Rh Blood Group Antigens and Alloimmunization Risk of Pregnant Women in South Western, Nigeria.

BACKGROUND: Rh blood group antigens are the second most important blood group antigens in clinical transfusion due to their immunogenicity and prevalence. Childbirth, miscarriage, and other obstetrics events are risk factors for alloimmunization in women which increases the likelihood of haemolytic blood transfusion reaction and hemolytic disease of the fetal/newborn (HDNF/B). Even though there are several data on the RhD status of our populations. However, there is a dearth of data on pregnant women's C, E, c, and e status, their alloimmunization risk, and rates in Nigeria. OBJECTIVES: This study aims to provide information on the distribution of the Rh major antigens and risk factors for alloimmunization in pregnant women in southwestern Nigeria. MATERIALS AND METHODS: This was a descriptive cross-sectional study of 133 pregnant women attending routine ante-natal clinics. Questionnaires were administered to collect biodata and obstetrics history. ABO blood grouping and Rh phenotyping were carried out on their blood samples using RAPID LABS Monoclonal Rhesus Typing Reagent. RESULTS AND DISCUSSION: Rh blood group antigen c was present in 100% of the women, followed by e (98.5%) and D (95.5%). C and E are the least prevalent antigens and probably the ones to which antibodies may be formed. The commonest Rh phenotype was Dce. Of all the pregnant women, alloimmunization was present in 0.8%. Of those who were RhD negative, alloimmunization was present in 16.7%. Pregnant women are more likely to be alloimmunized against C and E antigens than c and e antigens due to their low and high frequencies respectively.

CONTEXTE: Les antigènes du groupe sanguin Rh sont les seconds plus importants en transfusion clinique en raison de leur immunogénicité et de leur prévalence. L'accouchement, la fausse couche et d'autres événements obstétriques sont des facteurs de risque d'alloimmunisation chez les femmes, augmentant ainsi la probabilité de réactions hémolytiques lors de transfusions sanguines et de maladies hémolytiques du fœtus/nouveau-né (HDNF/B). Bien qu'il existe plusieurs données sur le statut RhD de nos populations, il y a un manque de données sur le statut des antigènes C, E, c et e chez les femmes enceintes, leur risque d'alloimmunisation et les taux associés au Nigéria. OBJECTIFS: Cette étude vise à fournir des informations sur la distribution des principaux antigènes Rh et les facteurs de risque d'alloimmunisation chez les femmes enceintes dans le sud-ouest du Nigéria. MÉTHODOLOGIE: Il s'agit d'une étude descriptive transversale de 133 femmes enceintes fréquentant les cliniques prénatales de routine. Des questionnaires ont été administrés pour collecter des données biodémographiques et des antécédents obstétriques. La détermination des groupes sanguins ABO et le phénotypage Rh ont été réalisés sur leurs échantillons de sang à l'aide du réactif de typage Rh monoclonal RAPID LABS. RÉSULTATS ET DISCUSSION: L'antigène c du groupe sanguin Rh était présent chez 100 % des femmes, suivi de e (98,5 %) et D (95,5 %). Les antigènes C et E sont les moins prévalents et probablement ceux contre lesquels des anticorps peuvent être formés. Le phénotype Rh le plus courant était Dce. Parmi toutes les femmes enceintes, l'alloimmunisation était présente chez 0,8 %. Parmi celles qui étaient RhD négatives, 'alloimmunisation était présente chez 16,7 %. Les femmes enceintes sont plus susceptibles de développer une alloimmunisation contre les antigènes C et E que contre les antigènes c et e en raison de leurs fréquences respectives faibles et élevées. MOTS-CLÉS: Antigènes du groupe sanguin Rh, Phénotype, Alloanticorps érythrocytaires, Femmes enceintes.

Frequency of Duffy, Kidd, Lewis, and Rh Blood Group Antigens and Phenotypes Among Donors in the Al-Ahsa Region, Saudi Arabia.

BACKGROUND: In Al-Ahsa, Saudi Arabia, the high consanguinity rates contribute to the prevalence of inherited hemoglobinopathies such as sickle cell disease and thalassemia, which frequently require blood transfusions. These transfusions carry the risk of alloimmunization, necessitating a precise blood component matching to mitigate health risks. Local antigen frequency data is vital for optimizing transfusion practices and enhancing the safety of these medical procedures for the Al-Ahsa population. METHODS: This study investigated the distribution of Duffy, Kidd, Lewis, and Rh blood group antigens in 1,549 individuals from the region; comparing the frequencies with global data. RESULTS: Serological analyses revealed a high prevalence of the Fy(a+b-) and Jk(a+b+) phenotypes in the Duffy and Kidd blood groups, respectively, with Jk(a-b-) being notably scarce. The Lewis blood group exhibited a significant presence of Le(a-b+) and Le(a+b-) phenotypes, whereas Le(a+b+) was less common. In the Rh system, the D antigen was most prevalent, with other antigens following in descending order of frequency. CONCLUSIONS: The study underscores the regional variation in antigen frequencies, emphasizing the need for local blood banks to adapt their screening and matching practices to mitigate the risk of alloimmunization and enhance transfusion safety. These findings are pivotal for refining transfusion strategies and understanding the immunohematology landscape in Al-Ahsa.

Application of RhD Blood Group to Simulate Antibody Identification Test in Immunohematology Education.

BACKGROUND: Immunohematology skill education is an important part of the transfusion medicine professional training. We tried to solve the difficulty of obtaining suitable and sufficient positive samples in the immunohematology education. METHODS: Different identification panels and panel cells were created by RhD-positive red blood cells (RBCs) and RhD-negative RBCs, according to the underlying antibodies. Diluted anti-D reagent was used as simulated plasma for identification. RESULTS: The antibody identification of single antibody with dose-effect and two antibodies present at the same time were successfully simulated. CONCLUSIONS: It is a practical and cheap method for antibody identification training to use RhD blood group, especially when positive samples are short.

Serologic profiling of D variants in donor routine: unveiling the impact on false-negative results and alloimmunization.

The high number of D variants can lead to the unnecessary use of Rh immune globulin, overuse of D- RBC units, and anti-D allommunization. D variant prevalence varies among ethnic groups, and knowledge of the main variants present in a specific population, their behavior in serologic tests, and their impact on clinical practice is crucial to define the best serologic tests for routine use. The present study aimed to explore the serologic profile of D variants and to determine which variants are most associated with false-negative D typing results and alloimmunization. Donor samples were selected in two study periods. During the first period, D typing was performed on a semi-automated instrument in microplates, and weak D tests were conducted in tube or gel tests. In the second period, D typing was carried out using an automated instrument with microplates, and weak D tests were performed in solid phase. Samples from patients typed as D+ with anti-D were also selected. All samples were characterized by molecular testing. A total of 37 RHD variants were identified. Discrepancies and atypical reactivity without anti-D formation were observed in 83.4 percent of the samples, discrepant D typing results between donations were seen in 12.3 percent, and D+ patients with anti-D comprised 4.3 percent. DAR1.2 was the most prevalent variant. Weak D type 38 was responsible for 75 percent of discrepant samples, followed by weak D type 11, predominantly detected by solid phase. Among the D variants related to alloimmunization, DIVa was the most prevalent, which was not recognized by serologic testing; the same was true for DIIIc. The results highlight the importance of selecting tests for donor screening capable of detecting weak D types 38 and 11, especially in populations where these variants are more prevalent. In pre-transfusion testing, it is crucial that D typing reagents demonstrate weak reactivity with DAR variants; having a serologic strategy to recognize DIVa and DIIIc is also valuable.

A patient with anti-f in India identified by extensive immunohematologic workup.

Anti-f is produced by exposure to the compound antigen ce (f) on red blood cells (RBCs), expressed when both c and e are present on the same protein (cis position). Although anti-f was discovered in 1953, there are few cases reported worldwide because the presence of anti-f is often masked by anti-c or anti-e and is not generally found as a single antibody. In the present case, anti-f was identified by using three-cell screening and 11-cell identification panels. The identification of anti-f was further supported by additional testing, including (1) Rh antigen typing; (2) antibody identification panels (enzyme-treated panel [ficin] and an in-house-constructed Rh panel); (3) look-back and phenotyping of donor RBC units, which were responsible for alloimmunization; and (4) molecular testing of the patient's RBCs.

The Variation of RhD Blood Group in Different Periods in a Patient with Systemic Lupus Erythematosus.

BACKGROUND: Autoimmune hemolytic anemia disease often produces a large number of various autoantibodies, and some autoantibodies may be related to Rh blood group. In rare cases, autoantibodies can specifically target Rh antigen, thus interfering with the identification of Rh blood group. METHODS: A case of systemic lupus erythematosus (SLE) with inconsistent RhD blood group identification results in different periods was reported and the reasons were analyzed. RESULTS: Some autoantibodies can completely block D antigen on red blood cells, resulting in no redundant D sites on red blood cells binding to reagent anti D. In addition, the immunity of the body is extremely low, and the expression of red blood cell blood group antigens in part of the body is inhibited, which will cause the weakening of the expression of Rh antigen in red blood cells. Therefore, when testing the RhD blood type of the patient, the reagent anti D does not agglutinate with the patient's red blood cells, and a false negative result of the initial screening appears. Through the RhD negative confirmation test, the patient's blood type is a serologically weak D phenotype. CONCLUSIONS: If the result of serological preliminary screening test is RhD negative or RhD variant, the recipient should be treated as RhD negative, and RhD negative red blood cells should be transfused during blood transfusion. Conditional laboratories can implement RHD genotyping, which is conducive to improving the precise blood transfusion management level of RhD negative blood recipients, saving rare blood resources and improving the treatment efficiency of patients.

When and why is red blood cell genotyping applicable in transfusion medicine: a systematic review of the literature.

This review aims to provide a better understanding of when and why red blood cell (RBC) genotyping is applicable in transfusion medicine. Articles published within the last 8 years in peer-reviewed journals were reviewed in a systematic manner. RBC genotyping has many applications in transfusion medicine including predicting a patient's antigen profile when serologic methods cannot be used, such as in a recently transfused patient, in the presence of autoantibody, or when serologic reagents are not available. RBC genotyping is used in prenatal care to determine zygosity and guide the administration of Rh immune globulin in pregnant women to prevent hemolytic disease of the fetus and newborn. In donor testing, RBC genotyping is used for resolving ABO/D discrepancies for better donor retention or for identifying donors negative for high-prevalence antigens to increase blood availability and compatibility for patients requiring rare blood. RBC genotyping is helpful to immunohematology reference laboratory staff performing complex antibody workups and is recommended for determining the antigen profiles of patients and prospective donors for accurate matching for C, E, and K in multiply transfused patients. Such testing is also used to determine patients or donors with variant alleles in the Rh blood group system. Information from this testing aides in complex antibody identification as well as sourcing rare allele-matched RBC units. While RBC genotyping is useful in transfusion medicine, there are limitations to its implementation in transfusion services, including test availability, turn-around time, and cost.

Estimating waiting time for compatible blood: A Negative Binomial approach.

OBJECTIVES: Screening blood units for compatibility constitutes a Bernoulli series. Estimating the number of units needed to be screened represents a classic waiting time problem that may be resolved using the Negative Binomial Distribution. The currently recommended method for estimating the number of units screened, n, to find a required number of compatible units, r, with a given probability, p, is n = r/p. This coincides with the mean of the Negative Binomial Distribution so that the actual number of units screened will often be underestimated by the current method. METHODS: The cumulative distribution function of the Negative Binomial Distribution provides the probability of success (compatibility), F(n;r,p), as a function of the number of trials performed (attempted crossmatches), n, the probability of success on each trial, p, and the number of successes (compatible units) required, r. Choosing a threshold cumulative probability sufficiently high, such as F ~ 0.9, for example, will provide confidence that the projected number of units screened will be underestimated less often (~10% of the time). RESULTS: With F ≥ 0.9, the estimated number of attempted crossmatches ranges from 1.3 to 2.3 times as many as the number calculated by the current method. As a rule of thumb approximately 1.6 times the current estimated number provides a similar estimate (n ~ 1.6∙r/p). CONCLUSIONS: Waiting time underestimation will be reduced significantly by using the Negative Binomial Distribution solution and should be accompanied by improved customer satisfaction.

Meeting the transfusion needs of a patient with anti-Ena requires an international effort.

This extraordinary case showcases the identification of a rare anti-Ena specificity that was assisted by DNA-based red blood cell antigen typing and collaboration between the hospital blood bank in the United States, the home blood center in Qatar, the blood center Immunohematology Reference Laboratory, as well as the American Rare Donor Program (ARDP) and the International Society for Blood Transfusion (ISBT) International Rare Donor Panel. Ena is a high-prevalence antigen, and blood samples from over 200 individuals of the extended family in Qatar were crossmatched against the patient's plasma with one compatible En(a-) individual identified. The ISBT International Rare Donor Panel identified an additional donor in Canada, resulting in a total of two En(a-) individuals available to donate blood for the patient.

Serology and molecular genetic analysis of two unrelated individuals with the same novel CisAB blood type.

OBJECTIVE: This study aims to report two unrelated individuals with the same novel CisAB blood type and confirm this rare blood type using a comprehensive approach that combines serological and molecular biology techniques. METHODS: Peripheral blood samples were collected from two patients and their family members. ABO blood typing and antibody detection were performed using conventional tube methods. Molecular biology techniques were employed to amplify and sequence the 6th and 7th exons of the ABO gene, with reference to gene mutation databases provided by NCBI and ISBT. RESULTS: The genotypes of the two unrelated individuals were identical and were confirmed as a new genotype through ISBT gene database comparison. Serological testing results showed different antigen reaction patterns, especially in terms of reverse typing. Gene sequencing identified a series of mutation points, and both unrelated individuals and one of their daughters had mutations at 297 A>G, 526 C>G, 657 C>T, 703 G>A, 803 G>C, and 930 G>A. According to the comprehensive results from The Blood Group Antigen Gene Mutation Database provided by NCBI, the genotype was determined as Bw37. However, based on the results from Names for ABO (ISBT 001) blood group alleles v1.1 171023, the sequencing results indicated a novel mutation combination not found in the ISBT database. Considering the serological reactions of all three individuals, the final determination was CisAB. CONCLUSIONS: This study confirmed the novel CisAB blood type in two individuals through the comprehensive application of serology and molecular biology techniques. The identified gene mutation points were not recorded in known databases, emphasizing the uniqueness of CisAB blood types. This research provides important insights into the genetic basis of ABO subtypes and the characteristics of CisAB blood types, and the relevant results have been submitted to the ISBT website for further research.

Evaluating the TaqMan Jra-Genotyping Method for Rapidly Predicting the Presence of Anti-Jra Antibodies.

Background: The Jra antigen is a high-prevalence red blood cell (RBC) antigen. Reports on cases of fatal hemolytic disease of the fetus and newborn and acute hemolytic transfusion reactions suggest that antibodies against Jra (anti-Jra) have potential clinical significance. Identifying anti-Jra is challenging owing to a lack of commercially available antisera. We developed an alternative approach to rapidly predict the presence of anti-Jra using the TaqMan single-nucleotide polymorphism (SNP)-genotyping method. Methods: Residual peripheral blood samples from 10 patients suspected of having the anti-Jra were collected. Two samples with confirmed Jr(a-) RBCs and anti-Jra were used to validate the TaqMan genotyping assay by comparing the genotyping results with direct sequencing. The accuracy of the assay in predicting the presence of anti-Jra was verified through crossmatching with in-house Jr(a-) O+ RBCs. Results: The TaqMan-genotyping method was validated with two Jr(a-) RBC- and anti-Jra-confirmed samples that showed concordant Jra genotyping and direct sequencing results. Jra genotyping for the remaining samples and crossmatching the serum samples with inhouse Jr(a-) O+ RBCs showed consistent results. Conclusions: We validated a rapid, simple, accurate, and cost-effective method for predicting the presence of anti-Jra using a TaqMan-based SNP-genotyping assay. Implementing this method in routine practice in clinical laboratories will assist in solving difficult problems regarding alloantibodies to high-prevalence RBC antigens and ultimately aid in providing safe and timely transfusions and proper patient care.

Application of a simplified PCR-SSP method to detect A4GALT*01 and A4GALT*02 typing among Thai blood donors.

OBJECTIVES: An intronic A4GALT single nucleotide variant, rs5751348:G>T, P2 or A4GALT*02 allele has a lower level of the enzyme-encoding A4GALT transcripts than the P1 individuals. Here, we first develop and validate a simple inhouse PCR-SSP method to detect A4GALT*01 and A4GALT*02 alleles, and second, apply this method to compare the allele frequencies between Thai and other populations. MATERIAL AND METHODS: The conventional test tube technique was used to detect the P1 antigen in 222 blood samples from Thai blood donors at Thammasat University Hospital. A PCR-SSP method was optimized and validated for reproducibility and specificity to identify these alleles and was subsequently tested on 1,840 DNA samples of unknown phenotypes obtained from central, northern and southern Thais. In addition, allele frequencies of central Thais were compared with those of other populations. RESULTS: In the tested cohort (n = 222), P1 and P2 phenotypes were typed in 26.13 and 73.87% of donors, respectively. The developed PCR-SSP was successfully optimized, and the outcomes were consistent with those of serological phenotyping and DNA sequencing results, demonstrating its validity for predicting P1/P2 phenotype. For central, northern and southern Thais, the A4GALT*01 frequency was 0.1579 (430/2,724), 0.1183 (71/600), and 0.2575 (206/800), whereas the A4GALT*02 frequency was 0.8421 (2,294/2,724), 0.8817 (529/600), and 0.7425 (594/800), respectively. Their observed frequencies among central Thais significantly differed from those in other populations (p < 0.05). CONCLUSION: Our study has successfully developed a simple, precise, and reliable method to genotype A4GALT*01 and A4GALT*02 using inhouse developed PCR-SSP for predicting P1/P2 status.

Does decreasing the incubation period used in the antibody screen affect its sensitivity?

BACKGROUND: Pre-transfusion testing (PTT) encompasses a set of mandatory laboratory tests performed before red blood cell transfusion. The antibody screen, one component of PTT, commonly includes a 10-20 min incubation. The primary aim of this study was to determine if this period can be reduced when using current immunohematology methodologies. METHODS AND MATERIALS: Antibody screens were performed on reagent samples using Glass or Gel-based column agglutination technologies (CAT) and a solid phase red cell adherence (SPRCA) assay, with incubation periods of 1, 5, 10 and 15 min, and 20 min (SPRCA assay only). For each method, the shortest period producing a minimum of a 1+ reaction with all reagent samples was considered optimal. The sensitivity of each assay using the optimal period was calculated after performing antibody screens on 100 patient samples. RESULTS AND DISCUSSION: It was demonstrated that the incubation period in the SPRCA and Glass CAT systems can be reduced to 5 and 10 min, respectively, while achieving high assay sensitivity (98.9% in both). The incubation period in the Gel CAT system cannot be reduced from 15 min. Significant association between titre and reaction strength was observed for all three screening methods (p < 0.001 for both CAT methods, p = 0.041 for SPRCA). This study demonstrates that the incubation period used in the antibody screen can be reduced when using systems employing the Glass CAT and SPRCA methods, without affecting assay sensitivity. If confirmed, it could result in faster completion of PTT.

Assessment of Minor Blood Group System Antigens and Their Phenotype among Voluntary Blood Donors in Ethiopian Blood and Tissue Bank Service, Addis Ababa, Ethiopia.

Background: Red blood cell antigens are numerous in structural and functional diversity; some are proteins while others are carbohydrates. The international society of blood transfusion currently recognized 43 blood group systems containing 349 red cell antigens. It also acknowledged 9 blood group systems (ABO, Rhesus, Kell, Duffy, Kidd, MNS, P, Lewis, and Lutheran) that are clinically significant and associated with hemolytic transfusion reactions as well as hemolytic disease of fetuses and newborns. The objective of this study was to assess the distribution of minor blood group antigens and their phenotype among voluntary blood donors in Ethiopian blood and tissue bank service in Addis Ababa. Method: A cross-sectional study was conducted from January to March 2022 among 260 volunteer blood donors to determine minor blood group antigens and their phenotype at EBTBS, Addis Ababa, Ethiopia. Tests were performed using Galileo Neo Immucor, which is fully automated Immunohematology analyzer. Result: A total of 260 blood donors were screened of which 153 (59%) were males. The antigen frequencies of minor blood group systems were: Fy(a), Fy(b), Jk(a), Jk(b), k, S, s were 33.5%, 43.5%, 97.7%), 40.4%), 100%, 45%, 90%, respectively. Regarding phenotype distribution, the most common phenotypes were: Duffy Fy (a-b+) 36.9%, MNS S-s+ 55% and Kidd Jk (a+b-) 59.6%. Conclusion: This study highlights the frequencies of Fy(a), Fy(b), Jk(a), Jk(b), k, S and s blood group antigens and their phenotypes in volunteer blood donors at EBTBS, Addis Ababa. For the management of alloimmunization cases in transfused patients, knowledge of these minor blood group antigens is relevant.

Transfusion Preparedness in the Labor and Delivery Unit: An Initiative to Improve Safety and Cost.

OBJECTIVE: To evaluate patient safety, resource utilization, and transfusion-related cost after a policy change from universal type and screen to selective type and screen on admission to labor and delivery. METHODS: Between October 2017 and September 2019, we performed a single-center implementation study focusing on risk-based type and screen instead of universal type and screen. Implementation of our policy was October 2018 and compared 1 year preimplementation with 1 year postimplementation. Patients were risk-stratified in alignment with California Maternal Quality Care Collaborative recommendations. Under the new policy, the blood bank holds a blood sample for processing (hold clot) on patients at low- and medium-risk of hemorrhage. Type and screen and crossmatch are obtained on high-risk patients or with a prior positive antibody screen. We collected patient outcomes, safety and cost data, and compliance and resource utilization metrics. Cost included direct costs of transfusion-related testing in the labor and delivery unit during the study period, from a health system perspective. RESULTS: In 1 year postimplementation, there were no differences in emergency-release transfusion events (4 vs 3, P>.99). There were fewer emergency-release red blood cell (RBC) units transfused (9 vs 24, P=.002) and O-negative RBC units transfused (8 vs 18, P=.016) postimplementation compared with preimplementation. Hysterectomies (0.05% vs 0.1%, P=.44) and intensive care unit admissions (0.45% vs 0.51%, P=.43) were not different postimplementation compared with preimplementation. Postimplementation, mean monthly type and screen-related costs (ABO typing, antibody screen, and antibody workup costs) were lower, $9,753 compared with $20,676 in the preimplementation year, P<.001. CONCLUSION: Implementation of selective type and screen policy in the labor and delivery unit was associated with projected annual savings of $181,000 in an institution with 4,000 deliveries per year, without evidence of increased maternal morbidity.

Analysis of ABO grouping discrepancies among patients from a tertiary hospital in Korea.

BACKGROUND: Accurate ABO typing is essential for preventing ABO incompatibility reactions. However, the causes of ABO grouping discrepancy has not been sufficiently studied, and it may vary among different ethnic populations. Thus, the aim of this retrospective study was to investigate the causes of ABO discrepancy in the East Asian population. MATERIALS AND METHODS: A retrospective observational study on ABO typing discrepancy among patients in a tertiary hospital was carried out using the electronic medical record database of Samsung Medical Center (Seoul, Korea) between July 2016 and May 2019. RESULTS: ABO grouping was performed on 551,959 blood samples during the study period; 1468 events of serologic ABO discrepancy were determined from 1334 (0.24 %) samples. A total of 134 samples (0.02 %) presented multiple causes of ABO discrepancy. Weak/missing serum reactivity (594, 40.5 %) was the most frequent reason for ABO discrepancy, followed by extra serum reactivity (370, 25.2 %), weak/missing red cell reactivity (267, 18.2 %), mixed-field red cell reactivity (176, 12.0 %), and extra red cell reactivity (61, 4.2 %). In the category of weak/missing red cell reactivity, ABO subgroup was the most common reason, and using ABO genotyping, 26.2 % of the cases genotyped were found to be related to the cis-AB allele. CONCLUSIONS: Our results suggest that the incidence and cause of ABO typing discrepancies vary among institutes and ethnic groups. Our data helps to better understand and facilitate the resolution of ABO typing discrepancies in patients.

Comparison between a laser lancing device and lancet for capillary blood sampling, capillary blood hemoglobin measurement, and blood typing.

BACKGROUND: Blood donor screening includes tests using capillary blood, which is usually obtained by finger pricking using a lancet; however, the lancet has some shortcomings, such as skin puncture pain and needle stick injury. Recently, laser lancing devices for finger-prick sampling have been developed. We compared capillary blood Hb (cHb) levels and blood typing results obtained using a laser lancing device with those obtained using a lancet. STUDY DESIGN AND METHODS: cHb levels, blood typing results, and skin puncture pain scores were assessed in 191 participants. Finger-prick sampling was performed using LMT-1000 (LaMeditech, Seoul, Korea) and a lancet on the same finger on different hands. Paired venous Hb (vHb) levels were assessed in 103 participants using an automated hematology analyzer and compared with the cHb levels obtained using both lancing devices. RESULTS: The paired cHb results obtained with the laser lancing device and lancet showed a strong correlation (r = 0.927, p < .001) without any significant difference (p = .113) and a substantial agreement (κ = 0.654) for the identification of participants with a low Hb level (<12.5 g/dl). cHb levels were significantly higher than vHb levels with both lancing devices (mean differences: 0.27-0.43 g/dl). The results of blood typing using the laser lancing device showed 100% accuracy. Use of the laser lancing device showed significantly lower skin puncture pain scores (p < .001). CONCLUSION: Use of a laser lancing device for capillary Hb measurement and blood typing showed accurate results, with significantly reduced skin puncture pain. Laser lancing devices could be feasible for donor screening tests.

Combined liver-kidney transplantation with positive crossmatch: Role of delayed kidney transplantation.

BACKGROUND: Positive crossmatch (XM+) combined liver-kidney transplantation due to preformed donor-specific human leukocyte antigen antibodies has produced mixed results. We sought to understand the role of delayed kidney transplant approach in XM+ combined liver-kidney transplantations. METHODS: XM+ combined liver-kidney transplantations were retrospectively reviewed. T- and B-cell XM, complement-dependent cytotoxic crossmatch, and flow cytometric crossmatch were performed prospectively. RESULTS: Of 183 combined liver-kidney transplantations performed (2002-2019), 114 (62%) were with "delayed" kidney transplant approach and 19 (19 of 183, 10%) were XM+. Of 19 XM+ combined liver-kidney transplantations, kidney transplant was "delayed" in 14 by an average of 47 hours (range 24-64 hours) from liver transplant. There was a significant reduction in both class I (mean pre-liver transplant mean fluorescence intensity (MFI) 26,230 versus mean post-liver transplant and pre-delayed kidney transplant MFI 3,272, P = .01) and total MFI (mean pre-liver transplant MFI 27,233 vs mean post liver transplant and predelayed kidney transplant MFI 11,469, P = .01). However, there was no significant change in the MFI of class II donor-specific antibodies (mean pre-liver transplant MFI 17,899 versus post-liver transplant and pre-delayed kidney transplant MFI 14,341, P = .19). None of XM+ delayed kidney transplants had delayed graft function, and there was no antibody-mediated rejection. One-year patient survival for the XM+ combined liver-kidney transplantation with delayed kidney transplant approach was 92.9%, which is comparable to patient survival of XM- combined liver-kidney transplantation. Whereas patient survival in recipients before "delayed" approach ("simultaneous"; n = 5) was 40% when liver-kidney transplants were performed simultaneously (P = .06). CONCLUSION: In sensitized combined liver-kidney transplantation recipients, the "delayed" kidney transplant approach is associated with a significant reduction in total and class I donor-specific antibodies after liver transplant before kidney transplant, enabling therapeutic interventions such as plasmapheresis, if needed, providing optimal outcomes similar to crossmatch recipients.