Immune regulatory gene polymorphisms as predisposing risk factors for the development of factor VIII inhibitors in Indian severe haemophilia A patients

Immune gene polymorphisms associated with poor response to platelet transfusion and recombinant factor VII administration in Glanzmann thrombasthenia

INTRODUCTION

Poor response to platelet and recombinant factor VII administration is a major problem in patients with Glanzmann Thrombasthenia (GT). The risk factors associated with poor response to treatment in these patients are unknown. Some genetic variations of cytokines may contribute to therapy resistance.

AIMS

We evaluated, for the first time, whether genetic polymorphisms on cytokine genes are related to poor treatment response in GT patients.

METHODS

We enrolled 30 patients with GT (15 resistant and 15 non-resistant) and 100 healthy controls. Gene polymorphisms of IL-10 and TNF-α were analysed using TaqMan Realtime PCR, and IL-1, IL-1R1 and IL-1RN were investigated with the RFLP method. In-silico analyses were performed to predict the potential impact of these polymorphisms.

RESULTS

In the resistant group, all patients had a variant of the IL-10 gene at the -1082 position (rs1800896), with a GG genotype that was significantly more frequent than the non-resistant group. Analysis between healthy controls and GT patients revealed a probable correlation between rs3783550, rs3783553, rs3917356 and rs2234463 and GT. The In-silico study indicated that TNF-α rs1800629 and IL-10 rs1800896 polymorphisms result in different allelic expressions which may contribute to poor response to therapy.

CONCLUSIONS

These findings suggest that polymorphisms in the IL-10 and IL-1 receptor antagonist genes may play a role in poor therapy response in GT patients. In addition, some polymorphisms in IL-1α, IL1-β, IL-1R1 and IL-R antagonists might be involved in the GT progression.

Immunogenicity of Therapeutic Biological Modalities - Lessons from Hemophilia A Therapies

The introduction and development of biologics such as therapeutic proteins, gene-, and cell-based therapy have revolutionized the scope of treatment for many diseases. However, a significant portion of the patients develop unwanted immune reactions against these novel biological modalities, referred to as immunogenicity, and no longer benefit from the treatments. In the current review, using Hemophilia A (HA) therapy as an example, we will discuss the immunogenicity issue of multiple biological modalities. Currently, the number of therapeutic modalities that are approved or recently explored to treat HA, a hereditary bleeding disorder, is increasing rapidly. These include, but are not limited to, recombinant factor VIII proteins, PEGylated FVIII, FVIII Fc fusion protein, bispecific monoclonal antibodies, gene replacement therapy, gene editing therapy, and cell-based therapy. They offer the patients a broader range of more advanced and effective treatment options, yet immunogenicity remains the most critical complication in the management of this disorder. Recent advances in strategies to manage and mitigate immunogenicity will also be reviewed.

Genome-Wide Association Study and Gene-Based Analysis of Participants With Hemophilia A and Inhibitors in the My Life, Our Future Research Repository

Introduction

Up to 30% of individuals with hemophilia A develop inhibitors to replacement factor VIII (FVIII), rendering the treatment ineffective. The underlying mechanism of inhibitor development remains poorly understood. The My Life, Our Future Research Repository (MLOF RR) has gathered F8 and F9 mutational information, phenotypic data, and biological material from over 11,000 participants with hemophilia A (HA) and B as well as carriers enrolled across US hemophilia treatment centers, including over 5,000 whole-genome sequences. Identifying genes associated with inhibitors may contribute to our understanding of why certain patients develop those neutralizing antibodies.

Aim and Methods

Here, we performed a genome-wide association study and gene-based analyses to identify genes associated with inhibitors in participants with HA from the MLOF RR.

Results

We identify a genome-wide significant association within the human leukocyte antigen (HLA) locus in participants with HA with F8 intronic inversions. HLA typing revealed independent associations with the HLA alleles major histocompatibility complex, class II, DR beta 1 (HLA DRB1*15:01) and major histocompatibility complex, class II, DQ beta 1 (DQB1*03:03). Variant aggregation tests further identified low-frequency variants within GRID2IP (glutamate receptor, ionotropic, delta 2 [GRID2] interacting protein 1) significantly associated with inhibitors.

Conclusion

Overall, our study confirms the association of DRB1*15:01 with FVIII inhibitors and identifies a novel association of DQB1*03:03 in individuals with HA carrying intronic inversions of F8. In addition, our results implicate GRID2IP, encoding GRID2-interacting protein, with the development of inhibitors, and suggest an unrecognized role of this gene in autoimmunity.

Polymorphisms in the cytotoxic T lymphocyte-associated protein-4 immune regulatory gene and their impact on inhibitor development in patients with hemophilia A

Objective

The development of inhibitors against infused factor VIII represents the most severe complication of substitution therapy in hemophilia A (HA) patients. Data on risk factors for inhibitor formation in Iraqi Kurdish patients with HA are unavailable. This study aimed to evaluate the impact of two single nucleotide polymorphisms (SNPs) in an immune regulatory gene in the emergence of inhibitors.

Methods

We focused on 126 patients with either severe or mild/moderate HA presenting with and without inhibitors. We analyzed the frequency of two polymorphisms in the cytotoxic T lymphocyte-associated protein-4 gene (CTLA-4; CTLA-4-318C > T and CTLA-4 + 49A > G). Genotyping was performed using restriction fragment length polymorphism–PCR and direct sequencing.

Results

We found no significant correlation between the CTLA-4-318 C > T T allele and inhibitor development among patients with severe or mild/moderate HA. However, a significantly high inhibitor risk was detected for the CTLA-4 + 49 A > G G allele (odds ratio [OR] = 3.1, 95% confidence interval [CI] = 1.383–7.024) and (OR = 4, 95% CI = 1.719–9.437) among patients with severe and mild/moderate HA, respectively.

Conclusion

We conclude that the CTLA-4 +49 A > G SNP plays a substantial role as a potential risk determinant for inhibitor formation in Iraqi Kurdish patients with HA.

Risk stratification integrating genetic data for factor VIII inhibitor development in patients with severe hemophilia A

Replacement therapy in severe hemophilia A leads to factor VIII (FVIII) inhibitors in 30% of patients. Factor VIII gene (F8) mutation type, a family history of inhibitors, ethnicity and intensity of treatment are established risk factors, and were included in two published prediction tools based on regression models. Recently investigated immune regulatory genes could also play a part in immunogenicity. Our objective is to identify bio-clinical and genetic markers for FVIII inhibitor development, taking into account potential genetic high order interactions. The study population consisted of 593 and 79 patients with hemophilia A from centers in Bonn and Frankfurt respectively. Data was collected in the European ABIRISK tranSMART database. A subset of 125 severely affected patients from Bonn with reliable information on first treatment was selected as eligible for risk stratification using a hybrid tree-based regression model (GPLTR). In the eligible subset, 58 (46%) patients developed FVIII inhibitors. Among them, 49 (84%) were “high risk” F8 mutation type. 19 (33%) had a family history of inhibitors. The GPLTR model, taking into account F8 mutation risk, family history of inhibitors and product type, distinguishes two groups of patients: a high-risk group for immunogenicity, including patients with positive HLA-DRB1*15 and genotype G/A and A/A for IL-10 rs1800896, and a low-risk group of patients with negative HLA-DRB1*15 / HLA-DQB1*02 and T/T or G/T for CD86 rs2681401. We show associations between genetic factors and the occurrence of FVIII inhibitor development in severe hemophilia A patients taking into account for high-order interactions using a generalized partially linear tree-based approach.

Inflammatory and immune response genes: A genetic analysis of inhibitor development in Iranian hemophilia A patients

A major problem of hemophilia A (HA) treatment is the development of factor VIII (FVIII) inhibitor, which usually occurs shortly after initiating replacement therapy. Several studies showed the correlation between inhibitor development and polymorphisms in inflammatory and immune response genes of HA patients; however, literature data are not available to prove this association in Iranian population. The aim of this study was to investigate a possible association between FVIII inhibitor formation and the polymorphisms of 16 inflammatory and immune response genes in Iranian severe HA patients (FVIII activity < 1%). This case-control study was performed on 55 patients with severe HA inhibitors and 45 samples without inhibitors from Iranian Comprehensive Hemophilia Care center. After extraction of whole genomic DNA from blood samples and design of primers for 16 genes, the genotyping was performed by Tetra primer ARMS PCR, and the validation of single nucleotide polymorphisms was determined by DNA sequencing. The data indicated that there was a significant association between inhibitor development, and F13A1 (TT), DOCK2 (CC& CT), and MAPK9 (TT) genotypes. Moreover, a considerably increased inhibitor risk carrying T, C, and T allele for F13A1, DOCK2, and MAPK9 genes was observed in patients with inhibitors, respectively. In contrast, there was no statistically significant difference between the genotypic and allelic frequencies for other genes in patients with inhibitors compared to patients without inhibitors. These results demonstrate that only polymorphisms in F13A1, DOCK2, and MAPK9 genes are associated with the risk of developing FVIII inhibitors in Iranian HA patients.

Prevalence of FVIII inhibitors in severe haemophilia A patients: Effect of treatment and genetic factors in an Indian population

INTRODUCTION

Factor replacement therapy in treatment of haemophilia A is complicated by the production of neutralising antibodies known as inhibitors. The formation of inhibitors is multifactorial being associated with both genetic and environmental factors.

AIM

To document the prevalence of inhibitors in severe haemophilia in the community where most patients receive only infrequent episodic replacement therapy and evaluate the factors which could be contributing to it.

METHODS

Community based camps were conducted in different parts of the country. Patients were assessed through a structured questionnaire and blood samples were obtained for laboratory evaluation of inhibitors and defined immunological parameters.

RESULTS

Inhibitors were present in 87/447 (19.5%) of the evaluated patients. High-titre inhibitor (>5 Bethesda Units [BU]) was identified in 31 (35.6%) patients. HLA DRB1-13-positive cases (RR = 2.04; 95% CI 1.06-3.911; P = 0.033) had an increased risk of inhibitor formation which was retained in the high-titre subset. A decreased risk of inhibitor formation was noted with heterozygous IL4-590 C/T allele (RR = 0.22; 95% CI 0.108-0.442: P = 0.000). There were no significant correlations between any of the evaluated environmental factors and the development of inhibitors in this study.

CONCLUSION

The overall prevalence of inhibitors in patients with severe haemophilia A is similar to that reported among patients receiving regular replacement therapy. The data from this study, limited by its retrospective and cross-sectional study design, would suggest that genetic rather than environmental are more likely to impact the development of inhibitors.

The Development of FVIII Inhibitors in Relation to IL10 Gene Polymorphism in Hemophilia A Egyptian Pediatric Patients

BACKGROUND

Development of inhibitors against Factor VIII (FVIII) in hemophilia A patients is a serious complication of therapy. Many cytokines, including interleukin-10 (IL10), may affect inhibitor development; however, literature data are not sufficient to prove this association. The aim of this study was to investigate the relation between FVIII inhibitor formation and IL10-1082A/G polymorphism among Egyptian hemophiliacs.

METHODS

Patients were screened for FVIII inhibitors using the Bethesda method. IL10-1082A/G polymorphism was detected by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

Six patients (12%) developed inhibitors. No statistically significant difference was found between inhibitor positive and negative patients regarding IL10-1082A/G genotypes, disease severity, or treatment-related variables (type of FVIII received, treatment regimen, age at first exposure to FVIII, and frequency of replacement therapy).

CONCLUSIONS

FVIII inhibitor formation in this group of Egyptian hemophiliacs was not correlated to IL10-1082A/G polymorphism, disease severity, or any of the treatment variables.

F8 gene mutation profile in Indian hemophilia A patients: Identification of 23 novel mutations and factor VIII inhibitor risk association

'FVIII inhibitors', especially in severe hemophilia A (HA) patients, is a serious adverse effect that complicates their clinical management. Many genetic and non-genetic risk factors have been proposed for FVIII inhibitor development, diverse in different population groups. This is the first study in Indian hemophiliacs that analyzes inhibitor risk in relation to the complete F8 mutation profile, in a case-control study that included 145 Indian severe HA patients, i.e. 69 inhibitor positive (with 18 inhibitor concordant/discordant family members), and 58 inhibitor negative patients, after informed consent. While 53.54% (68/127) index cases were positive for intron 22 or intron 1 inversions, 55 causative F8 mutations were detected in the 59 inversion negative patients, of which 23 were novel mutations (in 24 patients) and 32 were reported earlier (in 35 patients). A higher incidence of mutations, in the C1 and C2 domains in inhibitor positive patients, and in the A1 domain in inhibitor negative patients was observed, though not significantly different. The study suggests that large F8 rearrangements (significantly higher in the inhibitor positive patients) pose the highest risk, while missense mutations (significantly higher in the inhibitor negative patients) pose the lowest risk of inhibitor development in Indian hemophilia A patients.

Antibody profile in Indian severe haemophilia A patients with and without FVIII inhibitors

Diagnosis and management of haemophilia patients with inhibitors is often tricky due to the heterogeneous nature of the antibodies with regard to their kinetics, as well as the co-existence of other interfering antibodies. Plasma samples from severe haemophilia A patients from India with and without FVIII inhibitors were analysed for the presence of possible co-existing antibodies such as lupus anticoagulants (LA), anti-cardiolipin antibodies (ACLA), anti-β2-glycoprotein-I (anti-β2-GP-I) antibodies, viral transfusion transmitted disease (HIV, HBsAg, HCV) related antibodies, anti-cyclic citrullinated peptides (anti-CCP), and anti-nuclear antibodies. A high incidence of LA and anti-HCV antibodies was detected in Indian haemophilia A patients similar to earlier reports. More importantly, a relatively high incidence of autoantibodies to nuclear antigens (18.62%) and anti-CCP antibodies (1.38%) associated with autoimmune disorders was also seen in these congenital haemophilia A patients with and without inhibitors. Knowledge on the antibody profile in these haemophilia patients especially in those with FVIII inhibitors along with correlation with the clinical manifestations and other risk factors for inhibitor development could possibly shed more light on the complex immune response in these patients.

FVIII inhibitors: pathogenesis and avoidance

The pathogenesis of inhibitory antibodies has been the focus of major scientific interest over the last decades, and several studies on underlying immune mechanisms and risk factors for formation of these antibodies have been performed with the aim of improving the ability to both predict and prevent their appearance. It seems clear that the decisive factors for the immune response to the deficient factor are multiple and involve components of both a constitutional and therapy-related nature. A scientific concern and obstacle for research in the area of hemophilia is the relatively small cohorts available for studies and the resulting risk of confounded and biased results. Careful interpretation of data is recommended to avoid treatment decisions based on a weak scientific platform. This review will summarize current concepts of the underlying immunological mechanisms and risk factors for development of inhibitory antibodies in patients with hemophilia A and discuss how these findings may be interpreted and influence our clinical management of patients.

The IL-10 polarized cytokine pattern in innate and adaptive immunity cells contribute to the development of FVIII inhibitors

BACKGROUND

Hemophilia A (HA) is an X-linked inherited bleeding disorder, resulting from a qualitative or quantitative deficiency of clotting factor VIII (FVIII). Antibodies against FVIII, also called inhibitors, block the procoagulant activity of FVIII; thus, impairing hemostatic activity in patients with HA. The exact mechanism underlying the immunological events behind the development of inhibitors remains unknown. This study aimed to understand immune response to FVIII in patients with HA who were either positive [HAα-FVIII(+)] or negative [HAα-FVIII(-)] for inhibitors.

METHODS

Cytokine profiles [interferon-γ (IFN - γ), tumor necrosis factor-α (TNF-α), interleukin-4 (IL-4), IL-5, and IL-10] of innate and adaptive immune cells present in the peripheral blood of participants were characterized.

RESULTS

Presence of inhibitors was significantly associated with decreased frequencies of TNF-α-positive monocytes and neutrophils, IL-5-positive monocytes, IL-4-positive neutrophils, and increased frequencies of IL-10-positive neutrophils and T cells. T cells from HAα-FVIII(-) patients expressed increased levels of almost all cytokines. In contrast, HAα-FVIII(+) patients showed lower levels of all cytokines in CD4(+) and CD8(+) T cells, except IL-10. B cells from HAα-FVIII(-) patients expressed increased levels of IL-4 while those from HAα-FVIII(+) patients expressed increased levels of IL-10.

CONCLUSIONS

The global cytokine profiles of innate and adaptive immune cells showed an anti-inflammatory/regulatory pattern in HAα-FVIII(+) patients and a mixed pattern, with a bias toward inflammatory cytokine profile, in HAα-FVIII(-) patients. The occurrence of these profiles seems to be associated with presence FVIII inhibitors.

Analysis of F8 inversions as risk factors for FVIII inhibitor development in Indian severe haemophilia A patients

FVIII inhibitor development in haemophilia A (HA) patients, especially those with severe manifestations is a serious adverse effect in patients with haemophilia A, and the clinical management of these patients is very difficult as most don't respond to conventional treatment. Many genetic and non-genetic risk factors have been proposed however, these are diverse in different population groups, highlighting the importance of determining specific risk factors for each population. F8 mutations and especially inversions, which are the most common causative mutation in severe HA, have been significantly associated with inhibitor development earlier, however there is no conclusive data so far with regard to Indian haemophiliacs. This study provides novel evidence that intron 22 inversions in the F8 gene are indeed significantly associated with FVIII inhibitor development in Indian haemophiliacs. Further studies with other risk factors would enable better insights into the immune response towards FVIII in these patients, and possibly help to characterize patients at a higher risk for inhibitor development.

The Epidemiology of FVIII Inhibitors in Indian Haemophilia A Patients

A serious complication of replacement therapy in patients with bleeding disorders is the development of 'inhibitors', particularly FVIII inhibitors in haemophilia A patients. This leads to an increase in the management cost, morbidity and mortality, especially post-operatively. The mechanism of FVIII inhibitor development is quite complex and it is difficult to predict inhibitor development, but a prompt and accurate diagnosis is critical as early therapy can save lives. The aim of this study was to screen patients with bleeding disorders in India for inhibitors, and to analyse and compare the prevalence of inhibitors in different regions in India. Patient details were recorded and blood samples were collected in sodium citrate vacutainers from 1,505 patients with bleeding disorders, in different cities in India. Coagulation and inhibitor screening assays were performed, followed by the Bethesda assay in inhibitor positive samples to quantify the FVIII inhibitor titre. Out of the 1,505 samples analysed, 1,285 were Haemophilia A patients, out of which 78 (6.07 %) were positive for 'FVIII Inhibitors'. The highest incidence of FVIII Inhibitors was seen in South India (13.04 %). The highest incidence of 20.99 % was observed in Chennai, followed by Hyderabad (13.33 %), Jammu (9.90 %) and Guwahati (8.51 %), respectively, with respect to the samples analysed. The other regions showed an inhibitor incidence <8 %. The incidence of inhibitors in haemophilia A patients is different in different regions of India; this may be due to the intensity of treatment, type of product or the genetic characteristics of these patients.

Impact of HLA alleles and cytokine polymorphisms on inhibitors development in children with severe haemophilia A

Human Leucocyte Antigen (HLA) alleles, cytokine polymorphisms and the type of factor VIII (FVIII) gene mutation are among predisposing factors for inhibitors (inh) development in children with severe haemophilia A (HA). The aim was to investigate the correlations among (i) FVIII gene intron-22 inversion, (ii) HLA alleles and haplotypes and (iii) certain cytokine polymorphisms, with the risk for FVIII inhibitors development in 52 Greek severe HA children, exclusively treated with recombinant concentrates. We performed Long-Range PCR for detection of intron-22 inversion and PCR-SSP, PCR-SSO for genotyping of HLA-A, B, C, DRB1, DQB1 alleles and also for cytokine polymorphisms of TNF-α, TGF-β1, IL-10, IL-6 and IFN-γ. Chi-squared test and Fischer's exact test were used for statistical analysis. A total of 28 children had developed inhibitors (Group I), 71.4% high responding, while 24 had not (Group II). No statistically increased intron-22 inversion prevalence was found in Group I compared with Group II (P = 0.5). Comparison of HLA allele frequencies between the two groups showed statistically significant differences in the following genotypes (i) promoting inhibitors development: DRB1*01(P = 0.014), DRB1*01:01(P = 0.011) and DQB1*05:01 (P = 0.005) and (ii) possibly protecting from inhibitors development: DRB1*11 (P = 0.011), DRB1*11:01 (P = 0.031), DQB1*03 (P = 0.004) and DQB1*03:01 (P = 0.014). Analysis of cytokines revealed a higher incidence of inhibitor detection only in homozygotes of the haplotypes ACC and ATA for IL-10 polymorphisms (P = 0.05). There is evidence that HLA alleles and cytokine polymorphisms play an important role in FVIII inh development. On the contrary, no statistically significant results were obtained for intron-22 inversion and its impact on FVIII inhibitors formation.