Protective Effect of HLA-B*5701 and HLA-C -35 Genetic Variants in HIV-Positive Caucasians from Northern Poland

Immune restoration affects 10-year survival in people living with HIV/AIDS

INTRODUCTION

In recent years, a reduction in the life expectancy gap between people living with HIV (PLWH) and the general population has been observed, irrespective of CD4 lymphocyte count, due to widespread access to antiretroviral treatment. The increase in the life expectancy of PLWH has increased awareness of both the ageing process and gender discrepancies in immune restoration and survival.

MATERIALS AND METHODS

Longitudinal data were collected for 2240 patients followed up at the Hospital for Infectious Diseases in Warsaw, Poland (n = 1482), and the Department of Acquired Immunodeficiency, Pomeranian Medical University, Szczecin, Poland (n = 758). Immune restoration was measured from the time of starting combination antiretroviral therapy until achieving 500 CD4 lymphocytes/μL, 800 CD4 lymphocytes/μL, and CD4/CD8 lymphocyte ratios of > 0.8 and > 1.0. Full recovery was achieved when the patient was restored to both 800 CD4 lymphocytes/μL and a CD4/CD8 lymphocyte ratio > 1.0.

RESULTS

For all endpoints, immune restoration had a protective effect by reducing mortality. Patients who achieved immune restoration had a greater chance of reduced mortality than those who did not achieve immune restoration: for CD4 count > 500 cells/μL, HR = 5.4 (interquartile range: 3.09-9.41), p < 0.001; for CD4 > 800 cells/μL, HR = 5.37 (2.52-11.43), p < 0.001; for CD4/CD8 ratio > 0.8, HR = 3.16 (1.81-5.51), p < 0.001; for CD4/CD8 ratio > 1.0, HR = 2.67 (1.49-5.24), p = 0.001, and for full immune recovery, HR = 3.62 (1.63-8.04), p = 0.002.

CONCLUSIONS

Immune restoration remains a powerful factor in improving the survival of PLWH, regardless of the speed of recovery.

Factors Influencing Immune Restoration in People Living with HIV/AIDS

Introduction: Immune restoration is a key clinical aspect that is pursued in the care of human immunodeficiency virus (HIV)-infected patients. Despite effective antiretroviral treatment and undetectable viremia, immune recovery is often incomplete. Materials and methods: Data from 311 Caucasian patients were collected. SNP in CCR2(rs1799864), CX3CR1(rs3732378), HLAC-35(rs9264942), and CCR5(promoter, rs1799988); a 32bp deletion(Δ32) in CCR5; and HLA-B*5701 genotypes were correlated with clinical data and selected endpoints. Kaplan−Meier and Cox proportional hazards models were used to analyze the effects of genetic factors over time. Results: For HLA-B*5701, the effect on the CD4+/CD8+ >0.8 cell ratio was lost within 48 months (HR = 2.04, 95% CI: 1.04−4.03), and the effect on the CD4+ cell count >500 cells/µL was lost within 12 months (HR = 2.12, CI: 1.11−4.04). The effect of CCR2 GG on the CD4+/CD8+ >0.8 cell ratio was lost within 36 months (HR = 1.7, CI: 1.05−2.75). For CCR5 wt/Δ32, the effect on the CD4+/CD8+ >1.0 cell ratio was lost within 24 months (HR = 2.0, CI: 1.08−3.69), and the effect on the CD4+ >800 cells/µL cell count was lost within 18 months (HR = 1.98, CI: 1.14−4.73). Conclusions: Selected genetic polymorphisms, namely CCR2 GG and CCR5 Δ32, and the presence of the HLA-B*5701 allele positively influenced immune restoration in cART-treated patients with HIV/AIDS.

Clinical parameters, selected HLA and chemokine gene variants associated with late presentation into care of people living with HIV/AIDS

INTRODUCTION

Late presentation into care remains a significant problem in the diagnosis of HIV infection, and may negatively impact the Joint United Nations Program HIV/AIDS elimination targets. Host genetics affects the tempo of HIV disease progression and therefore may influence clinical status at care entry.

MATERIALS AND METHODS

Longitudinal data were collected for 863 Caucasian patients followed up at Pomeranian Medical University, Szczecin, Poland. Single nucleotide polymorphisms in CCR2 (rs1799864), CX3CR1 (rs3732378), HLAC-35 (rs9264942), CCR5 promoter (rs1799988) as well as 32 base pair CCR5 mutation and HLA-B*5701 genotypes were correlated with the clinical and immunologic patient status at care entry. Late presentation was defined as baseline CD4 lymphocyte count <350 cells/μL or history of AIDS-defining illness, while advanced HIV disease as baseline CD4 lymphocyte count <200 cells/μL or AIDS.

RESULTS

Of the analyzed gene variants, the CCR2 (rs1799864) GG genotype was more frequent among patients presenting for care with a CD4 lymphocyte count <200/μL (82.6% for GG homozygotes vs. 74.5% for allele A carriers, p = 0.01). The presence of the heterozygous wt/Δ32 genotype at the CCR5 gene was associated with a higher frequency of asymptomatic infection (18.9% for wt/Δ32 heterozygotes vs. 12% for wt/wt homozygotes, p = 0.03). As expected, this association was also observed among late presenters compared to patients presenting for care earlier (13.7% vs. 19,7%, respectively, p = 0.04). Finally, HLA-B*5701 was less common among late presenters (5%) compared to patients who entered care early (9.6%, p = 0.01) or patients with advanced HIV disease (8.9% vs. 5.2%, p = 0.02).

CONCLUSIONS

Late presentation was associated with the GG homozygous genotype at the CCR2 rs1799864 SNP, while both the HLA-B*5701 variant and the CCR5 wt/Δ32 were associated with more favorable clinical profile at care entry.

Influence of HLA-B*5701 on 20 year survival rate among patients living with HIV

BACKGROUND

The life expectancy of people living with HIV (PLWH) remains shorter than that of the general population, despite significant improvement in the recent years. Mortality in HIV-infected individuals may be associated with a higher viral load at of diagnosis, a lower CD4 count, or clinical variables such as sex or route of transmission. This article investigated the role of the HLA-B*5701 varian on mortality among PLWH.

METHODS

Material for the analysis consist of the data of 2,393 patients for whom the HLA-B*57 variant was known. Those patients were followed under the care of the Infectious Diseases Hospital in Warsaw (n = 1555) and the Clinic of Acquired Immunodeficiency of the Pomeranian Medical University in Szczecin (n = 838). Factors such as age, gender, date of HIV diagnosis, route of transmission, date of death, baseline HIV viral load and baseline CD4 counts, were collected, and end-point cross-sectional analyses were marked at 60, 120, 180 and 240 month of observation.

RESULTS

HLA-B*5701 allele was found in 133 (5.5%) analyzed cases. Median age was notably higher for HLA-B*5701 positive patients [32.7 (28.3-41.3) vs. 31.6 (26.8-38.3)years p = 0.02]. HLA-B*5701 was associated with lower baseline viral load [4.21 (3.5-4.8) vs. 4.79 (4.2-5.3)log copies/ml p<0.001] and higher CD4count [448 (294.5-662) vs. 352 (176-514) cells/μl p<0.001]. There were no association between HLA-B*5701 and survival for any given end-point. Higher mortality was associated to male gender, intravenous drug users, lower CD4 count at baseline and higher baseline viral load.

CONCLUSIONS

In our study, the presence of HLA-B*5701 allel was not associated with mortality rate of HIV infected patients, irrespective of being associated with both higher baseline CD4 + cell count and lower baseline HIV viral load.

Interaction of the Host and Viral Genome and Their Influence on HIV Disease

The course of Human Immunodeficiency Virus type 1 (HIV) infection is a dynamic interplay in which both host and viral genetic variation, among other factors, influence disease susceptibility and rate of progression. HIV set-point viral load (spVL), a key indicator of HIV disease progression, has an estimated 30% of variance attributable to common heritable effects and roughly 70% attributable to environmental factors and/or additional non-genetic factors. Genome-wide genotyping and sequencing studies have allowed for large-scale association testing studying host and viral genetic variants associated with infection and disease progression. Host genomics of HIV infection has been studied predominantly in Caucasian populations consistently identifying human leukocyte antigen (HLA) genes and C-C motif chemokine receptor 5 as key factors of HIV susceptibility and progression. However, these studies don’t fully assess all classes of genetic variation (e.g., very rare polymorphisms, copy number variants etc.) and do not inform on non-European ancestry groups. Additionally, viral sequence variability has been demonstrated to influence disease progression independently of host genetic variation. Viral sequence variation can be attributed to the rapid evolution of the virus within the host due to the selective pressure of the host immune response. As the host immune system responds to the virus, e.g., through recognition of HIV antigens, the virus is able to mitigate this response by evolving HLA-specific escape mutations. Diversity of viral genotypes has also been correlated with moderate to strong effects on CD4+ T cell decline and some studies showing weak to no correlation with spVL. There is evidence to support these viral genetic factors being heritable between individuals and the evolution of these factors having important consequences in the genetic epidemiology of HIV infection on a population level. This review will discuss the host-pathogen interaction of HIV infection, explore the importance of host and viral genetics for a better understanding of pathogenesis and identify opportunities for additional genetic studies.

Association of Diverse Genotypes and Phenotypes of Immune Cells and Immunoglobulins With the Course of HIV-1 Infection

Disease progression among HIV-1-infected individuals varies widely, but the mechanisms underlying this variability remains unknown. Distinct disease outcomes are the consequences of many factors working in concert, including innate and adaptive immune responses, cell-mediated and humoral immunity, and both genetic and phenotypic factors. Current data suggest that these multifaceted aspects in infected individuals should be considered as a whole, rather than as separate unique elements, and that analyses must be performed in greater detail in order to meet the requirements of personalized medicine and guide optimal vaccine design. However, the wide adoption of antiretroviral therapy (ART) influences the implementation of systematic analyses of the HIV-1-infected population. Consequently, fewer data will be available for acquisition in the future, preventing the comprehensive investigations required to elucidate the underpinnings of variability in disease outcome. This review seeks to recapitulate the distinct genotypic and phenotypic features of the immune system, focusing in particular on comparing the surface proteins of immune cells among individuals with different HIV infection outcomes.

HLA based selection of epitopes offers a potential window of opportunity for vaccine design against HIV

The pace of progression to AIDS after HIV infection varies from individual to individual. While some individuals develop AIDS quickly, others are protected from the onset of disease for more than a decade (elite controllers and long term non-progressors). The mechanisms of protection are not yet clearly understood, though various factors including host genetics, immune components and virus attenuation have been elucidated partly. The influence of HLA alleles on HIV-1 infection and disease outcome has been studied extensively. Several HLA alleles are known to be associated with resistance to infection or delayed progression to AIDS after infection. Similarly, certain HLA alleles are reported to be associated with rapid progression to disease. Since HLA alleles influence the outcome of HIV infection differentially, selection of epitopes specifically recognized by protective alleles could serve asa rational means for HIV vaccine design. In this review article, we discuss existing knowledge on HLA alleles and their association with resistance/susceptibility to HIV and its relevance to vaccine design.

HIV and host immunogenetics: unraveling the role of HLA-C

Host genetic factors play a major role in determining the outcome of many infections including human immunodeficiency virus (HIV). Multiple host factors have been studied till date showing their varied role in susceptibility or resistance to HIV infection. HLA-C, however, has been recently started gaining interest in researchers mind revealing its polymorphisms to have an important effect on viral load set-points, disease progression as well as transmission. In this review report, we have compiled these significant findings of HLA-C in HIV infection, in an attempt to highlight the need for further research in the area in different ethnic population to establish its role in the infection.