The Association of HLA Alleles and Haplotypes with Age of Disease Onset in Pakistani Psoriatic Patients.

INTRODUCTION: The human leukocyte antigen (HLA) region on chromosome 6p21 is well known to carry the most important genetic factors in susceptibility to psoriasis. Different HLA alleles and haplotypes have been reported to be associated with psoriasis in different populations. Psoriasis has a variable age of onset and, based on this, it can be classified into two types; type I with age of onset before 40 years of age and type II with age of onset after 40 years of age. The objective of this study was to determine the association of HLA class I and class II alleles and haplotypes with disease and stratification using age of onset in Pakistani psoriatic patients. METHODS: A group of 603 individuals (326 cases and 277 controls) were analyzed for HLA class I and II alleles and haplotype association by sequence specific PCR. The association was further analyzed according to the age of onset of the patients. RESULTS: We found that HLA alleles B*57 and Cw*06:02, DQB1*03:03:02 are strongly associated with early onset psoriasis, while alleles B*15, DRB1*13:02 and DQB1*03:03:02 are associated with late-onset psoriasis. Cw*06:02 allele was not associated with late-onset psoriasis patients. Allele DQB1*03:03:02 had the highest odds ratio in all patients. We found a novel association specifically with late-onset psoriasis samples with the haplotype HLA-A*11; B*15; Cw*04; DRB1*15; DQB1*05 (Pc = 3.60 × 10-7). We also found strong association with previously reported extended haplotype EH-57.1: HLA-B*57; Cw*06:02; DRB1*07:01; DQB1*03:03:02 in all our patients (Pc = 8.34 × 10-07). CONCLUSION: Our results show that different HLA class I and II alleles and haplotypes are associated with psoriasis at different age of onset. In this study, we have reported novel alleles and haplotype association with late-onset psoriasis. Our data confirm the previous strong associations with HLA alleles and haplotypes and also reports novel alleles and haplotype association in Pakistani psoriasis patients.

Study of HLA class II loci reveals DQB1*03:03:02 as a risk factor for asthma in a Pakistani population.

Asthma, a chronic inflammatory disorder of the lungs and airways, typically results from a combination of multiple environmental and genetic factors. Human leucocyte antigen (HLA) region on chromosome 6p21 encodes the most highly polymorphic loci in the human genome, encoding genes with central roles in the immune function where HLA loci are strongly associated with various immune-mediated diseases such as autoimmunity, allergies and infection. The alleles of HLA class II genes such as DRB1 and DQB1 are the key genetic markers in the development of asthma and have been extensively studied in different ethnicities of the world population. However, the genetic screening of HLA class II alleles and haplotypes in Pakistani asthmatics has not been studied so far. The aim of the present study was to screen the HLA class II DRB1 and DQB1 alleles in asthma cases and controls in a Pakistani population. Seven hundred and two healthy controls and asthma patients were genotyped for HLA class II by sequence-specific polymerase chain reaction assays. The HLA-DRB1 and HLA-DQB1 allele and haplotype frequencies were calculated, and their risk or protective association with asthma was determined. Two-locus haplotypes of DRB1 and DQB1 alleles were imputed using Arlequin version 3.1 software. The signals of association with asthma were stronger at the DQB1 locus as compared to DRB1. HLA DQB1*03:03:02 (odds ratio [OR] = 2.42, 95% confidence interval [CI] = 1.34-4.25) was significantly associated with an increased risk of asthma, as was the haplotype comprised allele DRB1*07:01-DQB1*03:03:02 (OR = 2.40, 95% CI = 1.25-4.62). In contrast, DQB1*06 (OR = 0.39, 95% CI = 0.22-0.70) and DQB1*06:02 (OR = 0.27, 95% CI = 0.10-0.71) emerged as protective alleles for asthma. Our data concludes that the HLA DQB1*03:03:02 allele was a risk allele for asthma, whereas two DQB1 alleles, DQB1*06 and DQB1*06:02, were associated with asthma protection. Our findings highlight a prominent role for HLA-DQB1 alleles in asthma pathogenesis in studied Pakistani cases. More studies, especially with a larger study cohort are needed to confirm the utility of HLA DQB1*03:03:02 as a predictive marker.

Isolation, characterization, bacteriocin production and biological potential of Bifidobacteria of ruminants.

Bacteriocins exhibited a wide spectrum of antibacterial activity against different pathogens. The aim of current study was to characterize the bacteriocins produced by Bifidobacterium spp. isolated from ruminants. The Bifidobacterium isolates were identified as B. longum, B. pseudolongum, B. bifidum, B. thermophilum, B. boum, B. merycicum and B. ruminantium. Bacteriocins were found to be pH stable, heat resistant, highly diffusible, NaCl tolerant and resistant to UV radiations. SDS, EDTA and urea induced 14%, 21% and 24% bacteriocins activity loss. Modified MRS broth (1% tryptone, 1% yeast extract and 2% glucose) was found to be the best nutrient medium for optimal production of bacteriocins. Minimum inhibitory concentration (MIC) values varied from 300 µl/ml to 500 µl/ml and minimum bactericidal concentration (MBC) values ranged from 500 µl/ml to >500 µl/ml for E. coli and S. aureus respectively. The highest protein concentration (29.0248 mg/ml) was recorded for Bifidobacteria bacteriocin produced by B. longum. Tricine-Sodium Dodecyl Sulfate-Poly Acrylamide Gel Electrophoresis (SDS-PAGE) revealed that molecular weight of isolated bifidobacterial bacteriocins was in the range of 3.6 kDa-30 kDa. Current study indicated that bifidobacterial bacteriocins have considerable potential to be used as biopreservative.

The causes of Fanconi anemia in South Asia and the Middle East: A case series and review of the literature.

BACKGROUND: Fanconi anemia (FA) is an inherited bone marrow failure syndrome associated with characteristic dysmorphology primarily caused by biallelic pathogenic germline variants in any of 22 different DNA repair genes. There are limited data on the specific molecular causes of FA in different ethnic groups. METHODS: We performed exome sequencing and copy number variant analyses on 19 patients with FA from 17 families undergoing hematopoietic cell transplantation evaluation in Pakistan. The scientific literature was reviewed, and we curated germline variants reported in patients with FA from South Asia and the Middle East. RESULTS: The genetic causes of FA were identified in 14 of the 17 families: seven FANCA, two FANCC, one FANCF, two FANCG, and two FANCL. Homozygous and compound heterozygous variants were present in 12 and two families, respectively. Nine families carried variants previously reported as pathogenic, including two families with the South Asian FANCL founder variant. We also identified five novel likely deleterious variants in FANCA, FANCF, and FANCG in affected patients. CONCLUSIONS: Our study supports the importance of determining the genomic landscape of FA in diverse populations, in order to improve understanding of FA etiology and assist in the counseling of families.

Single-Nucleotide Polymorphisms of FAS and FASL Genes and Risk of Idiopathic Aplastic Anemia.

FAS/FASL signaling system plays a vital role in the regulation of apoptosis, envisaged as a death process required for immune surveillance to prevent autoimmunity and tumorigenesis along with several other biological activities. Several single-nucleotide polymorphisms (SNPs) of FAS/FASL system can result in aberrant apoptosis, which can cause different cancers and autoimmune diseases. Aplastic anemia (AA) is an autoimmune dysfunction characterized by peripheral blood pancytopenia associated with hypoplasia of bone marrow. The aim of this study was to screen Pakistani AA patients and controls for two Fas SNPs rs2234767 and rs1800682 and two FASLG SNPs rs763110 and rs5030772. Genotyping of 392 DNA samples was done by Tetra-ARMS polymerase chain reaction. Genotypic frequencies of Fas rs1800682 and FASLG rs5030772 showed significance difference in their distribution in both controls and patients, while Fas rs2234767 and FASLG rs763110 SNPs had no such difference. Carriers of rs1800682 AG+GG had a very odd ratio of 4.63, with 95% confidence interval (CI) of 3.01-7.11, while individuals with FASLG rs5030772 AG+GG were more common in controls than patients with OR 0.53 and 95% CI of 0.34-0.83. Cumulative effects of these SNPs were analyzed, and they showed almost similar trends; however, Fas rs2234767 and FASLG rs763110 genotypes in combination with Fas rs1800682 and FASLG rs5030772 demonstrated significant association. This study provided information that endorsed the involvement of FAS/FASL system SNPs in the pathogenesis of AA; further studies should be designed to understand the exact role of SNPs that can help in early diagnosis and treatment.

Single nucleotide polymorphisms in asthma candidate genes TBXA2R, ADAM33 FCER1B and ORMDL3 in Pakistani asthmatics a case control study.

BACKGROUND: Genetic variations in different loci and genes are important in asthma pathogenesis. There is much importance of various immunological pathways in the IgE secretion regulation. Alterations in any main part of these pathways can increase the risk of asthma development. Polymorphisms in these genetic markers can effect certain pathways which predict the asthma susceptibility. In the present study, SNPs directly or indirectly affecting the immunological process pathways are selected. METHODS: This study was conducted to determine association of 16 SNPs in 10 candidate genes with asthma in Pakistani population in 333 asthmatic cases and 220 healthy controls. Genotyping was performed using the Sequenom Mass ARRAY iPLEX platform (14 SNPs) and TaqMan assay (2 SNPs). RESULTS: The minor allele at two of the SNPs showed association with protection from asthma, rs1131882 in TBXA2R gene (OR 0.73, 95% CI 0.52-1.01, P = 0.05) and rs2280091 in the ADAM33 gene (OR 0.69, 95% CI 0.50-0.97, P = 0.03). For FCER1B gene, rs2583476 the asthmatic male gender had higher TT genotype counts as compared to controls (OR = 1.86, 95% CI = 1.09-3.17, p = 0.01). In rs11650680 of ORMDL3 gene the CT genotype is more prevalent in female asthma cases in comparison with female controls (OR = 1.99, 95% CI = 1.02-3.89, p = 0.03). CONCLUSIONS: This data suggests that variations at TBXA2R and ADAM33 genes are found to be associated with asthma susceptibility in Pakistan. FCER1B gene is associated with male and ORMDL3 in female asthmatics. These genetic markers can be important source of asthma risk in Pakistani population.

An angiotensin I-converting enzyme insertion/deletion polymorphism is associated with Pakistani asthmatic cases and controls.

Asthma is a chronic disease due to inflammation of the airways of lungs that is clinically characterized by variable symptoms including wheezing, coughing and shortness of breath. Angiotensin I-converting enzyme (ACE) plays a major role in fibrous tissue formation and is highly expressed in lungs. The main aim of this research work was to study the role of ACE insertion/deletion (I/D) polymorphism, rs4646994, in asthma in Pakistani patients. A total of 854 subjects, including 333 asthma patients and 521 ethnically matched controls, were studied. The ACE (I/D) polymorphism was genotyped using polymerase chain reaction (PCR). Chi-square, Fisher's exact and Hardy-Weinberg equilibrium tests were used to compare groups. Homozygous insertion genotype II (p less than 0.0001, OR=3.38) and insertion allele (I) was significantly more frequent in Pakistani asthmatics than in healthy controls (p=0.0007, OR=1.40). The ID genotype (p less than 0.0001, OR=0.43) and the deletion allele (D) were associated with protection of disease in Pakistani patients (p=0.0007, OR=0.71). These data suggest the involvement of ACE I/D polymorphism in asthma risk in the Pakistani population. This marker may be an important indication in the molecular mechanism of asthma and can become a useful tool in risk assessment and help in designing strategy to combat disease.

Association of Tumor Necrosis Factor Alpha 308 G/A Polymorphism with Asthma in Pakistani Population.

Asthma is a chronic inflammatory and remodeling disorder of the airways, in which many cells, cellular elements, and cytokines play important roles. The role of tumor necrosis factor-α (TNF-α) in asthma is unclear in Pakistani population. The aim of this study was to assess the relationship between TNF-α-308 polymorphism and asthma. Polymorphism of TNF-α (G-308-A locus; rs 1800629) in 329 asthmatic patients and 151 healthy controls was evaluated. DNA was prepared from blood samples of cases and controls. Samples were genotyped for TNF-α 308 G/A polymorphism. There was no significant difference in the frequency of GG (OR 1.049 with 95% CI 0.68-1.63) and GA (OR 0.987 with 95% CI 0.64-1.53) genotypes of TNF-α-308. The AA genotype was absent in cases and only one AA genotype was observed in the controls. The genetic polymorphism of TNF-α does not seem to be associated with asthma in Pakistani population.

Association of GSTM1 and GSTT1 deletion polymorphisms with Pakistani aplastic anemia patients and controls and meta-analysis.

Interaction of environmental and genetic elements plays a vital role in the pathogenesis of aplastic anemia (AA). Glutathione S-transferase (GST) is a key detoxifying enzyme. Absence or low levels of this enzyme may genetically predispose individuals to AA. GST genes GSTM1 and GSTT1 are polymorphic. The aim of this study was to screen Pakistani AA patients and controls for GSTM1 deletion GSTM0 and GSTT1 deletion GSTT0 and perform meta-analysis using our data and other published data regarding these polymorphisms. DNA samples from 137 patients and 220 controls were screened using multiplex polymerase chain reaction. GSTM0 emerged as susceptible genotype for AA in Pakistan with a percentage frequency of 49.6 % as compared to 30 % in controls with odds ratio (OR) of 2.25, 95 % confidence interval (CI) of 1.4-3.5 and corrected p = 0.006. The meta-analysis showed a significant association between the null genotype GSTT0 and AA in overall analysis with OR of 1.47, 95 % CI of 1.01-2.13 and p value of 0.04 in random effects model. Studies like these could play a role in understanding the underlying path in AA pathogenesis and therefore can help in designing means for prevention, diagnose and treatment.

Association analysis of GWAS and candidate gene loci in a Pakistani population with psoriasis.

Psoriasis is a common inflammatory and hyper proliferative condition of the skin and a serious chronic systemic autoimmune disease. We undertook an association study to investigate the genetic etiology of psoriasis in a Pakistani population by genotyping single-nucleotide polymorphisms (SNPs) previously reported to be associated in genome-wide association (GWAS) or in candidate gene studies of psoriasis. Fifty seven single-nucleotide polymorphisms (SNPs) from 42 loci were genotyped in 533 psoriasis patients and 373 controls. Our results showed genome wide significant association of the MHC region (rs1265181 being the most significant from five SNPs used with overall OR=3.38; p=2.97E-18), as well as nominally significant associations at ten other loci (p<0.05) in the Pakistani population (LCE3B, REL, IL13/IL4, TNIP1, IL12B, TRAF3IP2, ZC3H12C, NOS2 and RNF114 from GWAS and PRR9 from a previous candidate gene study). Overall, only nine SNPs out of the 42 GWAS loci, displayed an odds ratio in the opposite allelic direction and only three did not reach similar odds ratio within 95% confidence interval as previously reported (SLC45A1/TNFRSF9, ELMO1 and IL28RA). This indicates similar genetic risk factors and molecular mechanisms behind disease in Pakistani psoriasis patients as in other populations. In addition, we show that the MHC and TNIP1 regions are significantly different in patients with psoriasis onset before the age of 40 (type I) compared to after 40 years of age (type II). MHC being associated mainly with type I while TNIP1 with type II patients.

A study on the association of TNF-α(-308), IL-6(-174), IL-10(-1082) and IL-1Ra(VNTR) gene polymorphisms with rheumatic heart disease in Pakistani patients.

Inflammation is an important contributor to the pathogenesis of rheumatic heart disease (RHD), a disorder of heart valves caused by a combination of immune, genetic and environmental factors. Cytokines are important mediators of inflammatory and immune responses. The aim of this study was to investigate the role of cytokine gene polymorphisms and their potential usefulness as biomarkers in RHD patients from Pakistan. We screened 150 RHD patients and 204 ethnically matched controls for tumor necrosis factor (TNF)-α(-308)G/A, interleukin (IL)-10(-1082) G/A, interleukin (IL)-6(-174) G/C and a variable number of tandem repeats (VNTRs) polymorphism of the IL-1Ra gene using polymerase chain reaction. The results showed that TNF-α(-308) A and IL-6(-174) G alleles were associated with susceptibility to RHD (p=0.000; OR=2.81; CI=1.5-5.14 and p=0.025; OR=1.50; CI=1.04-2.16 respectively). The TNF-α(-308) AA and GA genotypes were associated with susceptibility to RHD (p=0.012; OR=9.94; CI; 1.21-217.3 and p=0.046; OR=1.97; CI=0.98-3.97 respectively) while the GG genotype seemed to confer resistance (p=0.003; OR=0.39; CI=0.20-0.76). The GG genotype for IL-6(-174) was significantly associated with predisposition to RHD (p=0.015; OR=2.6; CI=1.17-5.85). The A1 (four repeats) and A2 (two repeats) alleles at the IL-1Ra VNTR polymorphism were associated with resistance and susceptibility to RHD respectively. However, this polymorphism deviated from Hardy-Weinberg equilibrium in both patients and controls in our population. TNF-α(-308) and IL-6(-174) polymorphisms may be useful markers for the identification of individuals susceptible to RHD in Pakistan. These individuals could be provided aggressive prophylactic intervention to prevent the morbidity and mortality associated with RHD.

The frequency of HLA class I and II alleles in Pakistani patients with aplastic anemia.

Hematological disorders like Aplastic anemia are quite frequent in Pakistan. Human leukocyte antigen (HLA) system, have been implicated in the development of Aplastic anemia in various population-based studies, The aim of this study was to determine the role of the HLA Class I and Class II alleles in genetic susceptibility to Aplastic anemia in Pakistani patients. HLA A*, B* and DRB1* alleles were analyzed, in 61 Pakistani patients (Females n = 22, Males n = 39) and the control group consisted of 200 ethnically matched individuals (Females n = 89, Males n = 111). The allele frequency of DRB1*15 was found significantly higher in patients 0.36 (p = 0.001 with odds ratio = 1.97), as compared to the controls 0.212. Although DRB1*03 percent frequency was significantly higher in controls 0.175 (p = 0.023) with odds ratio = 0.514, as compared to patients 0.106.Therefore DRB1*15 emerged as a susceptible allele and DRB1*03 as a protective allele in Pakistani Aplastic anemia patients and control samples. No significant difference was found in allele frequencies of other HLA class I and HLA class II alleles for both patients and controls. Three haplotypes A*02 B*40 DRB1*15 (p = 0.021), A*31 B*51 DRB1*13 (p = 0.12) and A*33 B*58 DRB1*15 (p = 0.000) showed significant variations in the two groups.