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Transfusion Medicine Reviews Jul 2019Sickle cell disease (SCD) is the most common monogenic disorder in sub-Saharan Africa (SSA). Blood transfusion to increase the oxygen carrying capacity of blood is vital... (Meta-Analysis)
Meta-Analysis
Sickle cell disease (SCD) is the most common monogenic disorder in sub-Saharan Africa (SSA). Blood transfusion to increase the oxygen carrying capacity of blood is vital in the management of many patients with SCD. However, red blood cell (RBC) alloimmunization is a major challenge to transfusions in these patients. Commonly in SSA, pretransfusion tests only involve ABO D grouping and compatibility without RBC antibody testing. Data on the frequency of RBC alloimmunization in patients with SCD in SSA are limited. We performed a systematic review and meta-analysis on available data on alloimmunization in transfused patients with SCD to determine the published prevalence of RBC alloimmunization in SCD patients in SSA. Six databases were systematically searched to identify relevant studies, without year or language restrictions. In all, 249 articles were identified and 15 met our selection criteria. The overall proportion of alloimmunization was 7.4 (95% confidence interval: 5.1-10.0) per 100 transfused patients. Antibodies against E, D, C, and K antigens accounted for almost half of antibody specificities, and antibodies to low- and high-frequency antigens were also common and represented almost 30% (20% to low-frequency antigens and 9% to high-frequency antigens) of specificities. Heterogeneity between studies was moderate, and meta-analysis found region of Africa as the major contributor to the heterogeneity. We also observed inconsistencies across studies in reporting of factors that may influence alloimmunization. This review provides an overview of the extent of the alloimmunization problem in SSA and provides a baseline against which to compare the effect of any interventions to reduce the alloimmunization risk.
Topics: Africa South of the Sahara; Anemia, Sickle Cell; Blood Group Incompatibility; Erythrocyte Transfusion; Erythrocytes; Humans; Prevalence; Regression Analysis; Transfusion Reaction
PubMed: 31345590
DOI: 10.1016/j.tmrv.2019.06.003 -
Blood Mar 2017Several strategies can be used to manage fetal or neonatal alloimmune thrombocytopenia (FNAIT) in subsequent pregnancies. Serial fetal blood sampling (FBS) and... (Review)
Review
Several strategies can be used to manage fetal or neonatal alloimmune thrombocytopenia (FNAIT) in subsequent pregnancies. Serial fetal blood sampling (FBS) and intrauterine platelet transfusions (IUPT), as well as weekly maternal IV immunoglobulin infusion (IVIG), with or without additional corticosteroid therapy, are common options, but optimal management has not been determined. The aim of this systematic review was to assess antenatal treatment strategies for FNAIT. Four randomized controlled trials and 22 nonrandomized studies were included. Pooling of results was not possible due to considerable heterogeneity. Most studies found comparable outcomes regarding the occurrence of intracranial hemorrhage, regardless of the antenatal management strategy applied; FBS, IUPT, or IVIG with or without corticosteroids. There is no consistent evidence for the value of adding steroids to IVIG. FBS or IUPT resulted in a relatively high complication rate (consisting mainly of preterm emergency cesarean section) of 11% per treated pregnancy in all studies combined. Overall, noninvasive management in pregnant mothers who have had a previous neonate with FNAIT is effective without the relatively high rate of adverse outcomes seen with invasive strategies. This systematic review suggests that first-line antenatal management in FNAIT is weekly IVIG administration, with or without the addition of corticosteroids.
Topics: Adult; Disease Management; Female; Fetal Diseases; Humans; Immunoglobulins, Intravenous; Infant, Newborn; Intracranial Hemorrhages; Mothers; Pregnancy; Prenatal Care; Steroids; Thrombocytopenia, Neonatal Alloimmune; Treatment Outcome; Young Adult
PubMed: 28130210
DOI: 10.1182/blood-2016-10-739656 -
Asian Journal of Transfusion Science 2022Repeated allogeneic blood transfusions in thalassemia major patients stimulate the patient's immune system to generate antibodies against foreign erythrocyte antigens.... (Review)
Review
BACKGROUND
Repeated allogeneic blood transfusions in thalassemia major patients stimulate the patient's immune system to generate antibodies against foreign erythrocyte antigens. This study was carried out to systematically review the findings of available studies about the prevalence of alloantibodies and autoantibodies, as well as the type of causative antigens among transfusion-dependent thalassemia patients in Iran.
METHODS
Electronic search was conducted on Medline, PubMed, Cochrane, EMBASE, ScienceDirect, and Persians databases. All relevant articles published from January 1990 to July 2018 were included. Abstracts of conference booklets which that been published in the last 5 years were also included in the meta-analysis. The search language was restricted to English and Persian. The quality of studies was evaluated according to a checklist developed by authors, and Cochrane Risk of Bias Assessment Tool was used to evaluate the risk of bias.
RESULTS
Twenty-three relevant articles met all the inclusion criteria. The prevalence of alloimmunization was 13%. Our study showed that anti-D (25%) and anti-K (25%) were most prevalent among Iranian β-thalassemia patients. Data analysis shows the autoantibody prevalence to be 1% among 3787 patients. Meta-regression revealed that the prevalence of alloantibodies increases with each year as the average age of the study population increases.
CONCLUSION
The prevalence of red blood cell (RBC) alloantibodies in transfused Iranian β-thalassemia patients was high. Appropriate preventive strategies such as RBC phenotyping for patients before beginning transfusion and using extended RBC donor-recipient matching, specifically for Rh and Kell system, could be implemented to avoid complications in thalassemia patients.
PubMed: 36199396
DOI: 10.4103/ajts.AJTS_39_20 -
Transfusion Medicine Reviews Apr 2016Optimal selection of blood donors is critical for ensuring the safety of blood products. The current selection process is concerned principally with the safety of the... (Meta-Analysis)
Meta-Analysis Review
Optimal selection of blood donors is critical for ensuring the safety of blood products. The current selection process is concerned principally with the safety of the blood donor at the time of donation and of the recipient at the time of transfusion. Recent evidence suggests that the characteristics of the donor may affect short- and long-term transfusion outcomes for the transfused recipient. We conducted a systematic review with the primary objective of assessing the association between blood donor characteristics and red blood cell (RBC) transfusion outcomes. We searched MEDLINE, EMBASE, and Cochrane Central databases and performed manual searches of top transfusion journals for all available prospective and retrospective studies. We described study characteristics, methodological quality, and risk of bias and provided study-level effect estimates and, when appropriate, pooled estimates with 95% confidence intervals using the Mantel-Haenszel or inverse variance approach. The overall quality of the evidence was graded using Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. From 6121 citations identified by our literature search, 59 studies met our eligibility criteria (50 observational, 9 interventional). We identified the evaluation of association of 17 donor characteristics on RBC transfusion outcome. The risk of bias and confounding of the included studies was high. The quality of evidence was graded as very low to low for all 17 donor characteristics. Potential associations were observed for donor sex with reduced survival at 90 days and 6 months in male recipients that receive donated blood from females (hazard ratio 2.60 [1.09, 6.20] and hazard ratio 2.40 [1.10, 5.24], respectively; n = 1), Human Leukocyte Antigen - antigen D Related (HLA-DR) selected transfusions (odds ratio [OR] 0.39 [0.15, 0.99] for the risk of transplant alloimmunization, n = 9), presence of antileukocyte antibodies (OR 5.84 [1.66, 20.59] for risk of transfusion-related acute lung injury, n = 4), and donor RBC antigens selection (OR 0.20 [0.08, 0.52] for risk of alloimmunization, n = 4). Based on poor quality evidence, positive antileukocyte antibodies, female donor to male recipients, HLA-DR selected RBC transfusion, or donor RBC antigen selection may affect RBC transfusion outcome. Our findings that donor characteristics may be associated with transfusion outcomes warrant establishing vein-to-vein data infrastructure to allow for large robust evaluations. PROSPERO registration number: CRD42013006726.
Topics: Age Factors; Bias; Blood Donors; Donor Selection; Erythrocyte Transfusion; Evidence-Based Medicine; Female; HLA Antigens; Hospital Mortality; Humans; Isoantibodies; Male; Observational Studies as Topic; Research Design; Sex Factors; Survival Analysis; Treatment Outcome; Viremia
PubMed: 26920039
DOI: 10.1016/j.tmrv.2016.01.002 -
Ultrasound in Obstetrics & Gynecology :... Dec 2019To evaluate the performance of fetal middle cerebral artery peak systolic velocity (MCA-PSV) ≥ 1.5 multiples of the median (MoM) for the prediction of... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To evaluate the performance of fetal middle cerebral artery peak systolic velocity (MCA-PSV) ≥ 1.5 multiples of the median (MoM) for the prediction of moderate-severe anemia, in untransfused and transfused fetuses.
METHODS
A systematic search was performed to identify relevant observational studies reported in the period 2008-2018 that evaluated the performance of MCA-PSV, using a threshold of 1.5 MoM for the prediction of fetal anemia. Diagnosis of fetal anemia by blood sampling was the reference standard. A hierarchical summary receiver-operating characteristics (hSROC) curve was constructed using random-effects modeling. Subgroup and meta-regression analyses, according to the number of previous intrauterine transfusions, were performed.
RESULTS
Twelve studies and 696 fetuses were included in the meta-analysis. The area under the hSROC curve (AUC) for moderate-severe anemia was 83%. Pooled sensitivity and specificity (95% CI) were 79% (70-86%) and 73% (62-82%), respectively, and positive and negative likelihood ratios were 2.94 (95% CI, 2.13-4.00) and 0.272 (95% CI, 0.188-0.371). When considering only untransfused fetuses, prediction improved, achieving an AUC of 87%, sensitivity of 86% (95% CI, 75-93%) and specificity of 71% (95% CI, 49-87%). A decline in sensitivity for the prediction of moderate-severe anemia by MCA-PSV ≥1.5 MoM was observed (estimate, -5.5% (95% CI, -10.7 to -0.3%), P = 0.039) as the number of previous transfusions increased.
CONCLUSIONS
MCA-PSV ≥ 1.5 MoM for the prediction of moderate-severe anemia in untransfused fetuses shows moderate accuracy (86% sensitivity and 71% specificity), which declines with increasing number of intrauterine transfusions. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.
Topics: Anemia; Blood Flow Velocity; Blood Transfusion, Intrauterine; Female; Fetal Diseases; Fetus; Gestational Age; Humans; Middle Cerebral Artery; Observational Studies as Topic; Predictive Value of Tests; Pregnancy; Sensitivity and Specificity; Severity of Illness Index; Ultrasonography, Doppler, Color
PubMed: 30932276
DOI: 10.1002/uog.20273 -
Pediatrics Apr 2014Neonatal alloimmune thrombocytopenia (NAIT) is a potentially devastating disease that may lead to intracranial hemorrhage in the fetus or neonate, often with death or... (Review)
Review
BACKGROUND
Neonatal alloimmune thrombocytopenia (NAIT) is a potentially devastating disease that may lead to intracranial hemorrhage in the fetus or neonate, often with death or major neurologic damage. There are no routine screening programs for NAIT, preventive measures are taken only in a subsequent pregnancy. To estimate the population incidence of NAIT and its consequences, we conducted a review of the literature. Our results may aid in the design of a screening program.
METHODS
An electronic literature search included Medline, Embase, Cochrane database and references of retrieved articles. Eligible for inclusion were all prospective studies aimed at diagnosing NAIT in a general, nonselected newborn population, with sufficient information on platelet count at birth, bleeding complications, and treatment. Titles and abstracts were reviewed, followed by review of full text publications. Studies were independently assessed by 2 reviewers for methodologic quality. Disagreements were resolved by consensus, including a third reviewer.
RESULTS
From the initial 768 studies, 21 remained for full text analysis, 6 of which met the inclusion criteria. In total, 59,425 newborns were screened, with severe thrombocytopenia in 89 cases (0.15%). NAIT was diagnosed in 24 of these 89 newborns (27%). In 6 (25%) of these cases, an intracranial hemorrhage was found, all likely of antenatal origin.
CONCLUSIONS
NAIT is among the most important causes of neonatal thrombocytopenia. Intracranial hemorrhage due to NAIT occurs in 10 per 100 000 neonates, commonly before birth. Screening for NAIT might be effective but should be done antenatally.
Topics: Humans; Incidence; Infant, Newborn; Thrombocytopenia, Neonatal Alloimmune
PubMed: 24590747
DOI: 10.1542/peds.2013-3320 -
Hematology, Transfusion and Cell Therapy Feb 2024The clinical manifestation of foetal anaemia caused by maternal Kell alloantibodies differs from that caused by non-Kell alloantibodies. Severe anaemia develops in the... (Review)
Review
The role of measuring peak systolic velocity of the middle cerebral artery blood flow and anti-K1 titre during pregnancy to detect foetuses with severe anaemia, foetal hydrops, and the requirement of intrauterine transfusion: A systematic review and meta-analysis.
The clinical manifestation of foetal anaemia caused by maternal Kell alloantibodies differs from that caused by non-Kell alloantibodies. Severe anaemia develops in the foetus in the early weeks of gestation; therefore, proper management and early intervention are important. A systematic review and meta-analysis was performed to determine whether the anti-K1 titre can determine the sequelae of Kell alloimmunised pregnancies. Prospective and retrospective cohort studies were used to conduct a systematic review following a comprehensive literature search, in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. Studies were screened based on a defined set of inclusion and exclusion criteria. A total of 5143 potential articles were identified. Ten studies were used in the meta-analysis of pregnancy outcomes for a specific anti-K1 titre cut-off. The meta-analysis identified statistical significance for intrauterine transfusion (ARD: 0.351; 95 % CI: 0.593-0.109; p-value = 0.004), hydrops (ARD: 0.808; 95 % CI: 1.145-0.472; p-value <0.001), intrauterine foetal death (ARD: 0.938; 95 % CI:1.344 to -0.533; p-value <0.001) and intrauterine transfusion for Doppler middle cerebral artery >1.5 MoM (ARD: 0.381; 95 % CI:1.079 to -0.317; p-value = 0.285). It was concluded that there is no correlation between anti-K1 titre and Kell sensitised pregnancy outcomes, but monitoring the anti-K1 titre is important to manage the pregnancy and it helps clinicians determine the need for intrauterine transfusions. Doppler middle cerebral artery peak systolic velocity is strongly correlated with foetal anaemia and is an efficient routine method for determining the need for intrauterine transfusions in pregnancies affected by anti-K1.
PubMed: 38429195
DOI: 10.1016/j.htct.2024.02.002 -
Journal of Burn Care & Research :... May 2021Vascularized composite allotransplantation has been successfully employed for burn reconstruction since 2003. However, its safety in this population has been questioned... (Meta-Analysis)
Meta-Analysis
Vascularized composite allotransplantation has been successfully employed for burn reconstruction since 2003. However, its safety in this population has been questioned due to high levels of alloimmunization from burn care-related tissue exposures. To investigate this, a systematic review of vascularized composite allotransplantation employed for burn reconstruction was conducted, evaluating literature from January 2000 to September 2019. Articles containing vascularized composite allotransplantation, composite tissue allotransplantation, and burn reconstructive surgery were included; articles without published outcomes were excluded. Observational meta-analysis of pooled mortality and acute rejection episodes relative to allograft type (face vs extremity) and reconstruction type (burn vs non-burn) was performed. Twenty-four of the 63 identified articles met the criteria for inclusion, with 5 more articles added after secondary review. To date, 152 allotransplantations have been performed in 117 patients: 45 face transplants and 107 extremity transplants. Of these, 34 (22%) were performed for burn reconstruction in 25 patients (21%) with an overall higher 1-year mortality rate (12.0% vs 1.1%, P = .030). Of these deaths, 75% received three or more simultaneous allografts. Additionally, more episodes of acute rejection occurred compared to non-burn patients (4.4 vs 2.4, P = .035). Vascularized composite allotransplantation performed for burn reconstruction was found to be associated with a greater risk of 1-year mortality and nearly twice the number of episodes of acute rejection. Future studies should seek to identify unique risk factors of burn patients undergoing this operation and evaluate the relationship between antigenic burden and surgical outcomes.
Topics: Burns; Graft Rejection; Graft Survival; Humans; Vascularized Composite Allotransplantation
PubMed: 33091131
DOI: 10.1093/jbcr/iraa188 -
Obstetrics and Gynecology Sep 2001To estimate, in maternal red blood cell alloimmunization, the diagnostic value of fetal ultrasonography and Doppler blood flow velocity in the evaluation and prediction... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To estimate, in maternal red blood cell alloimmunization, the diagnostic value of fetal ultrasonography and Doppler blood flow velocity in the evaluation and prediction of fetal anemia.
METHODS
Literature from 1970 to 2000 was identified using general bibliographic databases (MEDLINE and EMBASE), the Cochrane Library and relevant specialist register of the Cochrane Collaboration, and by checking reference lists of known primary and review articles. Studies were selected if the accuracy of the fetal ultrasound parameters or Doppler studies of blood flow in the fetal vessels was estimated compared with a reference standard (fetal hemoglobin). The diagnostic tests evaluated were ultrasound measurement of the fetal spleen perimeter and Doppler studies of blood velocity estimates in the umbilical vein, ductus venosus, middle cerebral artery, thoracic aorta, and umbilical vessel combined with the thoracic aorta. Study selection, quality assessment, and data abstraction were performed independently and in duplicate. Data from the selected studies were abstracted as 2 x 2 tables comparing the diagnostic test result with the reference standard. Diagnostic accuracy was expressed as likelihood ratios.
RESULTS
The review included eight primary studies with 362 pregnancies affected by red cell alloimmunization. Prospective patient recruitment and complete population details were reported in half of the selected studies (four of eight). Only one study reported masking the diagnostic test results to clinicians. The diagnostic test performance varied widely according to the type of the test evaluated and the cutoff level used to define fetal anemia, which varied from study to study. The diagnostic test study of highest methodological quality reported a positive likelihood ratio of 8.45 (95% confidence interval 4.69, 15.56) and negative likelihood ratio of 0.02 (95% confidence interval 0.001, 0.25) for maximum middle cerebral artery Doppler velocity.
CONCLUSION
The literature reporting noninvasive techniques to predict fetal anemia is methodologically poor and a standard approach to the evaluation of these techniques is lacking. A recommendation for practice cannot be generated without further rigorous research.
Topics: Blood Flow Velocity; Erythroblastosis, Fetal; Female; Humans; Likelihood Functions; Middle Cerebral Artery; Predictive Value of Tests; Pregnancy; Rh Isoimmunization; Ultrasonography, Doppler; Ultrasonography, Prenatal; Umbilical Veins
PubMed: 11530138
DOI: 10.1016/s0029-7844(01)01425-9 -
Journal of Medicine and Life Jul 2023The D antigen of the Rh blood group is considered clinically significant due to its ability to cause hemolytic transfusion reactions and hemolytic disease in the fetus... (Meta-Analysis)
Meta-Analysis Review
The D antigen of the Rh blood group is considered clinically significant due to its ability to cause hemolytic transfusion reactions and hemolytic disease in the fetus and newborn. This systematic review discusses the prevalence of RhD variants among pregnant women and the importance of including RhD genotyping for prenatal testing to detect RhD variants and prevent anti-D alloimmunization. A comprehensive literature search was conducted using scientific search engines, including PubMed and MEDLINE databases, with the keywords 'anti-D alloimmunization', 'RhD variant', and 'pregnant women.' The review adhered to the PRISMA guidelines. Meta-analysis was performed using MedCalc version 20. A significance level of p≤0.05 was considered statistically significant for all two-tailed tests. The meta-analysis included four articles that met the inclusion criteria. The total prevalence of RhD positivity (RhD+) was 61% (95% CI:34%-85%). The prevalence ranged from 22% to 82%, indicating a high degree of heterogeneity between studies (I2=98.71%, p<0.0001). The overall prevalence of D variants was 15% (95% CI, 9%-23%) with a prevalence of 0.05% to 100%, showing a high degree of heterogeneity between studies (I2=99.89%, p<0.0001). Anti-D alloimmunization could occur in pregnant women with some types of RhD variants. All four studies focused on molecular testing of samples showing inconsistent or weak results with at least two anti-D antibodies using serological methods.
Topics: Infant, Newborn; Pregnancy; Female; Humans; Pregnant Women; Fetus; Prevalence
PubMed: 37900088
DOI: 10.25122/jml-2023-0004