Large-scale meta-analysis of interleukin-1 beta and interleukin-1 receptor antagonist polymorphisms on risk of radiographic hip and knee osteoarthritis and severity of knee osteoarthritis

OBJECTIVE

To clarify the role of common genetic variation in the Interleukin-1β (IL1B) and Interleukin-1R antagonist (IL1RN) genes on risk of knee and hip osteoarthritis (OA) and severity of knee OA by means of large-scale meta-analyses.

METHODS

We searched PubMed for articles assessing the role of IL1B and IL1RN polymorphisms/haplotypes on the risk of hip and/or knee OA. Novel data were included from eight unpublished studies. Meta-analyses were performed using fixed- and random-effects models with a total of 3595 hip OA and 5013 knee OA cases, and 6559 and 9132 controls respectively. The role of ILRN haplotypes on radiographic severity of knee OA was tested in 1918 cases with Kellgren-Lawrence (K/L) 1 or 2 compared to 199 cases with K/L 3 or 4.

RESULTS

The meta-analysis of six published studies retrieved from the literature search and eight unpublished studies showed no evidence of association between common genetic variation in the IL1B or IL1RN genes and risk of hip OA or knee OA (P>0.05 for rs16944, rs1143634, rs419598 and haplotype C-G-C (rs1143634, rs16944 and rs419598) previously implicated in risk of hip OA). The C-T-A haplotype formed by rs419598, rs315952 and rs9005, previously implicated in radiographic severity of knee OA, was associated with reduced severity of knee OA (odds ratio (OR)=0.71 95%CI 0.56-0.91; P=0.006, I(2)=74%), and achieved borderline statistical significance in a random-effects model (OR=0.61 95%CI 0.35-1.06 P=0.08).

CONCLUSION

Common genetic variation in the Interleukin-1 region is not associated with prevalence of hip or knee OA but our data suggest that IL1RN might have a role in severity of knee OA.

A genome-wide association study suggests that a locus within the ataxin 2 binding protein 1 gene is associated with hand osteoarthritis: the Treat-OA consortium

To identify the susceptibility gene in hand osteoarthritis (OA) the authors used a two-stage approach genome-wide association study using two discovery samples (the TwinsUK cohort and the Rotterdam discovery subset; a total of 1804 subjects) and four replication samples (the Chingford Study, the Chuvasha Skeletal Aging Study, the Rotterdam replication subset and the Genetics, Arthrosis, and Progression (GARP) Study; a total of 3266 people). Five single-nucleotide polymorphisms (SNPs) had a likelihood of association with hand OA in the discovery stage and one of them (rs716508), was successfully confirmed in the replication stage (meta-analysis p = 1.81×10⁻⁵). The C allele conferred a reduced risk of 33% to 41% using a case–control definition. The SNP is located in intron 1 of the A2BP1 gene. This study also found that the same allele of the SNP significantly reduced bone density at both the hip and spine (p<0.01), suggesting the potential mechanism of the gene in hand OA might be via effects on subchondral bone. The authors' findings provide a potential new insight into genetic mechanisms in the development of hand OA.

Progression of hand osteoarthritis over 2 years: a clinical and radiological follow-up study

OBJECTIVES

To investigate the course of hand osteoarthritis over 2 years by currently available outcome measures.

METHODS

189 participants of the Genetics, Arthrosis and Progression (GARP) study with hand osteoarthritis were followed for 2 years. Self-reported hand pain and functional limitations were assessed with the Australian/Canadian osteoarthritis hand index (AUSCAN LK 3.0). Pain intensity upon lateral pressure in the interphalangeal and thumb base joints was graded on a four-point scale. Osteophytes (0-3) and joint space narrowing (JSN) (0-3) was scored at baseline and after 2 years in interphalangeal and thumb base joints. Standardised response means (SRM) were calculated.

RESULTS

172 (91%) patients completed the 2-year follow-up (mean age 60.5 years, 78.5% women). Statistically significant increases in self-reported pain and function scores, in pain intensity scores as well as in osteophyte and JSN total scores were seen over 2 years. SRM were 0.25, 0.23, 0.67, 0.34 and 0.35, respectively, for self-reported pain and function scores, pain intensity scores, osteophyte and JSN total scores. Radiological progression was not associated with changes in self-reported pain and function. Women in an early post-menopausal stage were especially at risk of progressing radiologically.

CONCLUSIONS

Currently available outcome measures were able to assess progression over the relatively short time period of 2 years. Radiographic outcomes were more responsive than self-reported outcomes. Pain intensity upon lateral pressure seems to be a responsive measure but needs validation.

Progression of hand osteoarthritis over 2 years: a clinical and radiological follow-up study

OBJECTIVES

To investigate the course of hand osteoarthritis over 2 years by currently available outcome measures.

METHODS

189 participants of the Genetics, Arthrosis and Progression (GARP) study with hand osteoarthritis were followed for 2 years. Self-reported hand pain and functional limitations were assessed with the Australian/Canadian osteoarthritis hand index (AUSCAN LK 3.0). Pain intensity upon lateral pressure in the interphalangeal and thumb base joints was graded on a four-point scale. Osteophytes (0-3) and joint space narrowing (JSN) (0-3) was scored at baseline and after 2 years in interphalangeal and thumb base joints. Standardised response means (SRM) were calculated.

RESULTS

172 (91%) patients completed the 2-year follow-up (mean age 60.5 years, 78.5% women). Statistically significant increases in self-reported pain and function scores, in pain intensity scores as well as in osteophyte and JSN total scores were seen over 2 years. SRM were 0.25, 0.23, 0.67, 0.34 and 0.35, respectively, for self-reported pain and function scores, pain intensity scores, osteophyte and JSN total scores. Radiological progression was not associated with changes in self-reported pain and function. Women in an early post-menopausal stage were especially at risk of progressing radiologically.

CONCLUSIONS

Currently available outcome measures were able to assess progression over the relatively short time period of 2 years. Radiographic outcomes were more responsive than self-reported outcomes. Pain intensity upon lateral pressure seems to be a responsive measure but needs validation.

Risk factors in familial osteoarthritis: the GARP sibling study

PURPOSE

To investigate the association between systemic and local risk factors and familial osteoarthritis (OA) at multiple sites.

METHODS

Patients and their siblings had primary OA at multiple sites at middle age. OA diagnosis followed the American College of Rheumatology criteria. We recruited 345 controls (mean age 57 years (range 40-76), 64% women) by random sampling from the population by telephone and collected all data by questionnaires. Odds ratios (ORs) were adjusted for sex, age and body mass index (BMI) (kg/m(2)), 95% confidence intervals (CIs95) were computed using robust standard errors with the intra-family effect taken into account.

RESULTS

Three hundred and eighty-two patients (mean age 60 years [range 43-79]), 82% women had OA in the spine (80%), hands (72%), knees (34%) and hips (24%). In women, an association of familial OA with a young age at natural menopause (<45 years), OR=2.6 (CI95 1.5-4.5) was found. Physically demanding jobs led to an increased risk of familial OA in men: OR=2.6 (CI95 1.3-5.3). Familial OA was more prevalent in individuals with a BMI>30, OR=2.0 (CI95 1.3-3.2) compared to a BMI of <25. Taller persons had a lower risk of familial OA, OR=0.33 (0.1-0.8) in the height category >180 cm relative to a height of <160 cm. A history of meniscectomy, increased the risk of familial OA at multiple sites with knee involvement, OR=6.2 (CI95 3.0-12.7).

CONCLUSIONS

Systemic and local risk factors play a role in the etiology of familial OA at multiple sites.

Innate production of tumour necrosis factor alpha and interleukin 10 is associated with radiological progression of knee osteoarthritis

OBJECTIVES

Inflammation may contribute to progression of knee osteoarthritis (OA). Therefore, we investigated whether innate differences in the inflammatory response regarding cytokine production were associated with radiological progression of knee OA.

METHODS

Symptomatic patients with knee OA (n = 89) were included. Standardised posteroanterior knee radiographs were obtained at baseline and after 24 months. Medial and lateral tibiofemoral joint space narrowing (JSN) was graded with the Altman atlas. Radiological progression was defined as an increase of at least one score in JSN total scores. Whole blood samples were stimulated with lipopolysaccharide (LPS) (10 ng/ml). Relative risks (RR) with 95% CIs of OA progression in relation to quartiles of innate ex vivo production of interleukin (IL)1beta, tumour necrosis factor (TNF)alpha, IL1 receptor antagonist (Ra) and IL10 were calculated.

RESULTS

Progression of JSN was present in 29 (33.7%) of 86 followed patients after 2 years. Patients in the highest quartile of TNFalpha production had a sixfold increased risk of JSN progression (age, sex and body mass index adjusted RR 6.1, 95% CI 1.4 to 9.8) and patients in the highest quartile of IL10 production had a fourfold increased risk of JSN progression (age, sex and body mass index adjusted RR 4.3, 95% CI 1.7 to 6.2), both in comparison with those patients in the lowest quartile. No significant associations were found between variations in IL1beta and IL1Ra production and JSN progression.

CONCLUSION

The innate capacity to produce TNFalpha and IL10 upon LPS stimulation is associated with radiological progression of knee OA, even over a relatively short follow-up period of 2 years.

Evidence for the association of the S100beta gene with low cognitive performance and dementia in the elderly

Variations in the S100beta gene may be instrumental in producing a continuum from mild cognitive decline to overt dementia. After screening 25 single nucleotide polymorphisms (SNPs) in S100beta, we observed association of the rs2300403 intron 2 SNP with poorer cognitive function in three independent populations. Moreover, we detected a significant association of this SNP with increased risk of developing dementia or Alzheimer's disease (AD) in six independent populations, especially in women and in the oldest. Furthermore, we characterised a new primate-specific exon within intron 2 (the corresponding mRNA isoform was called S100beta2). S100beta2 expression was increased in AD brain compared with controls, and the rs2300403 SNP was associated with elevated levels of S100beta2 mRNA in AD brains, especially in women. Therefore, this genetic variant in S100beta increases the risk of low cognitive performance and dementia, possibly by favouring a splicing event increasing S100beta2 isoform expression in the brain.

IBD sharing around the PPARG locus is not increased in dizygotic twins or their mothers

Busjahn et al reported finding linkage between PPARG (3p25) and being a dizygotic (DZ) twin. We differentiate, as do the authors, between the conception of DZ twins, and being the viable result of such a conception.

Genetic polymorphisms of the renin-angiotensin system and complications of insulin-dependent diabetes mellitus

OBJECTIVE

Patients with insulin-dependent diabetes mellitus (IDDM) have a high risk of developing diabetic nephropathy, retinopathy and cardiovascular diseases. The contribution of gene polymorphisms of the renin angiotensin system to these complications is controversial and may differ among populations.

METHODS

In 257 Dutch IDDM patients (188 with urinary albumin excretion (UAE) <30 mg/24 h), logistic regression analysis was used to study the relationships among, on the one hand, the insertion/deletion gene polymorphism of the angiotensin-converting enzyme gene (ACE-ID), the M235T gene polymorphism of the angiotensinogen gene (AGT-M235T), and the A1166C gene polymorphism of the angiotensin type 1 receptor gene (AT1-A1166C), and, on the other hand, UAE, retinopathy, hypertension, and coronary heart disease.

RESULTS

The T-allele of the AGT-M235T polymorphism was associated with an increased risk of an elevated UAE (odds ratio (OR) 3.03; 95% confidence interval (CI) 1.06-8.61), but only when interaction with the D-allele of the ACE-ID polymorphism was considered. A previously described positive interaction between the T-allele of the AGT-M235T polymorphism and the D-allele of the ACE-ID polymorphism could not be confirmed. The T-allele was also associated with an increased risk of retinopathy (OR 3.89, 95% CI 1.79-8.47). The CC-genotype of the AT1-A1166C polymorphism was associated with hypertension (OR 3.58; 95% CI 1. 23-10.37).

CONCLUSIONS

In a Dutch IDDM population, including 69 patients with (incipient) diabetic nephropathy, the T-allele of the AGT-M235T polymorphism is associated with an elevated UAE and diabetic retinopathy and the CC-genotype of the AT1-A1166C polymorphism is associated with hypertension. A previously described interaction between the AGT-M235T and the ACE-ID polymorphisms could not be confirmed. Since the number of nephropathic patients in this study is small, these conclusions must be interpreted with caution.