Patient stratification for preventive care in dentistry.

Prevention reduces tooth loss, but little evidence supports biannual preventive care for all adults. We used risk-based approaches to test tooth loss association with 1 vs. 2 annual preventive visits in high-risk (HiR) and low-risk (LoR) patients. Insurance claims for 16 years for 5,117 adults were evaluated retrospectively for tooth extraction events. Patients were classified as HiR for progressive periodontitis if they had ≥ 1 of the risk factors (RFs) smoking, diabetes, interleukin-1 genotype; or as LoR if no RFs. LoR event rates were 13.8% and 16.4% for 2 or 1 annual preventive visits (absolute risk reduction, 2.6%; 95%CI, 0.5% to 5.8%; p = .092). HiR event rates were 16.9% and 22.1% for 2 and 1 preventive visits (absolute risk reduction, 5.2%; 95%CI, 1.8% to 8.4%; p = .002). Increasing RFs increased events (p < .001). Oral health care costs were not increased by any single RF, regardless of prevention frequency (p > .41), but multiple RFs increased costs vs. no (p < .001) or 1 RF (p = .001). For LoR individuals, the association between preventive dental visits and tooth loss was not significantly different whether the frequency was once or twice annually. A personalized medicine approach combining gene biomarkers with conventional risk factors to stratify populations may be useful in resource allocation for preventive dentistry (ClinicalTrials.gov, NCT01584479).

IL-1 receptor antagonist gene as a predictive biomarker of progression of knee osteoarthritis in a population cohort.

OBJECTIVE: Within the interleukin-1 (IL-1) cytokine family, IL-1 receptor antagonist (IL1RN) gene variants have been associated with radiological severity of knee osteoarthritis (OA) in cross-sectional studies. The present study tested the relation between IL1RN gene variants and progression of knee OA assessed radiographically by change in Kellgren-Lawrence (KL) score over time. DESIGN: 1153 Caucasian adults (age range: 44-89) from the Johnson County Osteoarthritis Project were evaluated for unequivocal radiographic evidence of knee OA at baseline, defined as KL score ≥2, and were re-examined after 4-11 years for radiographic changes typical of OA progression. IL1RN gene variants were tested for association with OA progression and for potential interaction with body mass index (BMI). Other IL-1 gene variations were tested for association with OA progression as a secondary objective. RESULTS: Of 154 subjects with OA at baseline, 88 showed progression at follow-up. Seven IL1RN single nucleotide polymorphisms (SNPs) and one IL-1 receptor SNP were associated with progression. Four IL1RN haplotypes, each occurring in >5% of this population, showed different relationships with progression, including one (rs315931/rs4251961/rs2637988/rs3181052/rs1794066/rs419598/rs380092/rs579543/rs315952/rs9005/rs315943/rs1374281; ACAGATACTGCC) associated with increased progression [odds ratio (OR) 1.91 (95%CI 1.16-3.15); P = 0.012]. Haplotypes associated with progression by KL score were also associated with categorical change in joint space narrowing. BMI was associated with OA progression in subjects carrying a specific IL1RN haplotype, but not in subjects without that haplotype. CONCLUSION: A significantly greater likelihood of radiological progression of knee OA was associated with a commonly occurring IL1RN haplotype that could be tagged by three IL1RN SNPs (rs419598, rs9005, rs315943). Interactions were also observed between IL1RN gene variants and BMI relative to OA progression. This suggests that IL1RN gene markers may be useful in stratifying patients for medical management and drug development.

Personalized medicine: will dentistry ride the wave or watch from the beach?

Human differences in disease phenotype and treatment responses are well documented. Technological advances now allow healthcare providers to improve the prevention and treatment of chronic diseases by stratifying patient populations. Although personalized medicine has great promise, it has, so far, been primarily applied in oncology. Wider adoption requires changes in the healthcare system and in clinical decision-making, and early applications of personalized medicine appear to require strong clinical utility and sufficient value to drive adoption. Personalized medicine is likely to enter dentistry as patients start to demand it and as new drugs are developed for pathways common to oral diseases.

A nonsynonymous substitution of cystatin A, a cysteine protease inhibitor of house dust mite protease, leads to decreased mRNA stability and shows a significant association with atopic dermatitis.

BACKGROUND: Cystatin A (CSTA) is a strong candidate for atopic dermatitis (AD) because it maps to AD susceptibility locus on chromosome 3q21 and it does inhibit Der p 1 and Der f 1, major house dust mite cysteine proteases and environmental triggers for AD and asthma. OBJECTIVE: To examine any association between polymorphisms in CSTA and AD and study the effect on the CSTA mRNA expression level. METHODS: We identified three polymorphisms and characterized the linkage disequilibrium mapping of the CSTA gene. All three CSTA polymorphisms were genotyped in 100 AD patients and 203 matched controls. Subsequently, we performed transfection-based RNA stability assays. RESULTS: We found a significant association between the CSTA +344C variant and AD [odds ratio (OR) = 1.91; P = 0.024]. When further 61 control samples were genotyped. The association with CSTA +344C allele was enhanced OR = 2.13; P = 0.006. To test whether the CSTA +344 affected the CSTA transcriptional activity, the decay rates of RNAs transcribed from the CSTA +344C and CSTA +344T variants were investigated. COS-7 cells were transfected with a pcDNA3.1-CSTA+344C or a pcDNA3.1-CSTA+344T construct and cultured in the presence or absence of actinomycin D. Real-time RT-PCR revealed that CSTA +344C mRNA is more than two times less stable than the CSTA +344T mRNA (P < 0.001). CONCLUSION: These results suggest that the CSTA +344C allele associated with unstable mRNA could result in failing to protect the skin barrier in AD patients from both exogenous and endogenous proteases.

Evidence of a pharmacogenomic response to interleukin-l receptor antagonist in rheumatoid arthritis.

Biological activity of the IL-1 system depends on the balance between two proinflammatory proteins (IL-1alpha and IL-1beta) and the related anti-inflammatory protein, the IL-1 receptor antagonist (IL-1Ra). The genes for these proteins lie within 430 kb on human chromosome 2. Based on a clinical trial of human recombinant IL-1ra in rheumatoid arthritis, we tested whether IL-1 genotype might be related to the likelihood of response to anti-IL-1 therapy. A positive response was defined as a reduction of at least 50% in the number of swollen joints by week 24, following treatment with either 150 mg/day IL-1ra or placebo. The response rate to treatment, independent of genotype, was 48% (44/91). A highly significant association was found between carriage of the rarer allele at IL1A(+4845) and response to treatment (P=0.0009; OR=4.85 (1.85,12.70)). The response rate in patients carrying this allele was 63.4% compared with 26.3% in noncarriers. A weaker association was found for IL1B(+3954) (P=0.02). There was a highly significant interaction between treatment (150 mg/day or placebo) and the composite genotype across IL1A(+4845) and IL1B(+3954) (P=7.6 x 10(-5)). No associations with IL-1 genotypes were found in patients receiving placebo. Thus, a significant pharmacogenomic effect was found in the treatment of RA patients with recombinant IL-1ra.

Genetic association between an AACC insertion in the 3'UTR of the stratum corneum chymotryptic enzyme gene and atopic dermatitis.

Atopic dermatitis is a disease with an impaired skin barrier that affects 15%-20% of children. In the normal epidermis, the stratum corneum chymotryptic enzyme (SCCE) thought to play a central role in desquamation by cleaving proteins of the stratum corneum (e.g., corneodesmosin and plakoglobin). Genetic variations within the SCCE gene could be associated with dysregulation of SCCE activity leading to an abnormal skin barrier. We screened the SCCE gene for variations and performed a case-control study on 103 atopic dermatitis patients and 261 matched controls. 16 synonymous single nucleotide polymorphisms (SNPs) have been identified and a 4 bp (AACC) insertion has been found in the 3'UTR. We performed an association study of the SCCE AACC insertion in the 3'UTR, and found a significant trend between the AACC allele with the two insertions and disease in the overall data set [odds ratio (OR)=2.31; p=0.0007]. The AACC insertion in the SCCE gene may result in a change to SCCE activity within the skin barrier. These findings suggest that SCCE could have an important role in the development of atopic dermatitis.

Functional correlates of the interleukin-1 receptor antagonist gene polymorphism in the colonic mucosa in ulcerative colitis.

Association studies have identified the interleukin-1 receptor antagonist gene allele 2(IL-1RN*2) as a marker of susceptibility in ulcerative colitis (UC). This study investigated the significance of the IL-1RN genotype with respect to protein and mRNA expression in the colonic mucosa. Homogenates of rectal biopsies from 99 UC and 54 controls were assayed for cytokines IL-1ra, IL-1a and IL-1b using ELISA. IL1RN, IL1A and IL1B genotypes were determined using restriction-enzyme analysis. The ability of the two IL1RN alleles to generate steady-state mRNA accumulation was assessed in the colonic mucosa of seven heterozygous patients. Stepwise linear regression demonstrated that IL-1RN genotype (P=0.001), diagnosis (P<0.0001) and treatment (P<0.03) were independent factors associated with the IL-1ra protein level whilst IL1RN genotype (P=0.005) and macroscopic inflammatory grade (P<0.0001) were associated with the IL-1ra/ total IL-1 ratio. The IL1RN*2 correlated with reduced IL-1ra and IL-1ra/IL-1 ratio with a gene dosage effect. In heterozygous UC patients the ratio of allele 1 mRNA / allele 2 steady state mRNA was always greater than 1 (range: 1.2-3.1) (P=0.018). The IL-1RN*2 is associated with reduced levels of IL-1ra protein and IL-1RN mRNA in the colonic mucosa, providing a biologically plausible explanation for the observed association of the allele with the disease.

Genetic analysis of the interleukin-1 receptor antagonist and its homologue IL-1L1 in alopecia areata: strong severity association and possible gene interaction.

Alopecia areata is an inflammatory hair loss disease with a major genetic component. The presence of focal inflammatory lesions with perifollicular T-cell infiltrates reflects the importance of local cytokine production in the pathogenesis. In addition to its fundamental pro-inflammatory role, the interleukin-1 (IL-1) system has major effects on hair growth regulation in vitro, with the inhibitory actions of IL-1alpha and IL-1beta being opposed by the receptor antagonist IL-1ra. The novel interleukin-1 like molecule 1 (IL-1L1) which has greatest gene sequence homology with IL1RN, the gene encoding IL-1ra, is another potential IL-1 antagonist. In view of previous studies suggesting a significant role for IL1RN polymorphisms in the pathogenesis of autoimmune/inflammatory disease, we have analysed polymorphisms of IL-1ra (IL1RN+2018) and its homologue IL-1L1 (IL1L1+4734) in a case-control association study on 165 patients and a large number of matched controls. Homozygosity for the rare allele of IL1RN (IL1RN*2) was significantly associated with alopecia areata [odds ratio (OR) = 1.89, 95% CI (1.09, 3.28); P = 0.02], confirming our previous findings of significant association with the IL1RN variable number tandem repeat (VNTR). The results also revealed a novel association involving a polymorphism of the interleukin-1 receptor antagonist homologue IL1L1 at position + 4734, IL1RN+2018, and alopecia areata. The effect of a genotype combining three copies of the rare alleles at the IL1RN and IL1L1 loci conferred a more than additive increase in the risk of disease compared to IL1RN+2018 or IL1L1+4734 alone [OR 3.37 (1.60, 7.06); P = 0.002], suggesting possible synergy between the IL1RN and IL1L1 genes. This effect was stronger in patients with severe disease (alopecia totalis/universalis) [OR 4.62 (1.87, 11.40), P = 0.0022], and in those with early age at onset (< 20 years) [OR = 6.38 (2.64, 15.42), P = 0.0002]. Our results suggest that these polymorphisms within IL1RN and IL1L1 themselves or a gene in linkage disequilibrium with IL1RN and IL1L1 predispose to the more severe forms of alopecia areata.

Analysis of the association between diabetic nephropathy and polymorphisms in the aldose reductase gene in Type 1 and Type 2 diabetes mellitus.

AIMS: To investigate the association between polymorphisms of the aldose reductase gene and diabetic nephropathy in both Type 1 and Type 2 diabetes mellitus, and to carry out a meta-analysis of published results. METHODS: We have investigated the role of two aldose reductase polymorphisms in four independent cohorts of cases and controls (two each with Type 1 and Type 2 diabetes) drawn from two ethnic populations, including 471 patients with nephropathy and 494 control diabetic patients without nephropathy. A C/T transition at position -106, and a (CA)n microsatellite marker 2.1 kb from the start site of the aldose reductase gene were genotyped in nephropathic patients and non-nephropathic controls from each cohort. RESULTS: Carriage of the -106 T allele was significantly associated with diabetic nephropathy in three of the four study groups. The Mantel-Haenszel combined odds ratio was 2.22 (95% CI 1.69, 2.94), P = 1.05 x 10(-8). We found no evidence for association of the microsatellite marker with nephropathy, despite moderate levels of disequilibrium between the two markers. Meta-analysis of published data yielded no evidence for association of the microsatellite marker with diabetic nephropathy in Type 2 diabetes, but varying degrees of association with diabetic nephropathy in Type 1 diabetes. CONCLUSIONS: Meta-analyses provide more convincing evidence of a role for the ALR2-106 marker than for the microsatellite marker in diabetic nephropathy (DN). More studies are now required to confirm these results and to establish whether the ALR2-106 polymorphism has a functional role in DN.

Association analysis of IL1A and IL1B variants in alopecia areata.

Alopecia areata is an inflammatory hair loss disease with a major genetic component. The disease is characterized by focal inflammatory lesions with perifollicular T-cell infiltrates, reflecting the role of local cytokine production in the development of patchy hair loss. IL-1 alpha and IL-1 beta are important inhibitors of hair growth in vitro. Their effect is opposed by the interleukin-1 receptor antagonist, IL-1ra. Genes of the IL-1 cluster are candidate genes in the pathogenesis of alopecia areata. To investigate the role of the IL-1 system in alopecia areata we examined three biallelic polymorphisms within the IL-1 gene cluster (IL1A+4845, IL1B+3954 and IL1B-511) in 165 patients and a large number of matched controls (n=1150). There was no significant association of IL1B-511 or IL1B+3954 genotypes with the overall dataset, or with disease severity or age at onset, in contrast with a previous report. The results suggested the possibility of an association with IL1A+4845 in the overall dataset [OR 1.39 (95% CI 1.00, 1.93)] although this was not statistically significant. This was due mainly to the contribution from mild cases of alopecia areata [OR 1.48 (0.96, 2.29)], suggesting that IL-1 alpha may have a particular role in the pathogenesis of this subgroup.

The interleukin 1 receptor antagonist gene allele 2 as a predictor of pouchitis following colectomy and IPAA in ulcerative colitis.

BACKGROUND & AIMS: The interleukin 1 receptor antagonist gene allele 2 has been suggested as a determinant of both disease susceptibility and extent in ulcerative colitis. The aim of this study was to assess the allele as a predictor of both the indication for colectomy and the occurrence of pouchitis after ileal pouch-anal anastomosis formation. METHODS: Genotyping for the +2018 single nucleotide polymorphism in the interleukin 1 receptor antagonist gene was performed in 109 patients who had undergone colectomy, including 82 patients who had been followed prospectively after ileal pouch-anal anastomosis formation. RESULTS: Patients with pouchitis had a higher allele 2 carriage rate compared with those without pouchitis (72% vs. 45%) and Kaplan-Meier survival analysis showed that allele 2 carriers had a significantly increased incidence of pouchitis compared with noncarriers (log-rank test, 6.5). After adjustment for confounding covariates in a Cox proportional hazards model, the relative hazard was 3.1 (95% confidence interval [CI], 1.2-7.8; P = 0.02). Although there was a higher allele 2 carriage rate in patients with chronic refractory compared with acute severe ulcerative colitis (63% vs. 48%), this difference was not significant (odds ratio, 1.9; 95% CI, 0.9-4.1; P = 0.1). CONCLUSIONS: The interleukin 1 receptor antagonist gene allele 2 predicts pouchitis after ileal pouch-anal anastomosis in ulcerative colitis.

A candidate gene analysis of three related photosensitivity disorders: cutaneous lupus erythematosus, polymorphic light eruption and actinic prurigo.

BACKGROUND: Polymorphic light eruption (PLE) is a common inherited photosensitivity disorder, which may predispose to several related but distinct conditions, including subacute cutaneous lupus erythematosus (SCLE), discoid lupus erythematosus (DLE) and actinic prurigo (AP). OBJECTIVES: To examine specific candidate genes for shared susceptibility alleles between these related phenotypes. METHODS: Eighty-five caucasian patients with annular SCLE or DLE were recruited, in addition to 102 first-degree relatives. The prevalence of PLE in both the patient and relative groups was determined by detailed interview and clinical examination. Eighty-five patients with pure PLE and 59 patients with AP were also recruited. Candidate genes were analysed by typing of single nucleotide polymorphisms of IL10 (-1082 G/A and -819 C/T), FCGR2A (131 R/H), SELE (128 S/R), ICAM1 (241 G/R and 469 E/K), IL1A (+ 4845 G/T), IL1B (-511 C/T and + 3954 C/T), IL1RN (+ 2018 T/C) and TNF (-308 G/A) using polymerase chain reaction (PCR) with sequence-specific primers and 5'-nuclease PCR. RESULTS: A significant association was found between SCLE and the rare TNF -308 A allele when compared with patients with DLE (P = 0.043), PLE (P = 0.001), AP (P < 0.001) and healthy controls (P < 0.001). However, there was strong linkage disequilibrium between TNF -308 A and the HLA A*01, B*08, DRB1*0301 haplotype. A negative association was also found between SCLE and the IL1B + 3954 T allele (P = 0.039), but the significance was lost on correction for multiple testing. CONCLUSIONS: We have demonstrated the association of SCLE with the rare TNF -308 A allele, which may be pathogenic or, alternatively, a marker allele for the extended HLA A*01, B*08, DRB1*0301 haplotype that is associated with a number of autoimmune conditions. Although many of the other loci that we chose failed to demonstrate an association, a candidate gene approach remains the most logical one, and the most likely to yield positive results in the future.

IL-1B and IL-1Ra gene polymorphisms and disease severity in rheumatoid arthritis: interaction with their plasma levels.

The balance between interleukin-1 (IL-1) and its competitive antagonist IL-1 receptor antagonist (IL-1Ra) may contribute to the pathogenesis of rheumatoid arthritis (RA). We analysed the frequency of different alleles in the IL-1B gene (at -511 and at +3954) as well as in the IL-1Ra gene (at +2018) in an association study involving 297 RA patients and 112 healthy controls from the same geographic area. We tested associations with RA susceptibility or severity, and with circulating levels of IL-1Ra and IL-1beta. Carriage of the rare IL-1B (+3954) allele 2 was increased in destructive arthritis (DRA) as compared to non-destructive arthritis (NDRA) (OR 1.7, 95% CI 1.1-2.8, 49.0% vs 35.9%) and controls (OR 1.7, 95% CI 1.1-2.8, 35.8%). Patients carrying this allele had a more destructive (Larsen wrist radiological index: mean +/- s.e.m., 2.1 +/- 0.2 vs 1.6 +/- 0.1, P = 0.005; Steinbrocker functional index: 2.4 +/- 0.1 vs 1.9 +/- 0.1, P = 0.002) and active disease (Ritchie articular index: 8.1 +/- 0.8 vs 5.3 +/- 0.6, P = 0.002; erythrocyte sedimentation rate (ESR): 36.6 +/- 2.9 mm/h vs 25.3 +/- 1.8 mm/h, P = 0.002). This contribution was independent from that of HLA DR4/DR1 to severity. IL-1Ra plasma levels adjusted to ESR values were significantly lower in IL-1B2 (+3954) positive than negative RA patients (1.0 +/- 0.1 vs 1.2 +/- 0.1 ng/ml, P = 0.01). This IL-1B (+3954) gene polymorphism may be an important marker for the severity of joint destruction in RA and is associated with an imbalance in IL-1Ra production. As this genetic association was independent and additive to the risk of HLA DR4/DR1 status, it could be a useful addition to HLA-DR4/1 as a genetic prognostic marker early in the course of the disease.

Association of the interleukin 1 receptor antagonist gene with ulcerative colitis in Northern European Caucasians.

BACKGROUND AND AIMS: An association between the allele 2 of the interleukin 1 receptor antagonist gene variable number tandem repeats polymorphism in intron 2 and ulcerative colitis was first reported in 1994. Subsequent studies in Caucasian Northern European patients have not confirmed this, although trends towards an association were observed. The lack of statistical significance could reflect inadequate power. In this study the association was reassessed in a large independent set of well characterised Caucasian patients and a meta-analysis of reported patient series was performed. PATIENTS AND METHODS: A total of 320 patients with endoscopically and histologically confirmed ulcerative colitis (124 pancolitis, 196 left sided and distal disease) and 827 ethnically matched controls were genotyped at polymorphic sites in the interleukin 1 receptor antagonist gene. Carriage rates were compared using chi(2) statistics. A meta-analysis of this and seven previous studies in North European Caucasian patients was performed using the Mantel-Haenszel chi(2) test. RESULTS: Patients had a significantly increased carriage rate of allele 2 compared with controls (52% v 45%; odds ratio 1.3 (95% confidence interval (CI) 1.01-1.7); p=0.04). The allele 2 carriage rate was highest in extensive colitis (carriage rate 56%; odds ratio 1.5 (95% CI 1.1-2.3) p=0.02) and in individuals who had undergone colectomy (carriage rate 55%; odds ratio 1.5 (95% CI 0.95-2.4); p=0.08). Meta-analysis of all eight studies showed a significant association between carriage of allele 2 and ulcerative colitis (odds ratio 1.23 (95% CI 1.04-1.45); p=0.01). CONCLUSIONS: The association of the interleukin 1 receptor antagonist gene polymorphism with ulcerative colitis is confirmed. The association is minor and confers only a small risk to an individual but will contribute a high attributable risk in a population due to the high allelic frequency. Accurate phenotypic characterisation defines more homogeneous subsets of patients, such as those with extensive disease, in whom the association is greater.

Candidate genes as potential links between periodontal and cardiovascular diseases.

Recent epidemiological associations between periodontal disease and cardiovascular disease have led to a search for biological mechanisms that explain the associations. Genetic factors that influence biological processes involved in both diseases represent one of the potential mechanisms that may link periodontitis and cardiovascular disease. At present, several candidate genes have been investigated in one of the diseases but not the other. Although there are limited data to support a specific candidate gene as the explanation for observed associations between the 2 diseases, a few candidates look promising. One candidate that influences inflammation, interleukin-1 gene polymorphisms, has been associated with periodontal disease and cardiovascular disease. This review will consider biological mechanisms and genes that may be reasonable candidates for an etiological mechanism that influences the clinical characteristics of both periodontal disease and cardiovascular disease.

Protective role against restenosis from an interleukin-1 receptor antagonist gene polymorphism in patients treated with coronary stenting.

OBJECTIVES: To test the hypothesis that interleukin-1 receptor antagonist (IL-1ra) gene polymorphism contributes to the risk of restenosis after coronary stenting. BACKGROUND: Cytokines of the interleukin-1 (IL-1) family play a central role in regulating inflammatory responses. There is strong evidence to support IL-1 involvement in smooth muscle cell mitogenesis and extracellular matrix metabolism. The IL-1ra counters the proinflammatory effects of IL-1. The interleukin-1 receptor antagonist gene (IL-1RN) contains several well-characterized polymorphic sites that correlate with altered IL-lra levels. METHODS: In 1,850 consecutive patients, clinical and angiographic measures ofrestenosis were evaluated over one year after coronary stent placement. Repeat angiography at six months was achieved in 84% of the patients; angiographic restenosis was defined < or =50% diameter stenosis at follow-up. Genotyping for an exon 2 polymorphism (+2,018) of IL-1RN (alleles 1 and 2) was based on a polymerase chain reaction technique. RESULTS: Allele 2 frequency was 0.28. Carriers of allele 2 had a significantly lower risk for angiographic restenosis, odds ratio (OR) of 0.78 (95% confidence interval, 0.63 to 0.97) and target vessel revascularization, OR of 0.73 (0.58 to 0.92) compared with noncarriers. Risk reduction was especially significant in patients <60 years (n = 696), with OR of 0.63 (0.43 to 0.91) for angiographic restenosis and 0.55 (0.39 to 0.78) for target vessel revascularization. CONCLUSIONS: Allele 2 of the IL-1ra gene was associated with a lower incidence of restenosis after coronary stenting, particularly in younger patients. This finding supports a role of inflammation in the development of restenosis after stent placement.

Evidence for an accessory protein function for Toll-like receptor 1 in anti-bacterial responses.

Members of the Toll-like receptor (TLR) family are components of the mammalian anti-microbial response, signaling with a domain closely related to that of IL-1 receptors. In this report the expression and function of TLR1, a TLR of unknown function, are examined. TLR1 is expressed by monocytes, as demonstrated using a novel mAb. Monocytes also express TLR2. TLR1 transfection of HeLa cells, which express neither TLR1 nor TLR2, was not sufficient to confer responsiveness to several microbial extracts. However, cotransfection of TLR1 and TLR2 resulted in enhanced signaling by HeLa cells to soluble factors released from Neisseria meningitidis relative to the response with either TLR alone. This phenomenon was also seen with high concentrations of some preparations of LPS. The N. meningitidis factors recognized by TLR1/TLR2 were not released by N. meningitidis mutant in the LpxA gene. Although LpxA is required for LPS biosynthesis, because cooperation between TLR1 and TLR2 was not seen with all LPS preparations, the microbial component(s) TLR1/2 recognizes is likely to be a complex of LPS and other molecules or a compound metabolically and chemically related to LPS. The functional IL-1R consists of a heterodimer; this report suggests a similar mechanism for TLR1 and TLR2, for certain agonists. These data further suggest that mammalian responsiveness to some bacterial products may be mediated by combinations of TLRs, suggesting a mechanism for diversifying the repertoire of Toll-mediated responses.

Microbiological parameters associated with IL-1 gene polymorphisms in periodontitis patients.

BACKGROUND, AIMS: Polymorphisms in the cluster of IL-1 genes have been significantly associated with the severity of adult periodontitis. The purpose of this study was to compare microbiological parameters in IL-1 genotype negative and positive adult subjects with a range of periodontitis severities. METHOD: The study included 108 subjects in good general health. Clinical parameters were recorded at 6 sites/tooth excluding 3rd molars and included: plaque accumulation, gingival erythema, bleeding on probing, suppuration, pocket depth and attachment level. Subgingival plaque samples were collected from the mesiobuccal surface of up to 28 teeth in each subject (mean 25.3) providing a total of 2736 samples. The levels of 40 subgingival taxa were determined in each sample using checkerboard DNA-DNA hybridization. Fingerstick blood samples were collected for IL-1A (+4845) and IL-1B (+3954) genotyping using PCR-based methods. RESULTS: The proportion of IL-1 genotype positive subjects that exhibited mean counts of specific subgingival species above selected thresholds was significantly higher than the proportion of genotype negative subjects. Prominent among species that were detected at higher levels in genotype positive subjects were members of the "red" and "orange" complexes and included: Bacteroides forsythus, Treponema denticola, the Fusobacterium nucleatum subspecies, Fusobacterium periodonticum, Campylobacter gracilis, Campylobacter showae and Streptococcus constellatus. Streptococcus intermedius, Streptococcus gordonii and 3 Capnocytophaga species were also detected more frequently at high numbers in genotype positive subjects. Significantly higher mean counts of B. forsythus, Porphyromonas gingivalis, T. denticola, the F. nucleatum subspecies, F. periodonticum, Campylobacter rectus, C. showae, Eubacterium nodatum, S. constellatus, S. gordonii, and S. intermedius were detected at periodontal pockets >6 mm in subjects who were genotype positive when compared with genotype negative subjects. The increase was due to increased numbers of cells of these species rather than a major shift in proportion. CONCLUSION: The data suggest that genotype positive subjects more frequently had higher levels of "red" and "orange" complex species that are known to be strongly associated with measures of periodontal inflammation.

An interleukin-1 genotype is associated with fatal outcome of meningococcal disease.

To determine whether known variants of the interleukin-1 (IL-1) and tumor necrosis factor (TNF) gene families are associated with severe manifestations of meningococcal disease, 276 white patients 4-70 years of age (median, 17 years) were genotyped. All patients had microbiologically proven Neisseria meningitidis infection; 39 died and 237 survived. A significant association (P<.001) was found between fatal outcome and genotype at IL1B (nucleotide position -511). Homozygous individuals, both for the common (1/1) and the rare (2/2) alleles, had increased odds ratios (ORs) for death, compared with heterozygous individuals (1/2): ORs (95% confidence intervals [CIs]) were 3.39 (1.39-8.29) and 7.35 (2.51-21.45), respectively. The mortality rates according to genotype at IL1B (-511) were 18.0% (1/1), 6.1% (1/2), and 32.3% (2/2), compared with 14.2% overall. The composite genotype, consisting of heterozygosity of IL1B (-511) together with homozygosity of the common allele of the IL-1 receptor antagonist gene (IL1RN) at +2018, was significantly associated with survival (P=.018; OR, 7.78 [95% CI, 1. 05-59.05]). There was no association between TNF genotype and fatal outcome. These data suggest that IL-1 genotype influences the severity of meningococcal disease.

IL-4 VNTR gene polymorphism in chronic polyarthritis. The rare allele is associated with protection against destruction.

OBJECTIVE: To evaluate the occurrence of variants of the interleukin 4 (IL-4) and IL-4 receptor (IL-4R) genes in patients with rheumatoid arthritis (RA) and their possible contribution to joint destruction. METHODS: Allelic frequencies for polymorphisms in the IL-4 [variable number of tandem repeat (VNTR) polymorphism in intron 3] and IL-4 receptor alpha chain (transition at nucleotide 1902) genes were assessed in 335 RA patients and 104 controls. Clinical indices of disease activity, disability and joint destruction and plasma levels of IL-1beta, IL-1Ra and sCD23 were assessed to evaluate a possible functional effect. RESULTS: Carriage of the rare IL-4(2) allele was higher in patients with non-destructive RA (40%) than in those with destructive RA (22.3%; odds ratio = 1.9, 95% confidence interval 1. 1-3.5, P = 0.0006) and in controls (26%, P = 0.002). Patients positive for this rare allele had significantly less joint destruction, assessed by the Larsen wrist index (P = 0.004) and a lower erythrocyte sedimentation rate (P = 0.04). A significantly higher carriage rate of IL-4(2) was seen in HLA-DR4/DR1(-) patients with non-destructive RA than in those with destructive RA. The IL-4 receptor polymorphism was not over-represented. Plasma levels of IL-1beta, IL-1Ra and sCD23, known to be modified by IL-4, were not different in individuals having different alleles. CONCLUSION: This IL-4 VNTR gene polymorphism may be a protective factor for severe joint destruction in RA that could be used as a prognostic marker early in the course of the disease.