HLA Class I and Class II Allele and Haplotype Distribution in the Venezuelan Population

Makhatadze, Nina J.; Franco, María Teresa Bejarano; Layrisse, Z.

doi:10.1016/s0198-8859(97)00088-8

Cited by 30 publications

(29 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Immunological studies performed in the Warao population confirmed inheritance and segregation of DW, an antigen of class II Human Leukocyte Antigen (HLA), HLA haplotypes, linkage disequilibrium defined only in homozygous typing cells of Warao origin, and DR/DQ associations not seen previously in other human populations 14,15 . The role of immunogenicity factors in influencing the incidence of pulmonary TB in a population is well known 14,15 . In the present work, we aimed to examine a polymorphism in IFNG, which is the most important cytokine in resistance to mycobacterial diseases, and its association with elevated susceptibility to TB in the Warao indigenous population.…”

Section: Discussionsupporting

confidence: 62%

Concordance between IFNγ gene +874 A/T polymorphism and interferon-γ expression in a TB-endemic indigenous setting

Araujo

Palacios

Biomon

et al. 2017

Rev. Soc. Bras. Med. Trop.

View full text Add to dashboard Cite

Introduction: Interferon-γ (IFN-γ) plays a crucial role in resistance to mycobacterial diseases; accordingly, variants of the gene encoding this cytokine may be associated with elevated risk of contracting pulmonary tuberculosis (TB). Methods: Blood samples were collected from 135 Warao indigenous individuals with newly diagnosed sputum culture-positive TB. Of these, 24 were diagnosed with active tuberculosis (ATB). The study comprised 111 participants, who were grouped as follows: 1) 14 tuberculin skin test (TST)-positive Warao indigenous individuals and 4 that were QuantiFERON-TBGold In-Tube (QFT-IT) test-positive, collectively comprising the latent TB infection group (LTBI), n = 18), and 2) healthy controls who were QFT-ITand TST-negative, comprising the control group (CTRL, n = 93). Detection of the IFN γ gene (IFNG) +874A/T polymorphism was performed via PCR and quantification of IFNG expression via qPCR. Results: Relative to indigenous and white Americans, ATB and CTRL groups had a higher frequency of the IFNG SNP (+874A): 23 (95.8%) and 108 (97.3%), respectively. Indigenous Warao individuals homozygous for the IFNG (+874) A allele exhibited 3.59-fold increased risk of developing TB (95% confidence interval, 2.60-4.96, p =0.0001). A decreased frequency of the AT genotype was observed in individuals with pulmonary TB (4.16%) and controls (0.90%). The frequency of the TT genotype was decreased among controls (1.80%); none of the patients with TB were found to have this genotype. The differences in IFNG expression between the groups, under unstimulated and stimulated conditions, were not statistically significant. Conclusions: Preliminary results demonstrate concordance between IFNG +874 A/A genotype and low expression of IFNG.

show abstract

Section: Discussionsupporting

confidence: 62%

Concordance between IFNγ gene +874 A/T polymorphism and interferon-γ expression in a TB-endemic indigenous setting

Araujo

Palacios

Biomon

et al. 2017

Rev. Soc. Bras. Med. Trop.

View full text Add to dashboard Cite

show abstract

“…For example, work analyzing the distribution of HLA class I and class II allele haplotypes among Venezuelan mestizos showed the genes of Mongoloid, Negroid and Caucasoid origin have created a distinctive HLA genetic profile in this mestizo population that influences HLA frequencies and, consequently, disease susceptibility. 22 Thus, although a clear ethnic specificity was observed when several alleles were compared, the association of HLA-DRB1*04 and DRB1*10 in Brazilian and Vietnamese individuals demonstrated that these alleles are major determinants of protective and susceptible cellular immune responses against M. leprae. It is known that polymorphic residues in the binding cleft of HLA class II molecules control the binding of foreign peptides, and consequently, the immune response.…”

Section: Discussionmentioning

confidence: 96%

HLA-DRB104 and DRB110 are associated with resistance and susceptibility, respectively, in Brazilian and Vietnamese leprosy patients

et al. 2007

View full text Add to dashboard Cite

The host genetic background has been considered one of the factors that influence leprosy outcome, a chronic infectious disease caused by Mycobacterium leprae. Genome scans demonstrated that the 6p21 region is associated with leprosy and a substantial number of population-based studies analyzing human leukocyte antigen (HLA) class II loci suggested association of HLA-DR with leprosy. However, some studies lacked robustness as they had limited power. Indeed, experimental designs require increased sample size to achieve adequate power, as well as replication studies with independent samples for confirmation of previous findings. In this work, we analyzed the influence of the HLA-DRB1 locus on leprosy susceptibility per se and disease type using a case-control design carried out in Brazilians (578 cases and 691 controls) and a replication study based on a family design in a Vietnamese population (n ¼ 194 families). The results showed that HLA-DRB1*10 is associated with susceptibility to leprosy and HLA-DRB1*04 is associated with resistance, both in the Brazilian and Vietnamese populations suggesting that these alleles play an important role in the activation of cellular immune responses against M. leprae.

show abstract

“…This indicates either that other antigens need to be assessed for diagnosis or it reinforces the idea of differential antibody responses due to genetic ethnic variation (Demkow et al 2004, Weldingh et al 2005. In the latter, few studies have addressed the importance of the antibody response due to a different genetic background.Serological response in pulmonary tuberculosis • Zaida Araújo et al 662 Official data on the TB situation in Venezuela showed that between 1997-2001, the TB rate was between 93.2-81.0 per 100,000 inhabitants among the Warao people (MSAS 1999, Fernandez de Larrea et al 2002, MSDS 2002 (Makhatadze et al 1997).In order to study the serological response in two populations with different genetic backgrounds, in the present work saliva IgA (sIgA) and serum IgM, IgE, IgG and IgG1, IgG2 and IgG3 subclass reactivities were measured against M. tuberculosis antigens in the Warao and Creole peoples. …”

mentioning

confidence: 99%

“…Serological response in pulmonary tuberculosis • Zaida Araújo et al 662 Official data on the TB situation in Venezuela showed that between 1997-2001, the TB rate was between 93.2-81.0 per 100,000 inhabitants among the Warao people (MSAS 1999, Fernandez de Larrea et al 2002, MSDS 2002 (Makhatadze et al 1997).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Comparison of serological responses in two different populations with pulmonary tuberculosis

Araujo

Giampietro

Cançado

et al. 2008

Mem. Inst. Oswaldo Cruz

View full text Add to dashboard Cite

Observational studies on the humoural immune responses of the Warao indigenous people from Delta Amacuro, an isolated area, were compared with urban residents of the Venezuelan capital. Mycobacterium tuberculosisspecific reactivities (IgM, IgE, sIgA, IgG and IgG subclasses) Key words: tuberculosis -Warao -Creole -IgG subclasses -purified protein derivative -diagnosis Tuberculosis (TB) diagnosis needs to be improved, as it largely depends upon clinical examination and radiographic findings, mainly confirmed by sputum smear microscopy and bacterial culture (Murray et al. 1980). The latter requires a long cultivation period and diagnostic confirmation still relies on sputum smear examinations. Many alternative methodologies have been applied in TB diagnosis, such as western blot, microscopic observed direct sensitivity culture, PCR and cell-mediated immune response reactions (Moore et al. 2006, Negi et al. 2006. These methods require trained personnel and specific laboratory conditions, which hinder their implementation in many areas of high TB endemicity (mainly low-income countries) and field work application. On the other hand, there are other options that are currently under evaluation, including antibody detection by serology. While specific antibody detection by serology is under evaluation for a definitive demonstration that the humoural response can be used as a tool for the diagnosis of TB, future studies should be carried out in order to combine serological and cellular methods, such as T.SPOT-TB or Quantiferon Gold assay, which are considered to be approved tools. Regarding the immunodiagnosis of TB based on the T cell response to ESAT-6 and purified protein derivative (PPD) antigens, recently it has been reported that the IFN-γ assay using ESAT-6 as an antigenic stimulus has the potential to be used as a tool for the immunodiagnosis of early TB in children ( Van-Lume et al. 2008).The demand for a rapid, reliable, cost-effective and easy TB diagnostic tool focuses on antibody detection by serology (Bothamley 1995). It has been reported that the isotypic restriction of antibodies correlates with the biochemical nature of antigens; most antibodies against proteins are of IgG1 and IgG3 isotypes, while in those against carbohydrates IgG2 is over-represented (Chiang et al. 1997, Gupta et al. 2005. This is reflected in vivo where, for instance, antibody responses to viral proteins are mainly of the IgG1 and IgG3 subclasses. In contrast, bacteria carbohydrates usually induce type 2 T-independent responses, mainly of the IgG1 and IgG2 isotypes. Several ELISA tests have been attempted and results have presented a large variability in their accuracy depending on the antigen employed (one alone or a pool) (Chiang et al. 1997, Gupta et al. 2005, the immunoglobulin (Ig) class, the subclass measured (Radin et al. 1983, Daniel & Debane 1987, Pottumarthy et al. 2000, Conde et al. 2004, Imaz et al. 2004 and Mycobacterium tuberculosis strain variation (Alde et al. 1989, Zheng et al. 1994, Raja et al. 2002. This indicate...

show abstract

HLA Class I and Class II Allele and Haplotype Distribution in the Venezuelan Population

Cited by 30 publications

References 12 publications

Concordance between IFNγ gene +874 A/T polymorphism and interferon-γ expression in a TB-endemic indigenous setting

Concordance between IFNγ gene +874 A/T polymorphism and interferon-γ expression in a TB-endemic indigenous setting

HLA-DRB104 and DRB110 are associated with resistance and susceptibility, respectively, in Brazilian and Vietnamese leprosy patients

Comparison of serological responses in two different populations with pulmonary tuberculosis

Contact Info

Product

Resources

About

HLA Class I and Class II Allele and Haplotype Distribution in the Venezuelan Population

Cited by 30 publications

References 12 publications

Concordance between IFNγ gene +874 A/T polymorphism and interferon-γ expression in a TB-endemic indigenous setting

Concordance between IFNγ gene +874 A/T polymorphism and interferon-γ expression in a TB-endemic indigenous setting

HLA-DRB1*04 and DRB1*10 are associated with resistance and susceptibility, respectively, in Brazilian and Vietnamese leprosy patients

Comparison of serological responses in two different populations with pulmonary tuberculosis

Contact Info

Product

Resources

About

HLA-DRB104 and DRB110 are associated with resistance and susceptibility, respectively, in Brazilian and Vietnamese leprosy patients