Haplotypes of the IL-1 gene cluster are associated with gastroesophageal reflux disease and Barrett’s esophagus

Objectives

Gastroesophageal reflux (GERD) is a one of the major public health problem that can lead to reflux esophagitis (RE), Barrett’s esophagus (BE), and esophageal adenocarcinoma (EAC). The aim of our study was to determine the impact of IL-1 gene polymorphisms on the development of GERD, RE and BE.

Methods

Three hundred and thirty-three Czech patients with gastroesophageal reflux and 165 healthy controls were included in this case-control study. Four polymorphisms in the genes of the IL-1 cluster [IL-1A(-889C/T), IL-1B(−511C/T), IL-1B(+3953C/T), and IL-1RN(VNTR)] were analyzed.

Results

Significant differences were found in IL-1RN 1/2 genotype between patients with GERD/RE and controls and in IL-1B+3953 T allele between patients with BE and healthy subjects. In addition, complex analysis revealed differences in IL-1 haplotype frequencies between the groups. Specifically, the haplotype TCCL was significantly more frequent (p = 0.016) in GERD patients than in controls and the haplotype CCCL more frequent (p = 0.008) in RE patients than in controls. However, in patients with BE, frequency of haplotype TCTL was lower (p = 0.05) and haplotypes CTCL and TCCL were higher (p = 0.03 and p = 0.02) in comparison with the controls.

Conclusions

Our results suggest that IL-1 haplotypes may be associated with susceptibility to GERD, RE and BE.     

Association of IL-1 gene complex members with ankylosing spondylitis in Chinese Han population

There are reports of IL-1 complex gene polymorphisms in ankylosing spondylitis (AS; MIM 106300), but the results have been inconsistent among populations. Moreover, few studies examine the association between IL-1 complex gene polymorphisms and clinical symptoms of AS patients. We investigated polymorphisms of IL-1 complex with AS in the Chinese Han population in this study. Chinese Han AS patients and ethnically matched healthy controls were genotyped for five single nucleotide polymorphisms (IL1β+3953, β-511, F10.3, RN.4, RN.6/1) and the IL1RN.VNTR of IL-1 gene cluster. Allele, Genotype and haplotype frequencies were compared between cases and controls by SHEsis software. The frequency of allele C of the marker IL1F10.3 was significantly increased in AS patients versus controls [p = 0.001, odds ratio (OR) = 1.54, 95% confidence interval (CI) = 1.19–1.20; p = 0.002, respectively]. Strong linkage disequilibrium was identified between IL1B-511, IL1B+3953 and RN4 in both patients and healthy controls (D′ > 0.95). Haplotypes of pairs of these markers (6) were also significantly associated with AS. The strongest associations observed was between allele combination B-511-T/B+3953-C/F10.3-C/RN4-T/RN2VNTR-1/RN6.1-C and AS (p = 3.32 × 10⁻⁵, OR = 4.41, 95% CI=2.1–9.3). Clinical manifestation showed week association between RN2VNTR A2 allele and risk of peripheral arthritis (OR = 0.2, 95% CI = 0.07–0.91). The IL-1 gene cluster is associated with AS in Chinese population. This finding provides strong statistical support for the previously observed relationship and indicates possible association between clinical manifestation and genetic factor.     

Associations between interleukin 1 polymorphisms and susceptibility to systemic lupus erythematosus: A meta-analysis

Objective

This study determined whether interleukin 1 (IL1) polymorphisms are associated with susceptibility to systemic lupus erythematosus (SLE).

Methods

A meta-analysis was conducted on the associations between the IL1A, IL1B, and IL1 receptor antagonist (IL1RN) polymorphisms and SLE.

Results

A total of 15 studies involving 1956 SLE cases and 2347 controls were included in the meta-analysis. The meta-analysis showed an association between SLE and the IL1A −889 T allele in the overall population and Europeans (OR = 0.858, 95% CI = 0.737–0.986, p = 0.032; OR = 0.827, 95% CI = 0.687–0.994, p = 0.043). Meta-analysis of the IL1RN polymorphism revealed an association with SLE in all study subjects (OR for IL1RN^∗2 = 1.539, 95% CI = 1.266–1.871, p = 1.5 × 10⁻²) and in Europeans and Asians (OR = 1.483, 95% CI = 1.187–1.852, p = 0.001; OR = 1.787, 95% CI = 1.167–2.736, p = 0.008). No associations were found between SLE and the IL1B −511 C/T, 3953 C/T, and IL1A +4845 G/T polymorphisms.

Conclusions

This meta-analysis suggests IL1A −889 C/T polymorphism is associated with susceptibility to SLE in Europeans, and that the IL1RN^∗2 allele is associated with susceptibility to SLE in Europeans and Asians.     

Association of interleukin (IL)-4 gene intron 3 VNTR polymorphism with multiple sclerosis in Turkish population

Objective

Genetic risk factors are known to contribute to the etiology of multiple sclerosis (MS). Interleukin (IL)-4 gene polymorphisms have been associated with immune-mediated diseases. The aim of this study was to explore the frequency of IL-4 gene intron 3 VNTR (variable number tandem repeat) polymorphism in a cohort of Turkish patients with MS.

Methods

The study included 125 patients with MS and 160 healthy controls. Genomic DNA was isolated and genotyped using polymerase chain reaction (PCR) analyses for the IL-4 gene intron 3 VNTR polymorphism.

Results

The distribution of genotype and allele frequencies of IL-4 gene intron 3 VNTR polymorphism was statistically different between MS patients and control group (p = 0.003 and p = 0.002, respectively). There were no statistically significant association between IL-4 VNTR polymorphism and clinical and demographical characteristics of MS patients.

Conclusion

The results of this study suggest that intron 3 VNTR polymorphism of the IL-4 gene was positively associated with predisposition to develop MS in Turkish population.     

Gender-related Distribution of the Interleukin-1β and Interleukin-1 Receptor Antagonist Gene Polymorphisms in Patients with End-stage Liver Disease

Interleukin-1β (IL-1β) genetic polymorphisms and IL-1 receptor antagonist (IL1RN) variable number tandem repeat (VNTR) seem to be related with the occurrence of chronic diseases. This study aimed to verify whether IL-1β -511>C/T, -31>T/C, +3953>C/T and IL1RN VNTR were associated to the development of liver cirrhosis. Two hundred forty cirrhotic patients were involved in the study. A significant trend was detected, for increasing cirrhosis frequencies, grouping the patients as follows: females and males carrying neither the IL-1β (-511 -31) T-C/T-C or T-C/(T-T or C-C) diplotypes nor any IL1RN A2 allele (138/292), males carrying either the IL-1β T-C/T-C or T-C/(T-T or C-C) diplotypes or at least one IL1RN A2 allele (74/147) and males carrying either the IL-1β T-C/T-C or T-C/(T-T or C-C) diplotypes and at least one IL1RN A2 allele (28/37) (p?<?0.01). IL-1β polymorphisms are associated with the occurrence of end stage liver disease. IL-1β inflammatory activity appears more pronounced in males.     

Lack of association between human longevity and polymorphisms of IL-1 cluster, IL-6, IL-10 and TNF-alpha genes in Finnish nonagenarians.

There has been increasing interest in research on genetic basis of longevity. Aging is accompanied by immune deterioration and dysregulation of cytokines. Increased IL-6 concentration in vivo and enhanced IL-6, IL-1beta, and TNF-alpha production in vitro have been reported in healthy elderly people. Cytokine gene polymorphisms have been demonstrated to be associated with cytokine production both in vivo and in vitro, and with some diseases. Thus, gene polymorphisms of cytokine may play a role in longevity by modulating an individual's responses to life-threatening disorders. Cytokine gene polymorphisms at IL1A-889, IL1B+3953, IL1B-511, IL1RN VNTR, IL6-174, IL10-1082, and TNFA-308 were genotyped in 250 Finnish nonagenarians (52 men and 198 women) and in 400 healthy blood donors (18-60 years) as controls. No statistically significant differences were found in the genotype distributions, allelic frequencies and A2+ carrier status of IL-1alpha, IL-1beta, IL-1RA, IL-6, IL-10, and TNF-alpha genes between nonagenarians and younger controls within Finnish population, nor between male and female nonagenarians. No differences emerged between nonagenarians and younger controls by comparing different IL-1 gene cluster haplotypes. Thus, there is no evidence of an association of IL-1 complex, IL-6, IL-10, and TNF-alpha gene polymorphisms with longevity, alone or in combination.     

Impact of genetic polymorphisms on the pathogenesis of idiopathic achalasia: Association with IL33 gene variant

Aim

To investigate the association of single nucleotide polymorphisms (SNPs) of genes involved in the regulation of immune responses, IL33, IL1RL1, IL23R, and IL10, with idiopathic achalasia in an Italian cohort of patients.

Materials and methods

A panel of eleven polymorphisms were genotyped in 116 unrelated idiopathic achalasic patients and 371 healthy subjects, by using TaqMan genotyping assays.

Results

Significant differences of allele (P = 0.0065, OR = 1.59, CI = 1.14–2.22) and genotype (P = 0.0097, OR = 1.74, CI = 1.14–2.65) frequencies of the IL33 rs3939286 variant were found between achalasic patients and controls. No association of the other investigated SNPs was detected. No differences in genotype and allele distribution were found with respect to clinical characteristics of patients.

Conclusion

We provide for the first time an association between the risk of developing idiopathic achalasia and IL-33 variant, underling the role of cytokines and inflammatory mediators on the pathogenesis of the disease.     

High expression of interleukine-1 receptor antagonist in rheumatoid arthritis: Association with IL1RN*2/2 genotype

Rheumatoid arthritis (RA) is an autoimmune disease characterized by inflammation and pro-inflammatory cytokines production. IL-1Ra is an anti-inflammatory cytokine codified by IL1RN gene that blocks IL-1 signalling. A VNTR polymorphism of 86?bp in IL1RN gene has been associated with RA risk and regulation of IL-1Ra expression. In this study, we determined mRNA and protein expression of IL-1Ra in RA patients and control subjects (CS). This study included 85 RA patients classified according to the ACR/EULAR 2010 criteria and 67 CS. Polymerase chain reaction was used to identify IL1RN VNTR polymorphism, the expression of sIL-1Ra (secreted isoform) mRNA was determined by SYBR Green-based real time quantitave-PCR assay, and IL-1Ra soluble levels quantification was evaluated by ELISA test. RA patients had higher soluble levels of IL-1Ra than CS (p?sIL-1Ra mRNA expression was higher in RA patients compared to CS (p?IL1RN*2/2 homozygous genotype show increased IL-1Ra soluble levels compared to IL1RN*long/long and IL1RN*2/long genotypes (p?IL1RN*2/2 genotype was 1.2 times higher compared to IL1RN*long/long genotypes in the same group. Regarding RA patients, high expression of sIL-1Ra mRNA on carriers of IL1RN*long/long genotype was observed. Nevertheless, in RA patients IL-1Ra soluble levels among genotypes did not show significant differences. High expression of IL-1Ra in RA patients under treatment or not with antirheumatic drugs was detected. Additionally, carriers of IL1RN*2/2 genotype had higher IL-1Ra expression than carriers of other genotypes.     

Impact de l’augmentation de l’incidence des entérobactéries productrices de bêta-lactamases à spectre étendu (EBLSE) sur l’application des précautions complémentaires dans un centre hospitalier universitaire

Aim of the study

The French national surveillance program of multidrug-resistant bacteria (MDR) shows an increase of enterobacteriaceae-producing extended-spectrum beta-lactamases (ESBLE) incidence. The objectives of this study were to assess: the incidence of EBLSE in a large French university hospital between 2005 and 2010, and the difference of barrier precautions implementation between ESBL and other MDR.

Methods

The ESBLE incidence measure used data from the laboratory of bacteriology. The application of isolation and barrier precautions was analyzed from the MRB national surveillance data over a 3-year period from 2006 to 2008. Data were entered and analyzed using Epi Info software. The Chi² test was used for the comparison of proportions.

Results

The overall incidence of ESBLE was significantly higher in 2010 than in 2005 (0.20/1000 patients-days vs 0.03/1000 patients-days, respectively) (P < 0.001). The same was observed for Escherichia coli incidence with rates ranging from 0.02/1000 patients-days in 2005 to 0.15/1000 patients-days in 2010. Isolation precautions for patients with EBLSE were applied in relation for most patients with MRB (ESBLE vs others), without significant difference.

Conclusion

The surveillance programme of MRB showed a significant increase of ESBLE, especially for E. coli. Isolation and barrier precautions were used for most patients with MRB, including ESBLE.     

Genetic analysis of interleukin-1 receptor antagonist and interleukin-1β single-nucleotide polymorphisms C−511T and C+3953T in alopecia areata: susceptibility and severity association

The present study was aimed to explore the effect of two selected polymorphisms from interleukin-1β (IL-1β) gene [SNPs ?511 and +3953] and a variable number of tandem repeat (VNTR) from interleukin-1 receptor antagonist (IL-1RN) on the susceptibility and severity of alopecia areata (AA) in Kuwaiti subjects. IL-1β SNPs C?511T, C+3953T, and IL-1RN VNTR were screened in 96 alopecia patients classified clinically, according to the disease severity as patchy (P), semiuniversalis (SU), and universalis (U), and in 100 ethnically matched healthy controls. Polymerase chain reaction followed by restriction fragment length polymorphism and direct DNA sequencing were employed for genotyping. Comparing the stratified AA cases based on severity, IL-β SNP C?511T showed a significant association (genotype and allelotype levels p = 0.03 and p = 0.028, respectively). Genotype CC was 50 % more frequent in U cases than in P or SU. When P and SU were grouped and tested against U, a significant difference was observed (genotype and allelotype levels p = 0.006 and p = 0.008, respectively). Compared to genotype CT, carriers of IL-1β ?511 CC genotype showed an increased risk to develop severe AA (p = 0.004, OR = 4.14, 95 % CI = 1.61–10.69). Four alleles and genotypes (1/1, 1/3, 1/4, and 2/2) of IL-1RN VNTR were detected in AA patients while only two (1/1 and 1/3) in controls. IL-1RN VNTR showed genotype and allelotype association with AA (p = 0.05 and p = 0.025, respectively). Our results showed that IL-1β and IL-1RN VNTR are significantly associated with the susceptibility to alopecia areata. Allele C of the IL-β C?511T SNP is linked to the severe form of AA.     

Environmental factors and not genotype influence the plasma level of interleukin-1 receptor antagonist in normal individuals

Cytokine production may be regulated by both genotypic (single nucleotide or tandem repeat polymorphisms) and non-genotypic factors relating to the environment and inherent biology (i.e. gender). Interleukin (IL)-1 is one of the body's most highly proinflammatory cytokines and is implicated in the pathophysiology of numerous diseases, but also in the maintenance of homeostasis in a number of tissues. The cytokine IL-1 receptor antagonist (IL-1Ra) is the competitive inhibitor of the IL-1 agonists IL-1alpha and IL-1beta. In vivo IL-1Ra was measured in a cohort of 200 + blood donors and the effect of the IL-1 gene polymorphisms, environmental and biological factors assessed. In this study, we observed that possession of particular alleles of 5 IL-1 gene polymorphisms (IL1A-889, IL1Alpha VNTR, IL1B -511, IL1B +3953 and the IL1RN VNTR) did not correlate with higher plasma IL-1Ra levels. Environmental factors such as smoking and non-steroidal anti-inflammatory drug ingestion were associated with higher in vivo IL-1Ra levels (P = 0.015 and 0.022, respectively), but biological factors such as gender, age and menstruation status did not have any impact upon in vivo IL-1Ra levels. Genotypic associations of IL-1 gene family polymorphisms with disease features may reflect characteristics of stressed rather than normal control circuits for cytokine production.     

Lack of association between IL-1 and IL-6 gene polymorphisms and myocardial infarction in Turkish population

Inflammation and genetics play a key role in the pathogenesis of atherosclerosis and its clinical result myocardial infarction (MI). Proinflammatory cytokines, IL-1 and IL-6, have been shown to play essential roles in developmental stages of coronary artery plaque formation. The aim of this study was to determine the association between IL-1 [IL-1RN, IL-1β (-511, +3953)], IL-6 [-174, -572, -597] gene polymorphisms and MI in Turkish population. A total of 402 people were participated; 235 healthy control subjects and 167 MI patients (MI<40, n: 72; MI>40, n: 95). Polymerase chain reaction (PCR) was used to determine the genotype of IL-1RN, whereas the genotypes of IL-1β (-511, +3953) and IL-6 (-174, -572, -597) were determined using PCR followed with restriction digestion analysis. There was no significant difference between MI and controls for IL-1RN, IL-1β-511, +3953 (P: 0.875, 0.608, 0.442) and IL-6 -174, -572, -597 (P: 0.977, 0.632, 0.584) gene polymorphisms. Lack of association was observed between MI at younger age (MI<40) and either IL-1RN VNTR, IL-1β-511, +3953 (P: 0.878, 0.732, 0.978) or IL-6 -174, -572, -597 (P: 0.313, 0.654, 0.552) gene polymorphisms. This study demonstrated that there was not any association between IL-1, IL-6 gene variants and MI in Turkish population. In addition, IL-1 and IL-6 gene polymorphisms did not affect MI at younger age (MI<40) or older age (MI>40). Thus, IL-1 and IL-6 single nucleotide polymorphisms may not be a risk factor for susceptibility to MI in Turkish population.     

IL10 polymorphisms associated with Behçet’s disease in Chinese Han

Objective

IL-10 is a potent anti-inflammatory cytokine that plays important roles in the pathogenesis of Behçet’s disease (BD). Two genome-wide association studies have identified IL10 as a potential risk factor for BD. Here, we investigated the association between IL10 polymorphisms and BD in Chinese Han.

Methods

407 BD patients and 679 healthy controls were enrolled, and genotyped by Sequenom MassArray system (Sequenom iPLEX assay, San Diego, CA).

Results

The frequency of risk allele of rs1800871 was notably higher in BD patients than in controls (71.9% vs. 66.2%, OR: 1.30, 95%CI: 1.08–1.58, p_c = 0.024). Similarly, rs1518111, which showed strong linkage disequilibrium (r² = 1) with allele rs1800871, was also associated with BD (p_c = 0.026). Rs3021094 was in association with BD in a dominant model (p_c = 0.035), and the haplotype (GACC) formed by rs1518111, rs3021094, rs3790622, and rs1800871 was associated with BD (p_c = 0.023). Results obtained from meta-analysis combined with our data showed that rs1800871 and rs1518111 were associated with BD.

Conclusion

IL10 may be the susceptibility gene for BD in Chinese Han population.     

Presence of the IL-1RA Allele 2 (IL1RN*2) is Associated with Enhanced IL-1β Production In Vitro

The genes of the interleukin-1 (IL-1) complex code for three proteins: IL-1α, IL-1β and the IL-1 receptor antagonist (IL-1RA). Each of these genes is polymorphic and there is increasing evidence that certain alleles are associated with increased susceptibility to a given disease of inflammatory nature. In the IL-1β gene there are two base-exchange polymorphisms in positions −511 and +3953, and IL-1RA gene has a penta-allelic polymorphic site in intron 2 containing variable numbers of an 86-bp tandem repeat sequence. As the IL-1β/IL-1RA ratio may be critical in the regulation of inflammation, we examined whether there are allelic associations between these loci (thus suggesting co-ordinate regulation) and whether these have an effect on the in vitro production of IL-1β. We found that the IL-1RA allele 2 (IL1RN*2) is associated with the presence of allele 2 of the IL-1β gene (position −511) and with the absence of allele 2 of the IL-1β gene (position +3953). Mononuclear cells from carriers of allele 2 (position −511) and non-carriers of allele 2 (position +3953) had a slight, but non-significant, elevated capacity to produce IL-1β in vitro . However, IL-1RA allele 2 strongly increased in vitro production of IL-1β, regardless of the presence or absence of these alleles. Taken together, these data suggest that the known allelisms in the IL-1β gene are not major regulators of the in vitro IL-1β production, but the IL-1RA allele 2 (or an unknown allele strongly associated with it) has a decisive role.     

Évaluation de la plate-forme de PCR en temps réel LightCycler 480 pour la mesure des charges virales CMV,EBV, HHV-6 et BKV dans le sang total

Objective

The Roche LightCycler^® 480 (LC480) system was evaluated for quantitative molecular diagnosis of opportunistic viral infections caused by human cytomegalovirus (CMV), Epstein-Barr virus (EBV), human herpesvirus 6 (HHV-6), and BK virus (BKV), in comparison with “in-house” real-time PCR assays.

Patients and methods

A total of 253 whole blood specimens obtained from transplant recipients were tested.

Results

Both the “in-house” and the LC480 methods were highly correlated (Spearman correlation coefficient Rho ≥ 0.85; p < 0.0001) with an excellent overall qualitative agreement (90.5 %) and no significant quantitative difference between both techniques for the four viruses tested. The accuracy of the LC480 protocols were confirmed further by the results obtained with the 44 samples from the Quality Control for Molecular Diagnosis (QCMD) 2008 proficiency panel.

Conclusion

The LC480 system constitutes a suitable and versatile real-time PCR platform in a routine laboratory setting for the diagnosis and monitoring of opportunistic viral infections in transplant recipients, by measuring HCMV, EBV, HHV-6, and BKV loads in whole blood samples.     

Inter-relation of Th1, Th2, Th17 and Treg cytokines in oral cancer patients and their clinical significance

Background

Altered cytokine production can lead to immune dysfunction in cancer patients. Hence, we investigated the cytokine balance in oral squamous cell carcinoma (OSCC) patients and their significance in providing new therapeutic insights.

Methods

We quantified Th17 (IL17A), Treg (TGFβ1), Th1 (IL2, IFNγ) and Th2 (IL4, IL10) like cytokines in the sera of 78 cases and 39 controls by ELISA. The intracellular expression of these cytokines was analyzed in 10 subjects from each group by flow cytometry.

Results

Serum levels of IL17A, TGFβ1, IL4 and IL10 were significantly higher while IL2 and IFNγ were relatively lower in patients as compared to controls. TGFβ1 (r = 0.55), IL4 (r = 0.75) and IL10 (r = 0.80) significantly (P < 0.0001) correlated with disease progression and their elevated levels showed increased odd ratios of approximately 18, 14 and 37, respectively. IL17A appeared as a risk factor (OR = 2.21, 95% CI = 0.89–5.42) although statistically insignificant. The levels neither correlated with disease progression nor with TGFβ1, IL4 and IL10 but showed positive association with IL2 (r = 0.51, P < 0.0001) and IFNγ (r = 0.24). Flow cytometry data also showed similar trend.

Conclusions

We reported a distinct TGFβ1 and Th2 (IL4, IL10) polarization with a borderline elevation of IL17A while, a suppression of Th1 (IL2, IFNγ) cytokines in OSCC patients.     

The interleukin 1B-511 polymorphism is associated with the risk of developing restenosis after coronary stenting in Mexican patients

Inflammation is the primary response to vessel wall injury caused by stent placement in coronary arteries. Cytokines of the interleukin-1 family are central regulators in immunoinflammatory mechanisms. The objective of this study was to test for association between IL-1 family gene polymorphisms and risk for restenosis after coronary stent placement. The IL-1B-511, IL-1F10.3, RN.4T>C, RN.6/1C>T, RN.6/2C>G, and IL-1RN VNTR polymorphisms were analyzed by 5' exonuclease TaqMan genotyping assays and polymerase chain reaction in a group of 165 patients who underwent coronary artery stenting. Basal and procedure coronary angiography were analyzed in search of angiographic predictors of restenosis and follow-up angiography was analyzed in search of binary restenosis. Patients with IL-1B-511 TT genotype had a 1.89-fold increased risk of developing restenosis. The analysis considering the lesions treated demonstrated that the lesions of patients with IL-1B-511 TT genotype had a 3.44-fold increased risk of developing restenosis. When the analysis considered the type of stent, the risk of developing restenosis was increased in lesions of patients with TT genotype (odds ratio = 4.50) who underwent coronary bare-metal stent implantation. Multiple logistic analysis identified IL-1B-511 TT genotype as an independent predictor for restenosis. The results suggest that IL-1B-511 polymorphism could be involved in the risk of developing restenosis after coronary stent placement.     

C‐reactive protein levels and common polymorphisms of the interleukin‐1 gene cluster and interleukin‐6 gene in patients with coronary heart disease

C‐reactive protein (CRP) is an inflammatory marker associated with increased cardiovascular risk. Production of CRP is regulated by interleukin (IL)‐1β, IL‐1 receptor antagonist and IL‐6. In 160 patients with coronary heart disease (CHD) confirmed by angiography, we examined the relationship between CRP level and five polymorphisms in genes coding for these cytokines: IL‐1B(?511), IL‐1B(+3954), a variable number tandem repeat (VNTR) polymorphism in intron 2 of IL‐1RN [IL‐1RN(VNTR)], IL‐6(?174) and IL‐6(?572). CRP values were logarithmically normalized (log‐CRP) for statistical calculations. In univariate analysis, carrier status for the IL‐1B(+3954)T allele and IL‐1RN(VNTR) allele 2 [IL‐1RN(VNTR)*2] correlated with higher (P < 0.01) and lower (P < 0.05) log‐CRP values, respectively. Among the potential confounding factors analysed, smoking, body mass index, total cholesterol (P < 0.05 for all) and diabetes (P = 0.056) were positively correlated with CRP level. After adjustment for non‐genetic covariates, CRP levels remained significantly (P < 0.01) higher in carriers of IL‐1B(+3954)T than in non‐carriers: mean log‐CRP (with 95% confidence interval) was 0.443 (0.311–0.574) for CT or TT genotypes compared with 0.240 (0.107–0.373) for the CC genotype, which corresponded to back‐transformed CRP levels of 2.77 and 1.74 mg l^?1, respectively. Adjusted association was also significant for IL‐1RN(VNTR)*2 (P < 0.01), with lower CRP levels in the presence of allele 2: the mean log‐CRP value was 0.252 (0.115–0.388) for carriers and 0.421 (0.290–0.552) for non‐carriers (CRP 1.79 and 2.64 mg l^?1, respectively). When alleles of both polymorphisms were entered into the model simultaneously, the association remained significant for IL‐1B(+3954)T (P < 0.05), but not for IL‐1RN(VNTR)*2. We conclude that IL‐1B(+3954)T is associated with higher CRP levels in patients with CHD, and we found that this association was significant after adjustment for major risk factors. Our data also suggest a possible relationship of IL‐1RN(VNTR)*2 with lower CRP levels in the same patients.     

Apport de la PCR dans la recherche et l’identification des microsporidies intestinales chez les sujets infectés par le VIH

Aim

Intestinal microsporidiosis are among the most frequent opportunistic diseases in immunocompromised subjects. This study aimed to evaluate the contribution of PCR for a better detection and species identification of microsporidia in stool specimens of HIV-infected patients.

Patients and methods

Stool samples obtained from 119 HIV-infected Tunisian subjects were screened for intestinal microsporidiosis by light microscopy using Weber's modified Trichrome stain and by a PCR method using universal primers V1/PMP2 which amplified a common fragment of the small subunit rRNA gene of microsporidia. The obtained PCR products were then sequenced using an ABI PRISM 377 DNA sequencer.

Results

The results showed a better sensitivity of PCR in the detection of microsporidia with an infection rate of 14.3% significantly higher than that of 6.7% obtained by light microscopy (p = 0.03). As previously described, intestinal microsporidiosis was associated with low CD4 cell counts; 23.9% infection rate in patients having CD4 cell count under 200/mm³ against 5.6% in patients with higher CD4 cell count (p = 0.008). The sequencing of 15 out of the 17 positive PCR products has confirmed in all cases the species identified based on the PCR fragment size i.e., 250 pb for Enterocytozoon bieneusi (seven cases) and about 270 pb for Encephalitozoon intestinalis (nine cases); one case revealed a double infection.

Conclusion

PCR proved to be more effective than classical Trichrome stain for the diagnosis of intestinal microsporidiosis. Moreover, the ability of PCR to identify the species involved could also be useful for cases management.     

Linkage disequilibrium analysis of case-control data: an application to generalized aggressive periodontitis

Several studies have shown a role for the involvement of interleukin (IL)-1 gene cluster polymorphisms in the risk of periodontal diseases. In the present study, we tested polymorphisms, derived from genes of the IL-1 cluster, for association with generalized aggressive periodontitis (GAP) through both allelic association and by constructing a linkage disequilibrium (LD) map of the 2q13-14 disease candidate region. The IL-1RN (VNTR) genotype distribution observed was significantly different in GAP and control subjects (P=0.019). We also observed some evidence for an association between GAP and the IL-1B(+3953) polymorphism (P=0.039). The pattern of association in the region, represented as an LD map, identifies a recombination hot area between the IL-1B(+3953) and IL-1B(-511) polymorphisms. Multilocus modelling of association with disease gives a location for the peak association at the IL-1B(+3953) marker, although support for the peak is not significant. Haplotype analysis identifies a IL-1B(+3953)-IL-1B(-511) haplotype as having the lowest P-value in the region. Recognition of the presence of a recombination hot area between the IL-1B(+3953) and IL-1B(-511) polymorphisms will have an important bearing on future efforts to develop higher resolution SNP analysis in this region for both this and other diseases for which this cluster is implicated.