Search

Background Hemolysis following the administration of intravenous immunoglobulin (IVIG) is an important adverse event (AE). While the monocyte monolayer assay (MMA) has been used to predict in vivo hemolysis when serologically incompatible blood may be transfused, it has also been shown to correlate with IVIG-associated hemolysis. In this study, the MMA was examined for its utility in assessing the risk of hemolysis after IVIG. Study design and methods Forty-two non-blood group O patients receiving high-dose IVIG (≥2 g/kg) were examined using an autologous and allogeneic MMA. Hemolysis was defined by a drop in hemoglobin of ≥1 g/L, a positive direct antiglobulin test (DAT) and eluate, and a decrease in haptoglobin or increase in lactate dehydrogenase and/or reticulocytes. Results Forty-two patients provided 50 assessable postinfusion samples, with hemolysis observed in 20 (40%) of cases. Autologous MMA using post-IVIG red blood cells significantly correlated with clinical outcomes when compared to allogeneic MMA (P = .0320 vs .5806, t test). No significant difference in receiver operating characteristics was observed when comparing autologous MMA testing against DAT for the diagnosis of IVIG-associated hemolysis. However, when using samples collected 5 to 10 days after receipt of high-dose IVIG, the autologous MMA had higher sensitivity than the DAT. Conclusion MMA testing with autologous monocytes collected 5 to 10 days after receipt of high-dose IVIG can be used for the diagnosis of IVIG-associated hemolysis and may be of particular value in cases in which the Day 5 to 10 DAT is negative.

Background Platelet transfusions are used to prevent or control bleeding in patients with thrombocytopenia or platelet dysfunction. The pretransfusion platelet count threshold has been studied extensively in multiple patient settings yielding high-quality evidence that has been summarized in several comprehensive evidence-based platelet guidelines. Study design and methods A prospective 12-week audit of consecutive platelet transfusions using validated and evidence-based adjudication criteria was conducted. Patient demographic, laboratory, and transfusion details were collected with an electronic audit tool. Each order was adjudicated either electronically or independently by two transfusion medicine physicians. The aim was to determine platelet transfusion appropriateness and common scenarios with deviations from guidelines. Results Fifty-seven (38%) of 150 hospitals provided data on 1903 platelet orders, representing 90% of platelet usage in the region during the time period. Overall, 702 of 1693 adult (41.5%) and 133 of 210 pediatric orders (63.3%) were deemed inappropriate. The most common inappropriate platelet order was for prophylaxis in the absence of bleeding or planned procedure in patients with hypoproliferative thrombocytopenia and a platelet count over 10 x 109 /L (53% of inappropriate orders in adults and 45% in pediatrics). Platelet transfusions ordered with either a preprinted transfusion order set (odds ratio [OR], 1.97; 95% confidence interval [CI], 1.44-2.73) or technologist prospective screening (OR, 1.40; 95% CI, 1.10-1.78) were more likely to be appropriate. Conclusion There is a discrepancy between clinical practice and evidence-based platelet guidelines. Broad educational and system changes will be needed to align platelet transfusion practice with guideline recommendations.

In this study, we assessed the association between preoperative hemoglobin and red blood cell transfusion in children undergoing spine surgery after the implementation of our preoperative iron supplementation protocol.We performed a retrospective analysis of patients who underwent posterior spinal fusion surgery between January 2013 and December 2017 and received preoperative iron supplementation. We used uni- and multivariable logistic regression to determine the association between preoperative hemoglobin level and red blood cell transfusion in patients receiving iron supplementation.A total of 382 patients treated with preoperative oral iron were included. Of these, 175 (45.5%) patients were transfused intraoperatively. Multivariable logistic regression analysis revealed nonidiopathic etiology of the scoliosis (OR 4.178 [95% CI: 2.277-7.668], P .001), the Cobb angle (OR 1.025 [95% CI: 1.010-1.040], P = .001), and number of vertebrae fused (OR 1.169 [95% CI: 1.042-1.312], P = .008) were associated with red blood cell transfusion. In addition, patients with a preoperative hemoglobin ≥ 140 g/L (OR 0.157 [95% CI: 0.046-0.540], P = .003), and hemoglobin between 130 and 140 g/L (OR 0.195 [95% CI: 0.057-0.669], P = .009) were less likely to be transfused compared with patients with preoperative hemoglobin between 120 and 130 g/L (OR 0.294 [95% CI: 0.780-1.082], P = .066) or120 g/L (reference).Our study suggests that higher preoperative hemoglobin levels (130 g/L) are associated with a reduced need for red blood cell transfusion in pediatric patients who have received iron supplementation before undergoing posterior spinal fusion in our institution. The effect of iron supplementation, the optimal dosing, and duration of supplemental iron therapy remains unclear at this time.

Hemolytic anemia resulting from IV Immunoglobulin (IVIG) treatment can be a serious complication, especially for those with underlying conditions with a high level of inflammation and after administration of high IVIG dosages, such as Kawasaki disease (KD), a multisystem vasculitis affecting young children. This hemolysis is caused by antibodies against blood groups A and B, but the precise mechanism for hemolysis is not known. We performed a single center, partly retrospective, partly prospective study of a cohort of 581 patients who received IVIG for treatment of KD from 2006 to 2013. Factors associated with hemolysis were identified through univariable and multivariable logistic regression. Six IVIG preparations were assayed for their hemolytic effect with serological and cellular assays to clarify the mechanism of red cell destruction. During the study period, a sudden increase in the incidence of hemolysis was observed, which coincided with the introduction of new IVIG preparations in North America that contained relatively high titers of anti-A and anti-B. These blood-group–specific antibodies were of the immunoglobulin G2 (IgG2) subclass and resulted in phagocytosis by monocyte-derived macrophages in an FcγRIIa-dependent manner. Phagocytosis was increased in the presence of proinflammatory mediators that mimicked the inflammatory state of KD. An increased frequency of severe hemolysis following IVIG administration was caused by ABO blood-group–specific IgG2 antibodies leading to FcγRIIa-dependent clearance of erythrocytes. This increase in adverse events necessitates a reconsideration of the criteria for maximum titer (1:64) of anti-A and anti-B in IVIG preparations.

Background Intravenous Immune Globulin (IVIG) is used to treat numerous immune-mediated and inflammatory conditions. There is growing awareness of hemolysis, occasionally severe, as a side-effect of this therapy. While most cases are associated with anti-A and/or anti-B isoagglutinins, the frequency and mechanism of hemolysis remain poorly characterized. Study design and methods A prospective observational study was conducted to determine incidence, natural history and risk factors for IVIG-mediated hemolysis. A total of 99 infusions of high-dose IVIG (2 g/kg or higher) administered to 78 non-group O patients were monitored and graded according to Canadian IVIG Hemolysis Pharmacovigilance Group. Serum ferritin and C3/C4 levels were monitored as indicators of macrophage activation and complement consumption, respectively. Supplementary investigations included assessment for ABO zygosity, Secretor status, FcR polymorphisms, eluate IgG subclass, monocyte monolayer assay, and a panel of cytokines. Results Hemolysis was observed in 32 of 99 (32%) of infusions, with 19 of 99 (19%) grade 2 or higher. Hemolysis was only apparent 5-10 days after a completed IVIG infusion in 84% of cases and was associated with increases in serum ferritin without complement-consumption. In univariate analysis, increased risk was observed in group AB patients, first-time IVIG recipients, those not taking immuosuppressive medications, or patients treated with a specific IVIG brand; however, in multivariate analysis, product association was no longer observed. No other patient- or practice-related risk factors were identified. Conclusion IVIG-mediated hemolysis is common and frequently severe. Monitoring for 5-10 days following an infusion should be considered in non-O patients receiving high-dose IVIG with known risk factors.

BACKGROUND Alloantibodies to the low-frequency antigen Scianna-2 (Sc2) have been implicated in cases of hemolytic disease of the fetus and newborn but never in hemolytic transfusion reactions (HTRs); thus, the clinical significance of anti-Sc2 has yet to be fully addressed. STUDY DESIGN AND METHODS A 26-year-old woman with thalassemia presented rigors, fever, nausea, abdominal pain, and hemolytic biochemistry after exposure to 75 mL of plasma-reduced red blood cells (RBCs). The RBC unit was issued by electronic crossmatch but was 3+ incompatible on recrossmatch by gel indirect antiglobulin test (IAT). The patient had anti-Sc2 previously identified, but considered to be clinically insignificant. The transfusion history was reviewed and a monocyte monolayer assay (MMA) was performed. RESULTS The patient was investigated for a RBC reaction 9 years prior, when she developed symptoms of HTR. The RBC unit was crossmatched by immediate spin due to consistent screen negativity. Full crossmatch found the RBC 1+ incompatible by gel IAT with both pre/post samples, while direct antiglobulin test was negative (pre) and 1+ immunoglobulin G positive (post). The antibody remained unidentified and she was committed to gel IAT crossmatch. Two-years later, the specificity to Sc2 was deduced when one RBC unit was found 3+ incompatible. Finally, the transfusion reaction reported herein occurred when she received by happenstance RBCs from the same donor who was associated with the remote reaction 9 years earlier. MMA yielded highly positive phagocytic indices only for Sc2+ RBCs, including the donor's RBCs that triggered the severe HTR. CONCLUSION This is the first case of HTR caused by anti-Sc2 confirmed by clinical findings and MMA.

TO THE EDITOR: Although frequently effective[1][1],[2][2] and usually benign, high-dose (2 g/kg) intravenous immunoglobulin (IVIG) therapy can result in marked red blood cell (RBC) hemolysis, which in some cases is life threatening in severity.[3][3][⇓][4]-[5][5] The mechanism by which this

BACKGROUND The optimal method of providing transfusion medicine (TM) education has not been determined. Transfusion Camp was established in 2012 at the University of Toronto as a centrally delivered TM education program for postgraduate trainees. The impact of Transfusion Camp on knowledge, attitudes, and self-reported behavior was evaluated. METHODS Didactic lectures (delivered locally, by webinar, or recorded) and locally facilitated team-based learning seminars were delivered over 5 days during the academic year to 8 sites: 7 in Canada and 1 in the United Kingdom. Knowledge assessment using a validated 20-question multiple-choice exam was conducted before and after Transfusion Camp. Attitudes and self-reported behavior were collected through a survey. RESULTS Over 2 academic years (July 2016 to June 2018), 390 trainees from 16 different specialties (predominantly anesthesia, 41%; hematology, 14%; and critical care, 7%) attended at least 1 day of Transfusion Camp. The mean pretest score was 10.3 of 20 (±2.9; n = 286) compared with posttest score of 13.0 (±2.8; n = 194; p < 0.0001). Lower pretest score and greater attendance (4-5 days compared with 1-3 days) were associated with larger improvement in posttest score; delivery format, specialty, and postgraduate year were not. Trainees reported an improvement in self-rated abilities to manage TM scenarios; 95% rated TM knowledge as very or extremely important in providing patient care; and 81% indicated that they had applied learning from Transfusion Camp into clinical practice. CONCLUSIONS Transfusion Camp increased TM knowledge, fostered a positive attitude toward TM, and enabled a self-reported positive impact on transfusion practice in postgraduate trainees. It is a novel and scalable approach to delivering TM education.

Aim To quantify circulating fibroblast activation protein (cFAP) and dipeptidyl peptidase 4 (cDPP4) protease activities in patients with rheumatoid arthritis (RA), systemic sclerosis (SSc), and a control group with mechanical back pain and to correlate plasma levels with disease characteristics. Methods Plasma was collected from patients with RA (n = 73), SSc (n = 37) and control subjects (n = 26). DPP4 and FAP were quantified using specific enzyme activity assays. Results Median cDPP4 was significantly lower in the RA group (P = 0.02), and SSc group (P = 0.002) compared with controls. There were no significant differences in median cFAP between the three groups. DPP4 and FAP demonstrated a negative correlation with inflammatory markers and duration of disease. There were no associations with disease subtypes in RA, including seropositive and erosive disease. Decreased cDPP4 was found in SSc patients with myositis. Plasma FAP was lower in RA patients receiving prednisone (P = 0.001) or leflunomide (P = 0.04), but higher with biologic agents (P = 0.01). RA patients receiving leflunomide also had decreased cDPP4 (P = 0.014). SSc patients receiving prednisone (P = 0.02) had lower cDPP4 but there was no association with cFAP. Conclusions No association was found between cFAP and RA or SSc. Plasma DPP4 was decreased in RA and SSc when compared with controls. cDPP4 and cFAP correlated negatively with inflammatory markers and there were no significant correlations with disease characteristics in this RA cohort.

In a failure event, circuit schematic analysis usually follows after fault isolation to increase the success rate. However, analyzing an extracted netlist of the isolated sub-circuit can be messy. Manual circuit translation from layout where the analyst is in control of the cell instance placement is one way to overcome this challenge. Although it is neater and intuitive for analysis, it can be time consuming to create the schematic. To analyze circuits in a systematic manner, cross-mapping between layout and schematic contents is the most commonly recognized approach. However, at times, cross-mapping alone is insufficient and some further simplification procedures are favorable. This paper describes the challenges and illustrates using real case studies, how schematics re-ordering and substitutions can be useful to simplify and enhance circuit analysis. These procedures can be implemented in an automated manner to enhance turnaround time for analysis.

BACKGROUND Blood transfusions and fractionated products are not without risk and may lead to acute and long-term adverse events. The objective of this study was to evaluate the appropriateness of usage of frozen plasma (FP), cryoprecipitate (CRYO), and recombinant factor VIIa (rVIIa) in a pediatric setting. METHODS All orders for FP, CRYO, and rVIIa were prospectively audited over 6 weeks. Data collected included demographics, laboratory values, indication, and adverse reactions. The appropriateness of each order was independently evaluated using adjudication criteria rated by two hematologists. RESULTS Two hundred sixty-five products were ordered; 67% of the orders were issued to operating rooms or intensive care units. The most common indication for all products was cardiac surgery. FP was ordered as fluid replacement (15/215; 7%) to correct abnormal coagulation tests (23/215; 11%) and for patients with minor or no bleeding (111/242; 46%). FP was more likely to alter the international normalized ratio (INR) if the INR was over 2.0 (P

The presence or absence of core fucose in the Fc region N-linked glycans of antibodies affects their binding affinity toward FcγRIIIa as well as their antibody-dependent cell-mediated cytotoxicity (ADCC) activity. However, the quantitative nature of this structure-function relationship remains unclear. In this study, the in vitro biological activity of an afucosylated anti-CD20 antibody was fully characterized. Further, the effect of fucose reduction on Fc effector functions was quantitatively evaluated using the afucosylated antibody, its "regular" fucosylated counterpart and a series of mixtures containing varying proportions of "regular" and afucosylated materials. Compared with the "regular" fucosylated antibody, the afucosylated antibody demonstrated similar binding interactions with the target antigen (CD20), C1q and FcγRIa, moderate increases in binding to FcγRIIa and IIb, and substantially increased binding to FcγRIIIa. The afucosylated antibodies also showed comparable complement-dependent cytotoxicity activity but markedly increased ADCC activity. Based on EC 50 values derived from dose-response curves, our results indicate that the amount of afucosylated glycan in antibody samples correlate with both FcγRIIIa binding activity and ADCC activity in a linear fashion. Furthermore, the extent of ADCC enhancement due to fucose depletion was not affected by the FcγRIIIa genotype of the effector cells.

Background Recombinant activated factor VII (rFVIIa) is a hemostatic agent developed for the treatment of bleeds in patients with hemophilia and inhibitors. Case reports/series document its growing use in patients without hemophilia. Such reports however do not accurately describe the proportion of rFVIIa used for various indications. We sought to document the complete use of rFVIIa at our institution over a 6-year period (2000–2005). Procedure Using a computerized registry documenting all rFVIIa use in our institution a complete list of patients receiving rFVIIa was generated. Clinical data on these patients was obtained through chart review. Results 111 patients received 7,016,400 µg of rFVIIa over the 6 years: 23 patients had congenital bleeding disorders (10 patients with hemophilia and inhibitors; 7 with congenital FVII deficiency; 6 with platelet function disorders). These 23 patients (21% of all patients receiving rFVIIa) accounted for 79.9% of all rFVIIa used; patients with hemophilia alone accounted for 68.6%. The 88 patients without a congenital bleeding disorder (79% of all patients using rFVIIa) accounted for 20.1% of rFVIIa used. However their annual use of rFVIIa increased 10-fold during the 6 years. Conclusions Patients with hemophilia use massive amounts of rFVIIa repeatedly while patients without hemophilia use rFVIIa infrequently and at smaller doses. The use of rFVIIa in patients without congenital bleeding disorders (all “off-label” use) is rapidly growing in both number of patients and in total use and has likely significant clinical and economic ramifications. Pediatr Blood Cancer 2008;50:1013–1017. © 2007 Wiley-Liss, Inc.

Hyperleukocytosis in children with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) is associated with early morbidity and mortality. The benefit from leukapheresis is controversial, and its complications are not well defined. We analyzed the frequency of early complications in children with ALL and AML presenting with white blood cell (WBC) count >100 × 10(9)/L, and the type and frequency of complications related to leukapheresis. During a 12-year period, 84 of 634 (13%) ALL and 18 of 143 (12.5%) AML patients presented with hyperleukocytosis. Leukapheresis was performed in 18 ALL and 12 AML patients. The median initial WBC was 474 × 10(9)/L in the leukapheresis group compared with 175 × 10(9)/L in the nonleukapheresis group. Neurological leukostasis occurred in 6 ALL (7.1%) and 4 AML (22.2%) patients. Pulmonary leukostasis occurred in 16 ALL (19%) and 4 AML patients (22.2%). Neurological symptoms improved in few patients after leukapheresis, except in patients with very high WBC (>650 × 10(9)/L in ALL and >400 × 10(9)/L in AML). Leukapheresis improved respiratory symptoms in some patients but caused worsening symptoms in others. Early death was associated with neurological complications, AML diagnosis, and coagulopathy. Leukapheresis did not delay initiation of chemotherapy, nor did it impact early response to chemotherapy or long-term survival. Complications included femoral vein thrombosis, electrolyte imbalances, and hemodynamic instability, which were all reversible. The role of leukapheresis as a cytoreductive procedure in childhood hyperleukocytic leukemia remains to be well defined.

Background: The aim of the present paper was to determine whether monthly i.v. immunoglobulin (IVIG) could be safely discontinued in antiretroviral-treated human immunodeficiency virus (HIV)-infected children. Methods: In a double-blind cross-over trial, children ≤18 years with HIV infection, well controlled on antiretroviral therapy, were randomized to alternating courses of 3 consecutive months of IVIG (400 mg/kg once a month) and 3 consecutive months of placebo for 1 year. The primary outcome was days of fever per month. Secondary outcomes were frequency of serious infections, changes in HIV viral load (VL), CD4+ counts and IgG levels. Results: Fifteen children were enrolled. Using the revised pediatric HIV clinical classification system of the Centers for Disease Control and Prevention, eight were severely symptomatic (C), four were moderately symptomatic (B) and three were mildly symptomatic (A). There were no statistically significant outcome measures. The mean number of days of fever per month with IVIG versus placebo was 0.55 days versus 1.48 days (P = 0.11). The difference was 0.9 days (95% confidence interval: +2.05 to −0.25). There were no serious infections in either period. For the IVIG versus placebo periods, mean CD4 counts were 970 cells/μL versus 906 cells/μL (P = 0.12), VL 2.90 log10 copies/mL versus 2.82 log10 copies/mL (P = 0.70) and IgG levels were 17.41 g/L versus 16.6 g/L (P = 0.13). Conclusion: In antiretroviral-treated HIV-infected children short-term withdrawal of monthly IVIG was not associated with a significant increase in incidence of infections or a decline in immunologic function (CD4 count, viral load and IgG levels). These results suggest that monthly IVIG can be safely discontinued in HIV-infected children who are clinically stable and receiving combination antiretroviral therapy.

An international project team (including members from US, Canada and UK) was formed from a number of interested biopharmaceutical companies and regulatory authorities to conduct a cross-organisation collaboration exercise. The results of the first comparison with eight different organisations that used instruments of the same equipment model, the same reagents, and the same methodology has been reported previously [1]. This report represents the addition of other instruments using a different run buffer. The relative migration times were different, as expected, prohibiting a direct comparison between companies. The within-organisation variability was low for both relative migration time (

Background: Intravenous immunoglobulin (IVIG) is the mainstay of treatment for Kawasaki Disease (KD). Due to the consolidation of IVIG manufacturers in 2008, different preparations of IVIG are currently available in Canada. An increase in adverse effects, especially hemolytic anemia, has been observed. Objective: To characterize the natural history of IVIG-associated hemolytic anemia in KD. Methods: A single-centre retrospective study was conducted at Toronto’s SickKids Hospital between January 2002 and December 2012. Medical records of all KD patients were reviewed and hemolytic anemia identified (drop in hemoglobin ≥20mg/dl post-IVIG treatment with 2 or more of the following criteria: reticulocytosis, positive direct anti-globulin test (DAT), and morphological changes on blood film). For statistical analysis, Chi-square tests and ANOVA with Tukey’s post-hoc correction for multiple comparisons were utilized. Results: Between 2002 and 2008, 2 of 370 patients diagnosed with KD who received Iveegam had hemolytic anemia (0.5%). After 2008, the rates of IVIG-associated hemolysis were as follows: Privigen 17% (8/48, p5) in the hemolysis group (17% vs. 5.3%). All patients who hemolyzed had non-O+ blood types. Out of the 17 patients with hemolysis, 9 required red cell transfusions (60%). Starting in 2012, a detailed hemolysis work-up was included as standard protocol for all KD patients. Hemolysis was mediated by anti-blood group A & B antibodies resulting in DAT positivity, but no complement fixation. This extravascular hemolysis was maximal at 72 hours post-IVIG infusion and appeared to be dose dependent. Conclusions: Hemolysis is seen in up to 17% of those receiving new IVIG preparations, which also appear to be less efficacious - associated with treatment failure and, possibly, poor coronary outcome. There are important implications for patient safety. Further study is required to develop evidence-based guidelines to improve our management of these children.

An 8-year-old boy with no history of allergies received craniospinal radiation and cycles of autologous transplantations, which included chemotherapy and blood product support, for the treatment of medulloblastoma. A few weeks after his third cycle, he experienced anaphylaxis within 10 minutes after

An international project team (including members from US, Canada and UK) has been formed from a number of interested biopharmaceutical companies and regulatory authorities to conduct a cross-organisation collaboration exercise. The results from this exercise demonstrate the robustness of CE-SDS across eight different organisations that used instruments of the same equipment model, the same reagents, and the same methodology. Data generated from the analysis of a series of molecular weight markers showed very good precision with regards to relative migration time (RMT) both within and between organisations. The apparent molecular weight of bovine serum albumin (BSA) was measured with good precision to within approximately 2% RSD across the participants. A representative IgG sample showed similar results with regards to relative migration time of its 3 main components, IgG Light Chain, IgG Non-glycosylated Heavy Chain, and IgG Heavy Chain. Fractional peak area for each peak also showed good agreement, with less than 9% RSD for all peaks. This exercise will facilitate both increased regulatory and industrial opinion of CE for biopharmaceutical analysis.

Summary. Seventy percent of children with acute lymphoblastic leukaemia (ALL) who may benefit from bone marrow transplant (BMT) lack a human leucocyte antigen (HLA)-matched related donor (MRD). For these children, BMT from a matched unrelated donor (MUD) represents a therapeutic option. We reviewed the course of 62 children with ALL who received fully matched marrow allografts at our institution between 1990 and 1998: 36 with MRDs and 26 with MUDs. Clinical characteristics were similar in the two groups. The interval from attainment of pre-BMT complete remission to transplant was significantly longer in the MUD group. Conditioning (etoposide/total body irradiation) and graft-versus-host disease (GVHD) prophylaxis regimens were the same for all patients, and all received T cell-replete bone marrow. There was no significant difference in probability of engraftment, or time to engraftment, in the two groups. MUD BMT recipients had a significantly greater incidence of grade II–IV acute GVHD (58% versus 24% in the MRD group; P= 0·02), and demonstrated a trend towards more chronic GVHD (39% versus 15%; P= 0·06). Three years post BMT, the probabilities of transplant-related mortality were 33 ± 11% and 20 ± 8% in MUD and MRD groups respectively (P = 0·38); the probabilities of relapse were 28 ± 12% and 41 ± 9% respectively (P = 0·19). Lansky or Karnofsky performance scores in event-free survivors were 90–100 in 87% of the MUD group and 83% of the MRD group. With a median follow up of 38 months (range, 3–97), 3-year event-free survival was 49 ± 11% and 47 ± 9% in the MUD and MRD BMT groups respectively (P = 0·71). These results suggest that MUD BMT is a valuable therapy for children with ALL in whom BMT is indicated, and underscore the importance of efforts aimed at expediting unrelated donor searches for patients lacking a MRD.

To review the epidemiology, pathophysiology, therapeutic and preventive strategies of transfusion associated graft versus host disease (TA-GVHD) and relate the findings to the critically ill child.Review article of published medical literature related to TA-GVHD.Medline, bibliography search, published national and institutional guidelines.Original publications including prospective studies, case reports, case series, laboratory studies, and animal work.Data were extracted manually after we reviewed selected articles and assessed their contribution to knowledge of TA-GVHD.New and significant historic information from the selected publications relating to incidence, therapy, prevention, and complications of preventive therapy of TA-GVHD was incorporated.Pediatric critical care practitioners should be aware of this preventable but fatal complication of cellular blood product transfusion. High-risk categories include congenital and acquired immunodeficiency, younger age, transfusion of blood donated by family members, and transfusion with fresh whole blood. Children at risk for the development of TA-GVHD include neonates, infants, and children with congenital heart disease, not restricted to children with "classic" DiGeorge syndrome. At present, risk identification and targeted prevention are the only methods to manage TA-GVHD. Aside from minimizing cellular blood product exposure, blood product irradiation is the only established and widely available method to prevent TA-GVHD. Transfusion guidelines need to reflect a balance between the incidence of TA-GVHD and the costs of instituting irradiation to selected groups or as routine transfusion policy.

Purpose: To date, there are no data to support the safety, efficacy, and cost-benefit ratio of donor-directed blood donation (DD). The objectives were to determine whether a DD program in pediatric general surgery practice is justified. Methods: A retrospective analysis was conducted of the transfusion practice and all DD requests received by transfusion services in a full calendar year (1997) at a tertiary care pediatric hospital. The authors examined the donations, utilization, and possible benefits for the recipients. Results: A total of 22,527 units of blood were transfused in 1997. General surgery used 471 (2%) of the total and 471 of 4,825 (10%) of all surgical transfusions. Total DD requests were 219 with only 11 of 219 (5%) originating from the general surgery department. After all the exclusions, 133 of 219 (61%) requests had DD blood available. DD blood had a higher true-positive rate for transmissible disease (1.1% v 0.10%), high-risk activity (2.5% v 1.2%), and malaria risk (3.1% v 0.31%). Total utilization of DD blood was 132 of 236 units (55.9%) and general surgery utilized 4 of 11 (36.4%) of their directed donations. Thirty-seven patients (27.8%) benefited from decreased donor exposure. No general surgery patient received more than 1 blood component to benefit from decreased donor exposure. Conclusion: DD deferral rates are higher than for volunteer donors for infectious disease markers, malaria, and high-risk activities. There is no evidence that DD is safer than volunteer donation. DD blood wastage of 63.6% is much higher than in volunteer donation (7%). Thirty-seven patients (28%) received multiple units from one donor suggesting a benefit from decreased donor exposure. Given the low frequency of transfusion and the poor utilization of DD in general surgical practice, a DD program is not justified. J Pediatr Surg 36:722-725. Copyright © 2001 by W.B. Saunders Company.

When selecting an antiarrhythmic agent the clinician needs to be able to accurately predict the probability that a particular drug will serve its intended purpose in a given patient. This is difficult because of the complexity of variables which govern the relationship between drug administration and clinical outcome. The efficacy of a drug may potentially be predicted from its mechanism of action. At least two classifications of antiarrhythmic agents based on mechanism of action have been proposed. The Vaughan Williams classification is based on the predominant electrophysiological effects of a drug on the action potential. In the Sicilian Gambit approach, a number of potential targets ('vulnerable parameters') for drug action are identified and antiarrhythmic drugs or substances that affect cardiac electrophysiology are characterised by their actions on each of these. The usefulness of these classification systems in predicting antiarrhythmic drug efficacy are limited. Furthermore, in the Vaughan Williams classification not all drugs in the same class have identical effects, whereas some drugs in different classes have overlapping actions. The Sicilian Gambit requires in-depth knowledge regarding cellular and molecular targets of antiarrhythmic agents which may make it intimidating or simply impractical for regular clinical use. Surrogate measures such as 24-hour Holter monitoring and programmed electrical stimulation have been used to predict anti-arrhythmic drug efficacy. However, studies such the Cardiac Arrhythmia Suppression Trial (CAST) have shown that suppression of ventricular ectopy on Holter monitoring does not necessarily correlate with improved survival and may in fact be dangerous. Conversely, studies using programmed electrical stimulation to assess drug effect on variables such as tachycardia inducibility, refractory period and ventricular tachycardia cycle length show that suppression of tachycardia inducibility, prolongation of refractory period and prolongation of ventricular tachycardia cycle length, are all associated with reduced recurrence of tachycardia and possibly improved survival. The most practical use of the current classification systems applied to antiarrhythmic agents may be in their ability to predict with reasonable accuracy, the risk and type of proarrhythmia based on the mechanism of action of an agent.

Programmed upper rate pacing occurred in a patient with a rate-adaptive pacemaker when he was connected to a cardiac monitor in an emergency department. The tachycardia was mistakenly interpreted to be ventricular tachycardia and the patient received multiple DC shocks as well as intravenous amiodarone and sotalol, resulting in severe hemodynamic deterioration. It is important that physicians working in the hospital environment be familiar with this pacemaker-monitor interaction as the problem may be easily rectified by disconnecting the monitor or by reprogramming the pacemaker to a nonrate-adaptive pacing mode.

Graft acceptance following pediatric ABO-incompatible heart transplantation has been associated with a deficiency of donor-specific isohemagglutinins (DSI) due to B-cell elimination. Recent observations suggest that some of these patients do produce DSI. The purpose of this study was to examine the pattern of, risk factors for development and clinical impact of DSI. All children who underwent an ABO-incompatible heart transplant (1996–2009) were included. Serial postheart transplantation DSI titers and clinical outcomes were reviewed. DSI were produced in 27% of the patients (n = 11/41). Anti-A production was significantly greater in “at risk” patients than Anti-B (39% vs. 8%; p = 0.04). Risk factors associated with the development of DSI included: older age at transplantation (HR: 1.15/month, p = 0.04), pretransplant Anti-B level ≥ 1:8 (HR: 9.61, p = 0.004) and HLA sensitization (HR: 2.80, p = 0.11). The presence of DSI did increase the risk of cellular rejection but not antibody-mediated rejection, allograft vasculopathy, graft loss or death. Although these antibodies do not result in any significant clinical consequences, their presence suggests that B-cell tolerance is not the sole mechanism of graft acceptance.

Midazolam and fentanyl together produce better sedation, analgesia and amnesia than do either drug alone, but the electrophysiologic effects of the combination are unknown. Twenty patients undergoing electrophysiologic studies for clinical reasons were studied. Blood pressure, heart rate, respiratory rate, oxygen saturation, and standard variables related to atrioventricular and ventriculoatrial conduction, dual pathways, accessory pathway conduction, sinus node function, and the inducibility of tachycardia were examined before and after intravenous injections of midazolam (0.07 +/- 0.03 mg/kg) combined with fentanyl (0.8 +/- 0.4 micrograms/kg). There were no significant changes in the electrophysiologic variables or ease of inducibility of tachycardia. The drugs were well tolerated; they produced minor and clinically unimportant reductions in mean blood pressure (99 +/- 13 to 89 +/- 16 mm Hg; p < 0.001) and respiratory rate (18 +/- 4 to 16 +/- 3 breaths/min; p = 0.05). Excellent sedation was achieved. Major amnesia was reported by 95% of patients. In conclusion, midazolam combined with fentanyl provides safe and effective sedation for electrophysiologic studies without significantly affecting electrophysiologic variables or the inducibility of tachyarrhythmias.

OBJECTIVE. Anecdotal reports have suggested differences in children's tolerance to different intravenous immunoglobulin products; however, there has been little research on this issue. We sought to determine whether different intravenous immunoglobulin products used in the treatment of juvenile dermatomyositis are equally well tolerated by patients and, if not, whether differences in tolerance are linked to immunoglobulin A content. PATIENTS AND METHODS. The intravenous immunoglobulin infusion history (product given and history of adverse events) of patients who were attending the juvenile dermatomyositis clinic at the Hospital for Sick Children from 1986 to 2005 was reviewed. Products with an immunoglobulin A content of >15 μg/mL were classified as “high immunoglobulin A.” Data were analyzed by using logistic regression models adjusted for repeated measures. RESULTS. Thirty-eight patients with juvenile dermatomyositis received 1056 infusions at the Hospital for Sick Children. Adverse events were reported on 92 occasions (9%), affecting 25 patients (66%), a frequency that is higher than that usually reported in adult patients ( CONCLUSIONS.Intravenous immunoglobulin was found to be safe and well tolerated by most children with juvenile dermatomyositis. However, in contrast to adult studies, we found that significant differences existed in tolerance to different intravenous immunoglobulin products, most likely because of immunoglobulin A concentration. This study confirms anecdotal reports that a high level of immunoglobulin A in intravenous immunoglobulin is less well tolerated by children and provides evidence that product choice is important in pediatrics.

A combination of fluorescence-activated cell sorting and interphase fluorescence in situ hybridization (FISH) techniques was used to detect a clonal chromosomal marker in blasts, granulocytes, and T and B lymphocytes of the peripheral blood from a patient with Down syndrome and acute megakaryoblastic leukemia (AMKL) associated with trisomy 8 as a karyotypic abnormality. Immunophenotypic studies with flow cytometry showed two populations of leukemic blasts distinguished by their expression of the CD34 antigen. Interphase FISH studies revealed clonal trisomy 8 FISH signals in almost all blast cells, regardless of CD34 expression, as well as in a small subpopulation of granulocytes. Normal chromosome 8 signal patterns were detected in T and B cells and in a great majority of granulocytes. The present study provides evidence for the clonal involvement of leukemic blasts in AMKL of Down syndrome, indicating that a trisomy 8 abnormality may be a primary event in leukemogenesis. The transformation occurs in progenitor cells with limited myeloid differentiation and without involvement of lymphoid lineage cells.

1Department of Comparative Molecular Medicine, School of Veterinary Science, The University of Liverpool, Liverpool, UK. 2Manchester Centre for Integrative Systems Biology, Manchester Interdisciplinary Biocentre, University of Manchester, Manchester, UK. 3Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester, UK. 4National Institute for Biological Standards and Guidelines for reporting the use of column chromatography in proteomics

In the early development of atherosclerotic plaque, monocytes are recruited to the arterial intima where they accumulate lipid and become foam cells. The recently described murine chemotactic S100 protein, CP-10, may have an important role in this process. Intraperitoneal injection of CP-10(42-55) (chemotactic hinge region peptide) into mice caused a sustained leukocyte recruitment with a sixfold increase in monocyte numbers over 24 h. CP-10(42-55)--elicited monocyte/macrophages accumulated significantly increased cholesteryl esters in response to acetylated LDL, both in vivo and in vitro and this was associated with a twofold increase in scavenger receptor expression. By contrast, thioglycollate- and macrophage colony-stimulating factor-elicited macrophages expressed levels of scavenger receptor similar to those on resident macrophages and did not exhibit enhanced acetylated LDL loading in vitro. The leukocyte integrin Mac-1 (CD11b/CD18) and its beta subunit (CD18), but neither lymphocyte function-associated antigen-1 nor very late activation antigen-4, were upregulated on monocyte/macrophages elicited by CP-10(42-55), thioglycollate, and macrophage colony-stimulating factor. Cholesteryl ester accumulation in vitro was significantly enhanced by adhesion, which appeared to involve macrophage activation via ligation of Mac-1. The initial events of monocyte recruitment and adhesion to the vessel wall may be important in macrophage foam cell development, and CP-10 or related S100 proteins may contribute to the early inflammatory events of atherogenesis by stimulating these events.

Abstract 3021 Umbilical Cord Blood (UCB) is frequently used as a source of stem cells for children undergoing allogeneic hematopoietic stem cell transplant (HSCT) for both benign and malignant disorders. Despite algorithms using both nucleated cell numbers and HLA typing, the rate of engraftment failure remains higher than rates observed using other stem cell products. We conducted a retrospective review of our centre's experience with HSCT with UCB to evaluate the impact of herpesvirus viremia on the rate of engraftment. Children who underwent allogeneic HSCT with UCB between 06/2005 and 05/2010 inclusive were identified from the program database. Engraftment was defined as the first day of three consecutive absolute neutrophil counts of > 0.5 × 10[exp 9]/L within 42 days of UCB infusion and evidence of donor DNA on chimerism testing. Blood samples were sent for qualitative herpesvirus polymerase chain reaction (PCR) weekly (HHV-6, HHV-7, EBV, CMV, HSV or VZV). If either CMV or EBV results were positive, a quantitative assay was performed as well. Viremia was considered to have occurred if the qualitative assay became positive. Anti-viral therapy was initiated for measurable amounts of either CMV or EBV DNA or selectively for HHV-6 DNA. Eighty-one HSCT utilizing UCB were performed during this period. One child was unevaluable (NRM at day +15) so the analysis was performed using the remaining 80 patients. Thirty HSCT (37.5%) were performed for non-malignant indications and 50 (62.5%) for malignant disorders. Ninety per cent were performed using unrelated UCB; 27 were 6/6 HLA matched UCB, 42 were 5/6 HLA matches and 11 were 4/6 matches. Four children were recovering counts at day +42 but had not reached the threshold neutrophil value. They were considered as delayed engraftment rather than engraftment failure. Eleven (14%) failed to engraft. Forty-two (52.5%) of the transplants were complicated by the detection of 1 or more herpesviruses (24 for only 1 virus, 15 for 2 viruses and 3 for 3 viruses). None of gender, ABO matching, recipient CMV pre-HSCT serostatus, disease category, use of ATG or TBI in the conditioning regimen, use of methotrexate as GVHD prophylaxis or positivity for any single herpesvirus was associated with engraftment failure. Numbers of viable nucleated cells and CD34+ cells were not different between those that engrafted and those that failed to engraft. Transplants complicated by viremia of more than 1 herpesvirus had a significantly poorer engraftment rate than others (0.667 vs 0.933, P=0.007); more specifically viremia due to CMV and any other herpesvirus was associated with a worse engraftment rate than others (0.643 vs 0.921, P=0.006) (table). Notably viremia due to HHV-6 and others or EBV and others were not related to engraftment failure.PCR resultEngraftedFailed to engraftNo CMV516CMV positive185CMV alone90CMV plus: HHV-632 HHV-721 EBV22 HHV-6 & HHV-710 HHV-6 & EBV10 Conclusion: A significantly poorer engraftment rate in children undergoing HSCT using UCB was seen in those with CMV viremia in the presence of another herpesvirus. Further research is needed to define cause and effect and the therapeutic strategies to prevent it. Disclosures: No relevant conflicts of interest to declare.

Background: A multi-organ donor seronegative for hepatitis C virus (HCV) by 1st generation enzyme immunoassay (EIA) supplied 5 solid organs and 2 corneas to 7 recipients. This donor was retrospectively shown to be 2nd generation HCV EIA-positive and polymerase chain reaction (PCR)-positive. All 5 solid organ recipients but none of the corneal recipients developed HCV infection. Objectives: To demonstrate the discordance between serological and PCR-based HCV detection in solid organ transplant recipients and the lack of transmission of HCV to the two corneal transplant recipients. Study design: All 5 solid organ recipients were retrospectively shown to be HCV PCR-negative and -seronegative pre-transplant and HCV PCR-positive post-transplant. Serial serum samples on 3 recipients were evaluated by 2nd generation EIA, a prototypic structural and non-structural dual bead assay (EIA-SA, Abbott), the Chiron Recombinant Immunoblot Assay, 2nd generation (RIBA-2), and the Chiron RIBA HCV Test System Strip Immunoblot Assay 3.0 (RIBA-3, Chiron). Results: The dual bead EIA-SA and RIBA-3 were able to detect HCV seroconversion approximately 6 months earlier than the 2nd generation EIA in 2 recipients, and in 1 recipient only PCR detected infection within the first 10 months. There was no evidence of HCV transmission to the corneal recipients. Conclusions: Although third generation assays such as the RIBA-3 and EIA-SA narrowed the window of HCV seronegativity in transplant recipients compared with the 2nd generation EIA, PCR was the most sensitive method of detecting acute HCV infection. Despite transmission of HCV to all of the solid organ recipients HCV was not transmitted to the corneal transplant recipients.

Between June 1994 and December 2003, 31 patients with haematological disorders presenting at the Hospital for Sick Children, Toronto, Canada, received a stem cell transplant (SCT) from a mismatched related donor. Diagnoses included ALL (15), AML (10), CML (1), JMML (1), SAA (2), de novo MDS (1) and Fanconi anaemia (1). Patients were aged between 0.9 to 17.8 years (mean 8.5 years). There were 20 males and 11 females. HLA typing included A, B and DRB1 on all patients (Class 1 alleles by low resolution molecular technique and Class 2 by high resolution technique). 22 patients had 1 major mismatch and 9 had 2–3 major mismatches. The source of stem cells was bone marrow in 15 patients (mean total nucleated cell dose 4.44 x 108/kg, range 1.89–6.63), peripheral blood (PBSC) in 15 patients (mean CD34 dose 11.80 x 106/kg, range 3.19–42.18) and one patient received both BM and PBSC. Of those who received PBSC, 9 had CD34 selection, 3 had CD34 selection and T-cell depletion, and 3 received an unmodified product. Conditioning regimens included cyclophosphamide and total body irradiation (TBI) (15), etoposide and TBI (6), busulfan and cyclophosphamide (6), etoposide and cyclophosphamide (1), fludarabine, cyclophosphamide and TBI (1), fludarabine and cyclophosphamide (1) and fludarabine, melphalan and thiotepa (1). Graft versus host disease (GvHD) prophylaxis included combinations of cyclosporine A, methotrexate, anti-thymocyte globulin and methylprednisolone. There was one primary graft failure and 3 secondary graft failures. Mean time to neutrophil engraftment was 17 days (range 9–36). The incidence of acute and chronic GvHD was 48% and 51% respectively. Of the 31 patients, 15 are alive (12 in complete remission (one of these with a secondary brain tumour) and 3 with relapsed disease) and 16 are dead (3 of relapsed progressive disease, 12 from transplant related mortality (TRM - 9 of these were in CR) and in one the cause is not known). Three year actuarial OS and EFS for the entire group were 50±9% and 45±9%, OS and EFS for those matched at 5/6 loci were 56±11% and 44±11% and OS and EFS for 3/6 and 4/6 matched were 38±16% and 36±16%. The mean follow-up time for survivors is 5.6 years (range 11.6 months to 9.7 years). In this series, there was no significant difference in survival when comparing BM vs. PBSC harvests; in one vs. 2–3 mismatch donors; and in the presence vs. absence of acute or chronic GvHD. These results confirm the feasibility and efficacy of using mismatched related donors for paediatric haematological disorders. Steps should be taken to decrease the TRM to achieve a better survival rate.