In-vivo evaluation of random donor platelet concentrates from pooled buffy coats

 Random-donor platelet concentrates (PC) prepared from pooled buffy coats have recently been described as an alternative method for platelet preparation. We evaluated such PCs in the clinical setting compared with a standard PC from platelet apheresis. PCs were prepared either from pools of buffy coats (BC-PC) or from single donors (SD-PC) with the cell separator CS-3000 plus. PCs were stored for up to 5 days before transfusion. We compared fresh PC (day 1) with stored (day 2–3) and long-stored PC (day 4–5). For analysis, platelet increment in the recipient was determined immediately and 16–22 h (mean 20 h) after transfusion, corrected for total body area and transfused platelets (CCI). A total of 316 PCs were administered to 36 thrombocytopenic patients suffering from various hematological disorders. Patients with detectable HLA or platelet-specific antibodies or splenomegaly were excluded from the study. Mean platelet content of the PC was 262×10⁹ for BC-PC and 251×10⁹ for SD-PC. The 20-h CCI after transfusion of fresh PC was slightly higher with BC-PC than with SD-PC (14.5 versus 11.9;p=0.19), but values did not differ significantly between the two types of PC on any day of storage. For BC-PC, 20-h CCI decreased with further storage by 30% (10.2;p=0.02). For SD-PC a decrease by 9% was not significant. In conclusion, platelet concentrates prepared from pools of buffy coats showed excellent transfusion results when administered fresh, but storage decreased the CCI by 30%. No significant difference from PCs from plateletpheresis was observed on any day of storage. Both types of platelet concentrates were capable of sufficient platelet increment even when stored for up to 5 days. Received: 28 December 1995 / Accepted: 14 May 1996     

Blood utilisation and transfusion reactions in adult patients transfused with conventional or pathogen-reduced platelets

Pathogen-reduced (PR) platelets are routinely used in many countries. Some studies reported changes in platelet and red blood cell (RBC) transfusion requirements in patients who received PR platelets when compared to conventional (CONV) platelets. Over a 28-month period we retrospectively analysed platelet utilisation, RBC transfusion trends, and transfusion reaction rates data from all transfused adult patients transfused at the Yale-New Haven Hospital, New Haven, CT, USA. We determined the number of RBC and platelet components administered between 2 and 24, 48, 72 or 96 h. A total of 3767 patients received 21 907 platelet components (CONV = 8912; PR = 12 995); 1,087 patients received only CONV platelets (1578 components) and 1,466 patients received only PR platelets (2604 components). The number of subsequently transfused platelet components was slightly higher following PR platelet components (P < 0·05); however, fewer RBCs were transfused following PR platelet administration (P < 0·05). The mean time-to-next platelet component transfusion was slightly shorter following PR platelet transfusion (P = 0·002). The rate of non-septic transfusion reactions did not differ (all P > 0·05). Septic transfusion reactions (N = 5) were seen only after CONV platelet transfusions (P = 0·011). These results provide evidence for comparable clinical efficacy of PR and CONV platelets. PR platelets eliminated septic transfusion reactions without increased risk of other types of transfusions with only slight increase in platelet utilisation.     

Factors predicting the postoperative outcome of lower gastrointestinal hemorrhage

Purpose  To examine the treatment outcome for patients with acute bleeding from the lower gastrointestinal tract requiring transfusion and acute surgical care as a function of various risk factors Materials and methods  Between 1999 and 2007, we collected data on 59 patients (39 male and 20 female patients) who received surgical intervention for acute lower intestinal hemorrhage requiring transfusion at our university clinic. Treatment complications and mortality were analyzed retrospectively. Results  The average age of the patients in this study is 70.0 ± 12.2 years (range, 39 to 97 years) with an overall mortality of 15.3%. Blood transfusions >10 U (p = 0.031), postoperative need for ventilation (p = 0.004), necessary reoperations (p = 0.016), and an initial hemoglobin level <80 g/L (p = 0.043) proved to be significant risk factors for death. Blood transfusions >10 U (p = 0.028), necessary reoperations (p = 0.001), and an initial hemoglobin level <80 g/L (p = 0.033) were found to be significant risk factors for postoperative complications. All other parameters have no significant impact. Conclusions  The decisive factors for the outcome of lower gastrointestinal hemorrhage requiring surgery are the severity of bleeding, beginning of treatment (initial hemoglobin level, need for packed red blood cells), and treatment efficiency (necessary reoperation).     

Comparative assessment of prophylactic transfusions of platelet concentrates obtained by the PRP or buffy-coat methods,in patients undergoing allogeneic hematopoietic stem cell transplantation

ABSTRACT

Objectives: Whole blood-derived platelet concentrates can be obtained by the platelet-rich plasma (PRP-PCs) or the buffy-coat (BC-PCs) method. Few studies have shown that BC-PCs display lower in vitro platelet activation, but scarce information exists regarding transfusion efficacy. We have performed a retrospective study assessing platelet transfusion in patients undergoing allogeneic hematopoietic cell transplantation (AHCT) in our clinic, before and after the implementation of BC-PCs.

Methods: We reviewed clinical records corresponding to 70 PRP-PCs and 86 BC-PCs prophylactic transfusions, which were performed to 55 AHCT patients. Transfusion efficacy was assessed by the 24-h post-transfusion corrected count increment (24-h CCI) and bleeding events. Clinical factors affecting transfusion outcome were also investigated.

Results: Clinical characteristics and the total number of platelet transfusions were similar among groups. Mean donor exposure was 5.8 and 5.0 in each single PRP-PCs and BC-PCs transfusion, respectively (p?<?0.01). The 24-h CCI was significantly higher in patients transfused with BC-PCs than in those receiving PRP-PCs (8.3[2.7–13.4] vs. 4.7[1.3–8.1]; p?<?0.01). Independent predictors of poor platelet transfusion response included diagnosis other than acute leukemia (HR 8.30; 95% CI 1.96–35.22; p?=?0.004), splenomegaly (HR 8.75; 95% CI 2.77–27.60; p?<?0.001), graft versus host disease prophylaxis different from cyclosporine A and methotrexate (HR 3.96; 95% CI 1.55–10.14; p?=?0.004) and PRP-PCs transfusion (HR 4.54; 95% CI 1.72–12.01; p?=?0.002). There were no differences between both groups regarding the bleeding events.

Conclusion: In the AHCT setting, we hypothesize that BC-PCs transfusion, when compared to PRP-PCs, results in higher CCI and reduced donor exposure, but provides no significant benefit regarding bleeding outcome.     

Restrictive guideline reduces platelet count thresholds for transfusions in very low birth weight preterm infants

Background and Objectives Platelet transfusions are performed almost entirely according to expert experience. This study assessed the effectiveness of a restrictive guideline to reduce platelet transfusions in preterm infants. Methods A retrospective cohort of preterm infants with a birth weight of <1500 g had been born in 2 periods. In Period 1, a transfusion was indicated for a platelet count of <50 000/ml in clinically stable neonates or <100 000/ml in bleeding or clinically unstable infants. In Period 2, the indications were restricted to <25 000/ml in clinically stable neonates, or <50 000/ml in newborns who were either on mechanical ventilation, subject to imminent invasive procedures, within 72 h following a seizure, or extremely premature and <7 days old. A count of <100 000/ml was indicated for bleeding or major surgery. Results Periods 1 and 2 comprised 121 and 134 neonates, respectively. The rates of ventricular haemorrhage and intrahospital death were similar in both periods. The percentage of transfused infants, the odds of receiving a platelet transfusion, the mean platelet count before transfusion and the percentage of transfusions with a platelet count >50,000/ml were greater in Period 1. Among thrombocytopenic neonates, the percentage of transfused neonates and the number of transfusions were similar in both groups. Conclusion The restrictive guideline for platelet transfusions reduced the platelet count thresholds for neonatal transfusions without increasing the rate of ventricular haemorrhage.     

Preprocedural prophylaxis with blood products in patients with cirrhosis: Results from a survey of the Italian Association for the Study of the Liver (AISF)

IntroductionThe concept of rebalanced hemostasis in cirrhosis challenges the policy of transfusing plasma or platelets before invasive procedures in patients with prolonged PT or severe thrombocytopenia. Recent guidelines recommend against plasma transfusion and suggest avoiding/minimizing platelet transfusions.AimWe assessed how hepato-gastroenterologists manage prolonged PT/INR or severe thrombocytopenia before invasive procedures.MethodsOn May 2021, AISF members were sent a questionnaire addressing the PT/INR and platelet thresholds required before invasive procedures, the use of other markers of bleeding risk or other hemostatic treatments and the burden of pre-emptive plasma and platelet transfusions.ResultsOf 62 respondents, 94% and 100% use PT/INR and platelet count to assess bleeding risk, respectively. Only 37% and 32% require less conservative PT/INR or platelet counts thresholds for low-risk procedures, respectively. As for those applying single thresholds, 68% require PT/INR <1,5 and 86% require platelet counts ≥50 × 10⁹/L. Half respondents use additional indicators of bleeding risk and 63% other hemostatic treatments. Low-risk procedures account for 70% of procedures, and for 50% and 59% of plasma and platelets units transfused, respectively.Conclusionsthe survey indicates lack of compliance with guidelines that advise against plasma and platelet transfusions before invasive procedures and the need for prospective studies and inter-society consensus workshops.     

An audit of platelet transfusion indications in acute leukaemia patients: six-year experience at an Academic Centre

BackgroundPlatelet transfusion plays a critical role in the supportive treatment of acute leukaemia patients who receive chemotherapy and haematopoietic stem cell transplantation (HSCT). There are few studies assessing appropriateness of platelet transfusion in this population. An audit was conducted to determine how appropriately platelets are transfused in acute leukaemia patients at a tertiary care health institution.Materials and methodsA six-year retrospective audit was conducted in acute lymphoblastic (ALL) and acute myeloid leukaemia (AML) patients in an Academic Centre. Episodes were assessed as either appropriate or inappropriate based on guidelines from the British Society for Haematology (BSH). Pre-transfusion platelet count, transfusion indication, World Health Organization (WHO) bleeding score, and antibiotic use were all documented.ResultsOverall, 745 platelet transfusion episodes in 154 patients were audited. The proportion of episodes appropriately indicated according to BSH guidelines was 75.3%. Paediatrics and Internal Medicine had the lowest and highest proportion of appropriateness by department at 63.9% and 86.8%, respectively. The best alignment to guidelines was found on the wards (82.3%). Inpatient cases were significantly better indicated (p=0.002), whereas therapeutic and HSCT-related transfusions were not. The majority of inappropriate transfusions had a pre-transfusion count >20×10⁹/L without a valid justification (45.1%), whereas appropriate episodes were mainly accounted for by a pre-transfusion count <10×10⁹/L (69%).DiscussionThe 25% rate of inappropriate platelet transfusion in acute leukaemia patients underscores the learning needs of physicians, particularly those in training, regarding adequate use of platelets in haematologic malignancies to optimise its utilisation and patient outcome.     

Therapeutic efficacy and safety of platelets treated with a photochemical process for pathogen inactivation: the SPRINT Trial

We report a transfusion trial of platelets photochemically treated for pathogen inactivation using the synthetic psoralen amotosalen HCl. Patients with thrombocytopenia were randomly assigned to receive either photochemically treated (PCT) or conventional (control) platelets for up to 28 days. The primary end point was the proportion of patients with World Health Organization (WHO) grade 2 bleeding during the period of platelet support. A total of 645 patients (318 PCT and 327 control) were evaluated. The primary end point, the incidence of grade 2 bleeding (58.5% PCT versus 57.5% control), and the secondary end point, the incidence of grade 3 or 4 bleeding (4.1% PCT versus 6.1% control), were equivalent between the 2 groups (P =.001 by noninferiority). The mean 1-hour posttransfusion platelet corrected count increment (CCI) (11.1 x 10(3) PCT versus 16.0 x 10(3) control), average number of days to next platelet transfusion (1.9 PCT versus 2.4 control), and number of platelet transfusions (8.4 PCT versus 6.2 control) were different (P <.001). Transfusion reactions were fewer following PCT platelets (3.0% PCT versus 4.4% control; P =.02). The incidence of grade 2 bleeding was equivalent for PCT and conventional platelets, although posttransfusion platelet count increments and days to next transfusion were decreased for PCT compared with conventional platelets.     

Molecular analysis of a patient with type I Glanzmann thrombasthenia and clinical impact of the presence of anti-αIIbβ3 alloantibodies

The occurrence of transfusion-related alloimmunization against αIIbβ3 is a major concern in patients with Glanzmann thrombasthenia (GT). However, few data are available about molecular defects of GT patients with anti-αIIbβ3 alloantibodies as well as clinical impact of these antibodies on platelet transfusion. Here, we report a case of type I GT with anti-HLA and anti-αIIbβ3 alloantibodies, who underwent laparoscopic total gastrectomy due to gastric cancer. We found a novel β3 nonsense mutation, 892C > T (Arg272X), and the patient was homozygous for the mutation. Laparoscopic gastrectomy was successfully performed with continuous infusion of HLA-matched platelet concentrates and bolus injection of recombinant factor VIIa at 2 h intervals. Total bleeding was 370 mL and no red-cell transfusion was necessary. Flow cytometric analysis employing anti-αIIbβ3 monoclonal antibody revealed that the transfused platelet count was maintained around 20–30 × 10⁹/L during the operation and 10 × 10⁹/L on the following day. Flow cytometric analysis also showed that transfused platelets retained normal reactivity to ADP stimulation. These results indicate that flow cytometry is useful to assess survival and function of transfused platelets in GT patients with anti-αIIbβ3 antibodies.     

The use of protamine after radiofrequency catheter ablation: A pilot study

Objective Evaluate the effect of administering intravenous protamine immediately post-radiofrequency catheter ablation (RFCA) on thrombotic and bleeding complications in heparinized patients. Methods Heparinized patients that had RFCA for atrial or ventricular arrhythmias at our institution between January 2001 and March 2006 and had a complete data set were included in this cohort evaluation. Patients receiving at least one dose of protamine within 15 min of RFCA were deemed the prophylactic group while those not receiving protamine within 15 min were the control group. Thrombotic (cerebrovascular event, transient ischemic attack, pulmonary embolism, deep vein thrombosis, or myocardial infarction) and bleeding events (blood loss requiring transfusion, hematoma requiring intervention, or intracranial hemorrhage) were compared between groups. Results Overall, 158 patients (74% male, 55 ± 13.5) met inclusion criteria. Of these, 73.4% received prophylactic protamine (average dose = 39 mg ± 17). Only one patient (0.9%) in the prophylactic protamine group and zero patients in the control group experienced a thrombotic event (p > 0.99). Only two patients (1.7%) in the protamine group (n = 2 blood transfusions) and zero patients in the control group experienced bleeding events (p = 0.839). Conclusions Administering prophylactic intravenous protamine to allow for quicker catheter removal following RFCA in heparinized patients did not markedly impact thrombotic or bleeding complication rates in our population. The perceived benefit in our institution to protamine administration in this population is a reduction in postoperative patient immobilization and discomfort, reduced PACU nursing care, and earlier time to discharge. Given the low rate of thrombotic and bleeding events, a study of several thousand patients would be needed to fully evaluate the impact on these events.     

Therapeutic rather than prophylactic platelet transfusion policy for severe thrombocytopenia during liver transplantation

Abstract

Platelet transfusion (PTx) has been identified as an important risk factor for morbidity and mortality after liver transplantation (LTx). Our aim was to evaluate the safety of therapeutic rather than prophylactic PTx policy in severe thrombocytopenic patients undergoing LTx. Recipients of LTx were divided into two groups: group I (GI) (n?=?76) platelet count (PC)?≥?50?×?10⁹/l and group II (GII) PC?<?50?×?109/l (n?=?76). Platelets were transfused following a thromboelastometry protocol and clinical signs of diffuse bleeding. Both groups were compared regarding hemoglobin (Hb), international normalized ratio (INR), fibrinogen level, blood loss (BL), blood products required, percentage of bloodless surgery, duration of mechanical ventilation, ICU stay, and vascular complications. Each group was further subdivided according to PTx into (GI NPTx and GII NPTx) with no platelet transfusion (NPTx) and (GI PTx and GII PTx) received PTx. These subgroups were further compared for some variables. Base line Hb was significantly higher while INR was significantly lower in GI.75% avoided PTx in GII. Comparisons of BL, packed red blood cells (PRBCs), and cryoprecipitate transfusion were insignificant. Fresh frozen plasma (FFP) transfusion was higher and the percentage of bloodless surgery was lower in GII. In GII, PC increased after start of surgery. Two cases of hepatic artery thrombosis in GI and one in GII were recorded. Recovery of platelets was quicker, and duration of mechanical ventilation and ICU stay was shorter in NPTx patients regardless the base line PC. Cut-off values of PC?30?×?10⁹/l (with sensitivity 73.7% and specificity 78.8%, p?<?0.01), BL of 3750?ml in GI (sensitivity of 75% and specificity of 69%, p?<?0.01) and of 3250?ml in GII (sensitivity of 84.2% and specificity of 87.7% (p?<?0.01)) could indicate the need of PTx. With therapeutic approach, 75% of patients in GII could avoid unnecessary PTx with its hazards without excessive bleeding. PC in GII increased intraoperatively, PTx may lead to delayed recovery of platelets, increased duration of mechanical ventilation and ICU stay. The given cut-off values may help to guide PTx.     

Evidence that circulating immune complexes remove transfused platelets from the circulation

Fifteen recently diagnosed patients with acute leukemias admitted for induction chemotherapy were selected for study. When thrombocytopenic (venous platelet count <20 × 10⁹/1) these patients received prophylactic platelet transfusions. A total of 67 platelet transfusion therapies were administered and evaluated. Using the Raji cell radioimmunoassay, the serum concentrations of circulating immune complexes (CIC) were measured immediately before and 10–12 hr after each platelet transfusion. In 36 instances, elevated values of CIC were present in the recipient's pretransfusion samples, the corresponding posttrans-fusion values being significantly lower (P < 0.05). Furthermore, in those 36 instances the mean percentage for the posttransfusion platelet increment was significantly lower (P < 0.001) than in the remaining 31 instances in which normal pretransfusion values of CIC were measured. We conclude that CIC were an important factor in rapidly removing transfused platelets from the circulation, thereby, adversely affecting the benefit of platelet transfusions.     

Transfusion of platelet concentrates – clinical evaluation of two preparations

Abstract: The aim of this study was to compare the clinical effect of transfusion of platelet concentrates (PC) prepared from pooled buffy coats (BC) and PCs collected from a single donor (SD) by an apheresis technique. The influence of storage time and various clinical conditions was also studied. Thirty-two patients suffering from haematological malignancies were given a total of 326 platelet concentrates; 180 BC-PCs and 146 SD-PCs, median 7 transfusions per patient. BC-PCs contained 312±52×10⁹ and SD-PCs 383 ± 133 × 10⁹ platelets/unit (mean ± SD). The mean storage time of BC-PC was 3 d and that of SD-PC 1 d. The mean platelet count of the patients before transfusion was 11 ± 8 ×10⁹/L. Regression analysis showed a significant decrease of the post-transfusion platelet corrected count increment (CCI) during storage of PCs for 1–5 d (BC-PC: p <0.01; SD-PC: p <0.05). There was no difference in platelet increment between BC-PC and SD-PC. Human leukocyte antigen (HLA) alloimmunization was the major cause of clinical refractoriness to random donor platelet transfusions but splenomegaly also caused low CCI values.     

An audit of platelet transfusion within the Wellington Cancer Centre

Aim: An audit of platelet transfusion was performed to assess adherence to local prophylactic policy and to assess if therapeutic transfusions were administered in line with international recommendations. Methods: A prospective audit of platelet transfusion therapy was conducted at the Wellington Cancer Centre in patients with hypoproliferative thrombocytopenia over a 3‐month period from 26 January 2008 to 30 April 2008. There were 398 episodes of evaluable clinical decision activity generated through either platelet counts <50 × 10⁹/L or platelet transfusion events. Each episode was assessed and defined as either adhering to or breaching the local prophylactic platelet transfusion policy. Results: Thrombocytopenia and/or platelet transfusion occurred in 63 patients aged 16–84 years with either a haematological or solid organ malignancy. Decisions to withhold prophylactic platelet transfusion in thrombocytopenic patients adhered to policy for 99% of platelet counts <50 × 10⁹/L. Where transfusions were administered, 77% were prophylactic and 23% were for therapeutic indications. Prophylactic transfusions adhered to policy for 72% of platelet counts <50 × 10⁹/L. Adherence to prophylactic transfusion policy for febrile patients with a threshold of ≤15 × 10⁹/L was 84%, compared to 63% for stable afebrile patients with a threshold of ≤10 × 10⁹/L. Where policy was breached, in 80% of cases the platelet count had not reached the prophylactic transfusion threshold. Of the clinical decisions leading to therapeutic transfusions, 67% were deemed appropriate and predominantly a single adult therapeutic dose of platelets was administered. Where multiple doses of platelets were transfused, 86% of these transfusion events either breached policy or were deemed suboptimal management. Conclusion: The audit demonstrated a high rate of adherence to local transfusion policy. Where policy was breached, predominantly a transfusion had occurred prior to a platelet count reaching the pre‐defined trigger. The use of multiple dose platelet transfusions was almost never appropriate. Educating staff in the use of a stringent transfusion policy may lead to reductions in platelet product use.     

Prospective,Randomized, Controlled Trial of Starion™ <Emphasis Type="Italic">vs.</Emphasis> Ligasure™ Hemorrhoidectomy for Prolapsed Hemorrhoids

Purpose This study was designed to evaluate the efficacy and outcome of the Starion™ and Ligasure™ vessel sealing systems for sutureless hemorrhoidectomy. Methods Sixty-four patients with Grades III and IV hemorrhoids were randomized into two groups: 1) Starion™ hemorrhoidectomy (32 patients), and 2) Ligasure™ hemorrhoidectomy (32 patients). The patient demographics, operative details, numbers of parenteral analgesic injections, postoperative pain scores (assessed by an independent assessor), operating time, intraoperative blood loss, hospital stay, early and delayed complications, and time off from work or normal activity were recorded. The patients were regularly followed-up at 1, 2, 4, 6, 8, and 12 weeks after surgery. Results The mean blood loss, mean operating time, duration of hospital stay, and time off from work or normal activity were not significantly different between the two methods (all P > 0.05), except for a lower pain score (P = 0.032) and reduced numbers of parenteral analgesic injections (P < 0.001) in Starion™ hemorrhoidectomy. In addition, there were no differences in the early and delayed postoperative complications between the two methods (all P > 0.05). Unfortunately, two patients with symptomatic anal stenosis requiring treatment were encountered by Ligasure™ hemorrhoidectomy, but none by Starion™ hemorrhoidectomy. Conclusions Starion™ hemorrhoidectomy with submucosal dissection is a safe and effective procedure, comparable to Ligasure™ hemorrhoidectomy. Patients derive a short-term benefit of less pain and reduced parenteral analgesic use by Starion™ hemorrhoidectomy. The superiority of no cases complicated with symptomatic anal stenosis requiring treatment by Starion™ hemorrhoidectomy seems to offer a better therapeutic alternative for prolapsed hemorrhoids.     

Functional capacity of transfused platelets estimated by the Thrombostat 4000/2

Abstract: Post-transfusion platelet increment is a useful test for the evaluation of transfusion efficacy. It does not, however, give information about the in vivo platelet function. We have evaluated the in vitro bleeding time (IVBT) using the Thrombostat 4000/2 with ADP as activating agent in 60 platelet transfusions given to 17 chemotherapy-induced severely thrombocytopenic patients. Determinations were performed before and after transfusion of platelet concentrates (PC) prepared from buffy coat. Both fresh and stored platelets resulted in significant reductions of the IVBT already 10 minutes after completed platelet transfusion. In the majority of patients there was a correspondence between IVBT and platelet increment. However, in 30% of the cases there was no improvement of the IVBT despite an increase of the platelet count. Fresh PCs were more effective I than stored. The IVBT seems to represent a clear-cut improvement in the possibilities for evaluating and monitoring the effect of platelet transfusion.     

Romiplostim in children with chronic refractory ITP: randomized placebo controlled study

Romiplostim stimulates thrombopoietin receptor to increase platelet production of megakaryocytes in idiopathic thrombocytopenic purpura (ITP). This study aimed to evaluate the safety and efficacy of romiplostim in children with chronic ITP. Eighteen patients with chronic ITP, either none responsive or failed to maintain response on two or more therapeutic modalities, were enrolled. Patients were randomized (2:1) to receive romiplostim or placebo for 12 weeks, initiated at 1 μg/kg/week, escalated to 5 μg/kg/week, and then tapered. Median patients' age was 8.5 years, and the median baseline platelet count (PC) was 10.5 × 10⁹/L. The median weekly dose of romiplostim was 2 μg/kg. Fifty percent of patients in both romiplostim and placebo arms had at least one adverse event (AE); none was serious. Ten patients on romiplostim (83.3%) maintained the efficacy endpoint (PC > 50,000). Romiplostim was well-tolerated and efficient in treating the children with chronic refractory ITP with no unexpected AEs.     

Successful treatment of platelet transfusion refractoriness: the use of platelet transfusions matched for both human leucocyte antigens (HLA) and human platelet alloantigens (HPA) in alloimmunized patients with leukaemia

Six patients, 4 with acute myeloid leukaemia and 2 with a myelodysplasia syndrome who were refractory to random donor platelet transfusions and alloimmunized to human leucocyte antigens (HLA) and human platelet alloantigens (HPA), were treated with HLA-and HPA-matched platelet transfusions. In all the patients refractoriness and alloantibodies to HLA as well as HPA-1b or HPA-5b were detected simultaneously. Sixty-seven transfusions (445 units) of HLA-and HPA-matched platelets were given and responses to them were, in general, satisfactory in all the patients. No major spontaneous bleeding occurred. Four patients underwent bone marrow transplantation despite alloimmunization. The percentages of platelet transfusion days with a platelet nadir below 20×10⁹/l were 88% for the last 3 random donor platelet transfusions and 39% for the first 3 HLA-and HPA-matched platelet transfusions, respectively (p=0.009, Fisher's exact test). Four patients received also HLA-matched platelets, but responses to them were poor. The small number of transfusions with HLA-matched platelets precluded comparisons to either the random donor or HLA-and HPA-matched platelet transfusions. It seems that HLA-and HPA-alloimmunized patients can be successfully supported with HLA-and HPA-matched platelet concentrates.     

Transfused stored platelets have the same haemostatic function as circulating native platelets

Background and objectives As thrombelastography^® (TEG) measures haemostasis in whole blood, we used this instrument to study whether transfused platelets (PLTs) have the same haemostatic function compared to native circulating PLTs. Further, we studied the effect of storage time on the haemostatic potential of platelet concentrates (PCs). Materials and methods During the decrease in PLT count after chemotherapy, TEG parameters were measured serially until the transfusion trigger was reached in 92 patients. TEG parameters for different ranges of native circulating PLTs could be assessed, which were compared to ranges obtained in the thrombocytopenic period in which the patient received PLT transfusions. Finally, we compared the haemostatic potential of fresh PCs (1–3 days) with PCs with longer storage time (4–5 days). Results No differences could be found in haemostatic potential between native PLTs and transfused stored PLTs (all P‐values ≥ 0·1). The transfusion of fresh PLTs demonstrated better haemostatic effects than longer stored PLTs, measured 1 h after transfusion. Both the time until a fixed level of clot firmness was reached (K‐time) and the rate of clot growth (alpha angle) were superior for fresh PCs. Conclusion TEG is able to monitor the haemostatic effects of PLT transfusion, with comparable haemostatic properties of native circulating and transfused stored‐PLTs. Further, our data suggest that limited storage time is associated with a better haemostatic capacity. However, before TEG can be applied as a qualitative test in PLT transfusion, further research is needed with focus on clinical outcomes like bleeding episodes.     

Use of Intracolonic Bypass Secured by a Biodegradable Anastomotic Ring to Protect the Low Rectal Anastomosis

Purpose Because of the relatively high morbidity and mortality of anastomotic leakage in patients with low rectal cancer who receive an anterior resection, many fecal diverting methods have been introduced. This study was designed to assess the efficacy and safety of the Valtrac™-secured intracolonic bypass in protecting low rectal anastomosis and to compare the efficacy and complications of Valtrac™-secured intracolonic bypass with those of loop ileostomy. Methods From January 2002 to April 2006, 83 patients with rectal cancer who underwent elective low anterior resection received intracolonic bypass or ileostomy. Demographics, clinical features, and operative data were recorded. Results Forty-four patients (53 percent) received a Valtrac™-secured intracolonic bypass and 39 patients (47 percent) a loop ileostomy. The demographics and clinical features of the groups were similar. None of the patients developed clinical anastomotic leakage. Longer overall postoperative hospital stay (21.3 ± 5.8 days) and higher costs incurred (3.1 ± 0.9 × $1,000 U.S. dollars) were observed in the ileostomy group than in the intracolonic bypass group (12.5 ± 6.3 days, 4.4 ± 1.2 × $1,000 U.S. dollars; P < 0.05). Stoma-related complications in the ileostomy group included dermatitis (12.8 percent), bleeding (2.6 percent), and intestinal obstruction after stoma closure (5.1 percent). No complications were observed in the intracolonic bypass group except for the Valtrac™ ring discharging en bloc, which compromised fecal evacuation in two cases (4.5 percent). Conclusions The Valtrac™-secured intracolonic bypass procedure is a safe, effective, but time-limited, diverting technique to protect an elective low colorectal anastomosis. Valtrac™-secured intracolonic bypass, in contrast to loop ileostomy, avoids stoma-related complications or readmission for closure and is associated with decreased hospital time and cost. Presented at the First National Conference on Colorectal Surgery, Zhu Hai, Guang Dong, China, November 2 to 5, 2006. Reprints are not available.