Red blood cell alloimmunization after blood transfusion

Current pretransfusion policy requires the patients__ serum to be tested for the presence of irregular red blood cell antibodies. In case of an antibody, red blood cells lacking the corresponding antigen are transfused after an antiglobulin crossmatch. The aim of the studies in this thesis is primarily to investigate whether this policy should change to improve transfusion safety. This thesis explores the risk on red blood cell alloimmunization after blood transfusion in oncohematologic patients and in patients who already formed antibodies after aprevious transfusion event. Furthermore, the risks of current pre-transfusion testing with regard to antibodies to low incidence antigens, timing of antibody testing and antibody persistence were studied. From these studies it was concluded that 1. oncohematologic patients have a high chance on developing antibodies despite immunosuppressive therapy, 2. patients with antibodies have a 20-25 times increased risk for additional antibodies after subsequent transfusions, compared to primo antibody formation, and preventive measures should be considered, 3. antibodies to low incidence antigens are common in immunized and non-immunized patients, 4. timing of antibody screening after transfusion influences the number as well as the specificity of the antibodies detected and 5. antibodies may become undetectable over time compromising transfusion safety.UBL - phd migration 201

Prevalence of red blood cell antibodies among transfused patients at Komfo Anokye teaching (Kath) hospital, Ghana

Red blood cell (RBC) alloimmunisation is a common problem in transfused patients because of the possibility of haemolytic reaction and limited availability of compatible blood. In highincome countries, pre-transfusion antibody screening is performed routinely. In Ghana, patients are transfused with ABO Rh ‘D’ compatible blood without screening for immune antibodies. We therefore studied the prevalence and specificities of RBC antibodies in transfused patients at Komfo Anokye Teaching hospital, Ghana. The study was cross-sectional, involving previously transfused patients who required another transfusion. Participants’ basic data on demography and transfusion history were recorded. Blood samples were screened and subsequently typed for RBC antibodies using a column gel agglutination test. A total of 106 transfused patients, 52 male and 54 females were enrolled. The patients had previously received a median of 4 RBC units (range 1-14). Of these, ten patients (9.4%) had 11 RBC alloantibodies, whose specificities were 2 anti-K; 2 anti-C; one each of anti-D, -E, -M, and -S; and 3 were pan-reactive. The number of transfusion episodes was significantly associated with the rate of alloimmunisation (p=0.000). In conclusion the overall alloimmunisation rate in the study was 9.4% and this was significantly associated with increasing number of transfusion episodes. Antibodies were mainly directed against antigens in the Rhesus system and K antigen. We recommend that antibody screening be incorporated into routine pre-transfusion testing procedures in Ghana. Keywords: Alloimmunisation, multi transfusion, Alloantibod

Comparing Single-Incision Midurethral Sling with Bulking Agents for Female Stress Urinary Incontinence:Rationale for a Non-Randomized Controlled Trial

Objectives: Midurethral slings are considered the gold standard for the surgical treatment of stress urinary incontinence (SUI), with an efficacy up to 80%. Another therapeutic option is the use of bulking agents, which create an artificial mass in the urethral submucosa, with an efficacy varying from 64% to 74%. Although bulking agents have a lower risk of complications than midurethral sling surgery, they are mainly used in case a midurethral sling is not an option or if midurethral sling surgery failed to cure stress urinary incontinence. In this study, we offer all patients with SUI in secondary care a choice between a single-incision midurethral sling procedure and treatment with a bulking agent. We want to examine patient preference and patient satisfaction for both procedures. We expect that offering both interventions in combination with standardized counselling will result in high patient satisfaction. Design: In this non-randomized controlled trial, 266 patients will be objectively counselled for both interventions, after which all patients will choose between single-incision midurethral slings and polyacrylamide hydrogel (PAHG), followed by the standard care procedure for women with SUI. Participants/Materials, Setting, Methods: From January 1, 2021, onward, all consecutive adult patients (between 18 and 80 years of age) attending the outpatient gynaecology department with objectively confirmed, moderate to severe SUI will be eligible for enrolment in this non-randomized study. The primary outcome is patient satisfaction at 1 year, measured by the Patient Global Impression of Improvement; secondary outcomes are patient satisfaction at 3 months, objective and subjective cure at 3 months and 1 year, adverse events, post-operative pain, and cost-effectiveness. Differences in outcome measures will be assessed through logistic and linear regression analyses, both unadjusted and adjusted with covariate adjustment using the propensity score. Results: No results are available yet. Limitations: The major disadvantage of this study design is the potential confounding bias. We intend to eliminate this bias by applying propensity scoring. Conclusion: By designing a non-randomized patient preference trial, we not only expect to demonstrate high patient satisfaction with both interventions but also provide insight into the possible role of PAHG-injections in the treatment of female SUI as a first-choice non-conservative treatment.</p

Urinary excretion of advanced glycation end products in dogs and cats

The present study was conducted with privately owned dogs and cats to investigate whether a relationship exists between the dietary AGEs and the urinary excretion of AGEs, as indication of possible effective absorption of those compounds in the intestinal tract of pet carnivores. For this purpose, data were collected from both raw fed and dry processed food (DPF) fed to dogs and cats, through spot urine sampling and questionnaires. Raw pet food (RF, low in AGE diets) was fed as a primary food source to 29 dogs and DPF to 28 dogs. Cats were categorized into 3 groups, which were RF (n = 15), DPF (n = 14) and dry and wet processed pet food (DWF, n = 25). Urinary-free carboxymethyllysine (CML), carboxyethyllysine (CEL) and lysinoalanine (LAL) were analysed using ultrahigh-performance liquid chromatography (UHPLC)—mass spectrometry, and were standardized for variable urine concentration by expressing the AGE concentrations as a ratio to urine creatinine (Ucr) concentration (µg/µmol Ucr). Urinary excretion of CML, CEL and LAL in dogs fed with DPF was 2.03, 2.14 and 3 times higher compared to dogs fed with RF (p <.005). Similar to the dogs, a significant difference in CML:Ucr, CEL:Ucr and LAL:Ucr between the three diet groups was observed in cats (p-overall < 0.005, ANOVA), in which the RF fed group excreted less AGEs than the other groups. Linear regression coefficients and SE of CML:Ucr, CEL:Ucr and LAL:Ucr showed that body weight and neuter status were significantly correlated with CML and CEL excretion, but not to LAL excretion. Our results revealed a significant correlation between dietary AGEs and urinary excretion of free CML, CEL and LAL, and also showed that endogenous formation of these AGEs occurs in both dogs and cats under physiological conditions.</p

The Effect of Body Mass Index on Outcome after Endovascular Treatment in Acute Ischemic Stroke Patients: A Post Hoc Analysis of the MR

Background: Though obesity is a well-known risk factor for vascular disease, the impact of obesity on stroke outcome has been disputed. Several studies have shown that obesity is associated with better functional outcome after stroke. Whether obesity influences the benefit of endovascular treatment (EVT) in stroke patients is unknown. We evaluated the association between body mass index (BMI) and outcome in acute ischemic stroke patients with large vessel-occlusion (LVO), and assessed whether BMI affects the-benefit of EVT. Methods: This is a post hoc analysis of the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands trial (-ISRCTN10888758). BMI was used as a continuous and categorical variable, distinguishing underweight and normal weight (BMI <25), overweight (BMI 25-30), and obesity (BMI ≥30). We used multivariable ordinal logistic regression analysis to estimate the association of BMI with functional outcome (shift analysis), assessed with modified Rankin Scale (mRs) at 90 days. The impact of BMI on EVT effect was tested by the use of a multiplicative interaction term. Results: Of 366 patients, 160 (44%) were underweight or normal weight, 145 (40%) overweight, and 61 (17%) were obese. In multivariable analysis with BMI as a continuous variable, we found a shift toward better functional outcome with higher BMI (mRS adjusted common OR 1.04; 95% CI 1.0-1.09), and mortality was inversely related to BMI (aOR 0.92; 95% CI 0.85-0.99). Safety analysis showed that higher BMI was associated with lower risk of stroke progression (aOR 0.92, 95% CI 0.87-0.99). Additional analysis showed no interaction between BMI and EVT effect on functional outcome, mortality, and other safety outcomes. Conclusion: Our study confirms the effect of obesity on outcome in acute ischemic stroke patients with LVO, meaning better functional outcome, lower mortality, and lower risk of stroke progression for patients with higher BMI. As we found no interaction between BMI and EVT effect, all BMI classes may expect the same benefit from EVT

Peripheral Artery Disease in Acute Ischemic Stroke Patients Treated With Endovascular Thrombectomy; Results From the MR CLEAN Registry

Background and Purpose: Though peripheral artery disease (PAD) is a well-known risk factor for ischemic events, better outcomes have been described in acute ischemic stroke patients with co-existing PAD. This paradoxical association has been attributed to remote ischemic preconditioning (RIPC) and might be related to better collateral blood flow. The aim of this study is to compare outcomes after endovascular thrombectomy (EVT) in acute stroke patients with and without PAD and to assess the relation between PAD and collateral grades. Methods: We analyzed acute ischemic stroke patients treated with EVT for an anterior circulation large artery occlusion, included in the Dutch, prospective, multicenter MR CLEAN Registry between March 2014 and November 2017. Collaterals were scored on CT angiography, using a 4-point collateral score. We used logistic regression analysis to estimate the association of PAD with collateral grades and functional outcome, assessed with the modified Rankin Scale (mRS) at 90 days. Safety outcomes included mortality at 90 days, symptomatic intracranial hemorrhage, and stroke progression. Results: We included 2,765 patients for analysis, of whom 254 (9.2%) had PAD. After adjustment for potential confounders, multivariable regression analysis showed no association of PAD with functional outcome [mRS cOR 0.90 (95% CI, 0.7-1.2)], collateral grades (cOR 0.85, 95% CI 0.7-1.1), or safety outcomes. Conclusion: In the absence of an association between the presence of PAD and collateral scores or outcomes after EVT, it may be questioned whether PAD leads to RIPC in patients with acute ischemic stroke due to large vessel occlusion

Improving quality of stroke care through benchmarking center performance:why focusing on outcomes is not enough.

Background: Between-center variation in outcome may offer opportunities to identify variation in quality of care. By intervening on these quality differences, patient outcomes may be improved. However, whether observed differences in outcome reflect the true quality improvement potential is not known for many diseases. Therefore, we aimed to analyze the effect of differences in performance on structure and processes of care, and case-mix on between-center differences in outcome after endovascular treatment (EVT) for ischemic stroke. Methods: In this observational cohort study, ischemic stroke patients who received EVT between 2014 and 2017 in all 17 Dutch EVT-centers were included. Primary outcome was the modified Rankin Scale, ranging from 0 (no symptoms) to 6 (death), at 90 days. We used random effect proportional odds regression modelling, to analyze the effect of differences in structure indicators (center volume and year of admission), process indicators (time to treatment and use of general anesthesia) and case-mix, by tracking changes in tau2, which represents the amount of between-center variation in outcome. Results: Three thousand two hundred seventy-nine patients were included. Performance on structure and process indicators varied significantly between EVT-centers (P < 0.001). Predicted probability of good functional outcome (modified Rankin Scale 0–2 at 90 days), which can be interpreted as an overall measure of a center’s case-mix, varied significantly between 17 and 50% across centers. The amount of between-center variation (tau2) was estimated at 0.040 in a model only accounting for random variation. This estimate more than doubled after adding case-mix variables (tau2: 0.086) to the model, while a small amount of between-center variation was explained by variation in performance on structure and process indicators (tau2: 0.081 and 0.089, respectively). This indicates that variation in case-mix affects the differences in outcome to a much larger extent. Conclusions: Between-center variation in outcome of ischemic stroke patients mostly reflects differences in case-mix, rather than differences in structure or process of care. Since the latter two capture the real quality improvement potential, these should be used as indicators for comparing center performance. Especially when a strong association exists between those indicators and outcome, as is the case for time to treatment in ischemic stroke

Reduction of anti-K-mediated hemolytic disease of newborns after the introduction of a matched transfusion policy:A nation-wide policy change evaluation study in the Netherlands

Background: During pregnancy, maternal red blood cell (RBC) antibodies can lead to life-threatening fetal hemolysis and anemia. Women can become immunized by a pregnancy or an unmatched transfusion. Our aim was to quantify the effect of a nationwide K-matched transfusion policy for women of childbearing age potential to prevent K-immunization in pregnancy. Study Design and Methods: In this nation-wide policy change evaluation study we determined the occurrence of RBC antibodies before and after introduction of a K-matched transfusion policy and evaluated the cause K alloimmunization 10 years after introduction of this measure. K-matched transfusion for females under 45 years of age is advised in the Dutch transfusion guideline since 2004. We used laboratory data from pregnancies with RBC antibodies identified in the period 1999-2018 obtained as part of a population-based screening program in the Netherlands. Results: Tests of 36 286 pregnancies produced a positive antibody screening result which concerned anti-K in 1550 pregnancies. The occurrence of anti-K decreased from 67.9 to 20.2 per 100 000 pregnancies. The relative risk reduction was 0.70 which largely exceeded the relative risk reduction of 0.27 for antibodies against RBC antigens for which no preventive matching is required. The number of pregnancies at risk for anti-K-mediated disease decreased from 9.7 to 4.2 per 100 000 pregnancies. Conclusions: A K-matched transfusion policy is associated with a major decrease in a number of pregnant women with anti-K and pregnancies at risk for anti-K-mediated disease. A relatively simple measure is now shown to impact prevention of hemolytic disease in the fetus and newborn