Red Cell Antibodies Research Articles

Serological characteristics of Lewis antibodies and their clinical significance – A case series

IntroductionLewis antibodies have been thought to play a small role in clinical transfusion practice, but recent reports suggest that they have gained more importance in the context of transfusion and transplantation. Data regarding the prevalence of Lewis antibodies and their clinical significance in the Indian context is very limited. Hence, this study was aimed at analyzing the serological characteristics and clinical significance of Lewis antibodies encountered in our patient and donor populations. MethodsThe retrospective data analyzed the records of red cell antibody screening results and the additional serological evaluation performed on the donor and patient samples included in the study. ResultsA total of 26 study subjects were noted to have Lewis antibodies (including 6 healthy donors and 20 patients). Of them, 13 individuals had anti-Leb, 10 had anti-Lea and the remaining three had an anti-Lea/Leb mixture. IgG Lewis antibodies were detected in 7 individuals. All cases of IgM Lewis antibodies detected were reacting at 37°C. Two patients were suspected of having hemolytic transfusion reactions due to Lewis antibodies. Antigen-negative cross-match compatible units were provided for transfusion in the recipients. ConclusionLewis antibodies of the IgM class reacting at 37°C should be regarded as clinically important. The present study findings urge that the lab personnel look for the thermal amplitude of Lewis antibodies, irrespective of the fact that the antibody class and antigen-negative crossmatch compatible units should be provided to avoid hemolytic transfusion reactions.

Perinatal risk factors associated with severity of haemolytic disease of the foetus and newborn due to Rhc maternal-foetal incompatibility: A retrospective cohort study.

Anti-c is the third red blood cell antibody responsible for haemolytic disease of the foetus and newborn (HDFN) requiring intrauterine transfusion. We aimed to identify risk factors associated with HDFN and severe HDFN due to Rhc maternal-foetal incompatibility. A retrospective cohort study was conducted in Paris and the surrounding area (France), between 2013 and 2015. We included mothers and their children managed by the National Reference Centre in Perinatal Hemobiology for alloimmunization and maternal-foetal incompatibility for the Rhc antigen (N= 121). We conducted bivariate analyses to assess a relationship between perinatal factors (e.g., titre and concentration of anti-c antibodies, direct antiglobulin test) and HDFN, its severity and duration. The incidence of HDFN was 30% (n= 36), including 11% of severe HDFN (n= 13). Seven percent (n= 9) of neonates received at least one transfusion during the first week and 21% (n= 26) after this period until 3 weeks of life. During pregnancy, a concentration ≥7.5IU/ml and a titre ≥4 and above were associated with HDFN and severe HDFN (p< 0.05). At birth, the high intensity of the quantitative direct antiglobulin test was associated with HDFN and severe HDFN (p< 0.05). A concentration ≥15 IU/ml is the best factor (area under curve [AUC]=0.78) in predicting HDFN, followed by a titre ≥8 (AUC=0.76). Anti-c alloimmunization causes neonatal anaemia, which is often belated. Paediatricians have to be aware of these risk factors and organize prolonged monitoring of neonates.

Case of Hemolytic Disease of the Newborn due to a Rare Red Cell Antibody.

Case of Hemolytic Disease of the Newborn due to a Rare Red Cell Antibody.

High-sensitivity detection of clinically significant red blood cell antibodies by the column agglutination technique.

The detection of clinically significant antibodies to red blood cell antigens is important for the selection of compatible blood for patients. The conventional test tube technique (CTT) is commonly used as the gold standard test, but manual testing and visual detection of hemagglutination may produce errors. A more recently developed method, the column agglutination technique (CAT), facilitates ease of testing. To investigate the specificity and sensitivity of the CAT compared to the CTT for the screening of clinically significant antibodies from the Rh blood group. Standard antibodies to the Rh blood group, anti-D, -C and -E, were used as examples of clinically significant antibodies in transfusion science. The antibodies were serially diluted by two-fold, then reacted with screening cells with different antigen expression. The hemagglutination reaction was investigated using both techniques, and the grades and scores of the reactions were used to analyze the sensitivity and specificity of the CTT and CAT. The CAT had a better sensitivity than the CTT. The lowest antibody dilution of 1:8192 could be detected using CAT, while a dilution of only 1:2048 could be detected with CTT. However, the CTT and CAT were equal in specificity. The 2 techniques specifically detected all antibodies to the screening cells. Both the CAT and CTT showed 100% specificity. However, the CAT exhibited more sensitivity than the CTT, and can be used in substitution of, or in parallel with, the CTT technique for red blood cell phenotyping, antibody screening, identification, and crossmatching.

Management and clinical consequences of red blood cell antibodies in pregnancy: A population-based cohort study.

Anti-D alloimmunization is the most common cause of severe hemolytic disease of the fetus and newborn (HDFN). The management of pregnancies affected by less frequent red blood cell (RBC) antibodies poses a challenge to clinicians, and perinatal outcomes are less well described. This study aimed to describe the frequency of clinically significant RBC antibodies in our pregnant population and analyze the risk of prenatal and postnatal treatment for HDFN in relation to our national risk classification system and management guidelines. A retrospective cohort study in the population of all alloimmunized singleton pregnancies in the Stockholm region 1990-2016. Descriptive summaries of different RBC antibodies and pregnancy outcomes were presented, the risks of intrauterine blood transfusion (IUT) and neonatal treatment for HDFN were estimated by type of antibodies. Of the 1724 alloimmunized pregnancies, 1079 (63%) were at risk of HDFN and constituted our study cohort. Anti-D was detected in 492 (46%) pregnancies, followed by anti-E in 161 (15%), and anti-c in 128 (12%). Eighty-seven (8%) pregnancies had IUT, with the highest risk in pregnancies affected by anti-D combined with other antibodies. The maximum titer recorded before IUT was 64 or above, except for two pregnancies affected by anti-c, for which the maximum titers were 8 and 16. For the 942 (95%) live-born neonates from 992 alloimmunized pregnancies without IUT, the median gestational age at birth was 38+5 weeks compared with 35+5 weeks for those who had IUT. Neonatal treatment was most common in the anti-D alone and anti-D combined groups, with 136 (57%) and 21 (44%), respectively, treated with phototherapy and 35 (15%) and 9 (20%) receiving exchange transfusions, respectively. For pregnancies complicated by moderate- and low-risk antibodies, phototherapy was less frequent (32 [36%] and 21 [19%]) and exchange transfusion was rare (5 [6%] and 3 [3%]). Anti-D, especially in combination with other antibodies, presents the highest risk of severe HDFN. The classification of less frequent and less well-known RBC antibodies into risk groups can help clinicians in assessing the risk of HDFN and counseling alloimmunized pregnant women regarding the risk of prenatal and postnatal treatments.

Prevalence of Unexpected Red Cell Antibodies in Healthy Donor Population in a Tertiary Care Center in South Kerala

Background and Objectives: Apart from naturally occurring red cell antibodies Anti-A and Anti-B in human plasma, there are two types of unexpected red cell antibodies: Alloantibodies and auto-antibodies. The presence of these antibodies, alone or in combination, makes difficulties with compatibility testing, thereby delaying in the issue of a compatible blood unit or may reduce posttransfusion red blood cells life span. Antibody screening is mandatory as laid down by the Drug and Cosmetic Act 1940 and Directorate General of Health Services guidelines. This goal of this paper was to study the prevalence of Unexpected Red Cell Antibodies in Healthy Donor Population in a Tertiary Care Centre in South Kerala. Methods: The sample size chosen for this study was 7000 randomly chosen healthy nonremunerated voluntary donors who attended in house and blood donation camps over a period between November 26, 2017, and February 15, 2019. Results: The prevalence of unexpected red cell antibodies was found to be 1 in 1000. Male blood donations were more than female and blood donors among 18–30 years of age were greater in number. There were no cases of direct antiglobulin test positivity encountered. Male: Female ratio is 2.5:1 and males had naturally occurring alloantibodies, whereas females had a previous history of pregnancy. Anti-M and Anti-Lewis antibodies were the most common alloantibodies followed by Anti-Rh (D and C) antibodies and Anti-IH in the current study. Benign cold agglutinins (BCA) were found predominately in the younger male population with a significant seasonal variation noted in the prevalence of these antibodies. Conclusion: All antibodies identified had the ability to cause immune hemolytic transfusion reactions in the recipients. BCA-positive cases were seen more during the winter season and rainy seasons when compared to hot climatic conditions.

Autoimmune Hemolytic Anemia and Hemolytic Transfusion Reactions in Two Patients with Waldenström Macroglobulinemia Treated with Combination BTK Inhibitor and PD-1 Inhibitor

IntroductionBruton's tyrosine kinase (BTK) inhibitors have recently been shown to be safe and highly active as monotherapy in Waldenström macroglobulinemia (WM). Immune checkpoint inhibitors are being actively investigated in many lymphoid malignancies, and the expression of programmed cell death protein 1 (PD-1) and its ligands on malignant B cells in WM provides a rationale for the use of PD-1 inhibitors.Two patients with relapsed WM were treated with a novel anti-PD-1 antibody (BGB-A317) in combination with BGB-3111, a BTK inhibitor, as part of a Phase 1b study (NCT02795182). Both developed a newly identified syndrome of severe direct antiglobulin test (DAT) negative hemolysis and reticulocytopenia associated with transfusions, requiring cessation of the anti-PD-1 antibody and initiation of additional therapies.Case descriptionsPatient 1 is a 62-year-old female with WM who had previously received rituximab, cyclophosphamide and dexamethasone, and later rituximab and bendamustine (BR). After her most recent relapse she was treated with BGB-3111 followed 7 days later by BGB-A317. Four weeks after administration of the anti-PD-1 agent she developed hemoglobinuria, flank pain and fever during a red cell transfusion, with biochemical markers of hemolysis. DAT was negative and no red cell antibodies were identified. BGB-A317 was ceased, however hemolysis persisted and she required 26 further red cell transfusions. She was profoundly reticulocytopenic throughout this time. Prednisolone at 1mg/kg was initiated with a rapid resolution of hemolysis. The steroids were weaned and ceased over 7 weeks and she remains 4 months transfusion independent. Her WM is responding to single agent BGB-3111.Patient 2 is a 67-year-old female initially managed for WM with fludarabine, cyclophosphamide and rituximab. First relapse was treated with BR followed by autologous transplant. After a 3-year remission, a further relapse led to initiation of BGB-3111 then BGB-A317. Fourteen days after infusion of BGB-A317 she developed a hemolytic transfusion reaction with hemoglobinuria and elevation of biochemical markers of hemolysis. The blood film was unremarkable, DAT was negative and no antibodies could be identified. Reticulocytopenia was notable and worsened with progressing hemolysis. Ongoing hemolysis of transfused and native red cells was refractory to high dose prednisolone and intravenous immunoglobulin. Life-threatening anemia (nadir hemoglobin 4.4 g/dL, peak LDH 1544 U/L) prompted therapy with cyclophosphamide and pulse methylprednisone. BGB-3111, briefly withheld due to thrombocytopenia, was reinitiated. These measures were effective and the hemolytic anemia resolved over 3 weeks. Prednisone was weaned and the patient remains 4 months transfusion independent. Notably, a brief cessation of BGB-3111 at a later stage resulted in a transient recrudescence of hemolysis.DiscussionImmune related adverse events are well described with immune checkpoint inhibitors, including a few reported cases of autoimmune hemolytic anemia. In our patients, there was a clear temporal relationship between the BGB-A317 and hemolysis, which started 28 and 14 days after the first dose. Subsequent resolution of the syndrome took 80 and 55 days from the final dose of BGB-A317, equivalent to 5 times the estimated elimination half-life of 11 to 17 days. The response to glucocorticoids and cyclophosphamide support an immune mechanism initiated by checkpoint inhibition. The profound reticulocytopenia and marked erythroid hypoplasia suggest that erythroid precursors may have been a predominant target of the immune attack.No other cancer patients treated with BGB-A317 have developed a similar reaction to the two patients, who were the first worldwide with WM to receive the agent. These observations suggest a pathophysiological role of WM, which is known to be associated with immune dysregulation and autoimmune phenomena. We hypothesize that control of the underlying lymphoma by BGB-3111 contributed to resolution of the hemolysis.Lymphoproliferative disorders such as WM involve complex aberrations of immune function and inhibition not limited to the malignant clone. The introduction of therapeutic agents harnessing the immune system in this patient population should be approached with caution, as demonstrated by the unexpected and severe adverse events suffered by these two patients. [Display omitted] DisclosuresTam:Roche: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding; Janssen Cilag: Honoraria, Research Funding. Huang:BeiGene: Employment. Lin:BeiGene: Employment. Hilger:BeiGene: Employment. Trotman:Roche: Membership on an entity's Board of Directors or advisory committees, Other: All positions non-remunerated, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Other: Funding facilitating research paid to third parties. All positions non-remunerated; Takeda: Membership on an entity's Board of Directors or advisory committees, Other: Position non-remunerated; Janssen Cilag: Membership on an entity's Board of Directors or advisory committees, Other: Funding facilitating research paid to third parties. All positions non-remunerated, Speakers Bureau.

Immunohematology and Transfusion Support of a Patient with Acute Myeloid Leukemia and an Anti-Vel

BackgroundTransfusion support of cancer patients presenting with red blood cell (RBC) antibodies against high-incidence antigens is a challenge for hospital-based Transfusion Services. For patients with antibodies against the high-frequency Vel antigen, only 0.0004% of blood donors will be Vel antigen-negative. Anti-Vel is notorious for looking like a benign, cold-reactive IgM antibody or a “high-titer, low-avidity” antibody; however, Vel-antibodies can fix complement at body temperatures and can cause severe hemolytic transfusion reactions. The immunohematology workup and RBC transfusion support are reported for a patient who developed an anti-Vel and other RBC antibodies during chronic transfusion therapy for myelodysplastic syndrome, with progression to acute myeloid leukemia. She was also evaluated for hematopoietic stem cell transplantation (HSCT).MethodsImmunohematologic workups were performed at a regional immunohematology reference laboratory. Since the patient had a positive autocontrol and a positive direct antiglobulin test (DAT), allogeneic adsorptions were performed at 37°C using R1R1, R2R2 and rr RBC reagents. Adsorbed plasma and eluates from adsorbed RBCs were then tested for alloantibody detection using manual tube method at both LISS and PEG reactivity. In preparation for possible HSCT, RBC alloantibody titers and monocyte monolayer assay (MMA) were performed. All samples were collected with pediatric phlebotomy tubes whenever possible.ResultsThe patient was a 66 year old woman with a myelodysplastic syndrome that transformed to acute myeloid leukemia (AML) with complex karyotype a year later. The RBC reference workup identified alloantibodies reacting to the high-incidence Vel antigen as well as low-incidence Yt(b) and Cw antigens. The patient's plasma was non-reactive with three of four Vel-negative (-) cells, whereas the reactive cell was Cw positive (+) and Yt(b+). Two allo-adsorptions were performed to remove anti-Vel. Upon repeat testing, anti-Cw was identified by LISS indirect antiglobulin test. Eluate from adsorbing RBCs was reactive with Vel- and Yt(b+) cells, suggesting presence of anti-Ytb. In preparation for HSCT, anti-Vel and anti-Cw were titered at 0 and 64, respectively. MMA for anti-Vel ranged at 0.2-2% (normal <3%). Nevertheless, the hospital-based Transfusion Service provided rare ABO/Rh Vel- CW- Yt(b-) crossmatch-compatible RBC to minimize the potential for stimulating anti-Vel, which might compromise a Vel+ HSCT. The patient required about 1 RBC unit per week to maintain hemoglobin above 4.5 g/dL. The Transfusion Service coordinated a search for antigen-negative RBCs with a national rare donor program, allowing at least 4 rare RBC units to be available at all times. Over an 18-month time period, the patient received 62 RBC Vel- units: 45 out of 62 (73%) were Cw- and 17 were Cw-unscreened but C-. Later in the patient's course, her transfusion rate increased to 2 RBC units per week. Because insufficient Vel- units were available within the USA, an international search by a rare donor program identified Vel- donors in Europe. FDA approval was obtained to import the rare units. She received 2 units from Spain and 2 units from Switzerland. Her leukemia progressed, and transfusion support was discontinued.ConclusionCoordination between hospital-based Transfusion Service, hematologists, and rare donor programs is required for rare RBC transfusion support in patients with antibodies against high-incidence antigens. A transfusion threshold of 4.5 g/dL may be tolerated when availability of rare RBC units is limited. DisclosuresNo relevant conflicts of interest to declare.

Epidemiologic Characterization of Transfusion Recipients with Red Blood Cell Alloantibodies from Four US Regions: Evidence from the REDS-III Recipient Database

Introduction: Red blood cell (RBC) alloimmunization is one of the most common complications of RBC transfusion. Despite the fact that alloimmunization impacts many transfusion recipients, the lack of standardized alloimmunization registries in the US has prevented large studies from being completed. Through the development of a uniform electronic research database, we investigated alloimmunization rates and diagnoses in inpatients and outpatients across the US.Methods: The REDS-III recipient database, established in 2013, houses demographic, diagnostic, transfusion, laboratory, and other information on inpatients and outpatients at 12 hospitals in 4 geographic regions. For this study, an antibody “responder” (R) was defined as an individual who had a putative transfusion (or pregnancy)-associated red cell antibody identified by screen at any point during the study period, independent of documented RBC exposure or pregnancy during the study period. An antibody “non-responder” (NR) was defined as an individual who was transfused with at least one unit of RBCs during the study period, and had a negative antibody screen at least 15 days post-transfusion. Anti-D antibodies were excluded from studied females, given an inability to distinguish passively administered anti-D in the database from authentic alloantibodies. Demographics, blood type, ICD9/10 codes, and antibody screen results were compared for R and NRs. Odds ratios were calculated for the likelihood of being a R or NR, based on the presence or absence of select chronic disease states.Results: 612,417 patients were recorded in the REDS recipient database from 2013-2016. 318,918 unique patients in the database had an RBC antibody screen during the study period. Of these, 6597 had at least one transfusion-associated RBC alloantibody identified by routine antibody screen (overall alloimmunization rate among all screened patients independent of RBC exposure = 2.07%). 63.8% of the R were female (alloimmunization rate 2.97%) and 36.2% were male (alloimmunization rate 1.35%). 30,468 unique patients (49.8% female and 50.2% male) were NR; the mean RBC exposure during the study period was similar between R and NR (mean, s.d., and median of 8.8, 18.2, and 4 units versus 9.3, 14.3, and 5 units). Approximately 60-70% of the antibodies in R were pre-existing, and the remainder were generated during the study period. Few children under 10 years of age were R compared to older age groups; an equation of R/R+NR = 26/26 + 467 = 5.3%. There were no differences in R vs NR by A/B/O blood type, though Rh negative patients (R/R+NR of 1175/1175 + 3901 = 23.1%) were significantly more likely to be R than Rh positive patients (R/R + NR of 5365/5365 + 26544 = 16.8%). .A total of 8892 clinically significant antibodies were detected, including 4749 (53.4%) in the Rh family (2588 anti-E, 780 anti-C, 556 anti-c, 105 anti-e, 525 anti-D), 1937 (21.8%) in the K family, 912 (10.3%) in the Kidd family, and 669 (7.5%) in the Duffy family, among others. Patients with sickle cell disease (n=554, OR 2.6, p<0.0001), sickle cell trait (n=117, OR 1.8, p=0.02), 'coronary atherosclerosis or heart disease (n=12,403, OR 1.2, p<0.0001), lupus (n=969, OR 1.3, p=0.002), rheumatoid arthritis (n=1213, OR 1.2, p=0.01), and myelodysplastic syndrome (n=1162, OR 1.3, p=0.0008) were more likely to be R than NR. In contrast, patients with leukemia (n=2801, OR 0.5, p<0.0001), solid tumors (n=17,513, OR 0.6, p<0.0001), and solid organ transplant (n=1491, OR 0.7, p=0.0001) were less likely to be R than NR.Conclusions: Data collected in this multi-center recipient database provide the largest RBC alloimmunized patient cohort ever studied in the US. The 2.07% overall rate of alloimmunization is similar to that reported in other retrospective studies, with females having higher alloimmunization rates than males. Rh negative individuals were significantly more likely to be alloimmunized than Rh positive patients, despite the exclusion of anti-D antibodies in females. Other unexpected findings include the predisposition to alloimmunization observed in patients with sickle cell trait and coronary artery disease. Ongoing studies are investigating the timing of RBC exposure to new antibody formation in this patient cohort, as well as potential physiologic explanations for the chronic disease associated findings. DisclosuresNo relevant conflicts of interest to declare.

Identification and management of fetal anaemia: a practical guide

Key content Fetal anaemia can be caused by alloimmune or infectious red cell destruction, disorders of fetal red cell production, fetal haemorrhage and as a complication of monochorionic multifetal pregnancy. A fetus at risk from maternal alloimmunisation can be detected by maternal serum screening for red cell antibodies and by fetal ultrasonography. Undiagnosed cases may present in routine obstetric practice, so awareness of the identification and initial management of fetal anaemia is important. Pregnancies must be triaged depending on clinical urgency, with input from fetal medicine specialists required. Developments in fetal ultrasound assessment and in fetal therapy have improved outcomes and contemporary research will focus on improving long term outcomes for neonatal survivors. Learning objectives To understand the varied aetiologies and pathophysiology of fetal anaemia and to adopt a system for reaching a diagnosis. To appreciate the different diagnostic tools available, comprising ultrasonography, microbiological testing, noninvasive and invasive tests in fetal medicine units and electronic fetal monitoring in the acute setting. Ethical issues Management involves balancing maternal and fetal risks. Research ethics should be considered in relation to experimental treatments and trials in fetal therapy.

A case series highlighting a common approach to identifying anti-Jk3.

Abstract The Kidd-null phenotype, Jk(a–b–), is rare, and a patient with this phenotype may develop anti-Jk3, a red blood cell (RBC) antibody reactive with a domain common to both Jka and Jkb. Like other antibodies to high-prevalence antigens, the presence of this antibody poses challenges in the immunohematologic evaluation of these patients. Thoughtful laboratory testing is necessary to resolve the antibody specificity and to reveal other underlying antibodies. Moreover, the rarity of the Kidd-null phenotype makes finding blood donors difficult for those who need transfusion and have developed anti-Jk3. This review describes methods used in identifying anti-Jk3 in four pregnant patients. Blood bank records were retrospectively reviewed to illustrate the common approach in anti-Jk3 identification. In all cases, pertinent blood bank history was gathered, and extended RBC phenotyping was performed, followed by adsorption studies and testing of selected RBCs. Underlying antibodies were found in two of the cases. This review also reiterates some common challenges encountered with Kidd antibody analysis and highlights the importance of patient ethnic ancestry and obtaining accurate patient transfusion history.

Non-ABO red cell antibodies and risk of COVID-19

It is not known whether non-ABO antibodies confer any protective effect against SARS-CoV-2 infection or COVID-19 severe illness alone or in conjunction with O blood group. This cohort study included 413 576 persons in Ontario, Canada with known ABO blood group and non-ABO antibody screen status, who subsequently underwent SARS-CoV-2 viral RNA polymerase chain reaction testing between January and November 2020. The risk of SARS-CoV-2 infection or COVID-19 severe illness was not associated with the presence of non-ABO antibodies, even among persons with O blood group.

Effect of fennel essential oil on performance, serum biochemistry, immunity, ileum morphology and microbial population, and meat quality of broiler chickens fed corn or wheat-based diet

ABSTRACT 1. The effect of Foeniculi aetheroleum essential oil (EO) on growth performance, nutrient utilisation, serum biochemistry, immune response, ileum morphology, microbial population and meat quality of broiler chickens fed a corn- or wheat-based diet were determined. 2. A total of 360 broiler chickens were arranged in a 2 × 2 factorial assay in a completely randomised design with six replicates and 15 birds per experimental unit. Birds were fed corn- or wheat-based diets supplemented with (200 mg/kg) or without fennel EO. 3. Birds fed wheat-based diets had lower BWG and FCR during grower period and lower FI during finisher period as compared to those fed corn-based diet (P < 0.05) whereas addition of fennel EO decreased chickens BWG during finisher period and EPEF, both in wheat or in corn-based diets. Dietary treatments had no effect on serum glucose, triglyceride, cholesterol, LDL-cholesterol, AST, ALT, ALP, and MDA concentrations (P < 0.05). 4. Antibody titres against avian influenza and sheep red blood cell antibody titres, crude protein and crude fat utilisation, villus height, crypt depth and epithelium thickness were not influenced by dietary treatments (P > 0.05). Inclusion of Fennel EO to the corn-based diet resulted in greater villus width and villus surface area while it reduced lamina propria thickness (P < 0.05). Fennel EO reduced ileal E. coli and Lactobacillus spp. populations (P < 0.05). Dietary treatments had no significant effect on meat pH, cooking loss, drip loss, crude protein, crude fat content and cholesterol concentration of breast and thigh meat, total phenolic and MDA concentrations, and breast meat sensory parameters (P > 0.05). 5. These results showed that addition of fennel EO to wheat-based diets had a negative effect on chicken growth performance variables and decreased gut E. coli populations. However, immunity, meat quality and nutrient utilisation were not affected by dietary treatments.

Survey of newborn direct antiglobulin testing practice in United States and Canadian transfusion services.

We hypothesized that variability in practice exists for newborn immunohematology testing due to lack of consensus guidelines. We report the results of a survey assessing that variability at hospitals in the United States and Canada. An AABB Pediatric Subsection working party developed and validated a survey of newborn immunohematology testing practice. The survey was sent electronically to transfusion service leadership at teaching institutions. The response rate was 67% (61/91); 56 surveys meeting inclusion criteria were analyzed. Approximately 90% (50/56) were from birth hospitals and 16.1% (9/56) were from pediatric hospitals. Newborn immunohematology testing is ordered as a panel by 66.0% (33/50) of birth hospitals. ABO group and DAT is mandated before discharge in 14/56 (25.0%) and 13/56 (23.2%), respectively. About 76.8% (43/56) selectively perform a DAT according to blood blank or clinical parameters. The most common DAT practices include anti-IgG only testing by 73.2% (41/56) and use of umbilical cord specimen type by 67.9% (38/56). A positive DAT is a critical value for 26.8% (15/56) and followed with eluate testing when a maternal antibody screen is positive for 48.2% (27/56). In the setting of a non-ABO maternal red cell antibody, 55.4% (31/56), phenotype neonatal red cells when the DAT is positive. Group O RBC are transfused irrespective of the DAT result for 82.1%, (46/56). There is variability in newborn immunohematology testing and transfusion practice and potential overutilization of the DAT. Evidence-based consensus guidelines should be developed to standardize practice and to improve safety.

The Screening and Identification of Atypical Red Cell Antibodies by Simultaneous LISS/Coombs and NaCl/Enzyme Gel Methods Prior to Blood Transfusion

Background: In this retrospective study, we measured the frequency of unexpected antibodies in the blood by Nacl/enzyme gel method or LISS/Coombs method and compared the result and frequency of identification in patients with a history of gestation or blood transfusion. Aims and Objectives: To detect unexpected/atypical red cell antibodies by simultaneous LISS/Coombs and NacL/enzyme gel methods prior to blood transfusion. Materials and Methods: Atypical antibody screening has done in all patients with the history of recurrent blood transfusion or history of gestation by commercially available red cell panel (ID–Dia panel, Diamed–ID Micro Typing System). Results: A total of 30 patients were screened for the presence of atypical antibody. Out of 30 patients, 1 (3.33%) patient showed the presence of alloantibody in the serum. The alloantibody identified was of anti-Lewis system. Conclusion: Screening for the presence of alloantibodies in patients is important to provide compatible blood and avoid adverse transfusion reactions.

Stimulation of humoral and cell-mediated immunities in healthy and cyclophosphamide-induced immunosuppressed rats by the lyophilized Houttuynia cordata fermented drink

ABSTRACTHouttuynia cordata fermented drinks (HCFDs) are dietary liquid supplements widely marketed and consumed for immune enhancement. In this study, the acute oral toxicity and immunostimulatory activity of the selected lyophilized HCFD in healthy and cyclophosphamide-induced immunosuppressed rats were evaluated. The lyophilized selected commercialized HCFD was safe in animal model as there was no acute oral toxic death at up to 2000 mg/kg in male Wistar rats. After 14 days of treatment, in immunosuppressed rats, lyophilized HCFD enhanced rat body weight gain and significantly increased spleen index at a dose of 100 mg/kg. Moreover, B-cell proliferation and anti-sheep red blood cell antibody production were significantly increased at doses of 100 and 200 mg/kg, respectively. The delayed-type hypersensitivity response was significantly stimulated at a dose of 200 mg/kg. These findings exhibited the immunostimulatory activity of the lyophilized HCFD by enhancing the immune responses in both humoral and cell-mediated immunities in immunosuppressed rats.

A case of hyperhaemolysis syndrome in a pregnant Chinese woman with β‐thalassemia during perinatal transfusion

To report a case of hyperhaemolysis syndrome (HHS) that occurred during perinatal blood transfusion in a pregnant Chinese woman with β-thalassemia to deepen the understanding of HHS and the risk of transfusion therapy for patients with thalassemia. Most HHS cases occur in people with sickle cell disease. So far, no cases of HHS have been reported in the Chinese population. Here, we report a pregnant Chinese women with β-thalassemia experiencing HHS. The patient received ABO- and RhD-matched red blood cell transfusion from six blood donors in four perinatal transfusions. Haemoglobinuria and lower haemoglobin levels compared to those before transfusion were observed after each transfusion, and the lactate dehydrogenase was consistently elevated. The blood samples were collected at different time points during the hospitalisation for direct antiglobulin test (DAT), antibody screening test and acid elution test. The antigens of six blood donors were identified, and the cross-matching tests were repeated using the blood sample of the patient with specific irregular antibodies after the last transfusion. The DAT of the patient was negative for anti-IgG and positive (1+) for anti-C3d, and no red blood cell antibodies were detected in the eluent before, between and after transfusions. Before and between transfusions, blood samples were negative for red blood cell irregular antibodies, whereas IgM anti-P1 and IgG anti-Jka were detected in blood samples the next day after the last transfusion. In the six donors, two were negative for P1 and Jka , one was positive for P1 and negative for Jka , and three were negative for P1 and positive for Jka . The tentative cross-matching tests using the indirect antiglobulin method in saline showed that only agglutination occurred in the blood samples of the patient collected after last transfusion and the three Jka -positive blood donors. The clinical manifestations and laboratory test results suggested that HHS occurred in this patient with β-thalassemia after each transfusion. Clinicians should be aware that HHS can occur with compatible blood transfusion.

Donation testing and transfusion transmissible infections

Donation testing and transfusion transmissible infections

Glossary

Glossary

Outcomes of Chronic Automated RBC Exchange Program in Omaha, Nebraska 2015-2020

Background: Red blood cell exchange (RBCX) is an effective therapy in the treatment of different hemoglobinopathies. The University of Nebraska Medical Center (UNMC) established a chronic RBCX program in November 2015, which took care of patients with multiple hemoglobinopathies. In this study, we aim to evaluate the outcomes of this program. Methods: This is a retrospective study. After an IRB approval, we reviewed the charts of patients who were enrolled in the chronic RBCX program between 11/2015-7/2020 at UNMC. Data was collected to evaluate indications of RBCX, types of hemoglobinopathies, hemoglobinopathies' complications before and after the enrollment in the program, and assessment of hospital visits before and after enrollment in the program. Results: In November 2015, the chronic RBCX program was established in Nebraska. Since the start, 24 patients came through the program and 20 patients are still actively enrolled and undergoing regular exchange transfusions. The four patients who left the program did it for the following reasons: moving out of state, stem cell transplant and change to different treatment modality. Four of 24 patients were beta thalassemia patients (two of them with combined HbE/beta thalassemia). Twenty patients had sickle cell disease with two of them having combined beta thalassemia and HbS and one with alpha thalassemia and HbS. The indications ranged from history of stroke, intracranial vascular stenosis, acute chest syndrome (ACS), iron overload, multiple vascular occlusive crises (VOC) and intolerance of medications with most of the patients having multiple indications from the list above (Figure 1). There are several positive outcomes from being on the program. In the patients who had been on the program for at least one year (n=11), nine started the program with iron overload and all of them had a significant decrease in serum ferritin (average 751 ng/mL) with three patients returning to normal range. In the patients who had been in the program at least six months (n=16), 13 patients started with iron overload with five returning to normal range and average decrease in ferritin of 585 ng/mL. Another positive outcome is the number of emergency department (ED) visits for pain crisis. We noted reduction in ED visits in all patients who were in the program for at least six months (n=14), with the exception of one patient where the visits were likely the part of drug seeking behavior. In fact 12 of 13 patients had one or no ED visits within one year after starting on the chronic exchange program having had from 2-11 visits a year prior. None of the patients in the program experienced more severe complications of sickle cell disease, like stroke and acute chest syndrome, while on the program. Due to high volumes of transfusion, there is a big concern about developing red blood cell antibodies in sickle cell disease patients who in general have higher red blood cell antibody burden. Out of 24 patients in the program, six had pre-existing antibodies. For the duration of the program, no new alloantibodies were discovered in the chronically exchanged patients despite high transfusion volumes (range 14L-30L/year). The transfused blood was matched for Rh and Kell antigens for the patients with no antibody history. The patients with previous antibody history had additional matching for the antigen to which antibody was directed. Conclusion:Automated chronic RBCX transfusion program is safe to perform. It leads to significant reduction in volume overload and ED visits. Performing high volume transfusions outside of acute sickle cell crisis and with Rh and Kell matched units prevents formation of RBC antibodies Disclosures Gundabolu: BioMarin:Consultancy;Bristol Myers Squibb pharmaceuticals:Consultancy.