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Komplexe Antikörperbefunde in der Immunhämatologie stellen eine große Herausforderung für die zeitgerechte Bereitstellung von passenden Erythrozytenkonzentraten dar. Der Einsatz rekombinanter Antigene erleichtert die Abklärung von Antikörpergemischen oder Antikörpern gegen hochfrequente Antigene beziehungsweise macht diese für die meisten immunhämatologischen Labore erst möglich. Die Erweiterung des Methodenspektrums durch rekombinante Antigene ermöglicht eine sicherere und schnellere Blutversorgung immunisierter Personen. [ABSTRACT FROM AUTHOR]

Background and Objectives: The anti-A and anti-B are naturally occurring antibodies in the human body but alloantibodies may be formed in individuals who lacks that corresponding red cell antigen after any sensitising event like blood transfusion or pregnancy. The aim of this study was to find the incidence of evanescenct RBC alloantibodies that may not be detectable at the time of pre-transfusion screening. Methods: This was a retrospective observational study from January 2017 to May 2019 in a tertiary care centre from North India. The data on antibody screening and identification retrieved from the departmental records. The patients were screened for red blood cell antibody and those with a positive screening test were further investigated for antibody identification. Antibody screening was performed by solid phase method using Immucor Capture-R Ready Screen (4 cell). Confirmed positive samples were investigated with advance methods of Antibody ID using Reagent panel Red Blood Cells Capture-R Ready ID (16 Cell) in Automated Analyzer Iris or Neo (Immucor Inc. Nocross, GA, USA). As and when required other advance techniques of adsorption and elution, etc were also performed too. Results: The total number of patient screened during this period were 8071. Amongst them 312 were positive for antibody screening (3.8%), of those 216 (62.9%) cases had alloantibodies and 96 (30.7%) cases had autoantibodies. Among the 216 cases of alloantibody, 147 (68.1%) cases had single alloantibody and 69 (31.9%) cases had multiple alloantibodies. Amongst the patients having single alloantibody, the prevalence was highest for Anti-D 54 (36.7%), followed by Anti-E 27 (18.3%), Anti-C 8 (5.4%), Anti-c 7 (4.7%), Anti-K 9 (6.1%), Anti-Fyb 11 (7.4%), Anti-M 18 (12.2%), Anti-N 4 (2.7%), Anti-Fyb 3 (2%), Anti-Lea 3 (2%), Anti-Cw 2 (1.3%) and Anti-Mia 1 (0.6%). Of the 96 patients with autoantibody 72 had warm autoantibody, 10 had cold autoantibody and there were 8 cases of mixed warm and cold autoantibodies. There were 6 patients with warm autoantibody with underlying alloantibody. Conclusion: In conclusion, the high prevalence of Anti-Rh (Anti-D, E), Anti-M, Anti-Fyb antibodies in patient requiring transfusion reiterates the importance of stringent antibody screening and identification as an essential step in preventing delayed hemolytic transfusion reaction. [ABSTRACT FROM AUTHOR]

BACKGROUND AND OBJECTIVE: A number of glycophorin variant phenotypes or hybrid glycophorin variants of the MNS blood group system bear multiple immunogenic antigens such as Mia, Mur, and MUT. In the East and Southeast Asian populations, glycoprotein (GP.) Mur is the most common glycophorin variant phenotype expressing those three immunogens. The aim of this study was to detect MNS system glycophorin variant phenotypes (GP. Mur, GP. Hop, GP. Bun, GP. HF, and GP. Hut) among Malaysian blood donors. MATERIALS AND METHODS: In this cross-sectional study, 144 blood donors were selected under stratified random sampling. The deoxyribonucleic acid was extracted from whole blood samples, followed by a polymerase chain reaction assay. Sanger sequencing was used to identify the specific MNS variants and then validated by a serological crossmatch with known anti-Mur and anti-MUT. RESULTS: GP. Mur was identified among Malaysian blood donors with a prevalence of 6.94%, and no other variants of the MNS system were found. CONCLUSION: The present study substantiates that GP. Mur is the main variant of the MNS system glycophorin (B-A-B) hybrid in Malaysian blood donors. GP. Mur-negative red blood cells must therefore be considered in the current transfusion policy in order to prevent alloimmunization and immune-mediated transfusion reactions, particularly in transfusion-dependent patients. [ABSTRACT FROM AUTHOR]

BACKGROUND: Multiple reports are available from different parts of the globe indicating the incidences of alloimmunization and blood transfusion-related reactions, which emphasizes the need for phenotyping and providing antigen-matched safe blood. AIMS AND OBJECTIVES: This study aims to determine the frequency of Rh and Kell antigens and phenotype for both donors and patients to propose the importance of providing Rh Kell phenotype cross-matched packed red blood cell (RBC) units to minimize the alloimmunization and transfusion reactions. MATERIALS AND METHODS: Ten thousand blood donors and four thousand patients were investigated between October 2017 and July 2019. Each donor unit was tested for blood grouping, antibody screening, and Rh Kell antigen Phenotyping, and the blood unit was issued after the patient's blood grouping, antibody screening by 3 cell panels, and Rh Kell antigen phenotyping followed by cross-matching with an Rh Kell-matched phenotype RBC unit. RESULTS: Nine thousand four hundred and fifty-two donors were D positive (94.5%) while 548 tested D negative (5.5%). Overall Rh and K antigens frequencies in donors were: "e" (98%) >"D" (94.5%) >"C" (86.6%) > "c" (57.5%) >"E" (18.8%) >K (0.98%). Among patients, 3762 tested D positive (94.05%), and 238 tested D negative (5.95%). Overall Rh and K antigens frequencies in patients were: "e" (98.5%) >"D" (94.05%) >"C" (90.2%) >"c" (51%) >"E" (18.2%) >K (1.8%). CONCLUSION: Our study has given us more clarity on the prevalence of major Rh and K antigens in our donor as well as patient populations, highlighting the similarities as well as differences. This variance holds a great significance, since such donor units when transfused into patients may lead to alloimmunization and adverse transfusion reactions. Hence, the determination of Rh and Kell phenotypes and providing phenotype-matched blood will help prevent such events. [ABSTRACT FROM AUTHOR]

Background and Objectives: The RHAG blood group system contains five antigens: Duclos (RHAG001), Ola (RHAG002), DSLK (RHAG003), Kg (RHAG005) and SHER (RHAG006). Individuals who are DSLK‐negative and Kg‐positive have the same allele RHAG*01.–3, with a single‐nucleotide variation (rs144305805), c.490A>C (p.Lys164Gln), in exon 3 of the RHAG gene. We aimed to confirm whether DSLK and Kg are antithetical antigens. Materials and Methods: Blood samples of the original DSLK‐negative proband with anti‐DSLK, her son and another DSLK‐negative individual were examined. The RHAG gene was analysed by polymerase chain reaction and Sanger sequencing. Immunocomplex capture fluorescence assays (ICFAs) and monocyte phagocytosis assays were performed to characterize the anti‐DSLK antibody. Cross‐testing of alloanti‐DSLK and monoclonal anti‐Kg (OSK46) was performed using transduced HEK293 cells by inducing the construct of expression vectors encoding wild‐type RHAG*01 or the variant RHAG*01.–3. Results: ICFA using monoclonal anti‐RHAG (LA18.18) revealed that the anti‐DSLK and anti‐Kg antibodies reacted with the wild‐type and variant RhAG (Rh‐associated glycoprotein), respectively. The proband and a DSLK‐negative individual appeared to be homozygous for variant RHAG*01.–3, and the proband's son was typed as RHAG*01/RHAG*01.–3 heterozygote. HEK293 cells with wild‐type RhAG reacted with the anti‐DSLK but not anti‐Kg antibody, whereas HEK293 cells expressing the variant RhAG reacted with the anti‐Kg but not anti‐DSLK antibody. Monocyte phagocytosis assays indicated that 64% of red cells sensitized with anti‐DSLK were phagocytosed by monocytes. Conclusion: Our results demonstrate that DSLK and Kg are antithetical antigens in the RHAG blood group system. Anti‐DSLK may be a clinically significant antibody. [ABSTRACT FROM AUTHOR]

Background: The administration of anti‐D for the prevention of hemolytic disease of the fetus and newborn is one of the most successful clinical uses of the phenomenon of antibody‐mediated immune suppression (AMIS). However, despite adequate prophylaxis, failures can still occur in the clinic and are poorly understood. Recently, the copy number of red blood cell (RBC) antigens has been shown to influence immunogenicity in the context of RBC alloimmunization; however, its influence on AMIS remains unexplored. Study Design and Methods: RBCs expressing approximately 3,600 and approximately 12,400 copy numbers of surface‐bound hen egg lysozyme (HEL), named respectively HELmed‐RBCs and HELhi‐RBCs, and selected doses of a polyclonal HEL‐specific IgG were transfused into mice. Recipient HEL‐specific IgM, IgG, and IgG subclass responses were evaluated by ELISA. Results: Antigen copy number affected the antibody dose required for AMIS induction with higher antigen copy numbers requiring larger doses of antibody. For instance, 5 μg of antibody caused AMIS for HELmed‐RBCs but not HELhi‐RBCs, while 20 μg induced significant suppression for both HEL‐RBCs. Overall, increasing amounts of the AMIS‐inducing antibody were associated with a more complete AMIS effect. In contrast, the lowest tested doses of the AMIS‐inducing IgG led to evidence of enhancement at the IgM and IgG levels. Discussion: The results demonstrate that the relationship between antigen copy number and antibody dose can influence the outcome of AMIS. Further, this work suggests that the same antibody preparation can induce both AMIS and enhancement but that the outcome may depend on the quantitative interrelationship of antigen–antibody binding. [ABSTRACT FROM AUTHOR]

Background and Objectives One of the antigens of the blood group is Duffy, which includes different subtypes. This system is of clinical importance in terms of blood transfusion, so accurate identification of this antigen is very important. In this study, the process of solubilization of the membrane of red blood cell (RBC) and purification of the Duffy antigen, were investigated. Materials and Methods In this experimental study, packed RBCs (O- and Fya+) were obtained from the blood donation center of Tehran province. The membranes of RBCs were solubilized using Nonidet P-40 detergent. In the next step, Fya antigen was purified by affinity chromatography method using a specific antibody against this antigen. The specificity of the purified protein was tested by ELISA technique Results The Fya+ characteristic of red blood cells of the RBC bag was confirmed. In addition, the specificity of the antigen was confirmed by ELISA method. The absorbance levels of the purified antigen (OD450nm) in ELISA method were 1.056 ± 0.137 and 0.197 ± 0.016 by employing the Fya and Fyb antibodies, respectively. Conclusions The present research showed that red blood cell membrane solubilization can be done to purify Fy antigen and this antigen may be used in various fields including immunization and antibody production. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Autoimmune hemolytic anemia is characterized by increased red cell destruction and/or decreased red cell survival due to autoantibodies directed against self-antigens on red cells. Since autoantibodies react with self and nonself red blood cells (RBCs), they tend to mask the underlying clinically significant alloantibodies and many a times mimic a specific pattern like alloantibodies. MATERIALS AND METHODS: We discuss three immune hematological cases of warm autoantibodies. Antibody screening was performed by solid-phase red cell adherence (SPRCA) technique on a fully automated platform NEO Iris (Immucor Inc., USA). In case of a positive antibody screen, antibody identification was performed using SPRCA, NEO Iris (Immucor Inc., USA). Alloadsorption for adsorbing the autoantibodies was done using in-house prepared allogenic packed RBCs – R1R1, R2R2, and rr. RESULTS: All cases had warm autoantibody with a broad specificity against self-Rh antigens. Anti "C" and Anti "e" antibodies were identified in case 1 and autoanti "e" antibody in cases 2 and 3. Case 3 had underlying alloanti "E" along with autoanti "e" which posed a transfusion challenge. CONCLUSION: Our case series highlights the importance of detecting the nature of the antibody whether it is alloantibody or autoantibody with antigen specificity. This would help in selecting appropriate antigen negative blood units for transfusion purpose. [ABSTRACT FROM AUTHOR]

A delayed haemolytic transfusion reaction (DHTR) encompasses a positive direct antiglobulin test (DAT) developed anytime between 24 hours to 28 days after cessation of transfusion, a positive eluate or a newly identified alloantibody in the plasma or serum along with features of haemolysis in the patient. Routinely, it is expected that with the transfusion of one unit of packed red cells in a patient of average height and weight, the haemoglobin level and hematocrit increase by 1 g/dL and 3% respectively. However, in a patient with DHTR, an inadequate rise of post-transfusion haemoglobin (< 1 g/dL) or rapid fall in haemoglobin back to pre-transfusion levels is observed. Kidd antibodies are particularly known to cause DHTR, maybe alone or in unison with other antibodies. Detection of these alloantibodies is consequential in providing good transfusion support to these patients. These events may be difficult to detect as they may present as varied clinical features or immunological nuisances. In this case series, we have presented three cases of DHTR with special emphasis on their clinical presentations, immunohaematological evaluations, laboratory parameters and the role of proper transfusion support in these patients to avoid further complications. [ABSTRACT FROM AUTHOR]

Anti-Cw antibody is an immunoglobulin against the red cell antigen Cw which is a low frequency red cell antigen that belongs to the Rh antigen system. It is a clinically significant antibody and may cause haemolysis on exposure to antigen positive red cells. Due to its low frequency, it is not included in routine antibody screening panels. A 32 years healthy male donor with no history of transfusion donated whole blood at the department of Transfusion Medicine & Blood Centre of our institute. As a part of routine pre-transfusion testing, the donor's samples were subjected to automated blood grouping and screening for unexpected red cell antibodies using 3 cells panel on solid-phase red-cell adherence (SPRCA) (Galileo Neo, Immucor, Norcross, USA). The antibody screening came out to be positive with a reaction in cell I of the antibody screening panel. Further the antibody was identified as anti Cw in using 16 cells panel, select cells and phenotyping. In the present case, the anti-Cw antibody was found to be reactive at 37 °C and AHG phase which could lead to haemolytic transfusion reaction. The fact that the male donor had no history of transfusion or transplant led us to the conclusion that it was a naturally occurring, but a clinically significant antibody. This case highlights the importance of performing an antibody screening for healthy donors as well and urges transfusion services to procure screening cells which incorporate Cw positive cells. [ABSTRACT FROM AUTHOR]

Background: Plasmodium falciparum-infected red blood cells (iRBCs) bind and sequester in deep vascular beds, causing malaria-related disease and death. In pregnant women, VAR2CSA binds to chondroitin sulfate A (CSA) and mediates placental sequestration, making it the major placental malaria (PM) vaccine target.Methods: In this study, we characterize an invariant protein associated with PM called P falciparum chondroitin sulfate A ligand (PfCSA-L).Results: Recombinant PfCSA-L binds both placental CSA and VAR2CSA with nanomolar affinity, and it is coexpressed on the iRBC surface with VAR2CSA. Unlike VAR2CSA, which is anchored by a transmembrane domain, PfCSA-L is peripherally associated with the outer surface of knobs through high-affinity protein-protein interactions with VAR2CSA. This suggests that iRBC sequestration involves complexes of invariant and variant surface proteins, allowing parasites to maintain both diversity and function at the iRBC surface.Conclusions: The PfCSA-L is a promising target for intervention because it is well conserved, exposed on infected cells, and expressed and localized with VAR2CSA. [ABSTRACT FROM AUTHOR]

Objective: To assess the clinicohaematological presentation and outcome of patients with antibodies to high frequency antigen (HFA) in our setup. Study Design: Cross sectional study. Place and Duration of Study: Armed Forces Institute of Transfusion, Rawalpindi, from Jan 2016 to Jan 2018. Methodology: We diagnosed 29 cases of uncommon red cell antibodies including antibodies to HFA, in a span of two years (2016-2018). Information regarding patient's age, diagnosis, transfusion history, incompatible cross match and history of pregnancy was obtained. Venous blood sample of 3ml was taken in EDTA for grouping, red cell phenotyping and Direct Anti-Globulin Test (DAT) and 5 ml venous blood was taken for Indirect Antiglobulin Test (IAT), antibody screening and identification. Tube method was used for forward and reverse blood grouping, DAT and IAT. Column Agglutination Technique (CAT) was used for antibody screening, identification and red cell phenotyping. Results: Out of a total of 29 cases, 24 (83%) were of anti H antibody (Bombay blood group). Rest of 5 (17%) included one each of anti Rh 17, anti Rh 29 (Rh null), anti P1Pk, anti-ENA/WRB and anti P antibodies. Anti H Lectin (Ulexeuropaeus) was used for confirmation of H antigen absence, while rest of antibodies were confirmed by IBGRL Bristol, UK. Conclusion: The sources of antigen negative blood are family members, rare donor registry, autologous donations and frozen blood banks. Finding compatible blood for patients with an antibody to HFA may be a challenge. [ABSTRACT FROM AUTHOR]

CONTEXT: Alloimmunization by foreign red cell antigens is a matter of concern as it may lead to hemolysis in transfused patients as well as fetus of pregnant females. AIMS: This study aimed to perform a comparative analysis of prevalence and type of irregular antibodies in healthy donors, vis-a-vis blood transfusion recipients. SETTINGS AND DESIGN: Blood samples of 4000 individuals comprising healthy donors, exposed patients, and nonexposed patients were collected and were analyzed for irregular antibodies. MATERIALS AND METHODS: Commercially available three-cell antigen panel was used for the antibody screening. The samples positive in antibody screen were further subjected to an extended 11-cell panel for antibody identification in low-ionic strength saline with and without enzyme. STATISTICAL ANALYSIS: Statistical analysis was done using SPSS for Windows 15.0 program. Chi-square test was used for detecting statistical significance of exposure to red blood cell antigens in the formation of alloantibodies. RESULTS: Of the 4000 samples, antibodies were identified in 105 (2.6%) samples. Overall, nonexposed group showed a seropositivity of 0.36%, while the exposed group showed a seropositivity of 9.4%. Anti-D was the most common antibody found in 38 patients (33.3%). Anti-E was the most common antibody in males, while anti-D was the most common antibody in females. CONCLUSIONS: Since the risk of alloimmunization is more common in multitransfused patients, it is advisable to screen at least those cases for irregular antibodies. [ABSTRACT FROM AUTHOR]

Background: Intraoperative blood salvage (IBS) is regarded as an alternative to allogeneic blood transfusion excluding the risks associated with allogeneic blood. Currently, IBS is generally avoided in tumor surgeries due to concern for potential metastasis caused by residual tumor cells in the erythrocyte concentrate. Methods: The feasibility, efficacy and safety aspects of the new developed Catuvab procedure using the bispecific trifunctional antibody Catumaxomab was investigated in an ex-vivo pilot study in order to remove residual EpCAM positive tumor cells from the autologous erythrocyte concentrates (EC) from various cancer patients, generated by a IBS device. Results: Tumor cells in intraoperative blood were detected in 10 of 16 patient samples in the range of 69–2.6 × 105 but no residual malignant cells in the final erythrocyte concentrates after Catuvab procedure. IL-6 and IL-8 as pro-inflammatory cytokines released during surgery, were lowered in mean 28-fold and 52-fold during the Catuvab procedure, respectively, whereas Catumaxomab antibody was detected in 8 of 16 of the final EC products at a considerable decreased and uncritical residual amount (37 ng in mean). Conclusion: The preliminary study results indicate efficacy and feasibility of the new medical device Catuvab allowing potentially the reinfusion of autologous erythrocyte concentrates (EC) produced by IBS device during oncological high blood loss surgery. An open-label, multicenter clinical study on the removal of EpCAM-positive tumor cells from blood collected during tumor surgery using the Catuvab device is initiated to validate these encouraging results. [ABSTRACT FROM AUTHOR]

Background: The pathogenesis of malaria in pregnancy (MiP) involves accumulation of P. falciparum-infected red blood cells (pRBCs) in the placenta, contributing to poor pregnancy outcomes. Parasite accumulation is primarily mediated by P. falciparum erythrocyte membrane protein 1 (PfEMP1). Magnitude of IgG to pRBCs has been associated with reduced risk of MiP in some studies, but associations have been inconsistent. Further, antibody effector mechanisms are poorly understood, and the role of antibody complement interactions is unknown.Methods: Studying a longitudinal cohort of pregnant women (n=302) from a malaria-endemic province in Papua New Guinea (PNG), we measured the ability of antibodies to fix and activate complement using placental binding pRBCs and PfEMP1 recombinant domains. We determined antibody-mediated complement inhibition of pRBC binding to the placental receptor, chondroitin sulfate A (CSA), and associations with protection against placental parasitemia.Results: Some women acquired antibodies that effectively promoted complement fixation on placental-binding pRBCs. Complement fixation correlated with IgG1 and IgG3 antibodies, which dominated the response. There was, however, limited evidence for membrane attack complex activity or pRBC lysis or killing. Importantly, a higher magnitude of complement fixing antibodies was prospectively associated with reduced odds of placental infection at delivery. Using genetically modified P. falciparum and recombinant PfEMP1 domains, we found that complement-fixing antibodies primarily targeted a specific variant of PfEMP1 (known as VAR2CSA). Furthermore, complement enhanced the ability of antibodies to inhibit pRBC binding to CSA, which was primarily mediated by complement C1q protein.Conclusions: These findings provide new insights into mechanisms mediating immunity to MiP and reveal potential new strategies for developing malaria vaccines that harness antibody-complement interactions. [ABSTRACT FROM AUTHOR]

Background: Despite the significant adverse clinical consequences of RBC alloimmunization, our understanding of the signals that induce immune responses to transfused RBCs remains incomplete. Though RBC storage has been shown to enhance alloimmunization in the hen egg lysozyme, ovalbumin, and human Duffy (HOD) RBC alloantigen mouse model, the molecular signals leading to immune activation in this system remain unclear. Given that the nonclassical major histocompatibility complex (MHC) Class I molecule CD1D can bind to multiple different lysophospholipids and direct immune activation, we hypothesized that storage of RBCs increases lysophospholipids known to bind CD1D, and further that recipient CD1D recognition of these altered lipids mediates storage-induced alloimmunization responses.Study Design and Methods: We used a mass spectrometry-based approach to analyze the changes in lysophospholipids that are induced during storage of mouse RBCs. CD1D knockout (CD1D-KO) and wild-type (WT) control mice were transfused with stored HOD RBCs to measure the impact of CD1D deficiency on RBC alloimmunization.Results: RBC storage results in alterations in multiple lysophospholipid species known to bind to CD1D and activate the immune system. Prior to transfusion, CD1D-deficient mice had lower baseline levels of polyclonal immunoglobulin (IgG) relative to WT mice. In response to stored RBC transfusion, CD1D-deficient mice generated similar levels of anti-HOD IgM and anti-HOD IgG.Conclusion: Although storage of RBCs leads to alteration of several lysophospholipids known to be capable of binding CD1D, storage-induced RBC alloimmunization responses are not impacted by recipient CD1D deficiency. [ABSTRACT FROM AUTHOR]

Extracorporeal membrane oxygen (ECMO) is increasingly used as a bridge to lung transplantation. Although other mechanical circulatory support devices have been associated with a transfusion-independent increase in calculated panel reactive antibodies (CPRA), it is unknown whether ECMO is a sensitizing exposure. In this single center retrospective cohort study of lung transplant candidates between 5/1/2015-6/30/2021, antibodies against human leukocyte antigens (HLA-Ab) were evaluated at the time of ECMO initiation and weekly thereafter. Multivariate logistic regression was used to evaluate associations between CPRA increase and ECMO exposure adjusting for a history of any packed red blood cell (PRBC) transfusion and female gender. Sixty-two candidates were placed on ECMO as a bridge to transplant. Of these, 39 (62.9%) either had available HLA-Ab screens from pre- and post-ECMO initiation or multiple HLA-Ab screens post-ECMO. Of the 250 non-ECMO exposed recipients, 224 (89.6%) had multiple pre-transplant screens and served as the comparison cohort. Nine (23.1%) ECMO bridged recipients had an increase in CPRA, compared to 16 (7.1%) of non-ECMO exposed recipients (Fisher's exact p=0.005). Among those with increased CPRA, the median increase was 6% in ECMO bridge patients and 9% in non-ECMO exposed patients. After adjusting for covariates, however, ECMO bridge was not an independent risk factor for increased CPRA (OR=1.85, 95% CI 0.58-5.95, p=0.30). A history of PRBC transfusion trended toward an association with increased CPRA (OR=2.93, 95% CI 0.98-8.78, p=0.06). Pre-lung transplant ECMO was not independently associated with an increase in CPRA when adjusting for PRBC transfusion, although the study was underpowered for small or moderate effect sizes. Where clinically appropriate, PRBC transfusions should be limited in these patients. [ABSTRACT FROM AUTHOR]

Anti-Kg antibodies induced the phagocytosis of RBCs with the Kg antigen in vitro, while the anti-D antibodies did so with the RhD antigen. Anti-Kg antibodies induce monocyte phagocytosis of the red blood cells Additionally, human anti-Kg antibodies (TO) induced phagocytosis at 96%, OSK46 antibodies at 90%, anti-Rh17 (DO) antibodies at 64%, and anti-Kg antibodies at 90%. [Extracted from the article]