Human leukocyte antigen class II allele frequencies and haplotype association in Iranian normal population

HLA class II profile in patients with different stages of cystic echinococcosis according to the WHO ultrasound imaging classification

The factors involving in the natural history and determinants of different features of human cystic echinococcosis (CE) are not adequately understood. Several host-related factors including the genetic structure of the host and human leukocyte antigens (HLAs) are believed to be involved in the natural history of CE in humans. The present study was conducted to investigate the association between HLA class II genes and active and inactive stages of hepatic cystic echinococcosis. Echinococcus granulosus cyst samples and patient information were collected from the biobank of the Iranian Hydatid Disease Registry from 2019 to 2022. HLA-DRB and HLA-DQB were characterized by PCR method. CE patients were categorized into three active (CE1 and CE2), inactive (CE4 and CE5), and transitional (CE3) stages according to the WHO ultrasound classification of CE. In total, 77 participants including 38 patients (36.8% men and 63.2% women) with different stages of CE as well as 39 healthy individuals (38.5% men and 61.5% women) were included in the study. Findings of the study showed that the frequency of HLA-DRB1*03 was significantly lower in the patients compared to the healthy individuals. The frequencies of HLA-DQB and HLA-DRB alleles were not differed significantly between active, inactive, and transitional stages of E. granulosus cysts. Findings of this study indicate the potential role of this allele in the susceptibility of human to cystic echinococcosis. Further large-scale studies in different endemic countries are required to document the significance of HLA-DQB and HLA-DRB as a host-related factor in the natural history of CE in human.

Prevalence of CCR5 Delta 32 Genetic Variant in the Turkmen Population of Golestan Province, Northeast of Iran

The 32 bp deletion in the chemokine receptor (C-C motif) 5 gene (CCR5Δ32) is a natural loss of function polymorphism that prevents the protein from locating on the cell surface. This genetic variation acts as a double-edge sword in the pathogenesis/defense mechanism of different health conditions, such as viral infections, autoimmune diseases, and cancers. Here, we evaluated the prevalence of the CCR5Δ32 polymorphism in the Turkmen population of Golestan province, northeast of Iran. Blood samples were collected from 400 randomly selected Turkmen populations (199 women and 201 men), and genomic DNA was extracted. Characterization of CCR5Δ32 genotypes was performed by PCR using primers flanking the 32-nucleotide deletion in the CCR5 gene. The amplified DNA fragments were visualized on 2% agarose gel electrophoresis with cybergreen staining under UV light. All individuals were of Turkmen ethnicity and lived in the Golestan province, northeast of Iran. The mean age of all participants was 35.46 years, with a 20-45 year range. All the studied subjects were healthy without any severe conditions such as autoimmune disease and viral infections. All individuals had no history of HIV infection. The PCR product visualization showed that all the samples are at the 330 bp size, which means the CCR5Δ32 allele was utterly absent from the study population. The presence of the CCR5Δ32 allele among Turkmens may be attributed to the admixture with European descent people. We conclude that the CCR5Δ32 polymorphism may be absent in the Iranian Turkmen population, and further studies with a large population are needed.

HLA alleles and haplotype frequencies in Iranian population

BACKGROUND

HLA genotyping is a prerequisite for selection of suitable donors in the process of bone marrow transplantation.

METHODS

In the current study, the frequencies of HLA-A, -B, -C and -DRB1 alleles and A-B-C-DRB1 haplotypes were assessed in 855 healthy Iranian persons using a low-resolution sequence specific primer (SSP) kit.

RESULTS

Frequencies were compared between 11 subpopulations including Armani, Balouch, Bandari, Turk, Turkaman, Arab, Fars, Kurd, Gilaki, Lor and Mazani. In total, 17 HLA-A alleles were detected, one of which (HLA-A*74) was present only among Lors. HLA-A*23 and -A*26 were the most frequent HLA-A alleles among Armanis. HLA-A*23 was also common among Turkamans. HLA-A*11 and -A*26 were most frequent among the Balouch subpopulation. The former allele was also frequent among Bandaris. HLA-A*02 was identified as the most common HLA-A allele among Turk, Arab and Fars subpopulations. HLA-A*30 were strongly enriched among Gilakis. A total of 31 HLA-B alleles were detected across the target population. While all alleles were present among Fars subgroup, Armanis and Turkamans had the lowest degree of diversity among the alleles examined. Moreover, HLA-B*35 and B*49 alleles were strongly enriched among Armanis and Turkamans, respectively. A total of 13 HLA-C alleles were identified across the population, all of which were present in the Fars subpopulation. HLA-C*03 and C*04 were the only HLA-C alleles identified among the Bandari subpopulation. HLA-DRB1*08 was not detected in any subpopulation other than Fars. HLA-DRB1*16 was significantly enriched among Bandaris.

CONCLUSION

These data have practical significance in anthropological studies, disease association investigations and bone marrow transplantation.

Carriage of HLA-DRB1*11 and 1*12 alleles and risk factors in patients with breast cancer in Burkina Faso

Several factors contribute to the development of breast cancer, including the immune system. This study is aimed to characterize the carriage of human leukocyte antigen (HLA)-DRB1*11 and 1*12 alleles in patients with breast cancer. This case-control study consisted of 96 histologically diagnosed breast cancer cases and 102 controls (cases without breast abnormalities). A multiplex polymerase chain reaction (PCR) was used to characterize the carriage of HLA-DRB1*11 and 1*12 alleles. The HLA-DRB1*11 allele was present in 26.59% of cases and 22.55% of controls. The HLA-DRB1*12 allele was present in 56.63% of cases and 55.88% of controls. This study found no direct association between the carriage of the HLA-DRB1*11 and HLA-DRB1*12 alleles and the occurrence of breast cancer. In addition, the deletion of the HLA-DRB1*11 allele is associated (beneficial effect) with obesity/overweight (OR = 0.13; 95% CI [0.01-1.14]; and p = 0.03) which is a risk for breast cancer. No direct association was found between the carriage of HLA-DRB1*11 and 1*12 alleles and breast cancer risk. However, further investigation of other HLA alleles involved in the occurrence of breast cancer may provide more information.

Diversity of HLA class I and class II alleles in Iran populations: Systematic review and Meta-Analaysis

The human leukocyte antigen (HLA) system plays an essential role in the peptides antigen presentation and more regulation of immune responses. Regarding all HLA molecules' associations with various diseases and their clinical utilities in understanding drug reactions or prediction of transplantation outcome, there is a need for much more extensive HLA data generated from Asian countries.

METHOD

A comprehensive search was conducted in electronic databases between 1990 and 2021 to identify relevant articles to HLA frequency in the normal Iranian population. Two independent reviewers screened and selected the eligible studies. After data extraction, the meta-analysis was performed using STATA version 14. The overall frequencies and their 95% confidence intervals (CIs) were obtained using the random-effects model.

RESULTS

Among 1141 studies 78 were eligible for this study and the sample sizes varied from 14 to 15,600. The most frequent alleles of HLA class I were HLA-A*02 (22%; 95%CI: 20-24%; I² = 88.63%), -B*35 (18%; 95%CI: 16-21%; I² = 90.95%), -C*12 (18%; 95%CI: 13-22%; I² = 89.51%). HLA-DQA1*01 (42%; 95%CI: 40-44%; I² = 56.80%), -DQB1*03 (38%; 95%CI: 35-42%; I² = 92.38%), and -DRB1*11 (24%; 95%CI: 22-26%; I² = 90.72%) were the most frequent alleles of HLA class II in Iran.

DISCUSSION

Our meta-analysis results point out that the comprehensive report of HLA allele frequency in the Iranian population could be helpful as reference data for planning and managing transplantation and immune disease treatment in Iran.

Developing a Vaccine to Block West Nile Virus Transmission: In Silico Studies, Molecular Characterization, Expression, and Blocking Activity of Culex pipiens mosGCTL-1

BACKGROUND

Mosquito galactose-specific C-type lectins (mosGCTLs), such as mosGCTL-1, act as ligands to facilitate the invasion of flaviviruses like West Nile virus (WNV). WNV interacts with the mosGCTL-1 of Aedes aegypti (Culicidae) and facilitates the invasion of this virus. Nevertheless, there is no data about the role of mosGCTL-1 as a transmission-blocking vaccine candidate in Culex pipiens, the most abundant Culicinae mosquito in temperate regions.

METHODS

Adult female Cx. pipiens mosquitoes were experimentally infected with a WNV infectious blood meal, and the effect of rabbit anti-rmosGCTL-1 antibodies on virus replication was evaluated. Additionally, in silico studies such as the prediction of protein structure, homology modeling, and molecular interactions were carried out.

RESULTS

We showed a 30% blocking activity of Cx. pipiens mosGCTL-1 polyclonal antibodies (compared to the 10% in the control group) with a decrease in infection rates in mosquitoes at day 5 post-infection, suggesting that there may be other proteins in the midgut of Cx. pipiens that could act as cooperative-receptors for WNV. In addition, docking results revealed that WNV binds with high affinity, to the Culex mosquito lectin receptors.

CONCLUSIONS

Our results do not support the idea that mosGCTL-1 of Cx. pipiens primarily interacts with WNV to promote viral infection, suggesting that other mosGCTLs may act as primary infection factors in Cx. pipiens.

In silico Evaluation of PLAC1-fliC As a Chimeric Vaccine against Breast Cancer

Background

Breast cancer is one of the most prevalent cancers among women. Common cancer treatment methods are not effective enough, and there is a need for a more efficient treatment procedure. Cancer vaccine is a novel immunotherapy method that stimulates humoral and/or cellular immunity against cancer. Placenta-specific protein 1 (PLAC1) is a cancer/testis antigen, prevalent in breast cancer and rarely found in normal tissues. FliC, as a bacterial adjuvant, when fused to PLAC1 can elicit humoral and cellular responses. Therefore, PLAC1-fliC is a chimeric protein, which can be considered a suitable candidate against breast cancer.

Methods

ProtParam was used to evaluate the physicochemical properties of PLAC1-fliC. Second structures were determined using the GOR V server. PLAC1-fliC 3D structure was modeled by Phyre2, and it was refined using GalaxyWEB. The refined model was submitted to RAMPAGE, PROCHECK, and ProSA-web for validation. Antigenicity and allergenicity of the construct were predicted by ANTIGENpro, VaxiJen, AllergenFP, and SDAP databases. Then MHC-I- and MHC-II-binding epitopes of PLAC1-fliC were forecasted by NetMHC 4.0 and NetMHCII 2.3 Servers. Finally, Ellipro and CTLpred were employed to predict B-cell and cytotoxic T lymphocyte epitopes.

Results

The construct was evaluated as a stable fusion protein, which could be antigenic and could stimulate B and T cells against breast cancer.

Conclusion

PLAC1-fliC, as a cancer vaccine candidate, might be suitable and specific for breast cancer, which could evoke humoral and cellular immunity against this type of tumor.

HLA-DRB1*01:01, but not HLA-DRB1:1503 or HLA-DRB1*11, is associated with decreased inhibitor risk in Iranian hemophilia A patients

BACKGROUND/OBJECTIVE

Hemophilia A is a genetic disorder through which patients suffer from recurrent bleeding. This can be caused by a defect in human plasma coagulation factor VIII. High incidence of FVIII inhibitors in some severe hemophilia A patients after FVIII therapy is a considerable complication. Determination of good predictive factors can improve the safety of this treatment. HLA-II have been shown as a predictive element for inhibitor development. The goal of this study is to determine the association between HLA-DRB1*15:03, HLA-DRB1*11 and HLA-DRB1*01:01 alleles and FVIII inhibitors in severe hemophilia A patients in Iran.

MATERIALS/METHODS

HLA-DRB1 genotyping was performed using Multiplex sequences Specific Primers (PCR-SSP) in two groups of severe hemophilia A patients comprising 51 and 50 individuals with and without FVIII inhibitors respectively. The levels of inhibitor were determined through Nijmegen-modified Bethesda assay. HLA-DRB1 allele frequencies were compared between groups by using multiple logistic regression models.

RESULTS

HLA-DRB1*01:01 allele frequency was significantly higher in patients without inhibitor OR_adj: 2.7 (95%CI: 1.08, 6.97; P = 0.034). There wasn't any statistically significant difference in HLA-DRB1*11 allele frequency between groups OR_adj: 0.7 (95%CI: 0.27, 1.82; P = 0.47). There was no connection between HLA-DRB1*15:03 and inhibitor development OR_adj: 0.94 (95%CI: 0.38, 2.35; P = 0.94).

CONCLUSION

An association between HLA-DRB1*01:01 and paucity of FVIII inhibitor showed that this allele has probably a protective effect in severe hemophilia A patients in Iran. Determination of the predictive and protective alleles are beneficial in pre-treatment activities and decrease the risk of unsuccessful therapy with FVIII in each population.

High-Resolution HLA-A Typing in Normal Iranian Population

Background:

Human leukocyte antigen (HLA) gene is a highly polymorphic region. HLA typing is required to match patients and donors for transplantation; therefore, development of HLA registries is necessary for finding HLA match donors. HLA system is highly informative, and numerous studies have been conducted on HLA allele distribution in different populations.

Methods:

In this study, 100 unrelated Iranian individuals were typed for HLA-A locus using sequence-based typing method. Samples were subjected to the PCR, followed by Sanger sequencing and software analysis.

Results:

A*02:01 (13%) and A*24:02 (12%) were the two most frequent alleles, while A*01:14, A*02:05, A*02:11, A*02:34, A*02:50, A*11:04, A*23:02, A*24:34, A*25:01, A*26:09, A*26:43, A*29:67, A*30:54, A*31:02, A*31:66, A*32:03, A*32:04, A*33:03, and A*66:15 alleles had the least frequencies (1%).

Conclusion:

This is the first report of HLA-A allele level typing in a randomized population of Iran and can be useful for development of national registries of HLA-typed volunteer marrow donors and local cord blood banks.

HLA-DRB and HLA-DQ genetic variability in patients with aspirin-exacerbated respiratory disease

BACKGROUND

Major histocompatibility complex (MHC) class II is involved in T-cell activation, cytokine secretion, and induction of immune responses. Cytokines, staphylococcus super antigens, and eosinophil activation are proposed to play important roles in aspirin-exacerbated respiratory disease (AERD).

OBJECTIVES

This study is aimed at investigating the association of HLA-DRB and DQ genetic variabilities in patients with AERD.

METHODS

A genetic association analysis in three different groups, including 33 patients with AERD, 17 patients with aspirin-tolerant asthma (ATA), and 100 healthy controls was performed. Oral aspirin challenge (OAC) test was performed to identify aspirin hypersensitivity. Pulmonary function test (PFT) was performed for all patients. Eosinophil percentage in nasal smear and peripheral blood and serum immunoglobin (Ig)E were investigated. HLA-DRB, HLA-DQA1, and HLA-DQB1 were genotyped using polymerase chain reaction.

RESULTS

HLA-DQB1*0302 (OR, 5.49, 95% confidence interval [CI],(2.40-12.59)), HLA-DQA1*0301 (OR, 2.90, 95% CI, (1.49-5.67)), HLA-DRB4 (OR, 2.94, 95% CI, (1.61-5.36)), and HLA-DRB1*04 (OR, 3.19, 95% CI, (1.57-6.47)) were higher in patients with AERD compared with controls. In patients with AERD, HLA-DQB1*0301 (OR,0.22, 95% CI, (0.09-0.54)), HLA-DQA1*0501 (OR, 0.42, 95% CI, (0.21-0.81)), HLA-DRB1*11 (OR, 0.30, 95% CI, (0.12-0.73)), and HLA-DRB3 (OR, 0.38, 95% CI, (0.21-0.70)) were significantly lower compared with healthy controls. Patients with AERD had lower frequencies of HLA-DQB1*0301 (OR, 0.27, 95% CI, (0.08-0.86)), and HLA-DRB1*011 (OR, 0.27, 95% CI, (0.08-0.86)) compared with ATA. Haplotypes of HLA-DRB1*04/ DQA1*0301/ DQB1*0302 (OR, 4.25, 95% CI, (1.94-9.29)) and HLA-DRB1*07 /DQA1*0201/ DQB1*0201 (OR, 3.52, 95% CI, (1.54-8.06)) were higher in patients with AERD compared with controls (all p < 0.05).

CONCLUSIONS

Results of this study suggest that HLA-DQB1*0302 and HLA-DRB1*04 and their related haplotypes are genes involved in predisposing patients to AERD, whereas HLA-DQB1*0301 and HLA-DRB1*011 have negative association with AERD.

Frequency of HLA-DRB1 and HLA-DQB1 Alleles and Haplotype Association in Syrian Population

The study of Human Leukocyte Antigen (HLA) system is very important in health and diseases. As the HLA loci are the most polymorphic in the human genome, it plays a very important role in the immune responses to self and nonself antigens. In the light of the growing importance of typing the HLA alleles in transplantation, autoimmune diseases, cancer, and many other diseases, we studied 225 unrelated healthy Syrian subjects for their HLA class II genotypes in an attempt to reveal the distribution of the HLA (DRB1-DQB1) alleles in the general Syrian population. Our results revealed that the most common alleles for the DRB1 locus were DRB1*11 (26.4%), DRB1*04 (14%), and DRB1*07 (12%). However, the most frequent alleles for the DQB1 locus were DQB1*03 (40.9%) and DQB1*05 (25.1%). The frequent of two-locus haplotypes carry the most frequent alleles at these loci. The most frequently detected class II ''haplotypes'' are DRB1*11-DQB1*03 (8.9%), DRB1*01-DQB1*05 (3.6%), and DRB1*04-DQB1*03 (2.7%). Compared with other populations, our result, deduced from the analysis of genetic distances and the construction of neighbor-joining (NJ) dendrogram, and principal component analysis (PCA) indicates that Syrians are related to Middle Eastern populations. Our data about the Syrian population will aid researchers in studying the relation of HLA class II with different diseases in a Syrian population and will add to the available international literature associated with these loci.

Association of HLA class II (DRB1, DQA1, DQB1) alleles and haplotypes with myasthenia gravis and its subgroups in the Iranian population

Heterogenic pattern of HLA associations with myasthenia gravis (MG) among different ethnicities and also among different MG subgroups has been the subject of debate in large series of many studies. One hundred and sixty Iranian MG patients were investigated for HLA class II (DRB1, DQA1, DQB1) associations compared to two hundred healthy controls from the same ethnic population. DRB1*11 DQA1*0501 DQB1*0301 haplotype was found to be protective for total (ocular plus generalized) MG (Pc=0.005, OR=0.49) and generalized MG (Pc=0.008, OR=0.49). DRB1*04 DQA1*0301 DQB1*0302 haplotype (Pc=0.03, OR=2.25) was predisposing for anti-acetylcholine receptor (AChR) antibody-positive MG, while DRB1*16 DQA1*0102 DQB1*05 (Pc=0.013, OR=4.28) was predisposing for anti-muscle specific tyrosine kinase (MuSK) antibody-positive MG. There was also a trend of positive association for DRB1*14 DQA1*0104 DQB1*05 haplotype with MuSK-positive MG (Pc=0.054, OR=3.97). Among other MG subgroups and with less significance, DRB1*0101 DQA1*0101 DQB1*05 haplotype (P=0.016, OR=3.68) had positive association with pure ocular MG, and DRB1*03 DQA1*0501 DQB1*0201 haplotype (P=0.024) had negative association with thymomatous MG. This study highlights the importance of appropriate MG subgrouping according to clinical and paraclinical characteristics in HLA studies among MG patients.

Pharmacogenetic tests to predict the efficacy of aspirin desensitization in patients with aspirin-exacerbated respiratory diseases; HLA-DQB302

This study is aimed at investigating the association of HLA-DRB1, HLA-DQA1, and HLA-DQB1 variability with the response to aspirin desensitization (AD). A total of 16 patients with aspirin-exacerbated respiratory diseases (AERD, 81.3% were female) with median age of 29 ± 4.3 years were included in this study. Following 6 months, Sino-Nasal Outcome Test-22 (SNOT-22), medication, symptom scores, and forced expiratory volume in 1 s (FEV1) (all p < 0.001) improved significantly. However, only seven patients (43.7%) had clinically significant improvement in all of the medication and symptom scores and FEV1, who were considered responders to AD. Responders to AD had significantly higher symptom scores compared with non-responders at baseline (20 ± 1.18 vs 10 ± 1.27; p = 0.003). HLADQB1*0302 was significantly lower in non-responders than in responders to AD (0.12 [0.02-0.76]; p = 0.022). Sensitivity and specificity of HLA-DQB1*0302 to predict response to AD was 71.4% (95% CI: 35.8-91.7) and 81.8% (95% CI: 52.3-94.8). This study introduces HLA-DQB1*0302 as a genetic marker for favorable response to AD.

The amino acid variation within the binding pocket 7 and 9 of HLA-DRB1 molecules are associated with primary Sjögren's syndrome

Primary Sjögren's syndrome (pSS) is associated with HLA-DRB1 loci, but the association of amino acid variations in the hypervariable region of the HLA-DR β1 chain with pSS is largely unknown. In this study, we aimed to identify the amino acid variations within the hypervariable region of HLA-DRB1 molecule which are associated with the susceptibility to pSS. We sequenced the 2nd exon of the HLA-DRB1 locus in 52 pSS patients and 179 controls. The HLA-DRB1*0803 is the allele that shows the strongest association with pSS in Chinese population (OR = 3.0, P = 2.4 × 10(-4)). Furthermore, amino acid variations within the binding pocket P7 and P9 are associated with the susceptibility to pSS. An interaction between two residues within P7, β47 and β67, is associated with pSS. Structural modeling studies demonstrated that the electrostatics of peptide binding pocket 9 are opposite in pSS-susceptible and -protective HLA-DRB1 alleles. In conclusion, our results suggest that structural heterogeneity of the HLA-DRB1 peptide binding pocket P7 and P9 might play a role in the pathogenesis of pSS.

HLA-DRB1 and susceptibility to kidney allograft rejection in Southern Iranian patients

Kidney transplantation is the best treatment option for the patients with end-stage renal disease. Viral infections and genetic factors such as HLA-II antigens may affect the kidney transplant outcome. The compatibility of HLA-DRB1 molecules in the survival of kidney transplant is important. Also, the correlation between these molecules and viral infections is significant. The current study investigates the allele frequency of HLA-DRB1 in 41 recipient kidney transplant and 203 normal healthy controls by polymerase chain reaction using sequence specific primers. Moreover the relation between HLA-DRB1 allelic groups and hepatitis B, hepatitis C and cytomegalovirus viral infections was also studied. However statistical analysis of the allele frequencies didn't show any significant association between HLA-DRB1 allelic group distributions or sharing and susceptibility to acute kidney transplant rejection (P > 0.05). Comparing the allele frequencies between HLA-DRB1*14 and DRB1*04 allelic showed a significant difference in controls and patients (P = 0.03 and P = 0.05 respectively). The results of the present study also showed a significant association between possession of HLA-DRB1*07 allele in kidney transplant recipients and hepatitis C virus infection (P = 0.009). In conclusion however the results of the present study did not showed relation between HLA-DRB1 allele's frequencies or sharing and kidney transplantation outcome, the results indicated that HLA-DRB1 alleles may susceptible individuals to renal disease or play a role in susceptibility to viral infection in kidney transplant patients.

Allele and haplotype frequencies for HLA-DQ in Iranian celiac disease patients

AIM

To assess the distribution of human leukocyte antigen (HLA)-DQ2 and -DQ8 in Iranian celiac disease (CD) patients and compare them to healthy Iranian controls.

METHODS

To predict the HLA-DQA1 and -DQB1 genes, we used six previously reported HLA-tagging single nucleotide polymorphism to determine HLA genotypes in 59 Iranian patients with 'biopsy-confirmed' CD and in 151 healthy Iranian individuals. To test the transferability of the method, 50 cases and controls were also typed using a commercial kit that identifies individual carriers of DQ2, DQ7 and DQ8 alleles.

RESULTS

In this pilot study 97% of CD cases (n = 57) and 58% of controls (n = 87) were carriers of HLA-DQ2 and/or HLA-DQ8 heterodimers, either in the homozygous or heterozygous state. The HLA-DQ pattern of these 57 CD patients: heterozygous DQ2.2 (n = 14) and homozygous DQ2.2 (n = 1), heterozygous DQ2.5 (n = 33) and homozygous DQ2.5 (n = 8), heterozygous DQ8 (n = 13) and homozygous DQ8 (n = 2). Two CD patients were negative for both DQ2 and DQ8 (3%).

CONCLUSION

The prevalence of DQ8 in our CD population was higher than that reported in other populations (25.4%). As reported in other populations, our results underline the primary importance of HLA-DQ alleles in the Iranian population's susceptibility to CD.

HLA-DRB, -DQA, and DQB alleles and haplotypes in Iranian patients with diabetes mellitus type I

Specific alleles at the HLA-DRB1, -DQA1, and -DQB1 loci seem to be associated with variable risks of developing type 1 diabetes (T1D). This study assessed the distribution of HLA-DR and -DQ alleles among Iranian T1D patients and healthy controls. In this study, HLA-DRB1, -DQA1, and -DQB1 alleles were determined in 100 children with T1D and 100 unrelated healthy controls. The following alleles were found to have a strong positive association with T1D: DRB1*0301, DRB1*0401, DRB1*0402, DQA1*0301, DQA1*0501, DQB1*0201, and DQB1*0302. Meanwhile, protective associations were found for DRB1*1001, DRB1*1101, DRB1*15, DRB1*16, DQA1*0102, DQA1*0103, DQB1*0301, DQB1*0501, and DQB1*0602 alleles. The haplotypes found most frequently among patients with T1D were DRB1*0301-DQA1*0501-DQB1*0201, DRB1*0401-DQA1*0301- DQB1*0302, and DRB1*0402-DQA1*0301-DQB1*0302, whereas DRB1*1101-DQA1*0501-DQB1*0301 and DRB1*16-DQA1*0102- DQB1*0501 haplotypes were negatively associated with the disease. These results confirm the previously reported association of specific HLA-DR and HLA-DQ alleles and haplotypes with T1D in Iranian population. The notable difference was the identification of DRB1*16-DQA1*0102-DQB1*0501 as a protective haplotype and the absence of a negative association of DRB1*1301-DQA1*0103-DRB1*0603 with T1D.

Association between HLA-DQB1 gene and patients with acute lymphoblastic leukemia (ALL)

Acute lymphoblastic leukemia (ALL) affects both children and adults. Survival in ALL has improved in recent decades due to recognition of its biological heterogeneity. Although children have higher remission and cure rates than adults, both populations have benefited from these improvements. Our aim in this study is to determine the association between HLA-DQB1 genes with childhood and adult ALL patients. To define this association, we compared HLA-DQB1 allele frequencies and allele carrier frequencies in a cohort of 135 adults and children with ALL with 150 controls, using polymerase chain reaction with sequence-specific primers. Allele carrier frequencies in childhood ALL show a deficiency in DQ2 (*0201) (P 0.049 and RR 0.75), but an increase in DQ5 (*0501-*0504) and DQ7 (*0301, *0304) compared to the control group (P 0.001 RR 1.89, P 0.003 RR 1.48, respectively). Allele carrier frequencies in adult ALL indicated an increase in DQ5 (*0501-*0504) (P0.045 RR 2.28). Allelic frequencies in childhood ALL revealed the same increase in DQ5 and DQ7, and a decrease in DQ2. In adult ALL it shows a decrease in DQ7. Therefore, our results in adult ALL were similar to childhood ALL addressing DQ5 allele carriers, which showed an increase in both age groups. We suggest that DQ5 could be more strongly considered as an ALL susceptibility allele, and that this allele may underlie a pathogenic phenotype with a major role in the immunologic process involved in both adults and children with ALL.

Molecular analysis of human leukocyte antigen class I and class II allele frequencies and haplotype distribution in Pakistani population

AIM:

Distribution of HLA class I and II alleles and haplotype was studied in Pakistani population and compared with the data reported for Caucasoid, Africans, Orientals and Arab populations.

MATERIALS AND METHODS:

HLA class I and II polymorphisms in 1000 unrelated Pakistani individuals was studied using sequence-specific primers and polymerase chain reaction and assay.

RESULTS:

The most frequent class I alleles observed were A*02, B*35 and CW*07, with frequencies of 19.2, 13.7 and 20%, respectively. Fifteen distinct HLA-DRB1 alleles and eight HLA-DQB1 alleles were recognized. The most frequently observed DRB1 alleles which represented more than 60% of the subjects were DRB1 *03, *07, *11 and *15. The rare DRB1 alleles detected in this study were HLADRB1 *08 and *09, having frequencies of 0.9 and 1.7%, respectively. In addition, at DRB1-DQB1 loci there were 179 different haplotypes and 285 unique genotypes and the most common haplotype was DRB1*15-DQB1*06 which represented 17% of the total DRB1-DQB1 haplotypes. In our population, haplotype A*33-B*58-Cw*03 comprised 2.8% of the total class I haplotypes observed. This haplotype was seen only in the oriental populations and has not been reported in the African or European Caucasoid.

CONCLUSION:

Our study showed a close similarity of HLA class I and II alleles with that of European Caucasoid and Orientals. In Pakistani population, two rare loci and three haplotypes were identified, whereas haplotypes characteristic of Caucasians, Africans and Orientals were also found, suggesting an admixture of different races due to migration to and from this region.

Human leukocyte antigen-DQA1 gene allelic distribution: experience of a major tertiary care center in Lebanon

AIMS

DQA1 is a human leukocyte antigen (HLA) class II molecule that is similar to the other class II molecules DR and DP. This study is the first of its kind to describe the distribution of HLA-DQA1 alleles in Lebanon.

METHODS

HLA-DQA1 typing was detected using the polymerase chain reaction/sequence-specific priming method in 111 Lebanese individuals referred for HLA typing and possible bone marrow donation.

RESULTS

Our data was compared to that of several populations. Some similarities were found between the Lebanese, Tunisian, Spanish, and Kuwaiti populations.

CONCLUSION

This very first report from Lebanon will be of great help for later research to study the association of DQA1 alleles with major diseases in the Lebanese population and will add to the published international literature related to this important histocompatibility locus.

Computer-aided analysis of structural properties and epitopes of Iranian HPV-16 E7 oncoprotein

Infection by human papillomavirus type 16 (HPV-16) is the cause of 50% or more of cervical cancers in women. The E7 oncoprotein of HPV-16 has long been known as a potent immortalizing and transforming agent. We used different servers like PseAAC, MHC_binding, MHC_II_binding and Expasy for the present computational prediction. The results for T cell epitopes showed that B1501, A0203, A0201, A0202, A6801 and DRB0405 alleles had lower IC50 than other alleles. We also predicted several peptides with the best binding affinities for alleles of the most frequent MHC class I and II alleles of the various ethnic groups living in the different region of Iran. Two peptides (26-35) and (44-52) were predicted as B-cell epitopes. According to this analysis 1 N-glycosylation site, 2 PKC sites, 4 CK2 sites and 3 disulfide sites were predicted. Our computational study predicted that B cell epitope 1 was Casein kinase II phosphorylated (site No. 31) and glycosylated (site No. 29). Putative MHC-I epitopes 3 and 5 and MHC-II epitopes 19, 21 and 26 were predicted to be casein kinase II phosphorylated. MHC-II epitopes 19 and 21 was predicted to be glycosylated. T cell epitopes 1, 13, 16 and 24 were demonstrated to be kinase C phosphorylated. The result of this analysis for Iranian HPV-16 E7 also indicated that 21.43%, 18.37% and 60.20% of the protein were in the α-helix, extended strand and random coil respectively.

The genetic relationship among Iranian ethnic groups: an anthropological view based on HLA class II gene polymorphism

Highly polymorphic human leukocyte antigen (HLA) genes are considered as useful markers by molecular anthropologists to determine genetic relationship among populations. This review summarizes the results of molecular analyses of HLA class II gene polymorphism in 816 DNA samples from 11 Iranian ethnic groups. The genetic relationship of Iranians to Asians and Europeans has also been reported here. The results of this study revealed a close genetic relationship among Iranian subpopulations which were well separated from other Asian and European populations, however, a genetic similarity was observed among Iranians, Macedonians, Greeks, and Italians.

Analysis of HLA DR2&DQ6 (DRB1*1501, DQA1*0102, DQB1*0602) haplotypes in Iranian patients with multiple sclerosis

Multiple sclerosis (MS) is prototype of inflammatory demyelinating disease of the central nervous system .The etiology of MS remains unclear, but according to current data the disease develops in genetically susceptible individuals and may require additional environmental triggers. The human leukocyte antigen (HLA) class II alleles (DRB1*1501, DQA1*0102, DQB1*0602) may have the strongest genetic effect in MS. In this study, the role of these alleles were investigated in 183 Iranian patients with multiple sclerosis and compared with 100 healthy individuals. HLA typing for DRB1*1501, DQA1*0102, DQB1*0602 was performed by polymerase chain reaction (PCR) amplification with sequence-specific primers (PCR-SSP) method. The results show that, HLA DR B1*1501 was significantly more frequent among MS patients (46% vs. 20%, PV = 0.0006) but DQA1*0102 haplotype was negatively associated with MS (30% vs. 50%, PV = 0.0049) and no significant association was found with DQB1*0602 and MS patients in comparison with control group (24% and 30%, PV = 0.43). No significant correlation was observed among these alleles with sex, type of disease; initial symptoms, expanded disability status scale (EDSS), as well as age at onset and familial MS. This study therefore indicates that there is no association of above HLA haplotypes with clinical presentation, disease duration, and disability in Iranian patients with MS which is in line with other previous studies in different ethnic groups.

HLA class II (DRB, DQA1 and DQB1) allele and haplotype frequencies in the patients with pemphigus vulgaris

INTRODUCTION

Pemphigus vulgaris (PV), an autoimmune disease affecting the skin and mucous membranes, is associated with some human leukocyte antigen (HLA) class II alleles and haplotypes.

MATERIALS AND METHODS

In order to evaluate the association of HLA-DR and DQ alleles and haplotypes in Iranian non-Jewish patients with PV, 52 patients with PV and 180 normal subjects as control group were investigated in this study.

RESULTS AND DISCUSSION

HLA-DRB1*04, -DRB1*1401, -DRB4, -DQA1*0104, -DQA1*03011, -DQB1*0302, and -DQB1*0502 alleles have been significantly increased in our patients group. Moreover, the haplotypes HLA-DRB1*04/-DQA1*03011/-DQB1*0302 and HLA-DRB1*1401/-DQA1*0104/-DQB1*0502 increased significantly in our patients. In contrast, the following alleles decreased significantly in our patients: HLA-DRB1*15, -DRB1*0301, -DRB1*07, -DRB1*11, -DRB5, -DQA1*0101, -DQA1*0103, -DQA1*201, -DQA1*05, -DQB1*0201, -DQB1*0301, -DQB1*06011, and -DQB1*0602. In addition, HLA-DRB1*15/-DQA1*0103/-DQB1*06011, HLA-DRB1*0301/-DQA1*05011/-DQB1*0201, HLA-DRB1*07/-DQA1*0201/-DQB1*0201, and HLA-DRB1*11/-DQA1*05/-DQB1*03011 decreased significantly in our patients. Genetic factors are involved in the occurrence of PV; HLA-DRB1*04 and -DRB1*1401 alleles and the related haplotypes are suggestive to be two major PV susceptibility factors in our population study.

Human leukocyte antigen class II allele association to disease progression in Iranian patients with chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is the most frequent type of leukemia in Western countries, but its incidence is low in Asian populations. In the present study we determined the frequency of DRB1 and DQB1 alleles in 87 Iranian CLL patients and 100 healthy controls using a polymerase chain reaction (PCR) technique. An increased frequency of DRB1*07 (p = 0.04), DQB1*06 (p = 0.01) alleles, and DRB1*13/DQB1*03 haplotype (p = 0.01) and decreased frequency of the DQB1*03 (p = 0.01) allele were observed in our patients compared with healthy controls. Comparison between patients with indolent (n = 42) and progressive (n = 38) disease revealed a significant increase in DRB1*04 and DRB5 alleles in progressive patients. Similarly, a higher frequency of DRB5 (p = 0.01) allele was observed in CD38(+) compared with CD38(-) patients. Classification of the patients into immunoglobulin variable region heavy-chain genes mutated and unmutated subtypes did not reveal significant differences for the expression of any of the HLA alleles or haplotypes between these two subtypes. Our findings observed in an Iranian population indicate that CLL could be associated with distinct HLA class II alleles and haplotypes of which the DQB1*06 allele and DRB1*13/DQB1*03 haplotype have not already been reported in CLL patients from other ethnic backgrounds. Some HLA class II alleles may contribute to disease progression in CLL.

Balancing selection and heterogeneity across the classical human leukocyte antigen loci: a meta-analytic review of 497 population studies

This paper presents a meta-analysis of high-resolution human leukocyte antigen (HLA) allele frequency data describing 497 population samples. Most of the datasets were compiled from studies published in eight journals from 1990 to 2007; additional datasets came from the International Histocompatibility Workshops and from the AlleleFrequencies.net database. In all, these data represent approximately 66,800 individuals from throughout the world, providing an opportunity to observe trends that may not have been evident at the time the data were originally analyzed, especially with regard to the relative importance of balancing selection among the HLA loci. Population genetic measures of allele frequency distributions were summarized across populations by locus and geographic region. A role for balancing selection maintaining much of HLA variation was confirmed. Further, the breadth of this meta-analysis allowed the ranking of the HLA loci, with DQA1 and HLA-C showing the strongest balancing selection and DPB1 being compatible with neutrality. Comparisons of the allelic spectra reported by studies since 1990 indicate that most of the HLA alleles identified since 2000 are very-low-frequency alleles. The literature-based allele-count data, as well as maps summarizing the geographic distributions for each allele, are available online.

The frequency of transforming growth factor-beta1 gene polymorphisms in a normal southern Iranian population

Several single nucleotide polymorphisms (SNPs) of the transforming growth factor-beta1 gene (TGFB1) have been reported. Determination of TGFB1 SNPs allele frequencies in different ethnic groups is useful for both population genetic analyses and association studies with immunological diseases. In this study, five SNPs of TGFB1 were determined in 325 individuals from a normal southern Iranian population using polymerase chain reaction-restriction fragment length polymorphism method. This population was in Hardy-Weinberg equilibrium for these SNPs. Of the 12 constructed haplotypes, GTCGC and GCTGC were the most frequent in the normal southern Iranian population. Comparison of genotype and allele frequencies of TGFB SNPs between Iranian and other populations (meta-analysis) showed significant differences, and in this case the southern Iranian population seems genetically similar to Caucasoid populations. However, neighbour-joining tree using Nei's genetic distances based on TGF-beta1 allele frequencies showed that southern Iranians are genetically far from people from the USA, Germany, UK, Denmark and the Czech Republic. In conclusion, this is the first report of the distribution of TGFB1 SNPs in an Iranian population and the results of this investigation may provide useful information for both population genetic and disease studies.

Frequency of cystathionine beta-synthase 844INS68 polymorphism in Southern Iran

Iranian population with an Indo-European origin is one of the oldest populations in the world. Historical evidence suggests the close similarity in the origin of Iranian, European and north Indian population. However, there are few anthropological and genetic evidences on this subject. This study, which is the first report from Iran, was performed to investigate the genetic origin of Iranian population using a polymorphism in Cystathionine beta synthase (CBS) gene known as 844INS68bp in this respect, genomic DNA was extracted from the whole blood of 480 healthy normal blood donors referred to Fars Blood Transfusion Center, using a salting out method. The fragment containing 844INS68bp was amplified, the normal fragment was 174 bp and the fragment containing the insertion was 242 bp in length. Results indicated that 418 (87.08%) out of 480 individuals had a normal (N/N) genotype, 59 (12.29%) individuals were heterozygote (N/I) and 3 (0.63%) had homozygote a mutated genotype (I/I). The total frequency of 844INS68bp allele was found 6.8% which is similar to with the reported in White Caucasians. Comparison of the genotype of this study with the polymorphism in other populations revealed that Southern Iranian population has a great similarity with other Caucasians populations' especially South Italy and North America while differed from East Asian and African populations. These results are in agreement with the result of other studied polymorphisms. Therefore, despite the great admixture of Iranian population with the neighboring non-Caucasian populations during the time, Iranian population still share a genetic background with other Caucasian populations.

Differential effects of DRB1*0301 and DQA1*0501-DQB1*0201 on the activation and progression of islet cell autoimmunity

Autoimmune diabetes shows extreme variation in age of onset and clinical presentation, although most studies have been done in children with the most severe subtype. Disease risk is strongly associated with HLA-DRB1*0301-DQA1*0501-DQB1*0201 (DR3-DQ2), but it has not been possible to separate the effects of the DR and DQ alleles. We have identified a large Bedouin kindred in which a high prevalence of islet autoimmunity is associated with two different DR3 haplotypes, one carrying the usual DQ2 and the other carrying DQA1*0102-DQB1*0502 (DQ5). Results of prospective follow-up studies indicate that DR3 is associated with the initial activation of islet autoimmunity whereas DQ2 is associated with early-onset and severe clinical disease. The association signals map to a 350-kb interval, thus implicating primary effects for DR3 and DQ2. Overall, our results emphasize the importance of prospective genetic studies that examine the full range of variation in the initiation, progression and expression of autoimmune disease.

Apolipoprotein E polymorphism in Southern Iran: E4 allele in the lowest reported amounts

BACKGROUND

Apolipoprotein E (apoE) with three major alleles E2, E3 and E4 is one of the critical genes in lipid metabolism. Common apoE alleles are in association with an increase in risk for central nervous and cardiovascular diseases such as Alzheimer's disease, dementia, multiple sclerosis, atherosclerosis, coronary heart disease, hyperlipoproteinemia and stroke. ApoE3 is known as the most frequent allele in all populations, while association of apoE gene polymorphism with reported diseases have mostly been related to other two major alleles especially apoE4.

OBJECTIVE

To determine of apoE alleles frequencies in Southern Iran and comparison of those frequencies with other populations.

METHODS

DNA was extracted from the whole blood of 198 healthy unrelated candidates from population of Fars Province, Southern Iran, for apoE genotyping who were checked up by a physician. The frequencies of apoE alleles were compared with other populations by chi(2) test.

RESULTS

The frequencies of E2, E3 and E4 were 0.063, 0.886 and 0.051 respectively. These values were similar to those reported from populations of Kuwait, Oman, Lebanon, India, Turkey, Greece, Spain, Sardinia Islands of Italy and two Iranian populations but were different from South of Italy and Caucasians in other Europe regions, American, American-Indian, African, East Asian and Saudi populations (P < 0.05).

CONCLUSION

The frequency of E4 allele as a genetic risk factor for some multifactorial diseases in the population of Southern Iran is in the lowest reported amounts in the world. Iranian population has Caucasoid origin but differs from some Caucasian populations in Europe and America. The results of present study are in agreement with the historical evidences which show admixture of Iranian population with other populations and some studies based on genetic polymorphisms in the population of Southern Iran.

Association of HLA class II allele and haplotype frequencies with chronic myelogenous leukemia and age-at-onset of the disease

Chronic myelogenous leukemia (CML) is characterized by the presence of Philadelphia chromosome resulting from bcr/abl translocation. To clarify the association between HLA class II allele and haplotype frequencies in CML, 50 patients referred to Hematology Oncology and Bone Marrow Transplantation (BMT) center, Shariaty Hospital, Tehran, Iran, were randomly selected and compared with a group of 80 unrelated healthy blood donor subjects. HLA class II alleles were determined by PCR-SSP method. The results showed that the frequencies of DQB1*03011 (P=0.01) and DQA1*0505 (P=0.05) were higher, while that of DQB1*03032 (P=0.04) was lower in patients than in the controls. Regarding age-at-onset, the frequency of HLA-DRB1*07 (P=0.03) and -DQA1*0201 (P=0.03) alleles were higher in patients younger than 35 years. The most frequent haplotypes in our CML patients were HLA-DRB1*11/-DQB1*03011/-DQA1*0505 (P=0.01) and HLA-DRB1*04/-DQB1*0302/-DQA1*03011 (P=0.02). In conclusion, it is suggested that positive and negative association in certain HLA alleles and haplotypes exist in Iranian patients with CML.

HLA-DRB1 frequencies of the Comorian population and their genetic affinities with Sub-Saharan African and Indian Oceanian populations

BACKGROUND

Ethnic-historic sources have considered the Comorian population to be the result of an amalgamation of African, Arabian and Southeast Asian groups.

AIM

This study seeks to determine the genetic relationships and contributions from Sub-Saharan Africa and Indian Oceania and to reconstruct past migration events.

SUBJECTS AND METHODS

The human leukocyte antigen (HLA) polymorphism of a Comorian population was described and analysed.

RESULTS

Genetic distances and multidimensional scaling analyses showed complex patterns of genetic differentiation in the Indian Oceanian area as a result of continuous gene flow occurring within the past approximately 2500 years. Nevertheless, the Comorian genetic pool appears to be a mix of Bantu-speaking and Arab populations as testified to by admixture estimations of almost 50-60% and 27-33%, respectively.

CONCLUSION

The Comorian population may represent the eastern limit of the recent and massive eastward Bantu expansion. In contrast to the population from Madagascar (Merina), only a restricted influence of Austronesian populations was found.

HLA class II gene polymorphism in Parsees and Zoroastrians of Iran

Extensive polymorphism of the HLA genes in different ethnic groups has been used as an invaluable tool for anthropological studies. In this study, HLA-DRB1, DQA1 and DQB1 allele frequencies and haplotypes were determined in 72 Parsees and 65 Zoroastrians living in Iran. The predominant DRB1 allele was *1103 = 4 in Parsees and *0701 in Zoroastrians. DQA1*0501 was the most common alleles in both spopulations. The most frequent DQB1 allele was *0301 in Parsees and *0201 in Zoroastrians. DRB1*1103 = 4-DQA1*0501-DQB1*0301 and DRB1*0701-DQA1*0201-DQB1*0201 were the most prevalent haplotypes in Parsees and Zoroastrians, respectively. Significant deviation from Hardy-Weinberg equilibrium was observed in DQA1 and DQB1 loci of Zoroastrians. The former locus also departed from neutrality due to balancing selection. All pairs of the studied loci in this study showed significant linkage disequilibrium. Analysis of molecular variance indicated that the main variation was confined to individuals within the studied populations. Neighbour-joining tree based on Nei's genetic distances according to DRB1 and DQB1 allele frequencies showed that Parsees and Zoroastrians of Iran were located in the same cluster of the phylogenetic tree. Furthermore, Zoroastrians of Iran and Pakistan are very close to each other. This study will serve as a reference for further anthropological studies when the HLA profile of all ethnic groups of Iran is investigated.

HLA-DRB1 association in Saudi rheumatoid arthritis patients

Association between HLA-DRB1 alleles and rheumatoid arthritis (RA) has been known for more than three decades. However, the strength of these links varies between ethnic groups. This study examines the frequency of HLA-DRB1 alleles amongst Saudi RA patients. The DRB1 region of major histocompatibility complex was screened by polymerase chain reaction/sequence specific primers (PCR/SSP) in a total of 140 subjects including 70 RA patients and 70 matched healthy controls. HLA-DRB1 *04 was found to be the most frequent allele associated with RA followed by DRB1 *08 and DRB1 *10. On the other hand, the frequency of DRB1*06 was found to be decreased in RA patients as compared to controls. Molecular sub typing of the most prevalent allele DRB1 *04 revealed a statistically significant association between RA and DRB1 *0405. We conclude that an improved understanding about the influence of HLA on RA might help in predicting the susceptibility or protection against disease.

HLA class II profile and distribution of HLA-DRB1 and HLA-DQB1 alleles and haplotypes among Lebanese and Bahraini Arabs

The gene frequencies of HLA class II alleles were studied in 95 healthy Lebanese Arab and 72 healthy Bahraini Arab subjects. Our aim was to establish the genetic relationship between Bahraini and Lebanese Arabs in terms of HLA class II gene and haplotype frequencies and to compare these results with frequencies for other countries with populations of Caucasian and non-Caucasian descent. Subjects were unrelated and of both sexes, and HLA-DRB1 and -DQB1 genotyping was done by the PCR sequence-specific primer technique. Comparative analysis of the HLA-DR and -DQ alleles revealed differences in the allelic distribution among Bahraini and Lebanese subjects. Analysis of the 25 HLA-DRB1 alleles that have been investigated showed that the DRB1*040101 and DRB1*110101 alleles were more frequent among Lebanese, whereas DRB1*030101 and DRB1*160101 alleles were more frequent among Bahrainis. Similarly, of the seven HLA-DQB1 alleles analyzed, the presence of DQB1*0201 was more frequent among Bahrainis, whereas DQB1*030101 was more frequent among Lebanese. The DRB1*160101-DQB1*050101 (0.1318 versus 0.0379%) and DRB1*030101-DQB1*0201 (0.1202 versus 0.0321%) haplotypes were more frequent among Bahrainis, while the DRB1*110101-DQB1*030101 (0.3142 versus 0.1198%) and DRB1*040101-DQB1*0302 (0.1416 versus 0.0278%) haplotypes were more frequent in Lebanese subjects. Furthermore, a high prevalence of the DRB1*040101-DRB1*110101-DQB1*0302-DQB1*030101 (12.63 versus 1.35%, P = 0.015) and the homozygous DRB1*110101-DRB1*110101-DQB1*030101-DQB1*030101 (7.37 versus 0.00%, P = 0.046) genotypes was seen among Lebanese, and DRB1*070101-DRB1*160101-DQB1*0201-DQB1*050101 (6.76 versus 0.00%, P = 0.034) was seen more frequently among Bahraini subjects. Our results underline significant differences between these two populations in HLA class II distribution, provide basic information for further studies of major histocompatibility complex heterogeneity among Arabic-speaking countries, and serve as a reference for further anthropological studies.

The frequency of CCR5Δ32 and CCR2-64I in southern Iranian normal population

Host genetic control of HIV infection involves certain polymorphisms of some chemokine receptor genes that are associated with susceptibility and progression of HIV-1 infection. Recent data suggest that two important polymorphisms in CCR2 and CCR5 chemokine receptors, CCR5Delta32 and CCR2-64I, prevent HIV transmission and delay disease progression. In this study allele and haplotype frequencies of the CCR5Delta32 and CCR2-64I mutations were determined in southern Iranian normal population using PCR and PCR restriction fragment length polymorphism (PCR-RFLP) assays. Allele frequencies and the fit to the Hardy-Weinberg equilibrium (HWE) were evaluated by Arlequin population genetic software. Frequencies of CCR5Delta32 and CCR2-64I alleles were 0.0146 and 0.1221, respectively. Moreover, higher and lower haplotype frequencies in 341 normal individuals were CCR2/CCR5 (0.8636) and CCR5/CCR2-64I (0.1217), respectively. Only one case with CCR5Delta32/CCR2-64I haplotype was found among the studied normal population. This data is the first finding on the frequencies of CCR5Delta32 and CCR2-64I alleles in Iranian population. Results of the present study suggest that low frequency of CCR5Delta32 allele may be related to higher genetic susceptibility to the HIV-1 infection in Iranians. Results also suggest that the CCR2-64I mutation is sufficiently common in Iranians and may be associated with slower HIV infection progression in Iran.

Distribution of HLA class II (DRB1/DQB1) alleles and haplotypes among Bahraini and Lebanese Arabs

The genetic relationship between Bahraini and Lebanese Arabs in terms of HLA class II (DRB1 and DQB1) gene and haplotype frequencies was investigated in a group of 90 Lebanese and 52 Bahraini Arabs. Subjects of both sexes were unrelated and HLA-DRB1 and DQB1 genes were genotyped using the polymerase chain reaction-sequence specific primer (PCR-SSP) technique. Analysis of the HLA-DRB1 alleles showed that the DRB1*040101 and DRB1*110101 alleles were more common among Lebanese, whereas DRB1*030101, DRB1*130701/1327, and DRB1*160101 alleles were more common among Bahrainis. Similarly, of the 7 HLA-DQB1 alleles analyzed, the presence of DQB1*0201 was higher among Bahrainis, whereas DQB1*030101 was higher among Lebanese. The DRB1*160101-DQB1*050101 (23.08%) and DRB1*030101-DQB1*0201 (21.15%) haplotypes were more frequent among Bahrainis, while the DRB1*110101-DQB1*030101 (56.67%), DRB1*040101-DQB1*0302 (28.89%) and DRB1*040101/DQB1*030101 (25.56%) haplotypes were more frequent in Lebanese subjects. Our results underline significant differences between these two populations in HLA class II distribution, and provide basic information for further studies of MHC heterogeneity among Arab-speaking countries, and as a reference for further anthropologic studies.

HLA class II typing in newborns reveals a low frequency of the DRB1*04 allele and a high frequency of DRB1*11 allele in three regions of continental Italy

As part of a longitudinal study aimed at defining the natural history of prediabetic autoimmunity and predicting the risk of future cases of type 1 diabetes, 3607 newborns from three regions of continental Italy (Lombardia, Liguria, and Lazio) were subjected to genetic testing to determine human leukocyte antigen-DRB1 (HLA-DRB1) and -DQB1 allele and phenotype frequencies. Polymerase chain reaction and immobilized sequence-specific oligonucleotide probe assays were used to identify ten DRB1 allele lineages and three DQB1 alleles. No major inter-regional differences emerged in the allelic distribution indicating homogeneous distribution of the HLA DRB1-DQB1 alleles among the three regions analyzed. Comparison of our data with those published for other Caucasian populations reveals that these three regions are characterized by a very low frequency of DRB1*04 (8%) and a high frequency of DRB1*11 (25%). The phenotype frequencies of HLA-DQB1*0302 and DQB1*0602 observed are also lower than those reported for other populations. Furthermore, the DRB1*04-DQB1*0302 haplotype was relatively infrequent in our population (5.3% of the newborns tested). These findings furnish a genetic "portrait" of the populations of the analyzed regions that will be useful not only for investigation of the genetic risk of type 1 diabetes mellitus in Italy but also for studies of other autoimmune diseases related to HLA genotypes.

Variation of HLA class II genes in the Nganasan and Ket, two aboriginal Siberian populations

Allelic frequencies at the three most polymorphic loci of the HLA class II region (DRB1, DQA1 and DQB1) were determined in the Nganasan and Ket, the remnants of the two most ancient groups in the Lower Yenisey River/Taimyr Peninsula region in northern Siberia. By single-stranded conformational polymorphism typing, verified by sequencing, 19 HLA-DRB1-DQA1-DQB1 haplotypes and 15 HLA-DRB1, seven DQA1 and 11 DQB1 alleles were found. The most frequent alleles were DRB1*1301 (23.5%), DQA1*0103 (29.4%), *0501/03/05 (29.4%), and DQB1*0301/09 (32.4%) in the Ket, and DRB1*0901 (25%), DQA1*0301 (39.6%), and DQB1*0301/09 (37.5%) in the Nganasan. The distribution patterns and comprehensive phylogenic analysis based on the haplotype frequencies of 17 Siberian populations suggest that the founders of both the Ket and the Nganasan came from Palaeolithic populations in the Altai-Sayan Upland.

Genetic polymorphism of HLA DR in a Scottish population of patients with pars planitis

PURPOSE

Human leucocyte antigen (HLA) class II influences the immunological susceptibility for a variety of diseases including many types of non-infectious intraocular inflammation. Previous studies on North American patients with pars planitis, a subtype of intermediate uveitis, reported an increased prevalence of HLA DR15 in this population. In contrast, two European studies could not find an association between HLA DR2 or its allelic subtype DR15 and various forms of intermediate uveitis. We therefore investigated the genotype frequency of HLA DR alleles in a Scottish population of patients with typical pars planitis.

METHODS

Twenty patients with pars planitis were identified from the uveitis database of Grampian University Hospitals. Only patients with bilateral vitritis and snowbanks in at least one eye in the absence of systemic disease were included in the study. Fifteen patients and 34 healthy controls underwent HLA DR genotyping for all DRB genes using PCR sequence specific primers.

RESULTS

HLA DR15 was found in 13% of patients with pars planitis and in 24% of controls. There was no statistically significant difference between these two groups. Furthermore, the frequencies of HLA DR 1, 3-14, and 16 did not differ significantly between patients and controls.

CONCLUSIONS

There appears to be no association between the occurrence of pars planitis and the HLA DR15 or other known HLA DR genotypes in Scottish patients. However, the small sample size limits the power of this study.

High risk HPV types in southern Iranian patients with cervical cancer

This study was undertaken to assess the rate of HPV infection in cervical carcinoma among southern Iranian patients. 101 archival cervical carcinoma tissue samples of a 10 year period were studied for the presence of HPV DNA in southern Iran by a polymerase chain reaction method. In addition, the presence of high risk HPV-16 and HPV-18 genotypes was investigated. In total, 88 (87.1%) of the samples were HPV DNA positive, of which 83 were squamous cell carcinomas and 5 were adenocarcinomas. HPV-16 genotype was detected in 26.7% of HPV positive cervical carcinomas; however, none of the samples were positive for the existence of HPV-18 genotype. Collectively, these results suggest that HPV-16 and HPV-18 are not the frequent high risk HPV types in our patients and circulating HPV types in southern Iranian population are different from many other populations.

PCR-SSOP molecular typing of HLA-C alleles in an Iranian population

HLA-C alleles were characterized by a polymerase chain reaction-sequence specific oligonucleotide probe (PCR-SSOP) hybridization protocol in a sample of 120 Iranians from Tehran. A total of 23 alleles were identified with the four most predominant--Cw*0401, Cw*0602, Cw*1202, and Cw*0701/06--accounting for almost 50% of HLA-C alleles. A comparison of HLA-C diversity among several populations indicates that Iranians stand at an intermediate genetic position between Europeans and Africans, an observation that may be related to their geographical location at a continental crossroads. The results also reveal a very high correlation between genetic and geographic distances on a global scale. A total of 30 HLA-C-DRB1 haplotypes were found in the Iranians, with the highest frequencies of 6.6% and 6.04 % being for Cw*0602-DRB1*0701 and Cw*1202-DRB1*1502, respectively.