Hyperfunction variant rs708035 of interleukin 1 receptor-associated kinases 2 gene involved in the predisposition of leprosy infection.

BACKGROUND: Mycobacterium leprae (slow-growing bacteria) is the etiological agent for leprosy infection, which is a chronic granulomatous disease. Symptoms initiate with the loss of sensation in the affected areas, which can lead to severe injuries, cuts and burns. IRAK2 (interleukin-1 receptor-associated kinases 2) is reported to function in the regulation of the NFκB pathway. The frequency of the IRAK2 polymorphism (rs708035) was unknown in the Pakistani population. Therefore, the study was designed to identify the role of the rs708035 SNP (single nucleotide polymorphism) in susceptibility to leprosy. METHODOLOGY: The case-control study was designed, and participants were selected by Ridley-Jopling Classification. Blood samples from healthy individuals and patients were collected after ethical approval. Genomic DNA was extracted for the amplification of selected polymorphisms by tetra-primer amplification refractory mutation system polymerase chain reaction. The desired products were observed via agarose gel (2.5%) electrophoresis followed by data analysis using bioinformatics tools (SNP Stats and SHEsis) and statistical tests (odds ratio, OR, and chi square). RESULTS: The study revealed that the mutant genotype (TT) was found to be frequent among cases (22.80%) in comparison with the controls (1.66%). The SNP rs708035 was significantly associated with the progression of leprosy (χ2  = 17.62, p < 0.0001). The targeted SNP significantly increases the risk of leprosy 2.3 times (OR = 2.3119, 95% CI 1.2729-4.1989, p < 0.01). The genetic model also confirms the significant association of the A/T genotype with leprosy in the over-dominant model (OR = 2.83, 95% CI 1.16-6.89, p < 0.001). CONCLUSIONS: The study revealed a significant association of the targeted SNP with leprosy and provided baseline data regarding the association of rs708035. The current research could be utilized for the preparation of biomarkers by considering a larger sample size. HIGHLIGHTS: The patients suffering from leprosy faced various comorbidities, including hypertension and diabetes. The study reports for the first time a significant association of interleukin 1 receptor associated kinases 2 (IRAK2) single nucleotide polymorphism (SNP) rs708035 among the Pakistani population (Karachi). The current study provides baseline data to develop diagnostic biomarkers for early detection of leprosy.

Human leukocyte antigens class I and class II alleles associated with vertical human immunodeficiency virus transmission - an exploratory study from Mumbai, India.

Background Human leukocyte antigens (HLA) an important host genetic factor is responsible for influencing human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) transmission and disease progression. Contributions of HLA I and II alleles have not been reported in the Indian population with respect to vertical HIV transmission. Aim In the current study we determined the frequencies of HLA class I and class II alleles in a cohort of children exposed to HIV through their mothers. Method In this exploratory study children perinatally exposed to HIV-1 who fit the study criteria and had completed 18 month follow-up were typed for HLA class I and class II alleles using polymerase chain reaction combined with sequence-specific oligonucleotides probes (PCR-SSOP) and sequence-specific primer (SSP) method. HLA typing was done in 30 positive and 60 HIV negative children along with confounding factors such as treatment regimens, viral load and CD4 count of the mother, feeding option, etc. SPSS software was used for statistical analysis and online docking tools for in-silico analysis. Results HLA-B*40 (p = 0.018) was significantly higher in negative children and was associated with protection, whereas HLA-A*01 (p = 0.05), HLA-B*37 (p = 0.032) and HLA-DRB1*09 (p = 0.017) were associated with transmission. Known protective allele HLA-B*27 was only present in negative children. Many specific haplotypes were exclusively present in the negative children or the positive ones. In-silico analysis was performed to predict the ability of HLA-B*40 to bind to antigenic peptides obtained from HIV-1 sequences in our study group. Limitations Small sample size is a concerning limitation of the study. Nonetheless this is a comprehensive study on HLA alleles in HIV exposed Indian children Conclusion Our study highlights the contribution of HLA class I and II alleles in the Indian children and further adds to understanding the immunogenetic mechanisms. These can be developed as markers for prediction of infection transmission. The observations also contribute to the database of genetic makeup of our population and can help in designing vaccine strategies.

Association between exonic polymorphisms of human leukocyte antigen-G gene and non-segmental vitiligo in the Korean population.

Background Vitiligo is a pigmentary skin disorder characterised by a chronic and progressive loss of melanocytes. Although several theories have been suggested to the pathogenesis of vitiligo, an autoimmune process leading to melanocyte destruction appears most likely. Human leukocyte antigen-G is a non-classic, major histocompatibility complex Class I molecule that plays an important role in the suppression of the immune response. Several recent studies have provided evidences that polymorphisms in the human leukocyte antigen-G gene might be related with autoimmune diseases. Objectives The aim of this study was to decide whether exonic single nucleotide polymorphisms in human leukocyte antigen-G contribute to the risk of developing non-segmental vitiligo in the Korean population. Methods To evaluate the associations between exonic single nucleotide polymorphisms (rs1630223 [Ala5Ala] and rs12722477 [Leu134Ile]) of human leukocyte antigen-G and vitiligo, 244 patients with vitiligo and 398 healthy controls were recruited. Genotyping was performed using Fluidigm 192.24 Dynamic Array with EP1 (Fluidigm Corp., CA). The SNP type assay (Fluidigm Corp., CA), which employs allele-specifically designed fluorescences (FAM or VIC) primers and a common reverse primer was applied and the data were analysed using the EP1 single nucleotide polymorphisms genotyping analysis software to obtain genotype calls. Results Two exonic single nucleotide polymorphisms (rs1630223 and rs12722477) exhibited significant associations with susceptibility and remained a statistically significant association following Bonferroni correction. These two single nucleotide polymorphisms were located within a block of linkage disequilibrium. Haplotypes G-C and A-A comprising rs1630223 and rs12722477 demonstrated a significant association with non-segmental vitiligo. Limitations The protein expression level of patients with vitiligo and controls was not studied and a replication study of the genetic association in an independent group was not managed. Conclusion Our results suggest that exonic human leukocyte antigen-G polymorphisms (rs1630223 and rs12722477) are associated with the development of non-segmental vitiligo.

Putative pathogen-selected polymorphisms in the PKLR gene are associated with mycobacterial susceptibility in Brazilian and African populations.

Pyruvate kinase (PK), encoded by the PKLR gene, is a key player in glycolysis controlling the integrity of erythrocytes. Due to Plasmodium selection, mutations for PK deficiency, which leads to hemolytic anemia, are associated with resistance to malaria in sub-Saharan Africa and with susceptibility to intracellular pathogens in experimental models. In this case-control study, we enrolled 4,555 individuals and investigated whether PKLR single nucleotide polymorphisms (SNPs) putatively selected for malaria resistance are associated with susceptibility to leprosy across Brazil (Manaus-North; Salvador-Northeast; Rondonópolis-Midwest and Rio de Janeiro-Southeast) and with tuberculosis in Mozambique. Haplotype T/G/G (rs1052176/rs4971072/rs11264359) was associated with leprosy susceptibility in Rio de Janeiro (OR = 2.46, p = 0.00001) and Salvador (OR = 1.57, p = 0.04), and with tuberculosis in Mozambique (OR = 1.52, p = 0.07). This haplotype downregulates PKLR expression in nerve and skin, accordingly to GTEx, and might subtly modulate ferritin and haptoglobin levels in serum. Furthermore, we observed genetic signatures of positive selection in the HCN3 gene (xpEHH>2 -recent selection) in Europe but not in Africa, involving 6 SNPs which are PKLR/HCN3 eQTLs. However, this evidence was not corroborated by the other tests (FST, Tajima's D and iHS). Altogether, we provide evidence that a common PKLR locus in Africans contribute to mycobacterial susceptibility in African descent populations and also highlight, for first, PKLR as a susceptibility gene for leprosy and TB.

Association of the polymorphism of the vitamin D receptor gene (VDR) with the risk of leprosy in the Brazilian Amazon.

The transmission and evolution of leprosy depends on several aspects, including immunological and genetic factors of the host, as well as genetic factors of Mycobacterium leprae. The present study evaluated the association of single nucleotide polymorphisms (SNPs) on the FokI (rs2228570), TaqI (rs731236), ApaI (rs7975232) regions of the vitamin D receptor (VDR) gene with leprosy. A total of 405 individuals were evaluated, composed by groups of 100 multibacillary (MB) and 57 paucibacillary (PB) patients, and 248 healthy contacts. Blood samples were collected from patients and contacts. The genotyping was performed by sequencing of the interest regions. The alleles of the studied SNPs, and SNP FokI genotypes, were not associated with leprosy. For the SNP on TaqI region, the relationship between the tt genotype, and for the SNP ApaI, the AA genotype, revealed an association with susceptibility to MB form, while Aa genotype with protection. The extended genotypes AaTT and AaTt of ApaI and TaqI were associated with protection against MB form. Further studies analyzing the expression of the VDR gene and the correlation with its SNPs might help to clarify the role of polymorphisms on the immune response in leprosy.

Association of PTPN22-C1858T Polymorphism With Susceptibility to Mycobacterium tuberculosis and Mycobacterium leprae Infection: A Meta-Analysis.

It was previously published that single-nucleotide polymorphism rs2476601 (PTPN22 [protein tyrosine phosphatase non-receptor type 22]-C1858T) might be related to increased sensibility to Mycobacterium tuberculosis and M. leprae infection. However, the results were inconclusive despite a high degree of similarity between both parameters. Herein, we carried out this meta-analysis to systematically summarize and articulate the correlation between PTPN22-C1858T polymorphism and mycobacterial infection. The susceptibility of PTPN22-C1858T carriers with autoimmune conditions receiving immunosuppressive therapy to M. tuberculosis and M. leprae infection was determined. A systematic retrieval of studies on relevance of PTPN22-C1858T polymorphism to susceptibility of M. tuberculosis or M. leprae infection was performed in Chinese National Knowledge Infrastructure, PubMed and Embase databases. We regarded Odds ratios (ORs) and 95% confidence intervals (CIs) as the determined effect size. Finally, four and two case-control studies on tuberculosis and leprosy, respectively, were included. In all genetic models, without indicated association between PTPN22-C1858T polymorphism and tuberculosis's susceptibility. [C versus T: OR = 0.22 (95% CI: 0.09-0.50, PH = 0.887); CT versus CC: OR = 0.21 (95% CI: 0.09-0.49, PH = 0.889); TT+CT versus CC: OR = 0.21 (95% CI: 0.09-0.49, PH = 0.889)]. A significantly increased risk of leprosy was perceived in patients with the PTPN22-C1858T polymorphism [C versus T: OR = 2.82 (95% CI: 1.02-7.81, PH = 0.108)]. While the PTPN22-C1858T polymorphism is irrelevant to higher susceptibility to the infection of M. tuberculosis in Caucasians and Asians, it is relevant to increased susceptibility to the infection of M. leprae. However, the results of M. leprae are supposed to interpreted with prudence owing to the limited quantity of studies and heterogeneity. Further well-designed studies with sufficient populations are required to verify our conclusions.

Study of TNF-α, IFN-γ, TGF-ß, IL-6, and IL-10 Gene Polymorphism in Individuals from the Leprosy-Endemic Area in the Brazilian Amazon.

This study aimed at verifying the relationship between the polymorphisms of the cytokines tumor necrosis factor-alpha (TNF-α) -308 G → A (rs1800629); interferon gamma (IFN-γ) +874 T → A (rs2430561); transforming growth factor-beta (TGF-ß) códon 10 (rs1982073) and códon 25 (rs1800471); interleukin (IL)-6 - 174 G → C (rs180079) and IL-10 - 1082 A→T (rs1800896); -819 C → T (rs1800871); -592 A→C (rs1800872); and leprosy. Blood samples were analyzed from 106 individuals, of whom 24 were paucibacillary (PB), 28 were multibacillary (MB), and 54 were patient contacts. Analysis of cytokine polymorphisms was typified by the polymerase chain reaction technique. For TGF-ß +869 T → C and +915 G→C, a tendency to associate the presence of the C allele at codon 10 with leprosy was demonstrated, with the T allele being most frequently found in the CCOSI (P = 0.056). For the polymorphisms IL-10 - 1082 A→T, -819 C→T, and -592 A→C, we found an association of the GCC/GCC genotype with the susceptibility to the disease and the A allele at position 1082 with the leprosy protection. Greater predominance was found of ACC/ATA (31.3%) and GCC/ATA (37.5%) (P = 0.03) and the A allele at position -1082 (76.85%) (P = 0.043) in the CCOSI groups, whereas the GCC/GCC was found in the MB group (22.2%) (P = 0.05). For the other cytokines's single-nucleotide polymorphisms, there were no associations with susceptibility to leprosy. These results are limited by sample size, may not be conclusive, and will need further confirmation in a larger cohort.

Association of MICA and HLA-B alleles with leprosy in two endemic populations in Brazil.

Leprosy is a prevalent disease in Brazil, which ranks as the country with the second highest number of cases in the world. The disease manifests in a spectrum of forms, and genetic differences in the host can help to elucidate the immunopathogenesis. For a better understanding of MICA association with leprosy, we performed a case-control and a family-based study in two endemic populations in Brazil. MICA and HLA-B alleles were evaluated in 409 leprosy patients and in 419 healthy contacts by PCR-SSOP-Luminex-based technology. In the familial study, analysis of 46 families was completed by direct sequencing of all exons and 3'/5'untranslated regions, using the Ilumina MiSeq platform. All data were collected between 2006 and 2009. Statistical analysis was performed using the Chi-square or Fisher's exact test together with a multivariate analysis. Family-based association was assessed by transmission disequilibrium test (TDT) software FBAT 2.0.4. We found associations between the haplotype MICA*002-HLA-B*35 with leprosy in both the per se and the multibacillary (MB) forms when compared to healthy contacts. The MICA allele *008 was associated with the clinical forms of paucibacillary (PB). Additionally, MICA*029 was associated with the clinical forms of MB. The association of MICA*029 allele (MICA-A4 variant) with the susceptibility to the MB form suggests this variant for the transmembrane domain of the MICA molecule may be a risk factor for leprosy. Two MICA and nine HLA-B variants were found associated with leprosy per se in the Colônia do Prata population. Linkage disequilibrium analysis revealed perfect linkage disequilibrium (LD) between HLA-B markers rs2596498 and rs2507992, and high LD (R2  = .92) between these and the marker rs2442718. This familial study demonstrates that MICA association signals are not independent from those observed for HLA-B. Our findings contribute the knowledge pool of the immunogenetics of Hansen's disease and reveals a new association of the MICA*029 allele.

Association between NDO-LID and PGL-1 for leprosy and class I and II human leukocyte antigen alleles in an indigenous community in Southwest Amazon

The frequencies of the Human leukocyte antigen (HLA) alleles in the Puyanawa indigenous reserve population and their association with the NDO-LID and ELISA PGL-1 rapid serological test was assessed. This was a cross-sectional study with an epidemiological clinical design conducted in two indigenous communities in the state of Acre, Brazil. Blood was collected in a tube with EDTA to identify HLA alleles and perform serological tests. DNA was obtained using the salting out procedure. The LabType™ technique (One-Lambda-USA) was used for HLA class I (loci A*, B* and C*) and II (loci DRB1*, DQA1* and DQB1*) typing. Allele frequency was obtained by direct count, and the chi-square test was used to assess the association with the NDO-LID and PGL-1 tests. The most frequent alleles in the two communities were: HLA-A*02:01, HLA-B*40:02, HLA-DRB1*16:02, HLA-DQA1*05:05 and HLA-DQB1*03:01. The allele HLA-C*04:01 was the most common in the Barão community, and the allele HLA-C*07:01 in Ipiranga. Among individuals who presented seropositivity to the NDO-LID test, the association with alleles HLA-A*02 (43.18% vs 24.8%, p = 0.03, OR = 2.35) and HLA-B*53 (6.83% vs 0.0%, p = 0.03, OR = 8.95) was observed in the Barão community. HLA-B*15 was associated with non-seroconversion to the NDO-LID test in Ipiranga. In both communities, HLA-B*40 and HLA-C*03 were associated with positive serological response to ELISA PGL-1. The HLA class I and II alleles most frequently found in this study have already been described among Terena indigenous groups, and HLA class I contributes to seroconversion to NDO-LID and PGL-1 tests in inhabitants of the Barão and Ipiranga communities(AU).

Association between NDO-LID and PGL-1 for leprosy and class I and II human leukocyte antigen alleles in an indigenous community in Southwest Amazon.

The frequencies of the Human leukocyte antigen (HLA) alleles in the Puyanawa indigenous reserve population and their association with the NDO-LID and ELISA PGL-1 rapid serological test was assessed. This was a cross-sectional study with an epidemiological clinical design conducted in two indigenous communities in the state of Acre, Brazil. Blood was collected in a tube with EDTA to identify HLA alleles and perform serological tests. DNA was obtained using the salting out procedure. The LabType™ technique (One-Lambda-USA) was used for HLA class I (loci A*, B* and C*) and II (loci DRB1*, DQA1* and DQB1*) typing. Allele frequency was obtained by direct count, and the chi-square test was used to assess the association with the NDO-LID and PGL-1 tests. The most frequent alleles in the two communities were: HLA-A*02:01, HLA-B*40:02, HLA-DRB1*16:02, HLA-DQA1*05:05 and HLA-DQB1*03:01. The allele HLA-C*04:01 was the most common in the Barão community, and the allele HLA-C*07:01 in Ipiranga. Among individuals who presented seropositivity to the NDO-LID test, the association with alleles HLA-A*02 (43.18% vs 24.8%, p=0.03, OR=2.35) and HLA-B*53 (6.83% vs 0.0%, p=0.03, OR=8.95) was observed in the Barão community. HLA-B*15 was associated with non-seroconversion to the NDO-LID test in Ipiranga. In both communities, HLA-B*40 and HLA-C*03 were associated with positive serological response to ELISA PGL-1. The HLA class I and II alleles most frequently found in this study have already been described among Terena indigenous groups, and HLA class I contributes to seroconversion to NDO-LID and PGL-1 tests in inhabitants of the Barão and Ipiranga communities.

Indonesians Human Leukocyte Antigen (HLA) Distributions and Correlations with Global Diseases.

In Human, Major Histocompatibility Complex known as Human Leukocyte Antigen (HLA). The HLA grouped into three subclasses regions: the class I region, the class II region, and the class III region. There are thousands of polymorphic HLAs, many of them are proven to have correlations with diseases. Indonesia consists of diverse ethnicity people and populations. It carries a unique genetic diversity between one and another geographical positions. This paper aims to extract Indonesians HLA allele data, mapping the data, and correlating them with global diseases. From the study, it is found that global diseases, like Crohn's disease, rheumatoid arthritis, Graves' disease, gelatin allergy, T1D, HIV, systemic lupus erythematosus, juvenile chronic arthritis, and Mycobacterial disease (tuberculosis and leprosy) suspected associated with the Indonesian HLA profiles.

Vitamin D Receptor Gene Polymorphisms Are Associated With Leprosy in Southern Brazil.

Vitamin D, together with its nuclear receptor (VDR), plays an important role in modulating the immune response, decreasing the inflammatory process. Some polymorphisms of the VDR gene, such as BsmI (G>A rs1544410), ApaI (G>T rs7975232), and TaqI (T>C rs731236) could affect its stability and mRNA transcription activity, while FokI T>C (rs2228570) gives a truncated protein with three fewer amino acids and more efficiency in binding vitamin D. This study evaluated these four polymorphisms in the immunopathogenesis of leprosy in 404 patients and 432 control individuals without chronic or infectious disease in southern Brazil. When analyzing differences in the allele and genotype frequency of polymorphisms between patients (leprosy per se, multibacillary, and paucibacillary clinical forms) and controls, we found no statistically significant association. Regarding haplotype analysis, the bAt haplotype was associated with protection from leprosy per se (P = 0.004, OR = 0.34, CI = 0.16-0.71) and from the multibacillary clinical form (P = 0.005, OR = 0.30, CI = 0.13-0.70). In individuals aged 40 or more years, this haplotype has also showed protection against leprosy per se and multibacillary (OR = 0.26, CI = 0.09-0.76; OR = 0.26, CI = 0.07-0.78, respectively), while the BAt haplotype was a risk factor for leprosy per se in the same age group (OR = 1.34, CI = 1.04-1.73). In conclusion, despite having found no associations between the VDR gene polymorphisms with the development of leprosy, the haplotypes formed by the BsmI, ApaI, and TaqI polymorphisms were associated with leprosy per se and the multibacillary clinical form.

The role of ESCO2, SALL4 and TBX5 genes in the susceptibility to thalidomide teratogenesis.

Thalidomide is widely used for several diseases; however, it causes malformations in embryos exposed during pregnancy. The complete understanding of the mechanisms by which thalidomide affects the embryo development has not yet been obtained. The phenotypic similarity makes TE a phenocopy of syndromes caused by mutations in ESCO2, SALL4 and TBX5 genes. Recently, SALL4 and TBX5 were demonstrated to be thalidomide targets. To understand if these genes act in the TE development, we sequenced them in 27 individuals with TE; we verified how thalidomide affect them in human pluripotent stem cells (hPSCs) through a differential gene expression (DGE) analysis from GSE63935; and we evaluated how these genes are functionally related through an interaction network analysis. We identified 8 variants in ESCO2, 15 in SALL4 and 15 in TBX5. We compared allelic frequencies with data from ExAC, 1000 Genomes and ABraOM databases; eight variants were significantly different (p < 0.05). Eleven variants in SALL4 and TBX5 were previously associated with cardiac diseases or malformations; however, in TE sample there was no association. Variant effect prediction tools showed 97% of the variants with potential to influence in these genes regulation. DGE analysis showed a significant reduction of ESCO2 in hPSCs after thalidomide exposure.

IL8 and IL17A polymorphisms associated with multibacillary leprosy and reaction type 1 in a mixed population from southern Brazil.

We evaluated the influence of the IL8 T-738A (nonidentified rs), IL8 T-353A (rs4073), IL17A G197A (rs2275913), and IL17F T7488C (rs763780) single-nucleotide polymorphisms on leprosy. The AA genotype of IL8 T-353A was observed as a risk factor for multibacillary leprosy, regardless of gender and age-of-onset of disease, considering the recessive model (OR, 3.8; 95% CI, 1.1-13.5; P, 0.023). Furthermore, the AA genotype of IL17A G197A was associated with leprosy type 1 reaction (OR, 2.4; 95% CI, 1.1-5.1; P, 0.026) when compared to the group without reaction, which was adjusted for gender and age-of-onset of disease by the model log additive. These results indicate association of IL8 and IL17A polymorphisms with the progression to multibacillary leprosy and with the type 1 reaction, respectively.

VDR polymorphism, gene expression and vitamin D levels in leprosy patients from North Indian population.

BACKGROUND: Leprosy is a chronic infectious disease caused by Mycobacterium leprae and mainly affects skin, peripheral nerves. Vitamin D receptor (VDR) gene polymorphism has been found to be associated with leprosy. Vitamin D has been shown to control several host immunomodulating properties through VDR gene. Vitamin D deficiency was also found to be linked to an increased risk for several infections and metabolic diseases. OBJECTIVE: In the present study, we investigated the association of VDR gene polymorphism, mRNA gene expression of VDR and the vitamin D levels with leprosy and its reactional states. METHODOLOGY: A total of 305 leprosy patients consisting of tuberculoid (TT), borderline tuberculoid (BT), borderline lepromatous (BL), lepromatous leprosy (LL), as well as 200 healthy controls were enrolled in the study. We identified single nucleotide polymorphisms (SNPs) of VDR Taq1, Fok1 and Apa1, as well as the expression of VDR mRNA gene using PCR-based restriction fragment length polymorphism (RFLP) analysis and real-time PCR respectively. We also performed ELISA to measure vitamin D levels. RESULT: We observed that SNP of VDR gene (Fok1 and Taq1) are associated with the leprosy disease. The allelic frequency distribution of T and t allele (p = 0.0037), F and f allele (p = 0.0024) was significantly higher in leprosy patients and healthy controls. ff genotype of Fok1 was found to be associated with leprosy patients [p = 0.0004; OR (95% CI) 3.148 (1.662-5.965)]. The recessive model of Fok1 genotype was also found to be significantly associated in leprosy patients in comparison to healthy controls [p = 0.00004; OR (95% CI) 2.85 (1.56-5.22)]. Leprosy patients are significantly associated with t-F-a haplotype. Further, VDR gene expression was found to be lower in non-reaction group compared to that of reaction group of leprosy and healthy controls. Paradoxically, we noted no difference in the levels of vitamin D between leprosy patients and healthy controls. CONCLUSION: Blood levels of vitamin D do not play any role in clinical manifestations of any forms of leprosy. ff genotype of Fok1 and tt genotype of Taq1 was found to be associated with leprosy per se. Association of t-F-a haplotype with leprosy was found to be significant and could be used as a genetic marker to identify individuals at high risk for developing leprosy. VDR gene expression was lower in TT/BT and BL/LL groups of leprosy in comparison to that of healthy controls.

Analysis of CTLA-4+49A/G gene polymorphism in cases with leprosy of Azerbaijan, Northwest Iran.

Leprosy, which is developed by the obligate intracellular Mycobacterium leprae (ML); has different manifestations, associated with the host immune responses. The protective immune response against ML includes T-cell-mediated immunity. The CTLA-4 has a great impact as a negative regulator of the immune response and maintenance of peripheral tolerance. This study analyzed the relationship between CTLA-4+49A/G gene polymorphism and clinical manifestation of leprosy disease and susceptibility among the Azeri population living Northwest Iran. One hundred and ninety-two leprosy patients and 185 healthy controls participated in the study. CTLA-4+49A/G genotyping was conducted via tetra-primer amplification refractory mutation system-polymerase chain reaction (T-ARMS-PCR) analysis. The allelic and genotypic frequencies of +49A/G gene polymorphism were similar in controls and patients. However, older ages, older age of onset and over-representation in male were observed in lepromatous leprosy patient carriers of GG genotype. The current study demonstrates that although CTLA-4+49A/G polymorphism was not correlated with a higher genetic risk for leprosy, the presence of a GG genotype was associated with older ages, older age of onset and over-representation in male in Iranian Azeri population.

Genome-Wide Analysis of Protein-Coding Variants in Leprosy.

Although genome-wide association studies have greatly advanced our understanding of the contribution of common noncoding variants to leprosy susceptibility, protein-coding variants have not been systematically investigated. We carried out a three-stage genome-wide association study of protein-coding variants in Han Chinese, of whom were 7,048 leprosy patients and 14,398 were healthy control subjects. Seven coding variants of exome-wide significance were discovered, including two rare variants: rs145562243 in NCKIPSD (P = 1.71 × 10-9, odds ratio [OR] = 4.35) and rs149308743 in CARD9 (P = 2.09 × 10-8, OR = 4.75); three low-frequency variants: rs76418789 in IL23R (P = 1.03 × 10-10, OR = 1.36), rs146466242 in FLG (P = 3.39 × 10-12, OR = 1.45), and rs55882956 in TYK2 (P = 1.04 × 10-6, OR = 1.30); and two common variants: rs780668 in SLC29A3 (P = 2.17 × 10-9, OR = 1.14) and rs181206 in IL27 (P = 1.08 × 10-7, OR = 0.83). Discovered protein-coding variants, particularly low-frequency and rare ones, showed involvement of skin barrier and endocytosis/phagocytosis/autophagy, in addition to known innate and adaptive immunity, in the pathogenesis of leprosy, highlighting the merits of protein-coding variant studies for complex diseases.

Association of Nitric Oxide Synthase2 gene polymorphisms with leprosy reactions in northern Indian population.

The pathogen Mycobacterium leprae causes leprosy that affects mainly skin and nerves. Polymorphisms of certain genes are substantiated to be associated with the susceptibility/resistance to leprosy. The present investigation addressed the association of Nitric Oxide Synthase2 gene polymorphisms and leprosy in a population from northern part of India. A total of 323 leprosy cases and 288 healthy controls were genotyped for four NOS2 promoter variants (rs1800482, rs2779249, rs8078340 and rs2301369) using FRET technology in Real Time PCR. None of these SNPs in promoter sites was associated with susceptibility/resistance to leprosy. NOS2 rs1800482 was found to be monomorphic with GG genotype. However, NOS2-1026T allele was observed to be in higher frequency with leprosy cases (BL and LL) who were not suffering from any reactional episodes compared to cases with ENL reaction {OR=0.30, 95% CI (0.10-0.86), p=0.024}. NOS2-1026GT genotype was more prevalent in cases without reaction (BT, BB and BL) compared to RR reactional patients {OR=0.38, 95% CI (0.17-0.86), p=0.02}. Although haplotype analysis revealed that no haplotype was associated with leprosy susceptibility/resistance with statistical significance, GTG haplotype was noted to be more frequent in healthy controls. These SNPs are observed to be in linkage disequilibrium. Although, these SNPs are not likely to influence leprosy vulnerability, -1026G>T SNP was indicated to have noteworthy role in leprosy reactions.

HLA Alleles are Genetic Markers for Susceptibility and Resistance towards Leprosy in a Mexican Mestizo Population.

Despite the use of multidrug therapy, leprosy remains endemic in some countries. The association of several human leucocyte antigen (HLA) alleles and gene polymorphisms with leprosy has been demonstrated in many populations, but the major immune contributors associated to the spectrum of leprosy have not been defined yet. In this study, genotyping of HLA-A, -B, -DR, and -DQ alleles was performed in leprosy patients (n = 113) and control subjects (n = 117) from the region with the highest incidence for the disease in México. The odds of developing leprosy and lepromatous subtype were 2.12- and 2.74-fold higher in carriers of HLA-A*28, and 2.48- and 4.14-fold higher for leprosy and dimorphic subtype in carriers of DQB1*06. Interestingly, DQB1*07 was overrepresented in healthy individuals, compared to patients with leprosy (OR = 0.08) and the lepromatous subtype (OR = 0.06). These results suggest that HLA-A*28 is a marker for predisposition to leprosy and the lepromatous subtype and DQB1*06 to leprosy and the dimorphic subtype, while DQB1*07 might be a resistance marker in this Mestizo population.