Normal Human Serum Contains Natural Antibodies Reactive With Autologous ABO Blood Group Antigens

Blood ◽  
1999 ◽  
Vol 93 (12) ◽  
pp. 4418-4424 ◽  
Author(s):  
Sergio H. Spalter ◽  
Srini V. Kaveri ◽  
Emmanuelle Bonnin ◽  
Jean-Claude Mani ◽  
Jean-Pierre Cartron ◽  
...  

It is widely accepted that the serum of healthy individuals contains natural antibodies only against those blood group A or B antigens that are not expressed on the individual’s red blood cells. The mechanisms involved in tolerance to autologous blood group antigens remain unclear. In the present study, we show that IgM and IgG antibodies reactive with autologous blood group antigens are present in the immunoglobulin fraction of normal human serum. Natural IgG anti-A antibodies purified by affinity chromatography from IgG of individuals of blood group A exhibited an affinity for A trisaccharide antigen in the micromolar range and agglutinated A red cells at sixfold higher concentrations than those required for agglutination with affinity-purified anti-A IgG of individuals of blood group B. Whereas autoantibodies reactive with self A and B antigens are readily detected in purified IgG and IgM fractions, their expression is restricted in whole serum as a result of complementary interactions between variable regions of antibodies. These observations suggest that tolerance to autologous ABO blood group antigens is dependent on peripheral control of antibody autoreactivity.

Blood ◽  
1999 ◽  
Vol 93 (12) ◽  
pp. 4418-4424 ◽  
Author(s):  
Sergio H. Spalter ◽  
Srini V. Kaveri ◽  
Emmanuelle Bonnin ◽  
Jean-Claude Mani ◽  
Jean-Pierre Cartron ◽  
...  

Abstract It is widely accepted that the serum of healthy individuals contains natural antibodies only against those blood group A or B antigens that are not expressed on the individual’s red blood cells. The mechanisms involved in tolerance to autologous blood group antigens remain unclear. In the present study, we show that IgM and IgG antibodies reactive with autologous blood group antigens are present in the immunoglobulin fraction of normal human serum. Natural IgG anti-A antibodies purified by affinity chromatography from IgG of individuals of blood group A exhibited an affinity for A trisaccharide antigen in the micromolar range and agglutinated A red cells at sixfold higher concentrations than those required for agglutination with affinity-purified anti-A IgG of individuals of blood group B. Whereas autoantibodies reactive with self A and B antigens are readily detected in purified IgG and IgM fractions, their expression is restricted in whole serum as a result of complementary interactions between variable regions of antibodies. These observations suggest that tolerance to autologous ABO blood group antigens is dependent on peripheral control of antibody autoreactivity.


Blood ◽  
1948 ◽  
Vol 3 (Special_Issue_Number_2) ◽  
pp. 66-79 ◽  
Author(s):  
ERNEST WITEBSKY ◽  
MRS. LIVIA BLUM ◽  
MISS DORIS HOWLES ◽  
MISS HELEN WARD

Abstract The isoantibodies anti-A and anti-B which are described differ in several respects from those occurring in normal human serum. This type of antibody has first been observed in the serum of an Rh negative woman who exhibited a history of erythroblastosis. Her husband belonged to the subtype Rh1 and to the blood group A. The patient’s serum completely neutralized with A and B substances still agglutinated strongly the husband’s cells provided normal human serum replaced physiological saline solution as a diluent for all dilutions. The impression was thus created that an Rh blocking antibody was responsible for the agglutination observed. It could be shown, however, that the abnormal antibody present in this patient’s serum was not an Rh antibody at all but instead, an antibody directed against the A property. This type of anti-A antibody resembles the Rh blocking antibody in many respects. It becomes manifest only if undiluted human serum is used as a diluent. Surprisingly enough this antibody agglutinated cells of group A, although the amount of AB substances added to the serum was sufficient to neutralize completely the isoagglutinin anti-A under normal conditions in which saline solution is used as a diluent. This anti-A antibody therefore cannot be neutralized as easily as the normal isoagglutinin anti-A. For its neutralization much larger amounts of the blood group specific substances are apparently necessary. The patient’s serum fixed complement when mixed with material containing water soluble A substance, in contrast to the normal isoantibody anti-A which failed to do so. The titer of isoantibodies found in the patient’s serum upon titration in saline solution was not extensively high and, as a matter of fact, was average. It is therefore felt that an extremely high titer is neither a necessary requirement nor proof of isoimmunization toward the A and B factors. Another interesting characteristic of the peculiar anti-A antibody occurring in our patient’s serum was the fact that it was essentially an anti-A1 antibody. The difference in agglutination between A1 and A2 cells respectively becomes manifest if normal serum is used as a diluent instead of saline solution. This difference becomes even more marked after neutralization of the patient’s serum with A and B substances. During the course of Mrs. Bong’s pregnancy the special anti-A antibody described did not increase but rather decreased in strength. However, even after delivery the antibody was demonstrable for at least several weeks although we had no opportunity to examine the patient’s serum further. That one must be very careful in contributing any pathological significance to isoantibodies anti-A or anti-B, even of the type described, is evident from the fact that the patient was delivered of a perfectly normal baby belonging to the blood group O and being Rh negative. Whether the difficulties experienced by the patient in previous pregnancies were due to sensitization toward the Rh factor or to the A factor cannot be decided. Antibodies anti-A and anti-B of the type reported were also found in the sera of patients who had received large amounts of pooled plasma or O blood conditioned with A and B specific substances. Again the anti-A antibody occurring in the serum of these patients was mainly directed against the A1 property. Under the experimental conditions described in this paper, such a serum can be used for the differential diagnosis of the subgroups A1 and A2 and constitutes a sensitive reagent for the recognition of the differences occurring within the A factor. With the aid of such a serum only 10 per cent of A cells were found to belong to subgroup A2, 75 per cent to A1, and 15 per cent were considered to be of the intermediate type. No subgroups were found so far in human cells of group B.


Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 925-925
Author(s):  
Romy Kronstein-Wiedemann ◽  
Laura Schmidt ◽  
Jörn Lausen ◽  
Erhard Seifried ◽  
Torsten Tonn

Abstract Background: The ABO blood group system is unequivocally the most important in clinical transfusion medicine. Furthermore ABO is implicated in the development of a number of human diseases. The ABO antigens are not confined to RBCs but are widely expressed in a variety of human cells and tissues. Thus, ABO matching is critical not only in blood transfusion but also in cell, tissue and organ transplantation. The molecular genetic basis of the ABO system has been known since 1990. However, despite extensive investigations about regulation of ABO blood group receptor expression, the mechanism is not fully resolved. Previously we found that miRNAs plays a critical role in regulation of ABO blood group antigen. Numerous miRNAs which were up- or downregulated in RBCs of blood group O and of heterozygous genotypes as compared to homozygous genotype possess potential binding sites in the 3'UTR of several transcription factors, such as SP1 and RUNX1. Here we show that silencing of the transcription factor RUNX1 leads to downregulation of blood group A antigen. Methods: We performed knockdown experiments for RUNX1 by lentiviral gene transfer of shRNA in primary hematopoietic stem cells (HSCs) and analyzed blood group A-antigen expression using different method, including flow cytometry, western blot and qPCR. Result: Knockdown of RUNX1 in HSCs leads to a 10-20% reduction of blood group A positive erythroid cells and a 30-40% reduction of blood group A antigens per cell in differentiated RBCs. Furthermore, microarray analysis showed a significant increase of miR-215-5p and miR-192-5p in RBCs of blood group O as compared to homozygous genotype. RUNX1 is known to be a target gene for these miRNAs. Conclusion: Glycosyltransferase A and B expression is regulated by different miRNAs, via simultaneously targeting of the transcription factors SP1 and Runx1 and glycosyltransferase A and B mRNA. The knowledge of the role of microRNAs and the transcription factors SP1 and RUNX1 in the expression of blood group antigens may be extended to other blood groups (Rhesus, Kell, Duffy) and may open the door for therapeutic interventions in diseases where blood group receptors promote disease pathology. Disclosures No relevant conflicts of interest to declare.


2021 ◽  
Vol 15 (1) ◽  
Author(s):  
S. Samra ◽  
M. Habeb ◽  
R. Nafae

Abstract Background A few people infected by the coronavirus become seriously ill, while others show little to no signs of the symptoms, or are asymptomatic. Recent researches are pointing to the fact that the ABO blood group might play an important role in a person’s susceptibility and severity of COVID-19 infection. Aim of the study: try to understand the relationship between ABO groups and COVID-19 (susceptibility and severity). Results A total of (507) patients were included in this study. The study population was divided based on the ABO blood group into types A+, A−, B+, AB, O+, and O−. Blood group A was associated with high susceptibility of infection: group A, 381 (75.1%); and less common in group O, 97 (19.2%), group B, 18 (3.5%), and group AB, 11 (2.2%). The severity of COVID-19 infection was common in non-blood group O where (20 (7.1%), 4 (26.7%), 2 (11%), and 1 (9%) in type A+, A−, B+, and AB, respectively), while in type O 3.1%. And mechanically ventilated patients were 22 (5.9%), 2 (13.4%), 2 (11.1%), and 1 (1%). Mortality was high in blood groups A and B, 16 (4.37%) and 1 (5.5%), respectively, while in blood group O, it was 1%. Conclusion The incidence, severity, and mortality of COVID-19 were common in non-blood group O. While blood group O was protected against COVID-19.


1989 ◽  
Vol 37 (7) ◽  
pp. 1153-1155 ◽  
Author(s):  
T F Orntoft ◽  
K Nielsen

Intratumor heterogeneity is a major problem in immunodiagnosis and treatment of carcinomas. To elucidate the well-known heterogeneity in transitional-cell carcinomas of the ability to express blood group ABO isoantigens, a stereological estimate of the mean nuclear volume in areas expressing blood group antigens was compared to the estimate from areas of identical pathological grade at which antigen expression was deleted. Four microscopic fields were examined from antigen-positive and four from antigen-negative areas in sections from 21 blood group O and 20 blood group A individuals. The sections were stained before examination by an indirect peroxidase method using monoclonal anti-H and anti-A antibodies. The mean nuclear volume increased, as expected, with increasing pathological grade. In blood group O individuals the mean nuclear volume was 241.5 microns 3 in antigen-positive areas and 338.2 microns 3 in antigen-negative areas (2p less than 0.0005) of identical pathological grade. In group A individuals the mean nuclear volume was 217.1 microns 3 in positive areas and 351.1 microns 3 in corresponding negative areas (2p less than 0.0025). The variation in volume parameter was essentially caused by a true variation between tumors (greater than 82%). The results indicate a complex biological mechanism associated with the cellular ability to express blood group antigens.


2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Maria Therese Ahlen ◽  
Anne Husebekk ◽  
Mette Kjær Killie ◽  
Jens Kjeldsen-Kragh ◽  
Martin L. Olsson ◽  
...  

Background. Maternal alloantibodies against HPA-1a can cross placenta, opsonize foetal platelets, and induce neonatal alloimmune thrombocytopenia (NAIT). In a study of 100, 448 pregnant women in Norway during 1995–2004, 10.6% of HPA-1a negative women had detectable anti-HPA-1a antibodies.Design and Methods. A possible correlation between the maternal ABO blood group phenotype, or underlying genotype, and severe thrombocytopenia in the newborn was investigated.Results. We observed that immunized women with blood group O had a lower risk of having a child with severe NAIT than women with group A; 20% with blood group O gave birth to children with severe NAIT, compared to 47% among the blood group A mothers (relative risk 0.43; 95% CI 0.25–0.75).Conclusion. The risk of severe neonatal alloimmune thrombocytopenia due to anti-HPA-1a antibodies is correlated to maternalABOtypes, and this study indicates that the observation is due to genetic properties on the maternal side.


2014 ◽  
Vol 96 (6) ◽  
pp. 442-445 ◽  
Author(s):  
CE Uzoigwe ◽  
RP Smith ◽  
A Khan ◽  
D Aghedo ◽  
M Venkatesan

Introduction The mechanism of falling has been proposed as the exclusive explanation for hip fracture pattern. Evidence exists that other genetic factors also influence proximal femoral fracture configuration. The ABO blood group serotype has been associated with other pathologies but any role in hip fracture has yet to be definitively characterised. Methods Our National Hip Fracture Database was interrogated over a four-year period. All patients had their blood group retrieved, and this was compared with hip fracture pattern and mortality rates. Confounding factors were accounted for using logistic regression and the Cox proportional hazards model. Results A total of 2,987 consecutive patients presented to our institution. Those with blood group A were significantly more likely to sustain intracapsular fractures than ‘non-A’ individuals (p=0.009). The blood group distribution of patients with intracapsular fractures was identical to that of the national population of England. However, blood group A was less common in patients with intertrochanteric fractures than in the general population (p=0.0002). Even after correction for age and sex, blood group A was associated with a decrease in the odds of suffering an intertrochanteric fracture to 80% (p=0.002). Blood group A had inferior survivorship correcting for age, sex and hip fracture pattern (hazard ratio: 1.14, p=0.035). This may be due to associated increased prevalence of co-morbid disease in this cohort. Conclusions Blood group is an independent predictor of hip fracture pattern, with group A patients more likely to sustain an intracapsular fracture and non-A individuals more likely to sustain an intertrochanteric fracture. The determinants of fracture pattern are likely to be related to complex interactions at a molecular level based on genetic susceptibility. The mechanism of fall may not be the only aetiological determinant of proximal femoral fracture configuration.


2000 ◽  
Vol 68 (5) ◽  
pp. 2971-2975 ◽  
Author(s):  
Antonio Barragan ◽  
Peter G. Kremsner ◽  
Mats Wahlgren ◽  
Johan Carlson

ABSTRACT The malaria parasite Plasmodium falciparum utilizes molecules present on the surface of uninfected red blood cells (RBC) for rosette formation, and a dependency on ABO antigens has been previously shown. In this study, the antirosetting effect of immune sera was related to the blood group of the infected human host. Sera from malaria-immune blood group A (or B) individuals were less prone to disrupt rosettes from clinical isolates of blood group A (or B) patients than to disrupt rosettes from isolates of blood group O patients. All fresh clinical isolates and laboratory strains exhibited distinct ABO blood group preferences, indicating that utilization of blood group antigens is a general feature of P. falciparumrosetting. Soluble A antigen strongly inhibited rosette formation when the parasite was cultivated in A RBC, while inhibition by glycosaminoglycans decreased. Furthermore, a soluble A antigen conjugate bound to the cell surface of parasitized RBC. Selective enzymatic digestion of blood group A antigen from the uninfected RBC surfaces totally abolished the preference of the parasite to form rosettes with these RBC, but rosettes could still form. Altogether, present data suggest an important role for A and B antigens as coreceptors in P. falciparum rosetting.


Parasitology ◽  
1989 ◽  
Vol 98 (3) ◽  
pp. 401-407 ◽  
Author(s):  
G. Verducci ◽  
S. Perito ◽  
R. Rossi ◽  
E. Mannarino ◽  
F. Bistoni ◽  
...  

SUMMARYNormal human serum (HS) contains trypanolytic activity and agglutinins toTrypanosoma equiperdum, while such activities are not found in sera from a range of animals susceptible to infection. HS given toT. equiperdum-infected mice caused a rapid decrease in the number of circulating trypanosomes and protection from lethal infection. Trypanolytic activity of human serum was found to be associated, after DEAE chromatography and Sephadex G-200 gel filtration, with the fraction containing 19S antibodies. Immunofluorescence assays confirmed a binding of human IgM and C1qcomplement component onto the surface ofT. equiperdum. Anti-T. equiperdumactivity of HS was specifically directed toT. equiperdumsurface components and not to some mouse serum components adsorbed on parasites during the growth in the host, because HS adsorbedin vivoin CD-1 mice retained full protective and agglutinating properties. Trypanocidal activity appears in human serum about the 7th month after birth and persists until late in life. On the contrary, human purified high-density lipoprotein had no significantin vitroorin vivotrypanocidal activity. In conclusion, strong natural anti-T. equiperdumactivity in human serum was mainly mediated by natural antibodies of the IgM class. The presence of natural IgM active againstT. equiperdumin HS could represent one of the natural mechanisms of resistance of refractory hosts against trypanosome infections. This phenomenon provides further evidence that host specificity of trypanosomes may be partly conditioned by the presence of natural antibodies.


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