Association between macrophage migration inhibitory factor-173G/C polymorphism and psoriasis risk: A meta-analysis.

Background The association between macrophage migration inhibitory factor (MIF)-173G/C polymorphism and psoriasis risk has been reported in several studies with inconsistent conclusions. Aims This study aims to obtain a more convincing estimate of the relationship between the MIF-173G/C polymorphism and psoriasis risk. Methods Web of Science, EMBASE, PubMed, Wan Fang Database and Chinese National Knowledge Infrastructure (CNKI) were searched up to September 2021 and eligible studies were collected. The pooled odds ratios with 95% confidence intervals were calculated to estimate the effects of MIF-173G/C polymorphism on psoriasis risk under different genetic models. All analyses were conducted using the STATA12.0 software. Results A total of 1101 psoriasis cases and 1320 healthy controls from 6 relevant studies were included in this meta-analysis. Pooled analysis suggested that MIF-173G/C polymorphism was associated with increased psoriasis risk under the allelic model (C vs. G: odds ratio = 1.30, 95% confidence interval = 1.04-1.63, P = 0.020), heterozygous model (GC vs. GG: odds ratio = 1.53, 95% confidence interval = 1.05-2.22, P = 0.027) and dominant model (CC + GC vs. GG: odds ratio = 1.51, 95% confidence interval = 1.05-2.18, P = 0.027). Limitation Very few studies on the MIF-173G/C polymorphism in psoriasis have been reported till now, thus the number of studies included in the present meta-analysis was relatively small. Due to the number of studies being relatively small and the lack of raw data, stratified analysis by ethnicity or type of psoriasis was not carried out. Conclusion This meta-analysis demonstrated that MIF-173G/C polymorphism might be related to psoriasis risk. Carriers of the C allele and the GC genotype might have higher odds to present with psoriasis.

Filaggrin gene polymorphisms in Indian children with atopic dermatitis: A cross-sectional multicentre study.

Background Filaggrin (FLG) gene encoding the protein filaggrin plays an important role in barrier function of the skin and its alteration is a predisposing factor for atopic dermatitis. FLG gene variants result in absent or decreased filaggrin protein. Worldwide, the prevalence of FLG variants ranges from 14 to 56%. FLG null variants are distinct in each population. Objectives To study the FLG gene polymorphisms in Indian children and attempt a genotype-phenotype correlation in atopic dermatitis. Methods This was a cross-sectional, multicentre study conducted on 75 Indian children. Demographic details, clinical features and identified FLG null variants were recorded. We performed a whole gene sequencing of the entire FLG coding region using next-generation sequencing technology. Results The prevalence of FLG null variants was 34.7%. A total of 20 different FLG loss of function variants in 26 children were documented. Sixteen (80%) variants were novel and four (20%) were previously reported in Asian and European populations. We found a statistically significant association between FLG variants with early age of onset of atopic dermatitis (P = 0.016) and elevated serum IgE levels (P = 0.051). There was no significant difference between atopic dermatitis phenotypes in children having one variant as compared to children harbouring two or more null variants. Limitation Small sample size. Conclusion Our study reports a unique set of FLG variants different from Asian and European populations, with these variants being significantly associated with an early age of onset of atopic dermatitis and elevated serum IgE levels.

Critical role of epigenetic modification in the pathogenesis of atopic dermatitis.

Atopic dermatitis is a chronic inflammatory skin disease characterised by recurrent eczema-like lesions and severe pruritus, along with drying and decrustation of skin. Current research relates the pathogenesis of atopic dermatitis mainly to genetic susceptibility, abnormal skin barrier function, immune disorders, Staphylococcus aureus colonisation, microbiological dysfunction and vitamin D insufficiency. Epigenetic modifications are distinct genetic phenotypes resulting from environment-driven changes in chromosome functions in the absence of nuclear DNA sequence variation. Classic epigenetic events include DNA methylation, histone protein modifications and non-coding RNA regulation. Increasing evidence has indicated that epigenetic events are involved in the pathogenesis of atopic dermatitis by their effects on multiple signalling pathways which in turn influence the above factors. This review primarily analyses the function of epigenetic regulation in the pathogenesis of atopic dermatitis. In addition, it tries to make recommendations for personalised epigenetic treatment strategies for atopic dermatitis in the future.

Allele-dependent interaction of LRRK2 and NOD2 in leprosy.

Leprosy, caused by Mycobacterium leprae, rarely affects children younger than 5 years. Here, we studied a multiplex leprosy family that included monozygotic twins aged 22 months suffering from paucibacillary leprosy. Whole genome sequencing identified three amino acid mutations previously associated with Crohn's disease and Parkinson's disease as candidate variants for early onset leprosy: LRRK2 N551K, R1398H and NOD2 R702W. In genome-edited macrophages, we demonstrated that cells expressing the LRRK2 mutations displayed reduced apoptosis activity following mycobacterial challenge independently of NOD2. However, employing co-immunoprecipitation and confocal microscopy we showed that LRRK2 and NOD2 proteins interacted in RAW cells and monocyte-derived macrophages, and that this interaction was substantially reduced for the NOD2 R702W mutation. Moreover, we observed a joint effect of LRRK2 and NOD2 variants on Bacillus Calmette-Guérin (BCG)-induced respiratory burst, NF-κB activation and cytokine/chemokine secretion with a strong impact for the genotypes found in the twins consistent with a role of the identified mutations in the development of early onset leprosy.

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.

Single-nucleotide polymorphism and haplotype analysis of macrophage migration inhibitory factor gene and its correlation with serum macrophage migration inhibitory factor levels in North Indian psoriatic patients with moderate disease severity: A cross-sectional study.

BACKGROUND: Psoriasis is associated with significant morbidity and impaired quality of life. Identification of the host genes that influence disease susceptibility and can potentially guide future, targeted therapy is the need of the hour. AIMS: The aim of the study was to investigate the associations of macrophage migration inhibitory factor (MIF) gene polymorphisms, that is, a 5-8-CATT tetra nucleotide repeats at -794 (-794*CATT5-8) and a single-nucleotide polymorphism at -173 (-173*G/C) with the risk of chronic plaque psoriasis and to observe the correlation, if any, of disease determinants with genetic functional variants and circulating MIF levels. METHODS: Five hundred and seventeen individuals (265 psoriasis patients and 252 controls) were genotyped for MIF gene polymorphisms. Data were analyzed with respect to disease susceptibility, serum MIF levels, disease severity, age at onset, disease duration and presence of comorbidities. RESULTS: The presence of co-morbidities was more frequently noted in patients with late onset disease (P = 0.01). No statistically significant differences were observed either in genotype (P = 0.680) or allele frequency (P = 0.69) with respect to distribution of MIF-173*G/C polymorphism between patients and controls. The frequencies of genotypes -794*CATT 5/7 and 7/7 were significantly lower in patients (P = 0.027* and 0.038*, respectively). CATT*5/MIF-173*C haplotype occurred at a higher frequency in patients (odds ratio 3.03, 95% confidence intervals 1.09-8.47, P = 0.02). The mean serum MIF levels were significantly higher in patients as compared to controls (P < 0.001). The presence of either extended MIF -794*CATT repeats or C allele did not reveal any significant association with serum MIF levels or age at onset. Analysis of effect of various disease determinants revealed no significant association with genetic variants and serum MIF levels. LIMITATIONS: The lesional expression of MIF could not be studied. CONCLUSION: Our results showed that CATT*5/MIF-173*C haplotype is associated with increased susceptibility to psoriasis vulgaris.

Interleukin-17A in Egyptian leprosy patients: a clinical, genetic, and biochemical study.

BACKGROUND: Leprosy represents a long-term communicable disease resulting from Mycobacterium leprae infection. IL-17A is one of the pro-inflammatory cytokines that protects humans against many fungal and bacterial pathogens. OBJECTIVE: To investigate IL-17A (rs2275913) gene polymorphism and its circulating level in leprosy patients, and to correlate the detected results with different clinical aspects of leprosy in the investigated patients. METHODS: 60 patients with leprosy, and 29 age and sex-matched volunteers were investigated for IL-17A serum level and IL-17A single nucleotide polymorphism (SNP) by ELISA and RFLP-PCR respectively. RESULTS: IL-17A serum level was significantly higher in leprosy patients than in controls (p=0.034), and in TL than LL (p=0.017). IL-17A (rs2275913 A/G) G allele and GG genotype were associated significantly with LL (p=0.005and 0.001 respectively). IL-17A (rs2275913 A/G) AG genotype carriers demonstrated the highest IL-17A serum levels; however, its lowest levels were found in IL-17A (rs2275913 A/G) AA genotype carriers (p=0.005). Grade 2 disability (p=0.030) and positive slit skin smear (SSS) (p=0.005) were significantly associated with IL-17A (rs2275913 A/G) GG genotype. STUDY LIMITATIONS: The small number of studied subjects. CONCLUSIONS: IL -17A may have a pivotal role in leprosy pathogenesis. IL-17A (rs2275913) GG genotype plus G allele might be related to the development of LL in the Egyptian population.

Genome-wide association study of leprosy in Malawi and Mali.

Leprosy is a chronic infection of the skin and peripheral nerves caused by Mycobacterium leprae. Despite recent improvements in disease control, leprosy remains an important cause of infectious disability globally. Large-scale genetic association studies in Chinese, Vietnamese and Indian populations have identified over 30 susceptibility loci for leprosy. There is a significant burden of leprosy in Africa, however it is uncertain whether the findings of published genetic association studies are generalizable to African populations. To address this, we conducted a genome-wide association study (GWAS) of leprosy in Malawian (327 cases, 436 controls) and Malian (247 cases, 368 controls) individuals. In that analysis, we replicated four risk loci previously reported in China, Vietnam and India; MHC Class I and II, LACC1 and SLC29A3. We further identified a novel leprosy susceptibility locus at 10q24 (rs2015583; combined p = 8.81 × 10-9; OR = 0.51 [95% CI 0.40 - 0.64]). Using publicly-available data we characterise regulatory activity at this locus, identifying ACTR1A as a candidate mediator of leprosy risk. This locus shows evidence of recent positive selection and demonstrates pleiotropy with established risk loci for inflammatory bowel disease and childhood-onset asthma. A shared genetic architecture for leprosy and inflammatory bowel disease has been previously described. We expand on this, strengthening the hypothesis that selection pressure driven by leprosy has shaped the evolution of autoimmune and atopic disease in modern populations. More broadly, our data highlights the importance of defining the genetic architecture of disease across genetically diverse populations, and that disease insights derived from GWAS in one population may not translate to all affected populations.

Identification of shared loci associated with both Crohn's disease and leprosy in East Asians.

Genome-wide association studies (GWAS) of Crohn's disease (CD) in European and leprosy in Chinese population have shown that CD and leprosy share genetic risk loci. As these shared loci were identified through cross-comparisons across different ethnic populations, we hypothesized that meta-analysis of GWAS on CD and leprosy in East Asian populations would increase power to identify additional shared loci. We performed a cross-disease meta-analysis of GWAS data from CD (1621 cases and 4419 controls) and leprosy (2901 cases 3801 controls) followed by replication in additional datasets comprising 738 CD cases and 488 controls and 842 leprosy cases and 925 controls. We identified one novel locus at 7p22.3, rs77992257 in intron 2 of ADAP1, shared between CD and leprosy with genome-wide significance (P = 3.80 × 10-11) and confirmed 10 previously established loci in both diseases: IL23R, IL18RAP, IL12B, RIPK2, TNFSF15, ZNF365-EGR2, CCDC88B, LACC1, IL27, NOD2. Phenotype variance explained by the polygenic risk scores derived from Chinese leprosy data explained up to 5.28% of variance of Korean CD, supporting similar genetic structures between the two diseases. Although CD and leprosy shared a substantial number of genetic susceptibility loci in East Asians, the majority of shared susceptibility loci showed allelic effects in the opposite direction. Investigation of the genetic correlation using cross-trait linkage disequilibrium score regression also showed a negative genetic correlation between CD and leprosy (rg [SE] = -0.40[0.13], P = 2.6 × 10-3). These observations implicate the possibility that CD might be caused by hyper-sensitive reactions toward pathogenic stimuli.

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.

Association between interleukin-17F rs763780 polymorphism and psoriasis risk: A meta-analysis.

BACKGROUND: The polymorphism of interleukin-17F rs763780 has been found to have a probable association with increased risk of developing psoriasis. AIMS: This study aims to get a more convincing estimation of the association between the interleukin-17F rs763780 T /C polymorphism and psoriasis risk. METHODS: Two authors independently searched the databases including PubMed, EMBASE, Cochrane Central Register of Controlled Trials, Chinese National Knowledge Infrastructure, Wanfang and Chinese Biomedical Literature Databases for case-control studies which reported the odds ratios with 95% confidence intervals comparing genotype and allele frequencies of the interleukin-17F rs763780 polymorphism in patients with psoriasis versus participants without psoriasis. RESULTS: A total of seven case-control studies incorporating 1824 cases and 1585 controls were identified. The pooled odds ratios indicated that interleukin-17F rs763780 C allele was a risk factor for psoriasis in allele frequency, recessive model and homozygote model (P < 0.05). Subgroup analysis by ethnicity further indicated that the C allele was closely related to increased risk of psoriasis in Asian populations (P < 0.05), but not in Caucasians. LIMITATIONS: Only a few studies on the interleukin-17F rs763780 polymorphism in psoriasis have been reported till date, thus the data is insufficient. Only one gene polymorphic site was selected for this study, and it is not clear whether other genetic mutation functional sites affect the gene. Further studies on confounding effects of other genetic polymorphisms are needed. CONCLUSION: The present meta-analysis results suggested that the interleukin-17F rs763780 T /C is significantly associated with psoriasis risk in Asians.

Deep resequencing identifies candidate functional genes in leprosy GWAS loci.

Leprosy is the second most prevalent mycobacterial disease globally. Despite the existence of an effective therapy, leprosy incidence has consistently remained above 200,000 cases per year since 2010. Numerous host genetic factors have been identified for leprosy that contribute to the persistently high case numbers. In the past decade, genetic epidemiology approaches, including genome-wide association studies (GWAS), identified more than 30 loci contributing to leprosy susceptibility. However, GWAS loci commonly encompass multiple genes, which poses a challenge to define causal candidates for each locus. To address this problem, we hypothesized that genes contributing to leprosy susceptibility differ in their frequencies of rare protein-altering variants between cases and controls. Using deep resequencing we assessed protein-coding variants for 34 genes located in GWAS or linkage loci in 555 Vietnamese leprosy cases and 500 healthy controls. We observed 234 nonsynonymous mutations in the targeted genes. A significant depletion of protein-altering variants was detected for the IL18R1 and BCL10 genes in leprosy cases. The IL18R1 gene is clustered with IL18RAP and IL1RL1 in the leprosy GWAS locus on chromosome 2q12.1. Moreover, in a recent GWAS we identified an HLA-independent signal of association with leprosy on chromosome 6p21. Here, we report amino acid changes in the CDSN and PSORS1C2 genes depleted in leprosy cases, indicating them as candidate genes in the chromosome 6p21 locus. Our results show that deep resequencing can identify leprosy candidate susceptibility genes that had been missed by classic linkage and association approaches.

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.

Approach to inherited hypertrichosis: A brief review.

Hypertrichosis refers to the growth of hair, of an excessive amount and thickness, on any part of the body. It must be distinguished from hirsutism which is characterized by excess growth of hair in androgen-dependent areas on the upper lip, chin, chest, linea alba, thigh and axilla. Hypertrichosis may be localized or generalized, and congenital or acquired. Excess hair growth has a psychological impact on the child as well as the parents due to the cosmetic disfigurement it produces. Current treatment options are limited and not wholly satisfactory. Treatment should be customized according to the area, nature and amount of hair growth, age of the patient and personal preferences. In addition, when hypertrichosis occurs as a component of a syndrome, multidisciplinary management is required to address the associated systemic features. A detailed review of inherited generalized hypertrichosis is presented here with emphasis on clinical clues to identifying complex syndromes with multisystem involvement.

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.

Predictive nomogram for leprosy using genetic and epidemiological risk factors in Southwestern China: Case-control and prospective analyses.

BACKGROUND: There is a high incidence of leprosy among house-contacts compared with the general population. We aimed to establish a predictive model using these genetic factors along with epidemiological factors to predict leprosy risk of leprosy household contacts (HHCs). METHODS: Weighted genetic risk score (wGRS) encompassing genome wide association studies (GWAS) variants and five non-genetic factors were examined in a case-control design associated with leprosy risk including 589 cases and 647 controls from leprosy HHCs. We constructed a risk prediction nomogram and evaluated its performance by concordance index (C-index) and calibration curve. The results were validated using bootstrap resampling with 1000 resamples and a prospective design including 1100 HHCs of leprosy patients. FINDING: The C-index for the risk model was 0·792 (95% confidence interval [CI] 0·768-0·817), and was confirmed to be 0·780 through bootstrapping validation. The calibration curve for the probability of leprosy showed good agreement between the prediction of the nomogram and actual observation. HHCs were then divided into the low-risk group (nomogram score ≤ 81) and the high-risk group (nomogram score > 81). In prospective analysis, 12 of 1100 participants had leprosy during 63 months' follow-up. We generated the nomogram for leprosy in the validation cohort (C-index 0·773 [95%CI 0·658-0·888], sensitivity75·0%, specificity 66·8%). Interpretation The nomogram achieved an effective prediction of leprosy in HHCs. Using the model, the risk of an individual contact developing leprosy can be determined, which can lead to a rational preventive choice for tracing higher-risk leprosy contacts. FUNDING: The ministry of health of China, ministry of science and technology of China, Chinese academy of medical sciences, Jiangsu provincial department of science and technology, Nanjing municipal science and technology bureau.

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.

Mapping leprosy-associated coding variants of interleukin genes by targeted sequencing.

Previous genotyping-based assays have identified non-coding variants of several interleukins (ILs) being associated with genetic susceptibility to leprosy. However, understanding of the involvement of coding variants within all IL family genes in leprosy was still limited. To obtain the full mutation spectrum of all ILs in leprosy, we performed a targeted deep sequencing of coding regions of 58 ILs genes in 798 leprosy patients (age 56.2 ± 14.4; female 31.5%) and 990 healthy controls (age 38.1 ± 14.0; female 44.3%) from Yunnan, Southwest China. mRNA expression alterations of ILs in leprosy skin lesions or in response to M. leprae treatment were estimated by using publicly available expression datasets. Two coding variants in IL27 (rs17855750, p.S59A, p = 4.02 × 10-8 , odds ratio [OR] = 1.748) and IL1RN (rs45507693, p.A106T, p = 1.45 × 10-5 , OR = 3.629) were significantly associated with leprosy risk. mRNA levels of IL27 and IL1RN were upregulated in whole blood cells after M. leprae stimulation. These data showed that IL27 and IL1RN are leprosy risk genes. Further functional study is required for characterizing the exact role of ILs in leprosy.

HLA-DPB1 and HLA-C alleles are associated with leprosy in a Brazilian population.

Despite intense efforts, the number of new cases of leprosy has remained significantly high over the past 20 years. Host genetic background is strongly linked to the pathogenesis of this disease, which is caused by Mycobacterium leprae (M. leprae), and there is a consensus that the most significant genetic association with leprosy is attributed to the major histocompatibility complex (MHC). Here, we investigated the association of human leukocyte antigen (HLA) class I and II genes with leprosy in a Brazilian population encompassing 826 individuals from a hyperendemic area of Brazil; HLA typing of class I (-A, -B, -C) and class II (-DRB1, -DQA1, -DQB1, -DPA1, and -DPB1) loci was conducted. Initially, the associations were tested using the chi-square test, with p-values adjusted using the false discovery rate (FDR) method. Next, statistically significant signals of the associations were submitted to logistic regression analyses to adjust for sex and molecular ancestry data. The results showed that HLA-C*08, -DPB1*04, and -DPB1*18 were associated with protective effects, while HLA-C*12 and -DPB1*105 were associated with susceptibility to leprosy. Thus, our findings reveal new associations between leprosy and the HLA-DPB1 locus and confirm previous associations between the HLA-C locus and leprosy.