HLA antigens in syphilis patients in Tuvinian population

have examined 133 healthy donors, 41 syphilis patients with symptoms, and 45 patients with early latent syphilis. All the examined persons were grouped by class I HLA antigens using the standard microlymphocytotoxic test. In syphilis patients, as compared to healthy persons, the frequency of HLA antigens A3, B17, and B40 was increased, while the frequency of B5 was decreased. In syphilis patients with symptoms, HLA antigens A3, B7, B17, B40 and HLA haplotypes A3B17, A3B40, A9B7 were observed with increased frequency. At the same time, in patients with early latent syphilis, HLA antigens A1, Cw3, B8, B17 and HLA haplotypes AB17, A9B8 were observed with increased frequency, while HLA antigen B5 occurred with decreased frequency. The influence of HLA antigens on occurrence of different forms of syphilis is discussed.

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Variation of class I HLA antigen expression among platelet density cohorts: a possible index of platelet age?

Blood ◽

10.1182/blood.v71.2.516.bloodjournal712516 ◽

1988 ◽

Vol 71 (2) ◽

pp. 516-519

Author(s):

J Pereira ◽

C Cretney ◽

RH Aster

Keyword(s):

Hla Antigens ◽

Antigen Expression ◽

High Density ◽

Class I ◽

Surface Markers ◽

Low Density ◽

Hla Antigen ◽

The Difference ◽

Hla Molecules

Platelet alloantigens and other surface markers were studied in platelet cohorts of different mean density, using monoclonal and polyclonal probes. High density (HD) platelets expressed 12% more P1A1 molecules (46,942) than low density (LD) platelets (41,892). However, LD platelets carried 42% more HLA-A2 molecules (6,267 +/- 184) than HD platelets (4,406 +/- 232) (P less than .01) and 55% more class I HLA antigens (17,034 +/- 2,062 v 11,007 +/- 2,190) (P = .05). The platelet subpopulations did not differ in their content of glycoprotein (GP)IIb/IIIa complex or Baka antigen. The difference in expression of class I HLA antigens on HD and LD platelets is consistent with two possibilities: either class I HLA molecules are acquired from plasma or they are released into plasma as platelets age in circulation. Accordingly, class I HLA molecules may provide a useful marker of platelet age.

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Quantitative analysis of platelet surface HLA by W6/32 anti-HLA monoclonal antibody

Blood ◽

10.1182/blood.v68.3.627.627 ◽

1986 ◽

Vol 68 (3) ◽

pp. 627-632 ◽

Cited By ~ 24

Author(s):

KJ Kao ◽

DJ Cook ◽

JC Scornik

Keyword(s):

Monoclonal Antibody ◽

Hla Antigens ◽

Integral Membrane Protein ◽

Class I ◽

Binding Assays ◽

Human Major Histocompatibility Complex ◽

Hla Antigen ◽

Platelet Surface ◽

Chloroquine Treatment ◽

Competitive Protein Binding

Abstract Class I molecules of human major histocompatibility complex (HLA) are the most important antigenic system in determining the survival of transfused platelets in alloimmunized patients. Platelets with reduced expression of a specific type of HLA antigen may escape specific anti- HLA antibody-mediated destruction. By using 125I-labeled Fab fragments of W6/32 anti-HLA monoclonal antibody and competitive protein binding assays, we measured the range of total HLA concentrations on platelets. In 12 individuals examined, the mean number of HLA-A, B, and C molecules per platelet was 81,587 +/- 20,016 (mean +/- SD); its range was between 54,782 to 116,185 molecules per platelet. After treatment with chloroquine, 79.9 +/- 7.0% (mean +/- SD, n = 6) of HLA antigens were removed from platelets as determined by binding of 125I-W6/32 Fab. A similar result was obtained when HLA antigens on chloroquine-treated platelets were evaluated with immunofluorescence flow cytometry. In contrast, chloroquine treatment did not remove integral membrane protein such as P1A1 antigens on platelets. The presence of HLA antigens in the chloroquine eluate of platelets could be demonstrated to contain HLA antigens similar in mol wts to intact class I molecules by an immunoblotting technique. These data suggest that 70% to 80% of platelet HLA antigens are adsorbed and that such HLA antigens are not proteolytic products of integral membrane class I molecules. The origin of the adsorbed platelet HLA-antigens remains to be determined.

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Maternal-Fetal HLA Compatibility in Uncomplicated and Preeclamptic Naturally Conceived Pregnancies

Frontiers in Immunology ◽

10.3389/fimmu.2021.673131 ◽

2021 ◽

Vol 12 ◽

Author(s):

Liseanne J. van ‘t Hof ◽

Naomi Schotvanger ◽

Geert W. Haasnoot ◽

Carin van der Keur ◽

Dave L. Roelen ◽

...

Keyword(s):

Hla Antigens ◽

Hla Class I ◽

Class I ◽

Extravillous Trophoblast ◽

Hla Matching ◽

Placental Development ◽

Hla Antigen ◽

Preferential Selection ◽

Uncomplicated Pregnancy ◽

Hla Compatibility

IntroductionIn pregnancy, the mother and fetus differ in HLA antigens, and yet the maternal immune system generally tolerates the fetus. KIR receptors expressed by maternal uterine NK cells at the maternal-fetal interface directly interact with HLA-C on extravillous trophoblast cells for optimal placental development. In this study, we aimed to determine whether there is a preferential selection for HLA compatibility and specific KIR/HLA-C combinations in uncomplicated and preeclamptic naturally conceived pregnancies compared to what would be expected by chance.MethodsGenotyping for maternal and fetal HLA-A, -B, -C, -DR, and -DQ, and maternal KIR was performed for 451 uncomplicated pregnancies and 77 pregnancies complicated with preeclampsia. The number of HLA antigen (mis)matches between mother and fetus was calculated and compared to expected values obtained by randomization of the HLA haplotype, inherited from the father, over the existing maternal haplotype of the fetuses. A similar methodology was executed for analysis of the KIR/HLA-C data (n=309).ResultsIn uncomplicated pregnancies, the degree of maternal-fetal HLA matching was not different than expected-by-chance values. In preeclamptic pregnancies, the degree of maternal-fetal HLA matching was different in observed compared to expected-by-chance values (p=0.012). More specifically, the degree of maternal-fetal matching of HLA-C was higher in the actual preeclamptic pregnancies than was expected-by-chance (p=0.007). Preeclamptic pregnancies showed an overall tendency towards higher maternal-fetal HLA compatibility, for total HLA matches (p=0.021), HLA class I (p=0.038) and HLA-C (p=0.025) compared to uncomplicated pregnancies.ConclusionThe data suggest that there is no preferential selection of maternal-fetal HLA compatibility in uncomplicated pregnancies. In contrast, increased total HLA, HLA class I and, especially, HLA-C compatibility is associated with preeclampsia, suggestive for a role of HLA mismatches in immune regulation leading to uncomplicated pregnancy.

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Peculiarities of phenotypes of patients with pyelo- and glomerulonephritis by HLA distribution analysis

Ukrainian Journal of Nephrology and Dialysis ◽

10.31450/ukrjnd.4(60).2018.02 ◽

2018 ◽

pp. 11-18

Author(s):

V. Driianska ◽

O. Petrina ◽

M. Velychko ◽

F. Haisenyuk ◽

G. Drannik

Keyword(s):

Kidney Diseases ◽

Hla Antigens ◽

Causal Role ◽

Control Group ◽

Distribution Analysis ◽

Immune Disorder ◽

Hla Antigen ◽

Healthy Donors ◽

Hla Phenotype ◽

High Production

Studies devoted to the role of human leucocyte antigens (HLA) in pathogenesis of chronic kidney disease (CKD) have demonstrated the associative links of the HLA antigens, which stipulate the relative and attributive risks of some autoimmune diseases, with immune disorder and a high production of pro-inflammatory cytokines. The aim of our study was to determine the peculiarities of phenotypes of CKD patients according to the distribution of HLA-A, B and DR antigens and to conduct their comparative analysis in patients with pyelonephritis (PN) and glomerulonephritis (GN). Methods: The distribution of HLA-A, B, DR antigens in 384 CKD patients (120 with PN and 264 with GN) was analyzed. HLA antigens were defined using a standard microlymphocytotoxic test on the Terasakiґs planchette with special panels of anti-HLA serums (20 antigens of locus A, 31 – B and 9 – DR). The control group consisted of 350 healthy donors. The HLA antigen frequencies in normal and diseased subjects were compared taking each antigen separately, using χ2 test. The etiologic fraction (attributive risk s > 0,1) was counted using the formula: s = x - y/I- y, where x is frequency of antigen in patients and y is frequency in healthy. The s reading was considered reliable when it exceeded 0.1. Results. The causal role (σ > 0,1) was determined for А10, А11; В14, В16 for PN; antigens-protectors - А2, В21, В35, В40. For CGN, NS the relative risk is high (RR > 2) at the presence of HLA-A23, А24, А28; B8, В38, В41, В44; DR1, DR4, DRw52 in phenotype, the causal role in etiopathology (σ>0.1) is indicated for A24,А28; B8; DR1, DR4, DRw52; the disease protectors are B12 and B16. Conclusion. Conclusion. The features of the HLA-phenotype of patients with pyelo- and glomerulonephritis were shown. It allowed to establish the interconnectedness of the antigens of the histocompatibility complex with the risk of kidney diseases developing, which could help to personificate of the treatment and predicte of the course of the disease.

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Variation of class I HLA antigen expression among platelet density cohorts: a possible index of platelet age?

Blood ◽

10.1182/blood.v71.2.516.516 ◽

1988 ◽

Vol 71 (2) ◽

pp. 516-519 ◽

Cited By ~ 22

Author(s):

J Pereira ◽

C Cretney ◽

RH Aster

Keyword(s):

Hla Antigens ◽

Antigen Expression ◽

High Density ◽

Class I ◽

Surface Markers ◽

Low Density ◽

Hla Antigen ◽

The Difference ◽

Hla Molecules

Abstract Platelet alloantigens and other surface markers were studied in platelet cohorts of different mean density, using monoclonal and polyclonal probes. High density (HD) platelets expressed 12% more P1A1 molecules (46,942) than low density (LD) platelets (41,892). However, LD platelets carried 42% more HLA-A2 molecules (6,267 +/- 184) than HD platelets (4,406 +/- 232) (P less than .01) and 55% more class I HLA antigens (17,034 +/- 2,062 v 11,007 +/- 2,190) (P = .05). The platelet subpopulations did not differ in their content of glycoprotein (GP)IIb/IIIa complex or Baka antigen. The difference in expression of class I HLA antigens on HD and LD platelets is consistent with two possibilities: either class I HLA molecules are acquired from plasma or they are released into plasma as platelets age in circulation. Accordingly, class I HLA molecules may provide a useful marker of platelet age.

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Quantitative analysis of platelet surface HLA by W6/32 anti-HLA monoclonal antibody

Blood ◽

10.1182/blood.v68.3.627.bloodjournal683627 ◽

1986 ◽

Vol 68 (3) ◽

pp. 627-632 ◽

Cited By ~ 37

Author(s):

KJ Kao ◽

DJ Cook ◽

JC Scornik

Keyword(s):

Monoclonal Antibody ◽

Hla Antigens ◽

Integral Membrane Protein ◽

Class I ◽

Binding Assays ◽

Human Major Histocompatibility Complex ◽

Hla Antigen ◽

Platelet Surface ◽

Chloroquine Treatment ◽

Competitive Protein Binding

Class I molecules of human major histocompatibility complex (HLA) are the most important antigenic system in determining the survival of transfused platelets in alloimmunized patients. Platelets with reduced expression of a specific type of HLA antigen may escape specific anti- HLA antibody-mediated destruction. By using 125I-labeled Fab fragments of W6/32 anti-HLA monoclonal antibody and competitive protein binding assays, we measured the range of total HLA concentrations on platelets. In 12 individuals examined, the mean number of HLA-A, B, and C molecules per platelet was 81,587 +/- 20,016 (mean +/- SD); its range was between 54,782 to 116,185 molecules per platelet. After treatment with chloroquine, 79.9 +/- 7.0% (mean +/- SD, n = 6) of HLA antigens were removed from platelets as determined by binding of 125I-W6/32 Fab. A similar result was obtained when HLA antigens on chloroquine-treated platelets were evaluated with immunofluorescence flow cytometry. In contrast, chloroquine treatment did not remove integral membrane protein such as P1A1 antigens on platelets. The presence of HLA antigens in the chloroquine eluate of platelets could be demonstrated to contain HLA antigens similar in mol wts to intact class I molecules by an immunoblotting technique. These data suggest that 70% to 80% of platelet HLA antigens are adsorbed and that such HLA antigens are not proteolytic products of integral membrane class I molecules. The origin of the adsorbed platelet HLA-antigens remains to be determined.

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HLA AND CANCER

Physical and rehabilitation medicine, medical rehabilitation ◽

10.36425/rehab79387 ◽

2021 ◽

Author(s):

Aleksandr S. Golota

Keyword(s):

Immune System ◽

Tumor Cells ◽

Immune Cells ◽

Hla Antigens ◽

Hla Class I ◽

Tumor Rejection ◽

Class I ◽

Hla Antigen ◽

Tumor Associated Antigens ◽

Metastatic Lesions

This review provides updated information on HLA class I and II antigens in cancer. The expression of HLA antigens in normal and tumor tissues, the physiological organization of the components of HLA antigen-processing machinery, the expression patterns of HLA antigens associated with the molecular and regulatory defects identified to date, as well as their functional and clinical significance, are described. This review summarizes clinical and experimental data on the complexity of immune escape mechanisms used by tumour cells to avoid T and natural killer cell responses. The variety of class I HLA phenotypes that can be produced by tumor cells during this process is presented. We also discuss here the potential capacity of metastatic lesions to recover MHC/HLA class I expression after immunotherapy, which depends on the reversible/ soft or irreversible/hard nature of the molecular mechanism responsible for the altered HLA class I phenotypes, and which determines the progression or regression of metastatic lesions in response to treatment. HLA сlass II genes play key roles in connecting innate and adaptive immunity in tumor rejection and when the escape route via HLA-I is already established. Antigens сlass II HLA expression in tumor cells and gives tumor cells the ability to present antigens, becoming less aggressive, and improves prognosis. Malignant tumors, as a genetic disease, are caused by structural alterations of the genome which can give rise to the expression of tumor-associated antigens in the form of either structurally altered molecules or of overexpressed normal molecules. Tumor associated antigens recognized by the immune system and induce a T-cell-mediated immune response. Outgrowing cancers use different strategies to evade destruction by the immune system. Immune evasion mechanisms affecting the expression and/or function of HLA-antigens are of special interest to tumor immunologists, since these molecules play a crucial role in the interaction of malignant cells with immune cells. This review describes the potential role of immunity control points in immunosuppression and therapeutic strategies for restoring the cytotoxicity of immune cells.

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MEGAKARYOCYTIC ORIGIN OF PLATELET HLA CLASS I ANTIGEN

10.1055/s-0038-1643546 ◽

1987 ◽

Author(s):

N Kieffer ◽

M Titeux ◽

A Henri ◽

J Breton-Gorius ◽

W Vainchenker

Keyword(s):

Hla Antigens ◽

Hla Class I ◽

Human Platelets ◽

Class I ◽

Double Labeling ◽

Hla Antigen ◽

Platelet Surface ◽

Hla Class I Antigens ◽

Hla Class I Antigen

The existence of HLA class I antigens on human platelets is well established. However, several authors have suggested that platelet HLA antigens are not integral membrane components but are acquired from soluble plasma sources and adsorbed to the platelet surface.In the present study, we used the monoclonal antibody W6/32, directed against a monomorphic epitope of the HLA class I antigen for the immunochemical characterization of platelet HLA. Immunoprecipitation experiments, performed after in vitro metabolic radiolabeling of human platelets revealed a band of molecular weight 44,000 identical to that precipitated from metabolic labeled U937 or HEL cells. When the same antibody was tested by indirected immunofluorescence in a double labeling technique on in vitro cultures of human megakaryocytes, performed in the absence of human serum in the culture medium, megakaryocytes identified by an anti-vWF MoAb revealed a membrane staining with W6/32 identical to that observed on other bone marrow cells, e.g. macrophages. Our results provide evidence that platelet HLA has a megaka-ryocytic origin and that residual biosynthesis of HLA antigen does still occur in circulating platelets. However, our results do not exclude the ability of human platelets to adsord circulating HLA class I antigen from plasma.

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Monitoring for HLA Antibodies in Cord Blood Transplantation.

Blood ◽

10.1182/blood.v110.11.2031.2031 ◽

2007 ◽

Vol 110 (11) ◽

pp. 2031-2031

Author(s):

Jonathan A. Gutman ◽

Susan K. McKinney ◽

Sandra L. Warnock ◽

Anajane Smith ◽

Ann E. Woolfrey ◽

...

Keyword(s):

Cord Blood ◽

Graft Rejection ◽

Cord Blood Transplantation ◽

Hla Antigens ◽

Class Ii ◽

Class I ◽

Antibody Specificity ◽

Hla Antigen ◽

Hla Antibodies ◽

Blood Transplantation

Abstract Though graft rejection in hematopoietic cell transplantation (HCT) is presumed to be mediated primarily by host anti-donor T cells and natural killer cells, host antibodies which generate antibody dependent cellular cytotoxic reactions to donor antigens may also contribute. For patients undergoing HCT with a cord blood graft which is usually markedly mismatched to the recipient, alloimmunization is a potential significant issue. Cross-matching is not able to be performed secondary to limited cell numbers available from a cord blood graft. Delayed hematopoietic recovery and graft failure are known complications of cord blood transplantation (CBT), and though likely related primarily to small graft size and presence of primarily naïve immune cells in a cord blood graft, HLA antibodies may also contribute. At our center, we investigate recipient alloimmunity in all patients undergoing CBT to guide donor selection. Patients are first screened for the presence of antibodies against HLA antigens using an ELISA-based assay in which patient serum is tested against pools of purified class I and class II HLA antigens bound in wells of a plastic microtiter plate. Serum from patients noted to have evidence of HLA antibodies prompts further testing to identify the specific HLA antibodies using panels of color coded plastic microspheres each coated with a single purified class I or class II HLA antigen. To date, 4 of 29 patients screened have had evidence of HLA alloimmunization. Further investigation of antibody specificity in one patient undergoing double unit CBT demonstrated antibodies to HLA-Bw6, an epitope known to be present on one of the donor units. Because no other donors were available, the unit was used. Following a reduced intensity preparative regimen (RIT), the patient engrafted neutrophils on day 24 and platelets on day 42. However, the HLA-Bw6 positive unit was absent on all chimerism studies (beginning day 21 post transplantation). Three other patients with HLA alloimmunization did not have identifiable antibody specificity directed against mismatched HLA antigens, and engrafted neutrophils on days 25, 29, 25 and platelets on days 29, 41, and 102 respectively. To our knowledge, we are the first to report monitoring for alloimmunization in CBT and the first to describe the outcome of grafting a cord blood unit known to be HLA antibody incompatible with the patient. When patients undergo double unit CBT, cells from both units can generally be detected in the blood of the recipient during the first month, especially following RIT conditioning, but one unit eventually and consistently prevails (though predictive factors for the winning unit have not yet been satisfactorily described). In this case the compatible unit prevailed and there was no evidence at day 21 of cells from the antibody incompatible unit. Although we cannot attribute cause and effect to the anti-Bw6 alloantibody, it is interesting to note that all seven other patients transplanted on the same RIT protocol have demonstrated at least minimal bone marrow contributions to chimerism from both units at day 28. Hence, alloimmunization may be an important factor influencing graft rejection in CBT. CBT patients should likely be screened for HLA antibodies, and positive screenings warrant further investigation to avoid whenever possible donor/recipient mismatches against which the patient is sensitized. Ongoing monitoring will help clarify the clinical significance of this issue.

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The source of HLA molecules on platelets: Does platelets adsorb soluble HLA molecules from their environment?

Iranian Journal of Pediatric Hematology & Oncology ◽

10.18502/ijpho.v9i4.1572 ◽

2019 ◽

Author(s):

Tahereh Dargahi ◽

Fatemeh Yari ◽

Negar Rezaei

Keyword(s):

Leukemia Cell ◽

Hla Antigens ◽

Hla Class I ◽

Class I ◽

Leukemia Cell Line ◽

Affinity Column ◽

Hla Antigen ◽

Hla Class I Molecules ◽

Soluble Hla ◽

Hla Molecules

Background: The origin and function of human leukocyte antigen (HLA) class I molecules on platelets are still highly arguable. Given the differences in the results of the previous studies in this regard, the lack of research in recent years, and the clinical importance of HLA class I molecules, the absorption capacity of platelets for soluble HLA class I molecules was studied in this investigation. Materials and Methods: In this experimental study, HLA-A2 antigen was purified from a B cell precursor leukemia cell line (Nalm-6) by cell membrane protein solubilization and usage of HLA-A2 affinity column. Platelet concentrates (PCs) were received from Tehran Blood Transfusion Center. Eighteen bags of HLA-A2-negative PCs were prepared randomly and treated with various concentrations of the purified HLA antigen (100, 500, and 1000 ng/ml) for 48 to 72 hours. Subsequently, the HLA-A2 levels were evaluated on platelets by flow cytometery technique. Data were evaluated using repeated measure ANOVA.P-values less than 0.05 were considered significant. Results: The results of this study showed that the purified protein was an HLA molecule (HLA-A2). After the treatment of platelets and HLA molecules, platelets inability was shown for the attracting of HLA molecules. This finding was true in both media of RPMI and plasma. The differences between the case (HLA-treated platelets) and control (untreated platelets) were not significant (p-values> 0.05). Conclusion: Platelets were unable to significantly adsorb exogenous HLA antigens from their environment. Further studies are needed to unravel the nature and origin of HLA molecules on platelets.

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