Influence of multicomponent apheresis on donors' haematological and coagulation parameters, iron storage and platelet function.

BACKGROUND AND OBJECTIVES: Multicomponent collection (MCC) enables production and processing of various blood components during one apheresis session. In this prospective crossover study, the effects of donating platelets (PLTs) and packed red blood cells (PRBCs) on donor's blood cell count, coagulation, PLT function and iron state were analysed. MATERIALS AND METHODS: Forty-eight MCCs were performed using two different cell separators (Fenwal Amicus(®), CaridianBCT Trima Accel(®)). Two units of platelet concentrates and one unit of PRBCs were collected during each session. Full blood cell count and iron status were obtained on day 0 before and after apheresis, day 2, day 14 and day 42. PLT function was analysed by aggregometry and rotation thromboelastometry in parallel with coagulation tests before and after MCC and at day 2. RESULTS: Multicomponent collection was well tolerated without adverse side effects. Blood cell count and iron parameters declined and most of them (haemoglobin, haematocrit, transferrin, transferrin saturation and ferritin) were significantly below baseline values until at least day 42 after donation. Absent iron stores were seen in 31·3% of the donors. In contrast, PLTs significantly exceeded pre-donation values after 14 days and remained significantly increased for 42 days. After 2 days, coagulation parameters were only slightly (P > 0·05) altered, whereas PLT function was significantly reduced. CONCLUSION: Multicomponent collection is an obviously safe procedure; however, the significant long-term impact on the donor's blood count and iron store, as well as impaired PLT function, has to be considered in regard to donor safety.

Function and activation state of platelets in vitro depend on apheresis modality.

BACKGROUND AND OBJECTIVES: In multicomponent collection, various blood components are prepared during one apheresis process. The aim of this prospective crossover study was to compare the function, metabolic parameters and activation state of fresh and stored platelets (PLTs) collected by two different cell separators. MATERIALS AND METHODS: Twenty-four donors underwent apheresis on each of two cell separators (Fenwal Amicus(®) and CaridianBCT Trima Accel(®)) with an interval of at least 2 months between donations. Per donation, one double dose of PLT concentrate (PC) and one unit of packed red-blood-cells were collected. In total, 48 single unit PCs were tested for pH, glucose, bicarbonate, lactate, potassium and LDH concentration during 7 days of storage. PLT function was analysed by aggregometry, rotation thrombelastometry and hypotonic shock response. The PLT surface expression of P-selectin (CD62P) and LAMP-3 (CD63) was estimated by flow cytometry. RESULTS: During storage, metabolic parameters were well maintained in both groups, but levels of glucose and pH were significantly lower, while lactate and LDH were significantly higher in Amicus(®)-PCs. Amicus(®)-derived PLTs were significantly more activated as evidenced by higher CD62P and CD63 expression. In parallel, the in vitro function of Amicus(®)-PLTs was significantly reduced compared to Trima(®)-PLTs. CONCLUSION: In multicomponent apheresis, standardized PLT collection is effective and well tolerated. The higher activation of Amicus(®)-derived PLTs may be because of the divergent centrifugation modalities during collection. Possible consequences for the clinical outcome of thrombocytopenic patients will be evaluated in further trials.

Successful treatment of premature rupture of membranes after genetic amniocentesis by intra-amniotic injection of platelets and cryoprecipitate (amniopatch): a case report.

BACKGROUND AND OBJECTIVES: Iatrogenic premature rupture of membranes (PROM) occurs in approximately 1% of patients after genetic amniocentesis. If membranes do not seal spontaneously, fluid leakage through the vagina may cause infection and pregnancy loss. Intra-amniotic infusion of a platelet concentrate followed by a cryoprecipitate (amniopatch) is a possible therapeutic approach to restore the amnio-corial link and to facilitate the amniotic repair process. MATERIALS AND METHODS: The autologeous platelet concentrate was produced by apheresis (MCS+, Haemonetics) and contained a total amount of 48 x 10(9) platelets in a volume of 30 ml. The concentration of fibrinogen in our cryoprecipitate (20 ml) was 680 mg/dl. An amniocentesis was performed to apply the amniopatch. The platelet concentrate was administered first followed by the cryoprecipitate. RESULTS: We report the successful treatment of a 38-year-old woman with ruptured membranes after genetic amniocentesis in the 16th gestational week. Ten days after placement of the amniopatch we found a complete closure of the rupture, and in the 36th week of gestation the patient delivered a healthy infant by Caesarean section. CONCLUSIONS: Intra-amniotic injection of platelets and cryoprecipitate was a successful and safe therapy for PROM in this patient. Knowledge of the site of rupture is not necessary for the amniopatch, as platelets seem to find their way to the defect and seal it. We consider that amniopatch therapy for iatrogenic PROM is a possible therapeutic alternative for prolonging and preserving pregnancy and improving the fetal outcome.

[Autologous blood donation with preliminary erythropoietin stimulation]. / Eigenblutspende bei zeitgerechter Erythropoetinstimulation.

Low basal hemoglobin and functional iron deficiency are the limiting factors in autologous blood donation program. Treatment with recombinant human erythropoietin can increase the volume of autologous blood and makes donation of > or = 3 units possible-even in patients with low basal hemoglobin. Best results are obtained if stimulation begins already one week before first donation.