, the reproducibility and robustness of the biotin labeling was assessed, as well as the stability of the biotin label on the (un-)irradiated RCC fraction. Additionally, parameters such as phosphatidylserine (PS) exposure, sodium (Na), potassium (K), free hemoglobin, adenosine triphosphate (ATP), pH, and morphology were determined prior to and after biotin labeling to rule out detrimental effects of the labeling procedure on the RCC. RESULTS: Our data show that RCCs can be labeled under sterile conditions in a closed system with two different biotinylation reagent concentrations, without affecting the biological activity. CONCLUSION: An easy, rapid (<2 hr), and robust method was developed to manufacture biotin-labeled RCCs for clinical research compliant to GPG.

Apheresis causes complement deposition on red blood cells (RBCs) and RBC antigen alterations, possibly inducing enhanced clearance.

BACKGROUND: Apheresis is increasingly being applied to collect cells or plasma, even allowing the collection of multiple blood components during one procedure. Although the quality of the cellular and plasma products that are obtained by apheresis have been extensively studied and shown to be of high quality, the impact of apheresis on the red blood cells (RBCs) that are returned to the donor has not been investigated. STUDY DESIGN AND METHODS: The effect of the plasma- or plateletpheresis procedures by four different devices-MCS+ (Haemonetics), PCS2 (Haemonetics), Trima Accel (Terumo BCT), and Autopheresis-C (Auto-C, Fresenius Kabi)-on the RBCs that are returned to the donor was tested in a blinded, prospective trial in a cohort of 25 donors. RESULTS: A rheologic analysis of donor RBCs before and after plasma- or plateletpheresis showed no differences in outcome. However, a strong increase in hemolysis was found in samples from the Trima Accel devices after plateletpheresis, compared to all other machines tested. Furthermore, an increase in complement deposition on RBCs was seen after all plasmapheresis procedures (MCS+, PCS2, and Auto-C). Finally, a significant decrease in the expression of the complement-regulating protein CD59 was seen in all postapheresis samples as well as a significant decrease of the adhesion molecule CD147. CONCLUSION: The increase in complement deposition and the decrease in the expression of CD59 suggests that RBC clearance might be enhanced after return to the donor. Possible side effects due to an increase in hemolysis after Trima Accel plateletpheresis should be further investigated.

Of macrophages and red blood cells; a complex love story.

Macrophages tightly control the production and clearance of red blood cells (RBC). During steady state hematopoiesis, approximately 10(10) RBC are produced per hour within erythroblastic islands in humans. In these erythroblastic islands, resident bone marrow macrophages provide erythroblasts with interactions that are essential for erythroid development. New evidence suggests that not only under homeostasis but also under stress conditions, macrophages play an important role in promoting erythropoiesis. Once RBC have matured, these cells remain in circulation for about 120 days. At the end of their life span, RBC are cleared by macrophages residing in the spleen and the liver. Current theories about the removal of senescent RBC and the essential role of macrophages will be discussed as well as the role of macrophages in facilitating the removal of damaged cellular content from the RBC. In this review we will provide an overview on the role of macrophages in the regulation of RBC production, maintenance and clearance. In addition, we will discuss the interactions between these two cell types during transfer of immune complexes and pathogens from RBC to macrophages.

Comparison of three radiotherapy modalities on biochemical control and overall survival for the treatment of prostate cancer: a systematic review.

BACKGROUND AND PURPOSE: For the radiation treatment of prostate cancer high dose should be delivered for optimal biochemical control. Treatment can be given by dose-escalated external beam radiotherapy (EBRT) or external beam radiotherapy combined with a radioactive seed implantation (EBSeeds) or high-dose rate (HDR) brachytherapy (EBTI). Differences in outcome between the modalities were assessed by a systematic review. MATERIALS AND METHODS: A systematic search was performed resulting in 40 articles to be used. Data were extracted on biochemical control and overall survival at 3, 5, and 8 years and other time points mentioned in the articles. Also known prognostic parameters were noted. Comparison of the modalities was done by a Weibull survival analysis and estimation of Hazard Ratio's (HR) was done with 95% confidence intervals (95% CIs). RESULTS: The HR for biochemical recurrence was 1.40 (95% CI 1.31-1.51) for EBRT relative to EBTI, and was 1.37 (95% CI 1.26-1.49) for EBSeeds relative to EBTI. The HR for overall survival was 1.50 (95% CI 1.29-1.73) for EBRT relative to EBTI, and was 2.33 (95% CI 2.04-2.66) for EBSeeds relative to EBTI. CONCLUSION: The combination of external beam radiotherapy and HDR brachytherapy results in a superior biochemical control and overall survival found in a systematic review on radiotherapy for prostate cancer.