Discordance in tests used to detect inhibition of the P2Y12 receptor in patients undergoing interventional neuroradiology procedures

BACKGROUND

Clopidogrel is an inhibitor of the P2Y12 platelet receptor but testing to demonstrate a drug effect is controversial since there are often discordant results between different tests methods.

METHODS

Samples from patients taking clopidogrel prior to intracranial flow-diversion procedures were tested using light transmission aggregometry (LTA), whole blood impedance aggregometry (WBIA) and the VerifyNow device (VND). Samples were classified as concordant if all test results were either responsive (inhibition) or resistant. Discordant results were separated using the VND into those with a responsive versus a resistant test result.

RESULTS

Samples from 96 patients were studied. Concordance for all three tests was seen in 53/96 (55%) of samples, of which 41 (43%) were responsive and 12 (12%) were resistant. Discordance was observed in 43 samples (45%), 37 (28%) of which were caused by responsive VND and either a resistant WBIA or LTA and 6 (7%) of which were caused by a resistant VND but a responsive test result using either WBIA or LTA. These two discordant groups differed in both platelet count and hematocrit, but no such difference was present between the two concordant groups.

CONCLUSION

Discordance in P2Y12 inhibition testing may be partly explained by sample platelet count and hematocrit.

Hereditary thrombocytopenia with platelet sialic acid deficiency and mutations in the GNE genes

BACKGROUND

The inherited macrothrombocytopenias are rare disorders and the underlying cause can be identified in many cases but in some, this can remain enigmatic. Platelet transfusions are often administered during hemorrhagic events.

METHODS

A patient with previously unexplained inherited macrothrombocytopenia with a platelet count between 3-20 × 10⁹ /L is described in which studies were performed using exome sequencing (ES) and platelet flow cytometry.

RESULTS

Both the hemoglobin and white cell counts were normal. ES revealed two suspicious variants, one likely pathogenic and one a variant of uncertain significance, in the UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE) gene, and flow cytometry showed diminished expression of surface platelet sialic acid (about 5%) but normal red cell sialic acid. The Thrombopoietin (TPO) level was low, and the patient responded to TPO-mimetic treatment with an increase in the platelet count.

CONCLUSION

Two variants in the GNE gene were able to be upgraded to pathogenic with apparently restricted expression to the megakaryocyte lineage. Platelet transfusion may be avoided in these patients with TPO-mimetic treatment.

Cerambycid Pheromones Attract Predators Temnoscheila virescens (Coleoptera: Trogossitidae), Chariessa pilosa (Coleoptera: Cleridae), and Apiomerus crassipes (Hemiptera: Reduviidae)

In 2011-2013, we determined the interactive effects of the cerambycid pheromones racemic syn-2,3-hexanediol, racemic 3-hydroxyhexan-2-one, and racemic 3-hydroxyoctan-2-one on trap catches of predators associated with bark and woodboring beetles in north Georgia and South Carolina. Temnoscheila virescens (F.) (Coleoptera: Trogossitidae) was attracted to traps baited with 3-hydroxyhexan-2-one; ethanol enhanced attraction. Traps baited with syn-2,3-hexanediol attracted Chariessa pilosa (Forster) (Coleoptera: Cleridae); attraction was interrupted by 3-hydroxyhexan-2-one. An assassin bug Apiomerus crassipes (F.) (Hemiptera: Reduviidae) was attracted to traps baited with 3-hydroxyhexan-2-one and/or 3-hydroxyoctan-2-one. Ethanol had no effect on trap catches of C. pilosa and A. crassipes. We compared response profiles of these predators to those of longhorn beetles captured in these same studies to provide insights on possible ecological interactions between these species.

In vitro comparison of CPD whole blood with conventional blood components

INTRODUCTION

Resuscitation of severely injured trauma patients is commonly performed using red blood cells in additive solution supplemented with plasma and platelet concentrates. There is an increasing interest in the use of low anti-A titer Group O whole blood (LTOWB) in the early management of the resuscitation. It is unclear whether clinical outcome is improved using this approach.

METHODS

Expired units of CPD-LTOWB were studied on Day 22 and expired units of thawed plasma on Day 6 and Day 7. LTOWB was assessed for hemoglobin content, clotting factor levels and platelet numbers and function using thromboelastography (TEG) and impedance aggregation. Assays of fibrinogen and FV, FVIII, FVII and FX were performed on the expired plasma. The LTOWB hemoglobin was compared to red cells in additive solution (AS-RBCs) and the clotting factor levels to those of expired thawed plasma. Platelet function was compared to fresh whole blood samples from healthy subjects.

RESULTS

LTOWB contained slightly more hemoglobin than the AS-RBCs (Medians, 66 v 59 G), and the plasma content of fibrinogen was similar. Other clotting factors were reduced by approximately 15% except for FVIII which was 30% less. Both TEG and impedance aggregometry showed evidence of residual platelet function despite the prolonged period of refrigerator storage.

CONCLUSION

LTOWB contains higher hemoglobin and adequate clotting factors, and residual platelet function is demonstrated indicating that this product would be expected to be at least equivalent to a single unit of each of the conventional components commonly used in trauma resuscitation.

Remote Dispensing of Emergency Release Red Blood Cells

OBJECTIVES

Patients with acute bleeding are frequently transfused with emergency release (ER) group O RBCs. This practice has been reported to be safe with a low rate of acute hemolytic transfusion reactions (AHRs).

METHODS

Records of patients who received ER RBCs over a 30-month period were examined at our hospitals. During this period, satellite refrigerators were on site in the emergency department (ED), which were electronically connected to the blood bank (electronically connected satellite refrigerator [ECSR]). Nurses accessing the refrigerator were required to give patient identification information, when known, prior to removal of the ER RBCs, allowing technologists the opportunity to check for previous serologic records and communicate directly with the ED if a serologic incompatibility was potentially present.

RESULTS

In total, 935 patients were transfused with 1,847 units of ER RBCs. Thirty of these patients had a current (22/30) or historic (8/30) antibody. In 15 cases, incompatible RBCs were interdicted. In six cases, the transfusion was considered urgent, and an AHR occurred in four of these six (overall 0.4%), including one fatal AHR due to anti-KEL1.

CONCLUSIONS

Use of KEL1-negative RBCs and ECSR merits consideration as approaches to mitigate the occurrence of ER RBC-associated AHRs.

Cerambycid Pheromones 3,2-Hydroxyketones Affect Catches of Some Bark and Ambrosia Beetles (Coleoptera: Curculionidae) in Ethanol-Baited Multiple-Funnel Traps in Southeastern United States

In 2012-2013, we assessed the interactive effects of the cerambycid pheromones syn-2,3-hexanediol, 3-hydroxyhexan-2-one, and 3-hydroxyoctan-2-one on catches of bark and ambrosia beetles (Coleoptera: Curculionidae) in ethanol-baited multiple-funnel traps in north Georgia and South Carolina. We found that catches for nine of eleven species of ambrosia beetles in ethanol-baited traps were either unaffected or enhanced by the addition of 3,2-hydroxyketones. Similarly catches of five species of bark beetles were either unaffected or enhanced by the addition of 3,2-hydroxyketones. In particular, catches of Xylosandrus crassiusculus (Motschulsky), Cnestus mutilatus (Blandford), and Monarthrum fasciatum (Say) in ethanol-baited traps increased with the addition of 3-hydroxyhexan-2-one and/or 3-hydroxyoctan-2-one. Catches of the bark beetles Hylocurus rudis (LeConte) and Hypothenemus rotundicollis (Eichhoff) were enhanced by the addition of 3-hydroxyhexan-2-one and 3-hydroxyoctan-2-one, respectively. syn-2,3-Hexanediol had no effect on catches of bark and ambrosia beetles in ethanol-baited traps. Our data provide support for the use of ethanol + cerambycid pheromones for targeting non-native species of bark and ambrosia beetles as well as cerambycids in detection programs.

Interactions Between syn- and anti-2,3-Hexanediol Lures on Trap Catches of Woodboring Beetles and Associates in Southeastern United States

In 2016, we conducted three experiments to clarify the effects of 2,3-hexanediols isomers on trap catches of Neoclytus acuminatus (F.) (Coleoptera: Cerambycidae). We also noted the effects of the isomers on trap catches of other cerambycids and associated species of predators and competitors. Catches of N. acuminatus in traps baited with ethanol + syn-2,3-hexanediol + racemic 3-hydroxyoctan-2-one were reduced with the addition of anti-2,3-hexanediol, an attractant for Curius dentatus Newman (Coleoptera: Cerambycidae). A fourth experiment conducted in 2017 verified that racemic 3-hydroxyoctan-2-one increases catches of N. acuminatus in traps baited with ethanol + syn-2,3-hexanediol. The addition of anti-2,3-hexanediol increased catches of Knulliana cincta (Drury) (Coleoptera: Cerambycidae) in traps baited with ethanol + racemic 3-hydroxyoctan-2-one, whereas attraction of Neoclytus scutellaris (Olivier) to traps baited with ethanol + racemic 3-hydroxyhexan-2-one was reduced by syn-2,3-hexanediol. Trap catches of the beetle predators Chariessa pilosa (Forster), Enoclerus ichneumonus (F.), and Madoniella dislocata (Say) (Coleoptera: Cleridae) were affected by 2,3-hexanediol isomers, whereas other common predators were unaffected by the isomers. Attraction of the bostrichid Xylobiops basilaris (Say) (Coleoptera: Bostrichidae) was increased by the 2,3-hexanediols; the relative effect of the two isomeric blends was dependent on trap co-baits of 3-hydroxy-2-ketones. The two enantiomeric blends of 2,3-hexanediol had minimal effects on catches of most species of ambrosia beetles, whereas the 3-hydroxy-2-ketones affected trap catches of some species.

Influenza-associated thrombotic thrombocytopenic purpura: A report of two cases and a brief review of the literature

BACKGROUND AND OBJECTIVES

Thrombotic thrombocytopenic purpura (TTP) is often preceded by a recent history of an acute infection and influenza is the most implicated virus.

MATERIALS AND METHODS

We identified two cases of TTP, which were preceded by influenza between 2010 and 2021. In one patient, we epitope mapped the binding specificity of antibodies using an overlapping peptide approach of the stalk protein of Influenza B and the cysteine-rich spacer domain (CRSD) of ADAMTS13. A literature search was performed for reports of influenza-associated TTP over the period 1980-2021.

RESULTS

Two patients were identified in which TTP was preceded by influenza, one Influenza A and the other Influenza B. Epitope mapping of the latter's plasma identified target epitopes in both the stalk protein of Influenza B and CRSD of ADAMTS13. The literature review revealed only seven case reports, all but one from Europe or Asia and associated with Influenza A. Severe ADAMTS13 deficiency was demonstrated in only four cases.

CONCLUSION

We report the first small case series of influenza-associated TTP. Moreover, it is the first case implicating Influenza B and a mechanism favouring polyclonal B-cell proliferation rather than molecular mimicry as the stimulus to form anti-ADAMTS13 auto-antibodies is suggested.

Laboratory Methods in the Assessment of Hereditary Hemostatic Disorders

In patients presenting with a suspect hereditary bleeding disorder a detailed bleeding history is first obtained. Testing proceeds in a tiered manner with platelet count, platelet morphology, platelet histogram, PFA-100, fibrinogen, prothrombin time, and activated partial thromboplastin time. More detailed testing includes von Willebrand factor, individual clotting factor assays, and platelet function testing. Next, testing for a dysfibrinogenemia, FXIII, or a fibrinolytic defect is considered. Hemostatic abnormality is not demonstrated in a fraction of patients. An approach to management in these patients, such as desmopressin or antifibrinolytic therapy, may be required and empiric use of blood component therapy is discouraged.

Causes of an elevated international normalized ratio in the intensive care unit and the implications for plasma transfusion

BACKGROUND

The presence of an elevated international normalized ratio (INR) is common in patients in the intensive care unit (ICU), but the cause rarely determined. These patients are at risk to receive prophylactic plasma prior to invasive procedures.

STUDY DESIGN AND METHODS

Samples from patients with an INR of 1.5 or greater were frozen and subsequently thawed and assayed for procoagulant and anticoagulant clotting factors and anti-Xa to determine the likely cause of the INR. Samples showing a low FVII, FX, PC, and PS were categorized as a vitamin K deficiency pattern. Samples showing a low FV, low or normal fibrinogen, and high FVIII were categorized as a liver disease pattern. Samples showing an anti-Xa >0.01 IU/ml were assayed for anti-Xa DOACs. Samples which could not be categorized were grouped as equivocal.

RESULTS

A total of 48 samples were obtained over a 6-month period. Nineteen showed a Vitamin K deficiency pattern, 17 a liver disease pattern, 7 showed an anti-Xa DOAC and 5 were equivocal. High FVIII and D-dimers and reduced levels of the anticoagulant proteins were present in the majority of the samples. FVII levels correlated inversely with the INR (r = -0. 81), as did FX (r = -0.67) but not FV (r = -0.04) nor fibrinogen (r = -0.15).

CONCLUSION

Transfusion of plasma to reverse an elevated INR in the ICU should be discouraged since such a practice is either avoidable by the use of vitamin K or inappropriate in the case of liver disease or an anti-Xa DOAC.

Red Cell Exchange as Adjunctive Therapy for Babesiosis: Is it Really Effective?

Human babesiosis is a parasitic disease prevalent in the Northeastern and Midwestern United States (US). Treatment with antibiotics is the standard of care but red cell exchange (RCE) has been used as an adjunctive treatment in more severe disease. Data for the efficacy of RCE in the treatment of babesiosis has been based on case reports and case series. An English language literature search was conducted for cases of babesiosis treated with RCE since 1980 and relevant laboratory and clinical outcome data were extracted. Similar data were obtained on severe cases of babesiosis referred for RCE in our hospitals in the time period 2000 to 2020. Fifty reports including forty-one individual case reports and nine case series were retrieved. There were 108 patients that underwent RCE with an overall mortality rate of 20%. Some patients had more than one RCE. The patients varied in the level of anemia and evidence of compromise of renal or pulmonary function. The pre-RCE level of parasitemia varied between 1.7% to 85% with the vast majority >10%. The post-RCE level of parasitemia varied between 1% to 10%. Since 2000, 32 patients were referred for RCE in our hospitals and RCE was performed on 23 of 32. There were more patients treated with RCE in the second decade as compared to the first decade, 19 versus 4 respectively. The overall mortality was 22% similar to the national data. Comparing the cohort treated with RCE to the 9 patients who were treated only with antibiotics, there were similar levels of parasitemia and laboratory parameters. The overall number of days needed to achieve a parasite count <1% was similar between the two cohorts and mortality for the antibiotics only cohort was 0%. More than 40 years after the first reported case of RCE in severe babesiosis it cannot be concluded that this adjunctive therapy favorably influences the clinical outcome. Since there is largely equipoise, a registry of severe patients treated with or without RCE could identify a benefit or otherwise.

Trap Height Affects Catches of Bark and Woodboring Beetles (Coleoptera: Curculionidae, Cerambycidae) in Baited Multiple-Funnel Traps in Southeastern United States

In north-central Georgia, trap height affected catches of some species of bark and woodboring beetles (Coleoptera) in traps baited with lures used in surveillance programs to detect non-native forest insects. Traps were placed within the canopy and understory of mature oak trees (Quercus spp.) with collection cups placed 18-23 m above ground level (AGL), and 0.3-0.5 m AGL, respectively. Traps were baited with ethanol to target ambrosia beetles (Curculionidae: Scolytinae) in one experiment, ethanol + syn-2,3-hexanediol + racemic 3-hydroxyhexan-2-one + racemic 3-hydroxyoctan-2-one to target hardwood woodborers (Cerambycidae) in a second experiment, and α-pinene + racemic ipsenol + racemic ipsdienol to target pine bark beetles (Curculionidae) and woodborers (Cerambycidae) in a third experiment. Canopy traps were more effective than understory traps for detecting Cnestus mutilatus (Blandford) (Curculionidae), Neoclytus scutellaris (Olivier), and Monochamus titillator (F.) (Cerambycidae). The reverse was true for Xylosandrus crassiusculus (Motschulsky), Dendroctonus terebrans (Olivier) (Curculionidae), and Neoclytus acuminatus (F.) (Cerambycidae). Catches of a third group which included Hylobius pales (Herbst), Ips grandicollis (Eichhoff) (Curculionidae), Neoclytus mucronatus (F.), and Anelaphus pumilus (Newman) (Cerambycidae) were largely unaffected by trap height. Similar patterns were noted for species of Cleridae, Scarabaeidae, Trogossitidae, and Zopheridae but not Histeridae or Tenebrionidae (Coleoptera). Catches of the bee assassin Apiomerus crassipes (F.) (Hemiptera: Reduviidae) in traps baited with the hardwood borer blend were greater in canopy traps than in understory traps.

False-negative compatible antiglobulin crossmatches in samples with alloantibodies to cognate red blood cell antigens

BACKGROUND

Patient samples showing a positive indirect antiglobulin test are further tested to identify alloantibody specificity using a panel of phenotypically characterized group O reagent red blood cells (RBCs). Donor RBCs phenotypically negative for the antibody specificity are then serologically crossmatched using an antiglobulin reagent. This latter test is performed to identify any incompatibility due to the presence of undetected minor blood group antibodies and considered an important step in patient safety.

STUDY DESIGN AND METHODS

Samples with well-characterized alloantibodies were intentionally crossmatched against donor RBCs expressing the cognate antigen. In a separate set of specimens, the alloantibody was titered and crossmatched against both heterozygous and homozygous cells.

RESULTS

Thirty-five samples containing 10 common alloantibodies crossmatched against 240 ABO-compatible donor cells phenotypically positive for the cognate antigen showed compatible crossmatches in 89 of 240 (37%). Antibody titering of 12 alloantibodies showed that a titer of 2 or more was required for incompatibility of all homozygous cells and a titer of 8 or more for incompatibility of all heterozygous cells.

CONCLUSION

The antiglobulin crossmatch has a high failure rate (false-negatives) related to antibody titer and donor cell zygosity and is not reliable in interdicting incompatibility due to minor blood group antibodies.

Hemolysis in In-Date RBC Concentrates

OBJECTIVES

Hemolysis is one of the most prominent changes that occur during the liquid storage of RBCs in additive solution (AS), but most studies have measured hemolysis only on day 42.

METHODS

Prestorage leukoreduced RBCs in AS-1 and AS-3 were studied, one group on day 42 and a second group between day 0 and day 40. Each product was sampled for direct measurement of supernatant hemoglobin and hematocrit.

RESULTS

Ninety day 42 and 218 day 7 to day 39 RBCs showed a mean ± SD supernatant hemoglobin of 75 ± 100 vs 25.5 ± 16 mg/dL respectively (P < .01). Supernatant hemoglobin correlated weakly with storage age (r = 0.2, P < .01) but more strongly with hematocrit (r = 0.4, P < .01).

CONCLUSIONS

There are minimal differences in supernatant hemoglobin until the final days of liquid storage when some high hematocrit RBCs show excessive hemolysis.

Interactions between Ethanol, syn-2,3-Hexanediol, 3-Hydroxyhexan-2-one, and 3-Hydroxyoctan-2-one Lures on Trap Catches of Hardwood Longhorn Beetles in Southeastern United States

The effectiveness of a four-component "super lure" consisting of ethanol (E) and the cerambycid pheromones syn-2,3-hexanediol (D6), racemic 3-hydroxyhexan-2-one (K6), and racemic 3-hydroxyoctan-2-one (K8) on trap catches of Cerambycidae (Coleoptera) was determined in southeast United States with seven trapping experiments in 2011-2013. We captured 74 species of longhorn beetles in our three-year study. Ethanol significantly increased the mean catches of seven species and increased the number of cerambycid species detected. Traps with the "super lure" were effective for 8 of 13 species of Cerambycidae previously shown to be attracted to binary combinations of ethanol plus one of the three pheromones. However, the "super lure" was less effective for the remaining five species with catch reductions of 40-90% compared with combinations of ethanol and one or two of the pheromones. For example, K6 + K8 lures reduced catches of Anelaphus villosus (F.) in traps with E + D6 by 90%. Similarly, catches of Anelaphus pumilus (Newman) in traps with E + K6 + D6 were reduced by 50% with the addition of K8. Catches of Knulliana cincta (Drury) in traps with K6 + K8 lures were interrupted by D6, an effect negated by the addition of ethanol. Given the interruptive effects on trap catches of some species when lures are combined in a single trap, developing optimal lure blends to maximize detection efficacy will be a challenge for managers of detection programs for non-native invasive species of longhorn beetles.

How do we reduce plasma transfusion in Rhode Island?

BACKGROUND

Plasma transfusions are given to patients with coagulopathy, either prophylactically, before an invasive procedure; or therapeutically, in the presence of active bleeding; and as an exchange fluid in therapeutic plasma exchange for disorders such as thrombotic thrombocytopenic purpura. There is consensus that many prophylactic plasma transfusions are non-efficacious, and the misdiagnosis of thrombotic thrombocytopenic purpura results in unnecessary therapeutic plasma exchange.

STUDY DESIGN AND METHODS

Beginning in 2001, programs to reduce plasma transfusion in the three major teaching hospitals in Rhode Island were initiated. The programs evolved through the establishment of guidelines, education for key prescribers of plasma, screening of plasma prescriptions, and engagement of individual prescribing physicians for out-of-guidelines prescriptions with modification or cancellation. Establishment of an in-house ADAMTS13 (ADAM metallopeptidase with thrombospondin type 1, motif 13) assay in 2013 was used to prevent therapeutic plasma exchange in patients with non-thrombotic thrombocytopenic purpura microangiopathy. Transfusion service data were gathered at the hospital level regarding blood component use, hospital data for discharges, inpatient mortality, and mean case-mix index, and, at the state level, for units of plasma shipped from the community blood center to in-state hospitals.

RESULTS

Between 2006 and 2016, a reduction in plasma use from 11,805 to 2677 units (a 77% decrease) was observed in the three hospitals and was mirrored in the state as a whole. This decline was not associated with any increase in red blood cell transfusion. Inpatient mortality either declined or was unchanged.

CONCLUSION

An active program focused on education and interdiction can achieve a large decrease in plasma transfusions without evidence of patient harm.

Acquired Factor XIII inhibitor associated with mantle cell lymphoma

BACKGROUND

Acquired Factor (F)XIII deficiency is a very rare bleeding diathesis with a potentially fatal outcome, previously described in the context of autoimmune disorders and leukemias. There is minimal information on autoantibody characterization and the role of antifibrinolytic therapy in patient management.

CASE REPORT

A 79-year-old woman with a 3-month history of bruising and heavy menorrhagia presented with ongoing vaginal bleeding, symptomatic anemia, and a right thigh hematoma. Initial management included an axillary lymph node biopsy and coagulation evaluation. Pathologic examination of the biopsy specimen revealed mantle cell lymphoma. Clot solubility assay was consistent with a FXIII activity of less than 3%. An anti-FXIII inhibitor was suspected, the epitope specificity of which was mapped by micropeptide array analysis to regions in the β-sandwich and catalytic core domain of the FXIII-A subunit. Management with cryoprecipitate, steroids, rituximab, and antifibrinolytic therapy resolved the bleeding diathesis and suppressed the inhibitor.

CONCLUSION

This is the first reported case of an acquired FXIII inhibitor associated with mantle cell lymphoma in which the epitope specificity of the pathologic autoantibody was accurately defined. Antifibrinolytic therapy played a prominent role in the prevention of bleeding complications in the window period between initiation of immunosuppression and disappearance of the pathologic anti-FXIII autoantibody.

Autoimmune Cytopenias: Diagnosis & Management

The autoimmune cytopenias are a related group of disorders in which differentiated hematopoietic cells are destroyed by the immune system. Single lineage disease is characterized by the production of autoantibodies against red cells (autoimmune hemolytic anemia [AIHA]), platelets (autoimmune thrombocytopenia [ITP]) and neutrophils (autoimmune neutropenia [AIN]) whereas multilineage disease may include various combinations of these conditions. Central to the genesis of this disease is the breakdown of central and/or peripheral tolerance, and the subsequent production of autoantibodies by both tissue and circulating self-reactive B lymphocytes with support from T helper lymphocytes. These disorders are classified as primary (idiopathic) or secondary, the latter associated with an underlying malignancy, systemic autoimmune disease, infectious disease or a specific drug. Non-specific immunosuppression with corticosteroids remains the first-line therapy for many of these disorders, and although associated with high response rates, is compromised by significant toxicity and high relapse rates. Management of patients with chronic refractory autoimmune cytopenias who have failed first-line and second-line (cytotoxic immunosuppressant therapy and or splenectomy) is particularly complex, with definitive treatment in select patients requiring hematopoietic stem cell transplantation. Given the toxicity concerns of non-selective immunosuppressants, development of therapeutic regimens that avoid steroids has progressed rapidly in recent decades. [Full article available at http://rimed.org/rimedicaljournal-2016-12.asp].

Pine Sawyers (Coleoptera: Cerambycidae) Attracted to α-Pinene, Monochamol, and Ipsenol in North America

Detection tools are needed for Monochamus species (Coleoptera: Cerambycidae) because they are known to introduce pine wilt disease by vectoring nematodes in Asia, Europe, and North America. In 2012-2014, we examined the effects of the semiochemicals monochamol and ipsenol on the flight responses of the sawyer beetles Monochamus carolinensis (Olivier), Monochamus clamator (LeConte), Monochamus mutator LeConte, Monochamus notatus (Drury), Monochamus obtusus Casey, Monochamus scutellatus (Say), and Monochamus titillator (F.) complex (Coleoptera: Cerambycidae) to traps baited with α-pinene. Experiments were set in pine forests in New Brunswick and Ontario (Canada), and Arizona, Georgia, Michigan, Montana, Oregon, South Carolina, Utah, and Washington (United States). In brief, 40 traps were placed in 10 blocks of 4 traps per block per location. Traps were baited with: 1) α-pinene; 2) α-pinene + monochamol; 3) α-pinene + ipsenol; and 4) α-pinene + monochamol + ipsenol. Monochamol increased catches of six species and one species complex of Monochamus with an additive effect of ipsenol for five species and one species complex. There was no evidence of synergy between monochamol and ipsenol on beetle catches. Monochamol had no effect on catches of other Cerambycidae or on any associated species of bark beetles, weevils, or bark beetle predators. We present a robust data set suggesting that the combination of α-pinene, ipsenol, and monochamol may be a useful lure for detecting Monochamus species.

Transfusion-transmitted anaplasmosis from a leukoreduced platelet pool

BACKGROUND

Human granulocytic anaplasmosis is an emerging tick-borne illness. Anaplasma phagocytophilum resides intracellularly, can cause asymptomatic infection, and can survive blood component refrigeration conditions for at least 18 days. To date, eight cases of transfusion-transmitted anaplasmosis (TTA) have been reported: seven attributed to red blood cell (RBC) units, five of which were prestorage leukoreduced using RBC leukoreduction filters, and one involving a process leukoreduced apheresis platelet (PLT) unit. Here, we report a case of TTA from a whole blood-derived PLT pool.

STUDY DESIGN AND METHODS

Donation segments from the 7 units of RBCs and two PLT pools transfused were examined. Fast protocol multiplex real-time A. phagocytophilum polymerase chain reaction (PCR) and serologic testing for immunoglobulin (Ig)M and IgG antibodies to A. phagocytophilum by enzyme immunoassay were performed.

RESULTS

Transmission was confirmed by positive A. phagocytophilum PCR and serology in one of 16 donors and by positive PCR and seroconversion in the recipient.

CONCLUSION

This is the first confirmed case of TTA from a whole blood-derived PLT pool prepared from PLT concentrates leukoreduced by in-line filtration of PLT-rich plasma.

Responses of Cerambycidae and Other Insects to Traps Baited With Ethanol, 2,3-Hexanediol, and 3,2-Hydroxyketone Lures in North-Central Georgia

In north-central Georgia, 13 species of woodboring beetles (Coleoptera: Cerambycidae: Cerambycinae) were attracted to multiple-funnel traps baited with ethanol and one of the following pheromones: (1) racemic 3-hydroxyhexan-2-one; (2) racemic 3-hydroxyoctan-2-one; and (3) syn-2,3-hexanediol. The following species were attracted to traps baited with ethanol and 3-hydroxyhexan-2-one: Anelaphus pumilus (Newman), Eburia quadrigeminata (Say), Euderces pini (Olivier), Knulliana cincta (Drury), Neoclytus mucronatus (F.), Neoclytus scutellaris (Olivier), and Xylotrechus colonus (F.). Clytus marginicollis Castelnau & Gory, and Anelaphus parallelus (Newman) were attracted to traps baited with ethanol and 3-hydroxyoctan-2-one, whereas traps baited with ethanol and syn-2,3-hexanediol were attractive to Anelaphus villosus (F.), A. parallelus, Neoclytus acuminatus (F.), Neoclytus jouteli jouteli Davis, and Megacyllene caryae (Gahan). Ethanol enhanced catches of seven cerambycid species in traps baited with syn-2,3-hexanediol and 3,2-hydroxyketones. Catches of bark and ambrosia beetles (Curculionidae: Scolytinae) in ethanol-baited traps were largely unaffected by the addition of syn-2,3-hexanediol and 3,2-hydroxyketone lures, except for two species. The mean catches of Hypothenemus rotundicollis Wood & Bright and Dryoxylon onoharaensum (Murayama) in ethanol-baited traps increased and decreased, respectively, with the addition of racemic 3-hydroxyoctan-2-one. Traps baited with ethanol and syn-2,3-hexanediol were attractive to Xylobiops basilaris (Say) (Bostrichidae) and Chariessa pilosa (Forster) (Cleridae), whereas Temnoscheila virescens (F.) (Trogossitidae) were attracted to traps baited with ethanol and 3-hydroxyhexan-2-one. The assassin bug, Apiomerus crassipes (F.) (Hemiptera: Reduviidae), was attracted to traps baited with ethanol and 3,2-hydroxyketones.

Ipsenol, Ipsdienol, Ethanol, and α-Pinene: Trap Lure Blend for Cerambycidae and Buprestidae (Coleoptera) in Pine Forests of Eastern North America

In 2007-2008, we examined the flight responses of wood-boring beetles (Coleoptera: Cerambycidae and Buprestidae) to multiple-funnel traps baited with the pine volatiles, ethanol, and α-pinene [85% (-)], and the bark beetle pheromones, racemic ipsenol and racemic ipsdienol. Experiments were conducted in mature pine stands in Canada (Ontario and New Brunswick) and the United States (Arkansas, Florida, Michigan, New Hampshire, North Carolina, Ohio, Tennessee, and Wisconsin). At each location, traps were deployed in 10 replicate blocks of four traps per block. The trap treatments were: 1) blank control; 2) ipsenol and ipsdienol; 3) ethanol and α-pinene; and 4) a quaternary blend of ipsenol, ipsdienol, ethanol, and α-pinene. Traps baited with the quaternary blend caught the greatest numbers of Acanthocinus nodosus (F.), Acanthocinus obsoletus (Olivier), Acmaeops proteus (Kirby), Astylopsis sexguttata (Say), Rhagium inquisitor (L.) (Cerambycidae), and Buprestis lineata (F.) (Buprestidae). Traps baited with ethanol and α-pinene caught the greatest numbers of Arhopalus rusticus (LeConte), Asemum striatum (L.), Tetropium spp., Xylotrechus sagittatus (Germar) (Cerambycidae), and Buprestis maculipennis Gory (Buprestidae) with minimal interruption by ipsenol and ipsdienol. Our results suggest that multiple-funnel traps baited with the quaternary lure blend of ipsenol, ipsdienol, ethanol, and α-pinene are effective for trapping various species of wood-boring beetles in pine forests of eastern North America, and may have utility in detection programs for adventive species in North America and overseas.

Sulfamethoxazole-induced thrombocytopenia masquerading as posttransfusion purpura: a case report

BACKGROUND

Drug-induced immune thrombocytopenia (DITP) is a rare clinical disorder characterized by accelerated platelet (PLT) clearance in the presence of drug-dependent antibodies. Distinguishing DITP from other immune-mediated disorders such as posttransfusion purpura (PTP) and autoimmune thrombocytopenia can represent a clinical challenge.

CASE REPORT

A 68-year-old male with no prior transfusion history presented to the emergency department (ED) with dyspnea, epistaxis, and severe thrombocytopenia (<10 × 10(9)/L) 12 days after discharge from a hospital admission for a coronary artery bypass graft. Evaluation of the degree of thrombocytopenia and the temporal association between the peri- and postoperative receipt of multiple transfusions and the acute decrease in PLT count indicated PTP as a possible cause of the severe thrombocytopenia. Treatment with 1 g/kg intravenous immunoglobulin (IVIG) was initiated and followed by a rapid 48-hour increase in the PLT count. PLT antibodies lacking serologic specificity were subsequently identified in a sample collected upon presentation. Two weeks later he again presented to the ED with epistaxis and severe thrombocytopenia (<10 × 10(9)/L). Clinical history now revealed that the patient had been treated with trimethoprim-sulfamethoxazole by his primary care physician after his first hospitalization for a "cellulitic-appearing" leg and again before his final presentation for surgical site erythema and edema. IVIG was administered again with a rapid return of PLT count to baseline. Sulfamethoxazole-dependent PLT antibodies were subsequently identified in the original patient sample.

CONCLUSION

This case report documents a case of IVIG-responsive DITP initially misdiagnosed as PTP, highlighting the clinical overlap of these immunologic-mediated phenomena.

Differences in the clinical course of heparin induced thrombocytopenia before and after the availability of HIT IgG class testing

INTRODUCTION

To determine whether the HIT IgG class platelet factor 4 (PF4) enzyme immunoabsorbant assay (EIA) influenced the duration of parenteral direct thrombin inhibitor (pDTI) therapy or bleeding risk in patients started on pDTI for a presumed diagnosis of HIT.

MATERIALS/METHODS

187 patients started on pDTI for presumed HIT were assessed in two time periods before (period 1, n=88 patients) and after the introduction of an IgG-specific assay (period 2, n=99 patients).

RESULTS

Patients in period 2 were treated with pDTI therapy for a median of 5 days less (p<0.0001) however the incidence of Grade III and IV bleeding episodes was not different. Bleeding was observed to occur early during the hospital course at a median of 2-3 days after initiation of the pDTI. The average pDTI drug acquisition cost was markedly decreased in period 2 when compared to period 1 (p<0.0001).

CONCLUSIONS

Implementation of the IgG class HIT EIA resulted in a decrease in the number of days on a pDTI and a decrease in the average pDTI acquisition cost per patient without an observed change in serious bleeding events.

Residual plasma in red blood cells and transfusion-related acute lung injury

BACKGROUND

Transfusion-related acute lung injury (TRALI) is the most common cause of death from blood transfusion and red blood cells (RBCs) now account for approximately 50% of these fatalities. RBCs from female donors have been implicated in large series and HLA Class II antibodies to cognate recipient antigens identified in small series and case reports. The absolute volume of residual plasma in these RBCs is unknown.

STUDY DESIGN AND METHODS

Two confirmed cases of RBC-associated TRALI in which the implicated donors had Class II antibodies were investigated, and the antibody strength against recipient cognate antigens was assessed using a fluorescent bead assay. RBCs in additive solution (AS) were studied on Day 42 of liquid storage to calculate residual anticoagulated plasma.

RESULTS

Both RBC units were stored in AS-1 and were from female donors who had anti-HLA Class II antibodies of high strength against cognate antigens in the recipients. Anti-DR4 was identified in both cases. Nineteen AS-1 RBC units manufactured from whole blood donations using a hard spin had a mean (±1SD) residual plasma content of 38 ± 8 mL, and 26 AS-3 RBC units manufactured using a soft spin had 66 ± 13 mL (p < 0.01).

CONCLUSION

RBCs continue to be manufactured from female donors of unknown or even known anti-HLA status. The residual plasma content of these RBCs may approach 100 mL. A combination of a high-strength antibody and large residual plasma volume could explain severe or even fatal RBC-associated TRALI.

Reduction in red blood cell transfusion associated with engagement of the ordering physician

BACKGROUND

Data on red blood cell (RBC) transfusion in the United States show variation in practice and overprescribing or overdosing is considered to be prevalent. Education or restrictive interventions could modify practice.

STUDY DESIGN AND METHODS

RBC transfusion and mortality rates were recorded in a single institution over a 15-year period. The first 3 years were used as a baseline. Education measures were used to influence practice for 3 years followed by a 9-year period when questionable RBC orders in nonbleeding inpatients resulted in prospective physician notification for potential modification. Physician notification was done by blood bank technologists with transfusion medicine physician support, if needed. Pretransfusion hemoglobin levels of more than 9 g/dL were recommended for cancellation and levels between 8 and 9 g/dL advised for a single unit, if 2 or more units were requested. RBC transfusion rates were described as inpatient units per 1000 discharges to allow for interyear comparison.

RESULTS

A downward trend in RBC transfusion was noted for the intervention period. Comparison of the baseline period with the past 3 years of the intervention period showed an approximate 33% decrease, which was highly significant (508 ± 66 vs. 341 ± 32, p < 0.01). Inpatient mortality rates declined over this period.

CONCLUSION

Physician education in appropriate transfusion practice is desirable but may not greatly impact RBC use. Engagement of physicians who prescribe RBCs that appear inappropriate for indication or dose was associated with a significant decline in RBC use without evidence of a change in mortality.

Advanced blood management strategies for elective joint arthroplasty

There is a high prevalence of anemia detected in the preoperative work-up of elective surgical patients preparing for total joint replacement. The impact of anemia in this population has significant implications due to elevations in postoperative morbidity and mortality. By using current clinical guidelines and medical evidence, clinicians can improve outcomes for these patients by employing a three-phase approach, focused on preoperative assessment, intraoperative hemostasis, and postoperative blood product management. Strategies to optimize preoperative hemoglobin levels, reduce intraoperative blood losses, and decrease postoperative transfusion rates can independently and collectively improve overall patient care and surgical outcomes following lower extremity total joint arthroplasty.

The effect of filtration on residual levels of coagulation factors in plasma

Leukoreduced blood components are commonly manufactured via filtration. There are specifications for the residual leukocyte content of any final cellular blood component but not for residual clotting factors. Leukoreduced and nonleukoreduced platelet-poor plasma products were manufactured from filtered vs unfiltered platelet-rich plasma, respectively, using platelet leukoreduction filters. The leukoreduced plasma showed lower levels of factor VIII (75% ± 16% vs 88% ± 18%, P ≤ .05), factor XI (86% ± 9% vs 96% ± 10%, P ≤ .01) and factor VII (87% ± 14% vs 98% ± 11%, P ≤ .01). No difference was seen with factor X, factor V, or fibrinogen. Plasma filtered through a whole blood filter showed a reduction in factor V (105% ± 12% vs 124% ± 10%, P ≤ .01) but a minimal reduction in factor VIII (80% ± 5% vs 82% ± 6%, P = .04). Filtration can alter the residual levels of clotting factors to a variable extent in manufactured plasma, most noticeably factors V, VII, VIII, and XI.

Effects of red wine and vodka on collateral-dependent perfusion and cardiovascular function in hypercholesterolemic swine

BACKGROUND

Moderate consumption of alcohol, particularly red wine, has been shown to decrease cardiac risk. We used a hypercholesterolemic swine model of chronic ischemia to examine the effects of 2 alcoholic beverages on the heart.

METHODS AND RESULTS

Yorkshire swine fed a high-cholesterol diet underwent left circumflex ameroid constrictor placement to induce chronic ischemia at 8 weeks of age. One group (HCC, n=9) continued on the diet alone, the second (HCW, n=8) was supplemented with red wine (pinot noir, 12.5% alcohol, 375 mL daily), and the third (HCV, n=9) was supplemented with vodka (40% alcohol, 112 mL daily). After 7 weeks, cardiac function was measured, and ischemic myocardium was harvested for analysis of perfusion, myocardial fibrosis, vessel function, protein expression, oxidative stress, and capillary density. Platelet function was measured by aggregometry. Perfusion to the ischemic territory as measured by microsphere injection was significantly increased in both HCW and HCV compared with HCC at rest, but in only the HCW group under ventricular pacing. Microvessel relaxation response to adenosine 5'-diphosphate was improved in the HCW group alone as was regional contractility in the ischemic territory, although myocardial fibrosis was decreased in both HCW and HCV. Expression of proangiogenic proteins phospho-endothelial nitric oxide synthase and vascular endothelial growth factor was increased in both HCW and HCV, whereas phospho-mammalian target of rapamycin was increased only in the HCV group. Expression of Sirt-1 and downstream antioxidant phospho-FoxO1 was increased only in the HCW group. Protein oxidative stress was decreased in the HCW group alone, whereas capillary density was increased only in the HCV group. There was no significant difference in platelet function between groups.

CONCLUSION

Moderate consumption of red wine and vodka may reduce cardiovascular risk by improving collateral-dependent perfusion through different mechanisms. Red wine may offer increased cardioprotection related to its antioxidant properties.

Does my patient have a life- or limb-threatening thrombocytopenia?

The diagnosis and management of severe thrombocytopenias can be difficult, but is necessary to avoid significant morbidity and mortality. The causes of severe thrombocytopenias, often with a platelet count of less than 10 × 10(9)/L, include heparin-induced thrombocytopenia, the thrombotic microangiopathies, the catastrophic antiphospholipid syndrome, preeclampsia/HELLP, and posttransfusion purpura. This review provides a brief overview of the key clinical features of each of these major clinical entities, and strategies for their diagnostic workup and therapeutic management.

Central line placement in patients with and without prophylactic plasma

Central line placement (CLP) is a common life-saving intervention in critically ill patients, and patients with coagulation abnormalities as identified by an abnormal international normalized ratio (INR) may receive prophylactic plasma transfusion before the procedure despite previously published data that such a practice is not efficacious. Over a 14-month period, 287 CLPs were performed in the intensive care unit. The use of plasma preprocedure in patients with an elevated INR was generally discouraged but left to the discretion of the operator. A total of 100 lines were placed in patients with a preprocedure INR greater than 1.5, 27 of whom received prophylactic fresh frozen plasma. Only 1 case of bleeding was observed in a patient with an INR of 3.9, who received fresh frozen plasma preprocedure (0/73 vs 1/27; P = .6). The occurrence of bleeding was very low overall with CLP (0.3%; 95% confidence interval, 0%-2%), and no benefit of prophylactic plasma was observed.

Manufacture of pooled platelets in additive solution and storage in an ELX container after an overnight warm temperature hold of platelet-rich plasma

The processing of whole blood-derived platelet-rich plasma (PRP) to a platelet concentrate and platelet-poor plasma is currently performed within 8 hours to comply with the requirements to manufacture fresh frozen plasma. Maintaining PRP at room temperature for a longer period can have the advantage of shifting the completion of component manufacture onto day shifts. Pairs of ABO-identical prepooled platelets were manufactured by the PRP method, using the current approach with platelet storage in a CLX HP container (Pall Medical, Covina, CA) and plasma, or a novel approach with an 18- to a 24-hour room temperature hold of the PRP and the manufacture of pooled platelets in a glucose-containing additive solution (AS) and storage in a new ELX container (Pall Medical). Standard in vitro assays were performed on days 2, 5, and 7. The results showed that the AS platelets in ELX have in vitro characteristics that are equivalent or superior to those of the standard product.

Red cell exchange transfusion for babesiosis in Rhode Island

We report four cases of clinically severe tick borne babesiosis treated with chemotherapy and adjunctive red cell exchange (RCE) at two Rhode Island hospitals from 2004 to 2007. All RCE procedures were performed using a Cobe Spectra device and were well tolerated without complications. The volume of allogeneic red cells used in the exchange was determined using the algorithm in the apheresis device with the input variables of preprocedure hematocrit, weight, height, an assumed allogeneic red cell hematocrit of 55 and a desired post procedure hematocrit of 27. The preprocedure level of parasitemia varied between 2.4% and 24% and the postprocedure level of parasitemia between 0.4 and 5.5% with an average overall percent reduction in parasitemia of 74%. Retrospectively, application of a new formula to calculate red cell mass appeared to correlate better with the percent reduction in parasitemia. Previous reports of RCE in babesiosis were reviewed. The reported reduction in parasitemia varied from 50% to >90%. Although a preprocedure level of parasitemia of 10% is sometimes used as a threshold for RCE in clinically severe babesiosis, this threshold does not have a firm empirical basis. No postprocedure desired level of parasitemia is indicated nor the mass of allogeneic red cells needed to achieve such a level. We conclude that current estimates of the dose of allogeneic red cells used in RCE are probably inaccurate, advocate a new formula to estimate this dose and suggest that a 90% reduction in parasitemia should be the minimally desired target of RCE in babesiosis.

Spatial localization of electrotactile stimuli on the fingertip in humans

This study was designed to determine the extent to which sensations elicited by discrete electrotactile stimulation can be spatially localized, with a qualitative comparison to mechanical stimulation, in a 2 x 2 electrode array on the fingertip. Electrotactile stimulation was delivered in two modes: (1) same current to all locations (constant) or (2) current adjusted to perceptual threshold of each location (varied). For each stimulus location, subjects were asked to identify the location of the stimulus. Mechanical stimulation of the same locations on the fingerpad was delivered through von Frey hairs (0.07, 0.2 and 0.4 g). The percentage of accurate responses was computed for all stimulation modes. We found that the accuracy of discrimination of stimulus location in both the constant (46%) and varied (40%) electrotactile stimulation modes was significantly higher than chance level (25%; p < 0.01). Furthermore, subjects were significantly more accurate in discriminating electrotactile stimuli in the constant than in the varied mode (p < 0.05). We also found that the accuracy of spatial discrimination was dependent on stimulation site for mechanical, but not electrotactile stimulation. Finally, we found a significant difference in accuracy over the duration of the experiment only for mechanical modes, which may indicate that electrotactile stimuli are less biased over time. These results suggest that, although low in accuracy, human subjects are able to extract spatial information from electrotactile stimuli. Further research is needed to optimize the amount of the information that can be delivered through electrotactile stimulation.