Immune thrombotic thrombocytopenic purpura in older patients: Results from the Spanish TTP Registry (REPTT)

Immune thrombotic thrombocytopenic purpura (iTTP) is an ultra-rare disease that seldom occurs in the elderly. Few reports have studied the clinical course of iTTP in older patients. In this study, we have analysed the clinical characteristics at presentation and response to therapy in a series of 44 patients with iTTP ≥60 years at diagnosis from the Spanish TTP Registry and compared them with 209 patients with <60 years at diagnosis from the same Registry. Similar symptoms and laboratory results were described in both groups, except for a higher incidence of renal dysfunction among older patients (23% vs. 43.1%; p = 0.008). Front-line treatment in patients ≥60 years was like that administered in younger patients. Also, no evidence of a difference in clinical response and overall survival was seen in both groups. Of note, 14 and 25 patients ≥60 years received treatment with caplacizumab and rituximab, respectively, showing a favourable safety and efficacy profile, like that observed in patients <60 years.

COVID-19 L·OVE repository is highly comprehensive and can be used as a single source for COVID-19 studies

Background and Objective

The coronavirus disease 2019 Living OVerview of Evidence (COVID-19 L·OVE) is a public repository and classification platform for COVID-19 articles. The repository contains more than 430,000 articles as of September 20, 2021 and intends to provide a one-stop shop for COVID-19 evidence. Considering that systematic reviews conduct high-quality searches, this study assesses the comprehensiveness and currency of the repository against the total number of studies in a representative sample of COVID-19 systematic reviews.

Methods

Our sample was generated from all the studies included in the systematic reviews of COVID-19 published during April 2021. We estimated the comprehensiveness of COVID-19 L·OVE repository by determining how many of the individual studies in the sample were included in the COVID-19 L·OVE repository. We estimated the currency as the percentage of studies that was available in the COVID-19 L·OVE repository at the time the systematic reviews conducted their own search.

Results

We identified 83 eligible systematic reviews that included 2,132 studies. COVID-19 L·OVE had an overall comprehensiveness of 99.67% (2,125/2,132). The overall currency of the repository, that is, the proportion of articles that would have been obtained if the search of the reviews was conducted in COVID-19 L·OVE instead of searching the original sources, was 96.48% (2,057/2,132). Both the comprehensiveness and the currency were 100% for randomized trials (82/82).

Conclusion

The COVID-19 L·OVE repository is highly comprehensive and current. Using this repository instead of traditional manual searches in multiple databases can save a great amount of work to people conducting systematic reviews and would improve the comprehensiveness and timeliness of evidence syntheses. This tool is particularly important for supporting living evidence synthesis processes.

Males and females with first episode psychosis present distinct profiles of social cognition and metacognition

Deficits in social cognition and metacognition impact the course of psychosis. Sex differences in social cognition and metacognition could explain heterogeneity in psychosis. 174 (58 females) patients with first-episode psychosis completed a clinical, neuropsychological, social cognitive, and metacognitive assessment. Subsequent latent profile analysis split by sex yielded two clusters common to both sexes (a Homogeneous group, 53% and 79.3%, and an Indecisive group, 18.3% and 8.6% of males and females, respectively), a specific male profile characterized by presenting jumping to conclusions (28.7%) and a specific female profile characterized by cognitive biases (12.1%). Males and females in the homogeneous profile seem to have a more benign course of illness. Males with jumping to conclusions had more clinical symptoms and more neuropsychological deficits. Females with cognitive biases were younger and had lower self-esteem. These results suggest that males and females may benefit from specific targeted treatment and highlights the need to consider sex when planning interventions.

Persons with first episode psychosis have distinct profiles of social cognition and metacognition

Subjects with first-episode psychosis experience substantial deficits in social cognition and metacognition. Although previous studies have investigated the role of profiles of individuals in social cognition and metacognition in chronic schizophrenia, profiling subjects with first-episode psychosis in both domains remains to be investigated. We used latent profile analysis to derive profiles of the abilities in 174 persons with first-episode psychosis using the Beck's Cognitive Insight Scale, the Faces Test, the Hinting Task, the Internal, Personal and Situational Attributions Questionnaire, and the Beads Task. Participants received a clinical assessment and a neuropsychological assessment. The best-fitting model was selected according to the Bayesian information criterion (BIC). We assessed the importance of the variables via a classification tree (CART). We derived three clusters with distinct profiles. The first profile (33.3%) comprised individuals with low social cognition. The second profile (60.9%) comprised individuals that had more proneness to present jumping to conclusions. The third profile (5.7%) presented a heterogeneous profile of metacognitive deficits. Persons with lower social cognition presented worse clinical and neuropsychological features than cluster 2 and cluster 3. Cluster 3 presented significantly worst functioning. Our results suggest that individuals with FEP present distinct profiles that concur with specific clinical, neuropsychological, and functional challenges. Each subgroup may benefit from different interventions.

Controlling selectivity in N-heterocycle directed borylation of indoles

Electrophilic borylation of indoles with BX₃ (X = Cl or Br) using directing groups installed at N1 can proceed at the C2 or the C7 position. The six membered heterocycle directing groups utilised herein, pyridines and pyrimidine, result in indole C2 borylation being the dominant outcome (in the absence of a C2-substituent). In contrast, C7 borylation was achieved using five membered heterocycle directing groups, such as thiazole and benzoxazole. Calculations on the borylation of indole substituted with a five (thiazole) and a six (pyrimidine) membered heterocycle directing group indicated that borylation proceeds via borenium cations with arenium cation formation having the highest barrier in both cases. The C7 borylated isomer was calculated to be the thermodynamically favoured product with both five and six membered heterocycle directing groups, but for pyrimidine directed indole borylation the C2 product was calculated to be the kinetic product. This is in contrast to thiazole directed indole borylation with BCl₃ where the C7 borylated isomer is the kinetic product too. Thus, heterocycle ring size is a useful way to control C2 vs. C7 selectivity in N-heterocycle directed indole C-H borylation.

Generation of a series of Bn fused oligo-naphthalenes (n = 1 to 3) from a B1-polycyclic aromatic hydrocarbon

The first three members of a series of {B-Mes} fused oligo-naphthalenes have been synthesised and trends in key properties of this series have been elucidated.

A modular route to boron doped PAHs by combining borylative cyclisation and electrophilic C-H borylation

Starting from simple alkynes, sequential borylative cyclisation/electrophilic C–H borylation represents a simple modular route to novel B-doped PAHs.

Heteroatom doping into polyaromatic hydrocarbons (PAHs) is a powerful approach for modifying key physical properties, however, there are extremely few modular routes that enable facile formation of B-, B₂- and B,N-(specifically not containing direct B–N bonds) doped PAHs despite the growing importance of these materials. Sequential, one pot borylative cyclisation/intramolecular electrophilic C–H borylation of naphthyl-alkynes provides a simple new route to access novel B-, B,N- and B₂-doped (PAHs). The initial products, dihydronaphthalene/dihydroquinoline B-mesityl PAHs, were reacted with [Ph₃C][BF₄]/pyridyl base to form the oxidised B-, and B,N-doped PAHs. However, for B-triisopropylphenyl (Trip) PAH congeners oxidation has to be performed prior to Trip installation due to preferential oxidation of an isopropylaryl moiety to the styrene. This alternative sequence enables access to Trip-B-PAHs and to structurally constrained B and B₂-PAHs. Analysis of the solid state structures and optoelectronic properties of these PAHs confirm that frontier orbital energies, extended packing structures, Stokes shift and quantum yields all can be rationally modified using this methodology. The simplicity of this synthetic approach makes it a powerful tool for rapidly generating novel bench stable boron doped PAHs, which is important for facilitating further structure–property relationship studies and the wider utilisation of these materials in optoelectronic applications.

Randomized control trial to assess the efficacy of metacognitive training compared with a psycho-educational group in people with a recent-onset psychosis

BACKGROUND

Aims were to assess the efficacy of metacognitive training (MCT) in people with a recent onset of psychosis in terms of symptoms as a primary outcome and metacognitive variables as a secondary outcome.

METHOD

A multicenter, randomized, controlled clinical trial was performed. A total of 126 patients were randomized to an MCT or a psycho-educational intervention with cognitive-behavioral elements. The sample was composed of people with a recent onset of psychosis, recruited from nine public centers in Spain. The treatment consisted of eight weekly sessions for both groups. Patients were assessed at three time-points: baseline, post-treatment, and at 6 months follow-up. The evaluator was blinded to the condition of the patient. Symptoms were assessed with the PANSS and metacognition was assessed with a battery of questionnaires of cognitive biases and social cognition.

RESULTS

Both MCT and psycho-educational groups had improved symptoms post-treatment and at follow-up, with greater improvements in the MCT group. The MCT group was superior to the psycho-educational group on the Beck Cognitive Insight Scale (BCIS) total (p = 0.026) and self-certainty (p = 0.035) and dependence self-subscale of irrational beliefs, comparing baseline and post-treatment. Moreover, comparing baseline and follow-up, the MCT group was better than the psycho-educational group in self-reflectiveness on the BCIS (p = 0.047), total BCIS (p = 0.045), and intolerance to frustration (p = 0.014). Jumping to Conclusions (JTC) improved more in the MCT group than the psycho-educational group (p = 0.021). Regarding the comparison within each group, Theory of Mind (ToM), Personalizing Bias, and other subscales of irrational beliefs improved in the MCT group but not the psycho-educational group (p < 0.001-0.032).

CONCLUSIONS

MCT could be an effective psychological intervention for people with recent onset of psychosis in order to improve cognitive insight, JTC, and tolerance to frustration. It seems that MCT could be useful to improve symptoms, ToM, and personalizing bias.

Front microrheology of the non-Newtonian behaviour of blood: scaling theory of erythrocyte aggregation by aging

We introduce a new framework to study the non-Newtonian behaviour of fluids at the microscale based on the analysis of front advancement. We apply this methodology to study the non-linear rheology of blood in microchannels. We carry out experiments in which the non-linear viscosity of blood samples is quantified at different haematocrits and ages. Under these conditions, blood exhibits a power-law dependence on the shear rate. In order to analyse our experimental data, we put forward a scaling theory which allows us to define an adhesion scaling number. This theory yields a scaling behaviour of the viscosity expressed as a function of the adhesion capillary number. By applying this scaling theory to samples of different ages, we are able to quantify how the characteristic adhesion energy varies as time progresses. This connection between microscopic and mesoscopic properties allows us to estimate quantitatively the change in the cell-cell adhesion energies as the sample ages.

Needs of People with Schizophrenia/Psychosis and their Caregivers: A Large Scale Survey

For the first time in Spain, a large scale survey (5205 people) was carried out to establish the real needs of those directly affected by the illness. Patients and caregivers responded to a 9-question survey concerning dimensions: personal, social, medical treatment, psychotherapy and rehabilitation. For patients, the most important need (an average score of 3.5 on a scale of importance from 1 to 4) was to feel their emotional needs covered. The following average scores were also obtained: feel well physically (3.42), improve autonomy (3.41), have leisure activities (3.21) and work/study (3.1). A total of 42% of patients indicated having little or no freedom over their lives. Thirty-six percent indicated that medical treatment did not start soon enough, 35% that psychotherapy started too late and 13% saying they had received no psychotherapy at all. The help from professionals most valued was provide information about the illness (3.4), dedicating more time (3.4) investigating new treatments (3.3) paying attention to secondary effects (3.3) and incorporating the patient in decision making (3.3). Most patients reported a state of health “regular to good” but 10% indicated not being understood at all in their social environment since onset of illness and 25% being little understood. The anti-stigma initiative most valued was to increase investment in schizophrenia in health planning. Integral health planning should incorporate patient insights concerning basic needs and treatment preferences.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Influence of the Structural Characteristics of Fibrous Heat Insulators upon Their Properties of Moisture Transfer

Glass fiber insulant is a medium which can be deformed when loaded. Moisture transfer can occur in it. An experimental installation has been de signed in order to determine the water content and the deformation. The basic idea is the principle of attenuation of two radioactive emissions As a first approach, the measures have been carried out with media held rigidly. They show how the fiber di ameter and nominal density act upon the coefficients of moisture transfer and the properties of capillarity of glass fiber insulant

Desensitization in ABO-Incompatible Kidney Transplantation With Low ABO Iso-Agglutinin Titers

BACKGROUND

In ABO-incompatible (ABOi) kidney transplantation (KT) with low iso-agglutinin (IG) titers (IGT), standard pre-conditioning treatment might be excessive. To try to answer this question, we evaluated the pre-conditioning requirements of a group of ABOi KT with low ABO IGT in our center. Our main objective was to assess desensitization requirements for ABOi KT with low IGT (<16) at Hospital Clinic of Barcelona from 2006 to 2014.

METHODS

A retrospective study of desensitization (rituximab and plasma exchange [PE]) requirements for ABOi KT with IGT <16 was conducted.

RESULTS

One and 5 years after KT, patient survival was 100%. Renal graft survival was 90% at 1 and 5 years after KT. Mean PE performed before KT was 1.7 (standard deviation [SD], 1.703); 50% of the patients did not receive PE after transplantation, 30% received 2 sessions of PE, and 20% received only 1. The average is 0.8 (SD, 0.91).Follow-up IG determinations remained with low titers (≤8/8). No rebounds of titers were observed during the first 4 to 6 months after transplantation.

CONCLUSIONS

Recipients with IGT ≤8 required none or only 1 PE session to reach acceptable titers (titers ≤4) to perform ABOi KT safely. This information is useful to assess the possibility of a minimized desensitization protocol in ABOi KT donors with low titers of IG to reduce adverse effects, reduce cost, and simplify pre-transplant logistics.

Capillary Filling at the Microscale: Control of Fluid Front Using Geometry

We propose an experimental and theoretical framework for the study of capillary filling at the micro-scale. Our methodology enables us to control the fluid flow regime so that we can characterise properties of Newtonian fluids such as their viscosity. In particular, we study a viscous, non-inertial, non-Washburn regime in which the position of the fluid front increases linearly with time for the whole duration of the experiment. The operating shear-rate range of our apparatus extends over nearly two orders of magnitude. Further, we analyse the advancement of a fluid front within a microcapillary in a system of two immiscible Newtonian liquids. We observe a non-Washburn regime in which the front can accelerate or decelerate depending on the viscosity contrast between the two liquids. We then propose a theoretical model which enables us to study and explain both non-Washburn regimes. Furthermore, our theoretical model allows us to put forward ways to control the emergence of these regimes by means of geometrical parameters of the experimental set-up. Our methodology allows us to design and calibrate a micro-viscosimetre which works at constant pressure.

Inter- and intra-molecular C–H borylation for the formation of PAHs containing triarylborane and indole units

Inter-/intra-molecular electrophilic C–H borylation of C4-substituted indoles enables the formation of fused polycyclic aromatic structures containing triarylborane and N-heterocyclic units.

A prospective, active haemovigilance study with combined cohort analysis of 19,175 transfusions of platelet components prepared with amotosalen-UVA photochemical treatment

BACKGROUND AND OBJECTIVES

A photochemical treatment process (PCT) utilizing amotosalen and UVA light (INTERCEPT(™) Blood System) has been developed for inactivation of viruses, bacteria, parasites and leucocytes that can contaminate blood components intended for transfusion. The objective of this study was to further characterize the safety profile of INTERCEPT-treated platelet components (PCT-PLT) administered across a broad patient population.

MATERIALS AND METHODS

This open-label, observational haemovigilance programme of PCT-PLT transfusions was conducted in 21 centres in 11 countries. All transfusions were monitored for adverse events within 24 h post-transfusion and for serious adverse events (SAEs) up to 7 days post-transfusion. All adverse events were assessed for severity (Grade 0-4), and causal relationship to PCT-PLT transfusion.

RESULTS

Over the course of 7 years in the study centres, 4067 patients received 19,175 PCT-PLT transfusions. Adverse events were infrequent, and most were of Grade 1 severity. On a per-transfusion basis, 123 (0.6%) were classified an acute transfusion reaction (ATR) defined as an adverse event related to the transfusion. Among these ATRs, the most common were chills (77, 0.4%) and urticaria (41, 0.2%). Fourteen SAEs were reported, of which 2 were attributed to platelet transfusion (<0.1%). No case of transfusion-related acute lung injury, transfusion-associated graft-versus-host disease, transfusion-transmitted infection or death was attributed to the transfusion of PCT-PLT.

CONCLUSION

This longitudinal haemovigilance safety programme to monitor PCT-PLT transfusions demonstrated a low rate of ATRs, and a safety profile consistent with that previously reported for conventional platelet components.

Molecular determinants of positive allosteric modulation of the human metabotropic glutamate receptor 2

BACKGROUND AND PURPOSE

The activation of the metabotropic glutamate receptor 2 (mGlu2 ) reduces glutamatergic transmission in brain regions where excess excitatory signalling is implicated in disorders such as anxiety and schizophrenia. Positive allosteric modulators (PAMs) can provide a fine-tuned potentiation of these receptors' function and are being investigated as a novel therapeutic approach. An extensive set of mutant human mGlu2 receptors were used to investigate the molecular determinants that are important for positive allosteric modulation at this receptor.

EXPERIMENTAL APPROACH

Site-directed mutagenesis, binding and functional assays were employed to identify amino acids important for the activity of nine PAMs. The data from the radioligand binding and mutagenesis studies were used with computational docking to predict a binding mode at an mGlu2 receptor model based on the recent structure of the mGlu1 receptor.

KEY RESULTS

New amino acids in TM3 (R635, L639, F643), TM5 (L732) and TM6 (W773, F776) were identified for the first time as playing an important role in the activity of mGlu2 PAMs.

CONCLUSIONS AND IMPLICATIONS

This extensive study furthers our understanding of positive allosteric modulation of the mGlu2 receptor and can contribute to improved future design of mGlu2 PAMs.

Counting platelets at transfusion threshold levels: impact on the decision to transfuse. A BEST Collaborative - UK NEQAS(H) International Exercise

BACKGROUND AND OBJECTIVES

Obtaining accurate and precise platelet enumeration in automatic platelet analysers at low platelet counts is a challenge. To explore the performance of current haematology analysers in counting platelet concentrations usually used as platelet transfusion threshold.

MATERIAL AND METHODS

An international exercise where four blood samples with platelet levels near usual platelet transfusion thresholds was prepared and distributed.

RESULTS

The samples shipped had a platelet count of 6·3, 13·3, 21·6 and 53·0 × 10(9) /l according to the international reference method. We received 82 sets of results from nine countries. Instruments from six different manufacturers were represented. Although the mean count for each of the four samples was very similar to the values, according to the reference method (9·0, 16·2, 23·0 and 57·6 × 10(9) /l), significant variability in the results was found. Assuming that these were patient samples and the result of the count used to indicate a prophylactic platelet transfusion, undertransfusion would have occurred for 24·5% of the LP1 samples at a transfusion threshold of 10 × 10(9) /l and, at a threshold of 20 × 10(9) /l, undertransfusion would have occurred for 7·2% of the LP1 and 16·2% of the LP2 samples and overtransfusion would have occurred with 23·1% of the LP3 samples.

CONCLUSION

The results suggest that significant inaccuracy exists in counting low levels of platelets and that this inaccuracy might have a significant impact in under- and overtransfusion of platelet concentrates to patients.

Clinical application of midtrimester non-invasive fetal RHD genotyping and identification of RHD variants in a mixed-ethnic population

OBJECTIVE

This study aims to assess the suitability of non-invasive prenatal RHD genotyping in non-immunized midtrimester pregnant women from a mixed ethnic population, to prevent unnecessary anti-D immunoglobulin prophylaxis and to identify RHD variants

METHODS

Rhesus D-negative pregnant women were offered fetal RHD genotyping at 24 gestational weeks. A total of 284 samples were tested for RHD status using multiplex rt-PCR amplification of exons 5 and 7 of the RHD gene and exons 6 and 10 in selected cases. Women carrying RHD-negative fetuses were counseled about their option to avoid routine antenatal anti-D immunoglobulin administration. Diagnostic accuracy of RHD genotyping was compared with postnatal Rhesus D serotyping.

RESULTS

A total of 184 positives (65%), 91 negatives (32%) and 7 cases (2.5%) compatibles with RHD variants were detected by RHD genotyping. No false negative results were found, and a single false positive was observed in a twin pregnancy. Genotyping was accepted when offered by 94% of women (284/302), and anti-D immunoglobulin was avoided in 95% (90/95) of RHD-negative fetuses.

CONCLUSIONS

Non-invasive routine antenatal RHD genotyping at 24 weeks of pregnancy is a highly accurate method, resulting in the avoidance of 95% of unnecessary administrations of anti-D immunoglobulin, with no false negative results.

Therapeutic efficacy of platelet components treated with amotosalen and ultraviolet A pathogen inactivation method: results of a meta-analysis of randomized controlled trials

BACKGROUND AND OBJECTIVES

There are conflicting data regarding the therapeutic efficacy of platelets inactivated using amotosalen and ultraviolet A light. We have performed a meta-analysis to summarize the results of different randomized controlled trials (RCT).

MATERIALS AND METHODS

Five RCTs reported through March 2011 met the criteria for meta-analysis. Weighted mean difference (WMD) in corrected count increment (CCI) at 1 h, CCI-24 h, and transfusion interval (days) and summary odds ratio (OR) of bleeding in inactivated platelet (I-P) group vs. noninactivated platelet (C-P) group were calculated across studies.

RESULTS

Randomized controlled trials were statistically homogeneous when we analysed CCI-24 h, and the transfusion of C-P was associated with a higher CCI-24 h when compared with the transfusion of I-P (WMD, 3×10(3); 95% CI, 2·32×10(3)-3·69×10(3); P<0·00001). RCTs were statistically heterogeneous when we analysed CCI-1 h, transfusion interval and OR of bleeding. Regarding the OR of bleeding in the I-P and C-P groups, it varied by as much as a multiple of four among the trials, from 0·66 to 2·66. When we combined double-blinded and high methodologic quality score RCTs, the use of I-P was not statistically associated with an increase in the OR of bleeding when compared with the use of C-P (OR, 0·97; 95% CI, 0·75-1·27; P=0·84).

CONCLUSION

Although the transfusion of I-P was associated with lower CCI-24 h when compared with the transfusion of C-P, this was not associated with differences in the OR of bleeding between I-P and C-P.

Neutrophil CD64: diagnostic accuracy and prognostic value in patients presenting to the emergency department

The purpose of this study was to evaluate the diagnostic accuracy and prognostic value of neutrophil CD64 expression for bacterial infection in febrile adult patients presenting to our hospital emergency department. We prospectively included 132 patients with fever ≥ 38ºC (≥ 100.4ºF) during the last 24 hours and we measured CD64 expression on neutrophils the day after admission at the emergency department. We followed the patients until full recovery or death. There were 115 (87%) patients with bacterial infection and 108 (94%) of them survived. There were 17 (13%) patients without bacterial infection and 12 (71%) of them survived. Patients with bacterial infection and patients who survived showed a CD64 index higher when compared with patients without bacterial infection and patients who died, respectively (3.7 ± 3.2 vs. 2.5 ± 2.3; p = 0.03; and 3.7 ± 3.1 vs. 1.7 ± 0.6; p = 0.002; Mann-Whitney U test). The receiver operating characteristic (ROC) curve analysis for detecting bacterial infection and predicting survival with the CD64 index showed an area under curve (AUC) of 0.66 (95% CI, 0.52-0.8; p = 0.03) and 0.71 (95% CI, 0.57-0.85; p = 0.01), respectively. Diagnostic accuracy and prognostic value of CD64 expression was good in adult patients with fever.

[Diagnostic utility of nail biopsy: a study of 15 cases]

INTRODUCTION

Nail biopsy is thought to be a useful technique for the diagnosis of diseases affecting the nail apparatus and may help avoid delays in the diagnosis of important mucocutaneous diseases. Furthermore, it has therapeutic value in its own right. It is not a difficult technique to perform but it requires an in-depth knowledge of the anatomy and physiology of the nail unit, as well as surgical experience and patient collaboration. In order to assess the diagnostic utility of this technique, we reviewed the nail biopsies performed in our department between June 2005 and May 2006.

PATIENTS AND METHODS

We identified 15 patients in whom nail biopsy had been performed. The clinical findings, type of biopsy performed, and histopathologic diagnosis were assessed.

RESULTS

Nail biopsy allowed diagnosis of a variety of skin disease in 13 out of 15 patients (psoriasis in 5, onychomycosis in 4, melanonychia in 2, melanoma in 1, and subungual hematoma in 1). None of the patients presented sequelae as a result of the intervention after several months of follow-up.

CONCLUSION

Nail biopsy is a useful tool in cases in which the patient history, clinical presentation, and additional tests have not led to a definitive diagnosis. In our experience, it can be performed safely and with minimal scarring.

Consensus and controversies in platelet transfusion: trigger for indication, and platelet dose

Platelet transfusion is about to commemorate its 50th year since its introduction in therapeutics. It is then surprising to see, that in spite of reaching this respectful age, we have not been able to definitely establish all the aspects related to its clinical use. Some of these facets are platelet transfusion threshold and the platelet dose to administer. Historically, two different transfusion triggers have been used for prophylactic and therapeutic platelet transfusions. For prophylactic platelet transfusion an increasing body of evidences suggests that a transfusion trigger of 10 x 10(9) per liter is appropriate for most clinical settings. In contrast, evidence for supporting a certain therapeutic transfusion trigger is lacking. Nevertheless, there is consensus that the platelet count should not be allowed to fall below 50 x 10(9) per liter in patients with acute bleeding. Another important aspect still pending of clear definition is the issue of the platelet dose to be transfused. It has been addressed by some small studies but a definite answer to this important clinical issue is, at least so far, still pending. The results of two ongoing trials, one sponsored by NIH through the Clinical Trials Network in Transfusion Medicine and Hemostasis and the other promoted by the BEST Collaborative Group are expected to help us to clearly defining the more effective and efficient way to transfuse platelet concentrates.

Effectiveness and safety of tranexamic acid administration during total knee arthroplasty

BACKGROUND

The administration of tranexamic acid (TA) is associated with a decrease in the number of red blood cell (RBC) units transfused. However, concerns about its safety have hindered its broader use.

STUDY DESIGN AND METHODS

We evaluated the effect of TA on RBC transfusion and thromboembolic complications in total knee arthroplasty. We retrospectively studied 414 patients, 215 immediately before introducing TA treatment (control group) and after, in 199 patients without history of thromboembolic diseases (TA group). In a subgroup of patients, a lower extremities contrast venography was performed.

RESULTS

Fifty-four per cent of control group patients were transfused with RBC while only 17.6% of TA group patients received RBCs. In the TA that group, those transfused received less units (2.83 vs. 1.89), showed smaller mean calculated perioperative blood loss and haemoglobin values at discharge were higher compared to control group (10.1 vs. 9.3 g/dl). Thromboembolic complications were diagnosed in 2.8% of the patients in the control group and in 1.5% in the TA group. Asymptomatic distal deep venous thrombosis was found in 54 (14.8%) of TA group patients and 54 (30.1%) of control patients. TA administration reduced the expenditure for RBC transfusion plus the cost of TA from 148.94 to 33.87 euro per patient.

CONCLUSION

Routine administration of TA during total knee arthroplasty to patients without history of thromboembolic disease is associated with a 67% reduction in RBC transfusions and, in those transfused, with a reduction in the number of units administered. TA treatment was not associated with an increase in thromboembolic complications. Transfusion costs are significantly reduced.

Comparison of three microtube column agglutination systems for antibody screening: DG Gel, DiaMed-ID and Ortho BioVue

The aims of the present study were to evaluate the estimated diagnostic accuracy of a new microtube column agglutination system (DG Gel, Diagnostic Grifols, Barcelona, Spain), to analyse the antibody reactivity and to compare the data with the two well-established DiaMed-ID and Ortho BioVue systems. We collected 3024 consecutive samples from blood donors, transfusion recipients and pregnant women, and 100 samples containing antibodies of known specificity. All these samples were tested in parallel by the three microtube agglutination systems. The estimated sensitivity was 100% for DG Gel and Ortho BioVue and 97.58% for DiaMed-ID. The estimated specificity was 99.93% for Ortho BioVue and 100% for DiaMed-ID and DG Gel. The score mean and range of the antibody titration of DG Gel, DiaMed-ID and Ortho BioVue were 34.31 (5-119), 30.3 (3-121) and 37.38 (3-112), respectively. All three column agglutination systems work well showing a high estimated diagnostic accuracy.

Methylene blue-photoinactivated plasma vs. fresh-frozen plasma as replacement fluid for plasma exchange in thrombotic thrombocytopenic purpura

BACKGROUND AND OBJECTIVES

Plasma exchange with fresh-frozen plasma (FFP) is the treatment of choice in thrombotic thrombocytopenic purpura (TTP). Methylene blue-photoinactivated plasma (MBPIP) has been proposed as a safer alternative to FFP, but its effectiveness in the treatment of TTP is not well established. The purpose of this study was to investigate whether MBPIP is as effective as FFP in the treatment of TTP by plasma exchange.

MATERIALS AND METHODS

A retrospective analysis was carried out of 56 TTP episodes, occurring between 1990 and 2003, which had been treated by plasma exchange. MBPIP was used for fluid replacement in 27 episodes and FFP in 29. The effect of plasma (MBPIP or FFP) on treatment outcomes was analysed by multivariate logistic regression.

RESULTS

Compared to patients treated with FFP, those receiving MBPIP had an increased risk of dying from progressive TTP [adjusted odds ratio (OR) = 31; 95% confidence interval (CI): 1.2 to > 100], a greater number of recurrences while on plasma exchange therapy (OR = 4.6; 95% CI: 1.2-17), and a lower probability of attaining a sustained remission within 9 days of starting plasma exchange (OR = 5.2; 95% CI: 1.3-20).

CONCLUSIONS

MBPIP seems to be less effective than FFP in the treatment of TTP. It is therefore prudent to avoid MBPIP until therapeutic equivalency to FFP has been established by randomized, controlled trials.

Incidence of clinically significant lymphoedema as a complication following surgery for primary operable breast cancer

There has recently been considerable interest for the need for specialist lymphoedema nurses to be appointed in the NHS. However, we had noticed in our cancer follow-up clinics that the incidence of lymphoedema appeared to be very low. Treatment for primary breast cancer (>5 cm) has been surgery and low axillary sampling (ANS). Radiotherapy (RT) or axillary clearance is subsequently performed in patients found to be node positive. The patients are followed-up in the primary breast cancer (PBC) clinic weekly. Follow-up is initially at 3-month intervals up to 2 years and then 1 yearly indefinitely. We conducted a two phased study in patients being followed up in our post cancer clinic in order to identify the incidence of LE in these patients. Phase 1 involved symptomatic patients identified at routine follow up in a 15-week period and the number of patients reporting arm swelling was recorded. The aim of this was to provide an estimate to power a phase 2 study (prospective questionnaire based). Phase 2 was conducted over a 13-week period. All patients attending the clinic were administered modified FACT B4, EQ-50 and Speilberger questionnaires. A total of 1242 patients were examined and lymphoedema found in 5 (0.04%). Of these 5, 3 had undergone axillary clearance, 1 ANS plus radiotherapy and only 1 had ANS alone. A policy of ANS, with prophylactic treatment for lymph node positivity either by surgery or RT alone, gives a very low rate of lymphoedema.

The direct antiglobulin test in a hospital setting

To evaluate the current use of the DAT in our hospital,we reviewed the charts of all patients who had a DAT performed in our laboratory. The collected data included DAT results and a previously completed laboratory evaluation of suspected hemolytic anemia. Four hundred sixty-three DATs were performed in our laboratory from April 1999 to October 2001. The DAT was negative in 434 (93.7%) cases and positive in 29 (6.3%) cases. A complete laboratory evaluation of suspected hemolytic anemia was seen in 179 (38.7%) cases. The incidence of a positive DAT was higher in the group of patients with > 2 signs of hemolysis (4/34 cases; 11.8%) than in the group of patients with </= 2 signs of hemolysis (5/145 cases; 3.4%) (RR = 0.029;95% CI:0.08-1.03; p = 0.06). When a patient with anemia is being investigated, a complete laboratory evaluation for suspected hemolytic anemia should be done before performing a DAT.