p 53 codon 72 polymorphism in stomach and colorectal adenocarcinomas in Iranian patients

BACKGROUND

The association of a functional single nucleotide polymorphism at codon 72 of the p53 gene (Arg72Pro) with malignancy is a subject of controversy. We analyzed this polymorphism in 224 patients with gastrointestinal cancers (92 with stomach cancer and 132 with colorectal cancer) and in 163 healthy controls.

MATERIAL AND METHODS

DNA was extracted from peripheral blood mononuclear cells and amplified with an allele-specific polymerase chain reaction.

RESULTS

There was no significant association between p53 alleles and gastrointestinal cancers. The frequency of the Arg allele was 59.7, 58.8, and 59.2% in the stomach cancer patients, colorectal cancer patients, and controls, respectively. Frequencies of the Pro allele were 40.3% in patients with stomach cancer, 41.2% in patients with colorectal cancer, and 40.8% in controls. Likewise, genotype frequencies did not differ significantly between the two patient groups and controls. There were no differences in genotype or allele frequencies by gender, age, or histological grade.

CONCLUSIONS

The data do not support the association of the p53 codon 72 polymorphism with stomach or colorectal cancers in Iranian patients.

CTLA4 exon 1 and promoter polymorphisms in patients with multiple sclerosis

OBJECTIVE

The polymorphisms of exon 1 (+49 A/G) and promoter regions (-1722 T/C, -1661 A/G and -318 C/T)of cytotoxic T lymphocyte antigen 4 (CTLA4) and also haplotypes constructed from mentioned loci were investigated amongst 153 Iranian patients with definite multiple sclerosis (MS) and 190 healthy controls.

METHODS

The polymorphisms were genotyped by PCR-restriction fragment length polymorphisms and PCR-amplification refractory mutation system. The 4-locus haplotypes were estimated by Arlequin software (University of Berne, Berne, Switzerland).

RESULTS

Preliminary results showed significant increase of +49 G allele and -1661 AG genotype, as well as TGCA haplotype among patients than controls (P < 0.036, P = 0.009 and P < 0.010, respectively). The distribution of -1722 T/C, -1661 A/G, -318 C/T and +49 A/G (TACA) haplotype, from the contrary, was observed to be significantly increased among controls (P < 0.001).

CONCLUSIONS

After Bonferroni correction, the results provide preliminary evidence that CTLA4 genetic variation at -1661 locus may render Iranian individuals to be more susceptible to MS, whereas harboring TACA haplotype might be protective.

Cell cycle analysis and cytotoxic potential of Ruta graveolens against human tumor cell lines

There are reports on the presence of various compounds exerting different biological activities in Ruta graveolens, a plant of Rutaceae family. The aim of the present study was to evaluate in vitro cytotoxicity of the total extract of R. graveolens against tumor cell lines of different origin. Aerial parts of the plant was extracted with 70% ethanol by sonication method and cytotoxic activity was examined on RAJI, RAMOS, RPMI8866, U937, Jurkat, MDA-MB-453, MCF-7, LNCap-FGC-10, 5637, HeLa, SK-OV-3, A549, Mehr-80 and also peripheral blood mononuclear cells (PBMC) by the use of WST-1 assay. Results were expressed as IC(50) values. R. graveolens extract showed high cytotoxic activity against RAJI and RAMOS, two Burkitt's lymphoma cell lines, with an IC(50) equal to 24.3 microg/ml and 35.2 microg/ml respectively and LNCap-FGC-10, a prostate adenocarcinoma cell line with an IC(50) equal to 27.6 microg/ml as well as Mehr-80, a newly established Large Cell Lung Carcinoma (IC(50)=46.2 microg/ml). No significant anti-proliferative activity was observed on other cell lines including MCF-7, MDA-MB-453, SK-OV-3, HeLa, 5637, JURKAT and RPMI8866. Adverse cytotoxic effect of R. graveolens was investigated against PBMCs and a significantly lower effect of this extract (IC(50)=104 microg/ml) was seen on normal cells compared with RAJI and RAMOS, two haematopoietic cell lines.

Exon-1 Polymorphism of ctla-4 Gene in Iranian Patients with Graves' Disease

Polymorphisms in ctla-4 gene have been shown to be associated with the Graves' disease (GD) susceptibility in different populations in the world. This study was undertaken to disclose the probable association of exon-1 polymorphism of ctla-4 with GD in Iranian patients. A49G polymorphism was investigated in 90 patients and 90 age/sex matched normal healthy controls, using PCR-SSCP and PCR-RFLP methods. Frequencies of AA, AG and GG genotypes among patients were found to be 21 (23.3%), 49 (54.5%) and 20 (22.2%) while these frequencies among healthy controls were 30 (33.3%), 53 (58.9%) and 7(7.8%), respectively. A significant increase of GG genotype and G allele was observed in patients (p = 0.012 and p = 0.025). In conclusion, consistent with the results of most other studies, the presence of a G allele in position 49 of ctla-4 exon-1 is associated with susceptibility to GD in Iranian population.

Placental transfer of tetanus-specific immunoglobulin G in Iranian mothers

OBJECTIVES

To investigate placental transfer of anti-tetanus immunoglobulin (Ig)G antibodies in Iranian mothers.

METHODS

Sera collected from 209 pregnant women and their paired infants were evaluated for tetanus-specific antibodies by a commercial enzyme-linked immunosorbent assay.

RESULTS

In total, 15 (7.2%) out of 209 mothers and 12 (5.7%) out of 209 newborns were negative for anti-tetanus IgG. A highly significant correlation was observed between maternal and fetal anti-tetanus IgG (r = 0.80). The mean cord/maternal blood ratio of anti-tetanus IgG was 1.22 +/- 0.97. The mean cord/maternal blood ratio of anti-tetanus IgG in mothers with blood groups B+ and AB+ was lower than in mothers with other blood groups (p = 0.027). In addition, among mothers who had more than 0.5 IU/ml anti-tetanus IgG, a higher percentage of cases with cord/maternal blood ratio of < 1 was observed in carriers of blood groups B+ and AB+ compared to those with other blood groups (45.2% vs. 41.8%). Parity of more than 4 had a significant negative effect on both frequency of high positive sera and the mean of anti-tetanus IgG level in maternal and neonatal sera.

CONCLUSIONS

A relatively high percentage of pregnant women were not immune against tetanus. It was also found that the main factors that affect infants' tetanus-specific IgG are maternal concentration of this immunoglobulin, parity and maternal blood group.

Association of interleukin-18 gene promoter polymorphisms with breast cancer

Interleukin-18 [IL-18] gene promoter polymorphism is reported to be a genetic risk factor for several types of cancer. The aims of this investigation were to evaluate and compare the frequencies of IL-18 gene promoter polymorphisms at positions -137 [G/C] and -607 [C/A] in breast cancer patients and healthy controls as well as to study the contribution of these data with clinicopathological parameters at diagnosis. The studied populations comprised 250 cases with breast carcinoma and 206 healthy subjects. IL-18 gene promoter polymorphisms at positions -137 and -607 were amplified in patient and control groups using allele specific polymerase chain reaction [AS-PCR]. The frequencies of GG, GC and CC genotypes of -137 SNP were 141 [56.4%], 96 [38.4%] and 13 [5.2%] in patients vs. 110 [53.4%], 72 [34.9%] and 24 [11.7%] in controls, respectively. A significant decrease of the CC genotype was observed in patients [p = 0.04]. The frequency of the CC genotype at position -137 was also significantly higher in patients with metastasis than non-metastatic patients [21.4% vs. 4.3%] [p = 0.02]. There was no significant association between genotype frequencies at position -607 with breast cancer or its clinicopathological parameters at diagnosis. Moreover, allelic frequencies at these positions did not contribute to breast cancer incidence. The distribution of IL-18 gene haplotypes and genotype combinations were not significantly different between patients and normal control individuals. This is the first report investigating the contribution of IL-18 gene promoter polymorphisms to breast cancer. These results suggest contrast effects of IL-18 gene in cancer induction and progression. Key words: Breast cancer, IL-18, polymorphism.

A novel duplex SSP-PCR typing method for KIR gene profiling

Killer-cell immunoglobulin-like receptors (KIR) control the function of natural killer cells. The number and type of KIR genes are substantially variable among individuals. Sequence-specific primer-directed polymerase chain reaction (SSP-PCR) based genotyping is the most commonly used method to assess the KIR gene content. However, it requires a minimum of 16 gene-specific amplifications and often yields false-negative results. Herein, we describe the development of a simple and efficient duplex SSP-PCR assay to identify the presence and absence of 16 KIR genes. This system further distinguishes subsets of KIR2DS4 and KIR3DP1 alleles. The assay was subjected to a blind validation using a panel of 78 reference DNA standards from the UCLA KIR Exchange Program, which showed 100% specificity and accuracy. Compared with the conventional SSP typing methods, the present method is an accurate, simple, cost-effective and labor-saving KIR genotyping method for high volume testing.

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.

A 2-year longitudinal study of eating attitudes, BMI, perfectionism, asceticism and family climate in adolescent girls and their parents

The aim of this longitudinal study of 383 Swedish adolescent girls (11 and 13 years old at year 1) and their parents was to examine changes in eating attitudes over a two-year period, and to investigate the predictive value of eating attitudes, perfectionism, asceticism, family climate and body mass index (BMI) for the development of disturbed eating attitudes. The following self-report questionnaires were used: Children's Eating Attitudes test, Eating Attitudes Test, Eating Disorder Inventory for Children, Eating Disorder Inventory 2, I Think I Am and The Family Climate. The frequency of disturbed eating attitudes increased with increased age in the girls. Children's eating attitudes, higher BMI than peers, the girls rating of a less healthy relation to family and their fathers' eating attitudes at year 1 contributed most to the prediction of disturbed eating attitudes for the girls 2 years later. The results suggest that early signs of disturbed eating attitudes and higher BMI than peers may be important predictors for the development of more serious eating disturbances among adolescent girls.

HLA class II similarities in Iranian Kurds and Azeris

The genetic relationship between Kurds and Azeris of Iran was investigated based on human leukocyte antigen (HLA) class II profiles. HLA typing was performed using polymerase chain reaction/restriction fragment-length polymorphism (PCR/RFLP) and PCR/sequence-specific primer (PCR/SSP) methods in 100 Kurds and 100 Azeris. DRB1*1103/04, DQA1*0501 and DQB1*0301 were the most common alleles and DRB1*1103/04-DQA1*0501-DQB1*0301 was the most frequent haplotype in both populations. No significant difference was observed in HLA class II allele distribution between these populations except for DQB1*0503 which showed a higher frequency in Kurds. Neighbor-joining tree based on Nei's genetic distances and correspondence analysis according to DRB1, DQA1 and DQB1 allele frequencies showed a strong genetic tie between Kurds and Azeris of Iran. The results of amova revealed no significant difference between these populations and other major ethnic groups of Iran. No close genetic relationship was observed between Azeris of Iran and the people of Turkey or Central Asians. According to the current results, present-day Kurds and Azeris of Iran seem to belong to a common genetic pool.

Promoter polymorphism of transforming growth factor-β1 gene and ulcerative colitis

AIM: To elucidate the possible difference in two promoter polymorphisms of the transforming growth factor-β1 (TGF-β1) gene (-800G > A, -509C > T) between ulcerative colitis (UC) patients and normal subjects.

METHODS: A total of 155 patients with established ulcerative colitis and 139 normal subjects were selected as controls. Two single nucleotide polymorphisms within the promoter region of TGF-β1 gene (-509C > T and -800G > A) were genotyped using PCR-RFLP.

RESULTS: There was a statistically significant difference in genotype and allele frequency distributions between UC patients and controls for the -800G > A polymorphism of the TGF-β1 gene (P < 0.05). The frequency of the TGF-β1 gene polymorphism at position -800 showed that the AA genotype and the allele A frequencies significantly differed between the patients and healthy controls (P < 0.05). At position -509, there was no statically significant difference in genotype and allele frequency between the patients and control subjects.

CONCLUSION: The results of our study indicate that there is a significant difference in both allele and genotype frequency at position -800G > A of TGF-β1 gene promoter between Iranian patients with UC and normal subjects.

Psychometric properties of the Eating Disorders in Obesity questionnaire: validating against the Eating Disorder Examination interview

Inconclusive results of how weight-loss treatment (WLT) results are affected by participants' eating disorders and/or binge eating are partly due to the variation caused by the multitude of assessment instruments used. The objective of the present study was to evaluate the psychometric properties of a short DSM-IV-based assessment instrument designed to be used specifically in WLT settings, the Eating Disorders in Obesity (EDO) questionnaire. Participants were 97 patients seeking WLT at four surgical and one non-surgical clinics. Participants were assessed by the EDO and the Eating Disorder Examination (EDE) interview . The validity and reliability of the EDO was measured as concordance with the EDE, and test-retest agreement of the EDO, respectively. Validity as well as reliability was found to be good for both eating disorders diagnoses and binge eating as a distinct symptom. Results suggest that the EDO is a short, easily administered instrument with good psychometric properties which makes it a suitable, economical method of assessing eating disorders and binge eating in clinical WLT settings.

Intercellular adhesion molecule-1 gene polymorphism in Iranian patients with multiple sclerosis

Intercellular adhesion molecule-1 (ICAM-1), an important molecule in leucocyte activation and migration, is expressed on the CNS endothelial cells of patients with multiple sclerosis. This study was conducted to determine whether ICAM-1 gene polymorphism influences the risk of developing multiple sclerosis in an Iranian population. We studied 157 patients with definite multiple sclerosis and 156 ethnically matched controls. The patients and the controls were genotyped for ICAM-1 gene polymorphism at codons 241 (exon 4) and 469 (exon 6). G/R241 and K/E 469 allele and genotype distribution did not show any significant difference between patient and control groups. We concluded that role of the ICAM-1 gene polymorphisms in the pathogenesis of multiple sclerosis is still controversial and should be studied further.

Remote treatment of bulimia nervosa and binge eating disorder: A randomized trial of Internet-assisted cognitive behavioural therapy

The present study investigated the efficacy of self-help based on cognitive behaviour therapy in combination with Internet support in the treatment of bulimia nervosa and binge eating disorder. After confirming the diagnosis with an in-person interview, 73 patients were randomly allocated to treatment or a waiting list control group. Treated individuals showed marked improvement after 12 weeks of self-help compared to the control group on both primary and secondary outcome measures. Intent-to-treat analyses revealed that 37% (46% among completers) had no binge eating or purging at the end of the treatment and a considerable number of patients achieved clinically significant improvement on most of the other measures as well. The results were maintained at the 6-month follow-up, and provide evidence to support the continued use and development of self-help programmes.

Association of chemokine receptor 5 (CCR5) delta32 mutation with Behçet's disease is dependent on gender in Iranian patients

OBJECTIVE

Behçet's disease (BD) is a recurrent multi-system inflammatory disorder caused by the combinations of multiple genetic and environmental factors. CCR5 is a Th1-dominant chemokine receptor whose levels are increased in patients with active BD. It is believed that a 32 bp deletion in the CCR5 gene reduces the expression of this receptor on the cell surface. The aim of the present study was to investigate the association of CCR5 delta32 allele with BD in Iranian patients.

METHODS

The study included 100 patients with BD and 380 healthy controls. Polymerase chain reaction (PCR) amplification was used for analysis of CCR5 delta32 allele.

RESULTS

The frequency of CCR5 delta32 allele was not statistically different between 100 patients with BD and 380 healthy individuals. However, categorizing patients according to gender revealed a significant difference in distribution of the CCR5 delta32 allele in female patients compared with female control individuals (p = 0.047, fisher's exact test, OR = 2.66).

CONCLUSION

The results suggest that the CCR5 delta32 allele may be a genetic risk factor for BD in Iranian women. These results warrant further investigation to clarify the underlying mechanism of CCR5 deficiency in the initiation of BD.

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.

Association of CTLA-4 gene promoter polymorphisms with systemic sclerosis in Iranian population

In a recent study, we were unable to show any association between CTLA-4 exon-1 polymorphism and systemic sclerosis (SSc) in Iranian population. In order to further explore the role of this immune inhibitory gene in SSc development, in the present study, the polymorphisms in the CTLA-4 promoter region (-1,722 T/C, -1,661 A/G and -318 C/T) were investigated in 83 SSc patients and 166 healthy controls. All genotypes and allele frequencies in patients were significantly different from the control group (P=0.022 for -1,722 T/C, P=0.03 for -1,661 A/G and P=0.014 for -318 C/T genotypes). The -1,722C, -1,661G and -318T alleles contributed to SSc with P=0.012, odds ratio (OR) 2.16, P=0.031, OR 1.82 and P=0.023, OR 2.45, respectively. A significant difference was observed in the frequency homozygous 'genotype combination' -1,722TT/-1,661AA/-318CC of these three polymorphisms (P(c)=0.003). The frequency of this genotype combination was significantly higher in the control group than in patients. Results of this investigation indicate that -1,722C, -1,661G and -318T alleles of CTLA-4 gene promoter appear to be associated with SSc, and individuals carrying these alleles may be more susceptible to this disease.

Cytotoxic T lymphocyte antigen-4 promoter variants in breast cancer

CTLA4 is a coinhibitory molecule expressed mainly on activated T lymphocytes. To test the putative involvement of CTLA-4 in inhibitory state of immunity to breast cancer, we genotyped 283 patients and 245 healthy control subjects for -1722 T/C, -1661 A/G, and -318 C/T single nucleotide polymorphisms in the promoter region of the CTLA4 gene. There were no significant differences in genotype, allele, or haplotype frequencies in all three loci between patients and healthy controls. Moreover, the incidence of the most frequent haplotype combination (TAC/TAC, T -1722, A -1661, C -318) was only slightly higher among healthy controls than patients (68.4 vs. 64.8%, P = 0.2). This haplotype combination was associated with lower stages of the disease (P = 0.0007), however, and higher estrogen receptor (ER) expression in patients (P = 0.006). Association with tumor prognostic or predictive factors was also observed with certain genotypes: the -1661 AA genotype was associated with lesser lymph node (LN) involvement (P = 0.017) and higher ER expression (P = 0.004), and the -318 CC genotype with lesser LN involvement (P = 0.007). These results suggest that CTLA4 promoter variants participate in the progression of breast cancer rather than in its initial development.

Association of IL-18 promoter polymorphisms with predisposition to Type 1 diabetes

AIMS

IL-18, a potent IFN-gamma-inducing cytokine, is capable of polarizing the immune response to a Th1 phenotype. Recent studies have demonstrated an association between single-nucleotide polymorphisms located at positions -607 (A/C) and -137 (C/G) in the promoter region of IL-18 gene and Type 1 diabetes. The aim of the present study was to determine whether the same polymorphisms of the gene were associated with Type 1 diabetes in Iranians.

METHODS

In 112 patients with Type 1 diabetes and 194 non-diabetic control subjects, these two single-nucleotide polymorphisms were analysed by sequence-specific PCR.

RESULTS

Allele and genotype frequencies of the IL-18 gene polymorphisms were similar in the whole group of Type 1 diabetic patients and controls. However, categorizing patients according to age at onset of diabetes revealed a significant difference in distribution of the genotypes at position -137 between patients with older age at onset (> 15 years) (GG 49%, GC 34%, CC 17%) and control subjects (GG 57.7%, GC 36.6%, CC 5.7%) (P = 0.027). Frequency of the C allele at position -137 was significantly higher in these patients than in controls (P = 0.038). Moreover, there was an association between -607AA/-137CC genotype combination and susceptibility to Type 1 diabetes in this subgroup of patients (pc = 0.027).

CONCLUSIONS

The results of this study show that polymorphisms of IL-18 promoter confer susceptibility to Type 1 diabetes in Iranian individuals with onset at older ages. Further investigations are necessary to clarify the effect of IL-18 variants on immune regulation.

Exon-1 polymorphism of ctla-4 gene is not associated with systemic sclerosis in Iranian patients

Although, the cytotoxic T lymphocyte antigen-4 gene polymorphism at position 49 of exon-1 has been strongly elucidated in different autoimmune diseases, but its role in predisposition to systemic sclerosis (SSc) is yet controversial. This study intends to analyze the genetic correlation of the ctla-4 gene locus with diffuse systemic sclerosis (dSSc), as well as to understand the influence of these genotypes in disease expression. Seventy known cases of SSc, and 151 age-matched healthy controls, were participated in this investigation. The frequencies of AA, GG and AG genotypes were found to be 26 (37.1%), 5 (7.2%) and 39 (55.7%) in patients, and 60 (39.7%), 19 (12.6%) and 72 (47.7%) in controls, respectively. As indicated, the differences in genotype and allele frequencies between patients and controls were insignificant (P>0.05). Moreover, the distribution of CTLA-4 polymorphism between patients did not differ significantly according to clinical and serologic features. In Iranian patients, susceptibility to SSc is not influenced by a bi-allelic ctla-4 gene (A49G) polymorphism.

Molecular analysis of HLA allele frequencies and haplotypes in Baloch of Iran compared with related populations of Pakistan

The extreme polymorphism in different loci of the human leukocyte antigen (HLA) system has been used as an invaluable tool for anthropological studies. Determination of HLA allele and haplotype frequencies in different ethnic groups is useful for population genetic analyses and the study of genetic relationships among them. In the present study, molecular analysis of HLA-A, -B, -C, -DQA1, -DQB1, and -DRB1 genes has been used to assign HLA allele and haplotype frequencies in 100 unrelated healthy individuals from the Baloch ethnic group of Iran. The results were compared with Baloch and other ethnic groups in the neighboring Pakistan. The results of this study showed that the most frequent HLA class I alleles were A*02011 (20.2%), B*4006 (11.1%), and C*04011 (28.6%). The most common HLA class II alleles were DQA1*0101/2 (42.5%), DQB1*0201 (32%), and DRB1*0301 (29%). Three-locus haplotype analysis revealed that A*11011-B*4006-C*15021 (5.8%) and DQA1*0501-DQB1*0201-DRB1*0301 (22.1%) were the most common HLA class I and II haplotypes, respectively, in this population. Neighbor-joining tree based on DA genetic distances and correspondence analysis according to HLA-A, -B, -DQB1, and -DRB1 allele frequencies showed that Baloch of Iran are genetically very close to Baloch and Brahui of Pakistan. This may reflect an admixture of Brahui and Baloch ethnic groups of Pakistan in the Balochistan province of Iran.

Heterozygosity inCTLA-4 gene and severe preeclampsia

OBJECTIVE

One of the major complications of pregnancy, preeclampsia makes pregnancy termination inevitable in most cases. Similarities exist between the mechanisms that maintain normal pregnancy, allograft transplants, and, it is postulated, peripheral self-tolerance. In addition, the critical role of the cytotoxic T-lymphocyte antigen-4 (CTLA-4) molecule in maintaining self-tolerance has been established. Therefore, the frequency of CTLA-4 A49G polymorphism was investigated in severe preeclampsia.

PATIENTS AND METHODS

Genomic DNA extracted from mononuclear cells of the peripheral blood of 36 pregnant women with severe preeclampsia and 151 healthy women was analyzed. A49G polymorphism in position 49 of exon-1 of the CTLA-4 gene was studied by the polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) method.

RESULTS

The frequency of the GG genotype was 2 (5.6%) in patients and 19 (12.6%) in controls, while the frequency of the AA genotype was 4 (11.1%) and 60 (39.7%). Interestingly, the frequency of the AG genotype was significantly higher in preeclamptic than in healthy women from the general population (83.3% vs. 47.7%; P=0.0005).

CONCLUSION

These data suggest that heterozygosity in the CTLA-4 A49G allele might be a predisposing factor for severe preeclampsia. Whether the observed association results from linkage imbalance with other loci on chromosome 2 or other polymorphisms of the CTLA-4 gene or even from a preferential transfer and/or expression of one allele from a heterozygous mother to the fetus will be the subject of future investigations.