High-Resolution Free-Breathing Automated Quantitative Myocardial Perfusion by Cardiovascular Magnetic Resonance for the Detection of Functionally Significant Coronary Artery Disease

AIMS

Current assessment of myocardial ischaemia from stress perfusion cardiovascular magnetic resonance (SP-CMR) largely relies on visual interpretation. This study investigated the use of high-resolution free-breathing SP-CMR with automated quantitative mapping in the diagnosis of coronary artery disease (CAD). Diagnostic performance was evaluated against invasive coronary angiography (ICA) with fractional flow reserve (FFR) measurement.

METHODS & RESULTS

Seven-hundred and three patients were recruited for SP-CMR using the research sequence at 3 Tesla. Of those receiving ICA within 6 months, 80 patients either had FFR measurement, or identification of a chronic total occlusion (CTO) with inducible perfusion defects seen on SP-CMR. Myocardial blood flow (MBF) maps were automatically generated in-line on the scanner following image acquisition at hyperaemic stress and rest, allowing myocardial perfusion reserve (MPR) calculation. 75 coronary vessels assessed by FFR, and 28 vessels with CTO were evaluated at both segmental and coronary territory level. Coronary territory stress MBF and MPR were reduced in FFR-positive (≤ 0.80) regions (median stress MBF: 1.74 [0.90-2.17] ml/min/g; MPR: 1.67 [1.10-1.89]) compared with FFR-negative regions (stress MBF: 2.50 [2.15-2.95] ml/min/g; MPR 2.35 [2.06-2.54] p < 0.001 for both). Stress MBF ≤ 1.94 ml/min/g and MPR ≤ 1.97 accurately detected FFR-positive CAD on a per-vessel basis (area under the curve: 0.85 and 0.96 respectively; p < 0.001 for both).

CONCLUSIONS

A novel scanner-integrated high-resolution free-breathing SP-CMR sequence with automated in-line perfusion mapping is presented which accurately detects functionally significant CAD.

Co-expression of CD21L and IL17A defines a subset of rheumatoid synovia, characterised by large lymphoid aggregates and high inflammation

OBJECTIVE

To determine whether the expression of IL17A and CD21L genes in inflamed rheumatoid synovia is associated with the neogenesis of ectopic lymphoid follicle-like structures (ELS), and if this aids the stratification of rheumatoid inflammation and thereby distinguishes patients with rheumatoid arthritis that might be responsive to specific targeted biologic therapies.

METHODS

Expression of IL17A and CD21L genes was assessed by RT-PCR, qRT-PCR and dPCR in synovia from 54 patients with rheumatoid arthritis. A subset of synovia (n = 30) was assessed by immunohistology for the presence of CD20+ B-lymphocytes and size of CD20+ B-lymphocyte aggregates as indicated by maximum radial cell count. The molecular profiles of six IL17A+/CD21L+ and six IL17A-/CD21L- synovia were determined by complementary DNA microarray analysis.

RESULTS

By RT-PCR, 26% of synovia expressed IL17A and 52% expressed CD21L. This provided the basis for distinguishing four subgroups of rheumatoid synovia: IL17A+/CD21L+ (18.5% of synovia), IL17A+/CD21L- (7.5%), IL17A-/CD21L+ (33.3%) and IL17A-/CD21L- (40.7%). While the subgroups did not predict clinical outcome measures, comparisons between the synovial subgroups revealed the IL17A+/CD21L+ subgroup had significantly larger CD20+ B-lymphocyte aggregates (P = 0.007) and a gene expression profile skewed toward B-cell- and antibody-mediated immunity. In contrast, genes associated with bone and cartilage remodelling were prominent in IL17A-/CD21L- synovia.

CONCLUSIONS

Rheumatoid synovia can be subdivided on the basis of IL17A and CD21L gene expression. Ensuing molecular subgroups do not predict clinical outcome for patients but highlight high inflammation and the predominance of B-lymphocyte mediated mechanisms operating in IL17A+/CD21L+ synovia. This may provide a rationale for more refined therapeutic selection due to the distinct molecular profiles associated with IL17A+/CD21L+ and IL17A-/CD21L- rheumatoid synovia.

Association of Crohn's disease-related chromosome 1q32 with ankylosing spondylitis is independent of bowel symptoms and faecal calprotectin

Background

Genome-wide association studies have identified a plethora of risk genes for both Crohn's disease (CD) and ankylosing spondylitis (AS). A subset of genes found to be risk factors for CD have also been found to be risk factors for AS. The objective of our study was to assess whether CD risk genes were associated with non-invasive clinical markers of gut inflammation in patients with AS, indicating a potential subset of patients with clinical as well as genetic overlap.

Methods

A total of 308 Caucasian patients who fulfilled the modified New York Criteria for AS, were assessed for bowel symptoms using the Dudley Inflammatory Bowel Symptom Questionnaire (DISQ). Of these patients, 157 also had faecal calprotectin measured. All AS patients and 568 healthy controls were genotyped for 10 CD risk loci using predesigned single nucleotide polymorphism (SNP) genotyping assays. Chi-square analysis was used to test for association between genotype and DISQ score and faecal calprotectin level.

Results

The minor allele of two SNPs, one in chromosome region 1q32 SNP (rs11584383), and one in the gene coding for IL23R (rs11209026) conferred protection against AS. Only the association of 1q32 remained significant after Bonferroni correction for multiple testing. Stratification by DISQ score and faecal calprotectin did not influence the association of 1q32 with AS.

Conclusion

In patients with AS, the association of the CD 1q32 SNP was independent of non-invasive markers of bowel inflammation. Other CD related SNPs were not found have a significant association with AS.

Expression of the genes facilitating methotrexate action within subcutaneous rheumatoid nodules

OBJECTIVES

We sought further understanding of the association between methotrexate (MTX) therapy and accelerated development of subcutaneous rheumatoid nodules. The objective was to establish expression of genes involved in the transport, metabolism, and mechanism of action of MTX within nodule tissue. We also examined for differences in gene expression between nodules from patients actively receiving MTX compared to those not receiving MTX.

METHODS

Subcutaneous nodule tissues (n=23) were obtained from 21 patients with RA, undergoing elective surgery. Expression of genes important to the transport (SLC19A1, ABCB1, ABCC1, ABCG2), metabolism (FPGS, GGH), and mechanism of action (TYMS, MTR, MTRR) of MTX, including for the adenosine receptors ADORA1, ADORA2A, ADORA2B, ADORA3 and ADORA3variant were quantitated by real-time PCR in each nodule sample.

RESULTS

Transcripts for all genes were found in all nodules. Expression of MTR was significantly reduced in nodules from patients receiving MTX therapy. Patterns of gene expression differed, with those metabolising MTX more prominent in nodules from patients receiving MTX when compared to nodules from those not receiving MTX, where genes involved in MTX transport were more prominent.

CONCLUSIONS

Genes involved in MTX handling are expressed in rheumatoid nodules, providing further evidence that metabolism of MTX within nodules could exert a local effect. Furthermore the profile of gene expression in nodules differed from that previously observed in rheumatoid synovial membrane. The significant reduction of MTR expression in nodules has implications for MTR- and MTRR-mediated re-methylation reactions. Our data suggest that in contrast to synovium, downstream methylation reactions involving methionine and the biosynthesis of S-adenosylmethionine (SAM) could be reduced in nodule tissue. This could help explain differing responses to MTX in rheumatoid nodules and synovium and warrants further investigation.

Coronary artery stenting in acute coronary syndrome associated with giant cell arteritis

Coronary vasculitis is a rare but devastating complication of giant cell arteritis, otherwise known as temporal arteritis. Originally named for its propensity to attack the superficial temporal arteries, it is now recognized that it commonly involves a number of medium and large arteries throughout the body. Here we describe two cases of giant cell arteritis affecting the coronary arteries, one discovered at post-mortem and one which was successfully treated with immunosuppressive therapy and drug-eluting coronary stents. <Learning objective: Giant cell arteritis is a large vessel vasculitis which commonly affects the superficial temporal, subclavian arteries, and aorta but in rare cases can involve the coronary arteries. In addition to standard corticosteroid therapy, drug-eluting stents may be useful in treating this rare but serious disease. Clinicians should both consider this condition in patients with atypical features of coronary artery disease and recognize drug-eluting stents as a potential effective therapy.>.

Prevalence of HLA-B27 in the New Zealand population: effect of age and ethnicity

INTRODUCTION

HLA-B27 genotyping is commonly used to support a diagnosis of ankylosing spondylitis (AS). A recent study has suggested that HLA-B27 may adversely affect longevity. The objectives of this study were to determine, for the first time, the prevalence of HLA-B27 in the New Zealand population, and to test whether HLA-B27 prevalence declines with age.

METHODS

117 Caucasian controls, 111 New Zealand Māori controls, and 176 AS patients were directly genotyped for HLA-B27 using PCR-SSP. These participants and a further 1103 Caucasian controls were genotyped for the HLA-B27 tagging single nucleotide polymorphisms (SNPs) rs4349859 and rs116488202. All AS patients testing positive for HLA-B27 of New Zealand Māori ancestry underwent high resolution typing to determine sub-allele status.

RESULTS

HLA-B27 prevalence was 9.2% in New Zealand Caucasian controls and 6.5% in Māori controls. No decline in HLA-B27 prevalence with age was detected in Caucasian controls (p = 0.92). Concordance between HLA-B27 and SNP genotypes was 98.7-99.3% in Caucasians and 76.9-86% in Māori. Of the 14 AS patients of Māori ancestry, 1 was negative for HLA-B27, 10 were positive for HLAB*2705, and 3 positive for HLAB*2704. All cases of genotype discordance were explained by the presence of HLAB*2704.

CONCLUSIONS

HLA-B27 prevalence in New Zealand Caucasians is consistent with that of Northern European populations and did not decline with increasing age. In Māori with AS who were HLA-B27 positive, 76.9% were positive for HLA-B*2705, suggesting that genetic susceptibility to AS in Māori is primarily due to admixture with Caucasians.

Sugar-sweetened beverage consumption: a risk factor for prevalent gout with SLC2A9 genotype-specific effects on serum urate and risk of gout

Objective

Consumption of high fructose corn syrup (HFCS)-sweetened beverages increases serum urate and risk of incident gout. Genetic variants in SLC2A9, that exchanges uric acid for glucose and fructose, associate with gout. We tested association between sugar (sucrose)-sweetened beverage (SSB) consumption and prevalent gout. We also tested the hypothesis that SLC2A9 genotype and SSB consumption interact to determine gout risk.

Methods

Participants were 1634 New Zealand (NZ) European Caucasian, Ma¯ori and Pacific Island people and 7075 European Caucasians from the Atherosclerosis Risk in Communities (ARIC) study. NZ samples were genotyped for rs11942223 and ARIC for rs6449173. Effect estimates were multivariate adjusted.

Results

SSB consumption increased gout risk. The OR for four drinks/day relative to zero was 6.89 (p=0.045), 5.19 (p=0.010) and 2.84 (p=0.043) for European Caucasian, Ma¯ori and Pacific Islanders, respectively. With each extra daily SSB serving, carriage of the gout-protective allele of SLC2A9 associated with a 15% increase in risk (p=0.078), compared with a 12% increase in non-carriers (p=0.002). The interaction term was significant in pooled (p_Interaction=0.01) but not meta-analysed (p_Interaction=0.99) data. In ARIC, with each extra daily serving, a greater increase in serum urate protective allele carriers (0.005 (p=8.7×10⁻⁵) compared with 0.002 (p=0.016) mmol/L) supported the gout data (p_Interaction=0.062).

Conclusions

Association of SSB consumption with prevalent gout supports reduction of SSB in management. The interaction data suggest that SLC2A9-mediated renal uric acid excretion is physiologically influenced by intake of simple sugars derived from SSB, with SSB exposure negating the gout risk discrimination of SLC2A9.

Expression of Methotrexate Transporters and Metabolizing Enzymes in Rheumatoid Synovial Tissue

Objective.

To determine whether methotrexate (MTX) affects the expression of genes involved in the transport [SLC19A1 (RFC1), ABCB1 (MDR1), ABCC1 (multidrug resistance proteins 1), ABCG2 (BCRP)], metabolism [γ-glutamyl hydrolase (GGH), folylpolyglutamate synthetase (FPGS)], and mechanism of action of MTX [thymidylate synthase, MTR, MTRR] in rheumatoid synovium.

Methods.

Synovial tissue samples were obtained from 20 patients with rheumatoid arthritis (RA). Gene expression was undertaken using quantitative real-time PCR.

Results.

All the genes examined were expressed in all samples. Expression of SLC19A1, GGH, FPGS, ABCC1, and MTRR was significantly higher in patients receiving MTX compared to those not receiving MTX (p < 0.05). The ratio of FPGS:GGH gene expression was 2.7 ± 0.51 ng/ml GAPDH (range 0.67–9.58).

Conclusion.

Genes involved in the transport, metabolism, and mechanism of action of MTX are expressed in rheumatoid joint synovium. These data provide evidence that MTX has the potential to be polyglutamated within the joint. The higher expression of FPGS compared to GGH in synovial tissue might favor production of long-chain MTX polyglutamates. Thus MTX has the potential to exert its therapeutic effects at the primary site of the inflammatory process in RA.

Dendritic cells provide a potential link between smoking and inflammation in rheumatoid arthritis

Introduction

Smoking increases the risk of developing rheumatoid arthritis (RA) and affects the severity of established RA. Smoking can impact on Th17 lymphocyte differentiation and function through activation of the aryl hydrocarbon receptor (AHR), a process with implications for the pathogenic mechanisms in RA that involve the cytokine, interleukin (IL)-17A. The objective of this study was to establish any effect of smoking on the inflammatory tissue lesions of rheumatoid arthritis via the AHR and IL-17A.

Methods

Twenty synovial and eighteen subcutaneous nodule tissue samples from 31 patients with RA were studied. Patient smoking status at the time of tissue collection was established. Expression of AHR, CYP1A1, AHRR, IL6, IL17A, IL17F, IL22, IL23, IL23R, IFNG, TBX21, IDO1 and FOXP3 genes were assessed in tissues and cultured cells using real-time PCR. Two-colour immunofluorescence was used to co-localise AHR and CYP1A1 protein in synovial tissues. The response of monocytes and monocyte-derived dendritic cells (mo-DCs) to the AHR agonist, benzo(a)pyrene (BaP) was compared in vitro.

Results

AHR gene expression was demonstrated in rheumatoid synovial tissues and nodules with significantly greater expression in synovia. Expression was not influenced by smoking in either tissue. Evidence of AHR activation, indicated by CYP1A1 and AHRR gene expression, was found only in synovia from patients who smoked. However, IL17A gene expression was lower in synovia from smokers. TBX21 and FOXP3 expression was not affected by smoking. Within the synovial tissues of smokers the principal cell type with evidence of AHR activation was a subset of synovial DCs. This observation was consistent with the sensitivity of human mo-DCs to BaP stimulation demonstrated in vitro. Exposure to BaP affected mo-DC function as demonstrated by decreased IL6 expression induced by PolyI:C, without affecting indoleamine 2,3 dioxygenase (IDO)1 expression.

Conclusion

Our findings show that one effect of smoking on inflamed rheumatoid synovial tissue involves activation of the AHR pathway. A subset of synovial DCs is important in the response to cigarette smoke. The potential for smoking to affect DC behaviour in joint tissues has relevance to both early and late phases of RA pathogenesis and warrants further investigation.

Hospital admissions associated with gout and their comorbidities in New Zealand and England 1999-2009

OBJECTIVES

To describe the national demographics, comorbidities and mortality of admissions associated with gout in New Zealand (NZ) from 1999 to 2009 and compare this with English gout admission data from the same period.

METHODS

The characteristics of all admissions due to or complicated by gout in NZ from 1999 to 2009 were analysed. These findings were then compared with the wider NZ population and the English National Health Service (NHS) gout admission rates from 1999 to 2009.

RESULTS

There were 10 241 admissions due to gout (group A) and 34 318 admissions complicated by gout (group B) in NZ from 1999 to 2009. There were 32 741 admissions due to gout in England over the same period. Gout admissions rose at 5.5% per year in NZ and at 7.2% per year in England over the study period. NZ gout patients admitted to hospital were more likely to be Māori or a Pacific Islander and had 3-7 comorbidities. Multiple admissions were common with 1479 NZ gout patients admitted more than once. Comorbidities varied between the NZ groups A and B: hypertension (19-39%), renal disease (16-27%) and diabetes mellitus (20-27%) were common. Heart failure (27.6%) and cardiovascular disease (39.1%) were common in those who had gout complicating their hospital admission. This group also had poorer survival compared with those admitted primarily for gout.

CONCLUSION

This is the first study to describe the epidemiology of admissions associated with gout across an entire country. Admissions are rising in both countries studied and those admitted in NZ have a high rate of comorbidity and re-admission.

Adenosine receptor expression in rheumatoid synovium: a basis for methotrexate action

INTRODUCTION

Methotrexate (MTX) exerts at least part of its anti-inflammatory effects through adenosine receptors (ADOR). The aims of this study were to determine the expression of all four adenosine receptor genes (ADORA1, ADORA2A, ADORA2B, ADORA3 and ADORA3variant) in rheumatoid synovial tissue and any influence of MTX exposure on this expression. Furthermore, we investigated whether polymorphisms within ADORA3 were associated with response and/or adverse effects associated with MTX.

METHODS

Adenosine receptor gene expression was undertaken using PCR in 20 rheumatoid arthritis (RA) synovial samples. A separate cohort of 225 RA patients receiving MTX was genotyped for SNPs in the ADORA3 receptor gene. Double immunofluorescence was used to identify cells expressing ADOR protein.

RESULTS

All ADOR genes were expressed in all synovial samples. ADORA3 and A3variant were the dominant subtypes expressed irrespective of MTX therapy. Expression of ADORA2A and ADORA2B was increased in patients receiving MTX compared to those not receiving MTX. There was no association between the ADORA3 rs1544224 SNP and high and low disease activity or MTX-associated adverse effects. ADORA2B protein expression was most obvious in vascular endothelial cells whereas ADORA3 protein was more abundant and expressed by synovial fibroblasts.

CONCLUSIONS

We have shown that adenosine receptors are expressed in RA synovium. There is differential expression of receptors such that ADORA3 is expressed at significantly higher levels. This evidence demonstrates the potential for MTX to exert its anti-inflammatory effects at the primary site of pathology within the joints of patients with RA.

The renal urate transporter SLC17A1 locus: confirmation of association with gout

INTRODUCTION

Two major gout-causing genes have been identified, the urate transport genes SLC2A9 and ABCG2. Variation within the SLC17A1 locus, which encodes sodium-dependent phosphate transporter 1, a renal transporter of uric acid, has also been associated with serum urate concentration. However, evidence for association with gout is equivocal. We investigated the association of the SLC17A1 locus with gout in New Zealand sample sets.

METHODS

Five variants (rs1165196, rs1183201, rs9358890, rs3799344, rs12664474) were genotyped across a New Zealand sample set totaling 971 cases and 1,742 controls. Cases were ascertained according to American Rheumatism Association criteria. Two population groups were studied: Caucasian and Polynesian.

RESULTS

At rs1183201 (SLC17A1), evidence for association with gout was observed in both the Caucasian (odds ratio (OR) = 0.67, P = 3.0 × 10-6) and Polynesian (OR = 0.74, P = 3.0 × 10-3) groups. Meta-analysis confirmed association of rs1183201 with gout at a genome-wide level of significance (OR = 0.70, P = 3.0 × 10-8). Haplotype analysis suggested the presence of a common protective haplotype.

CONCLUSION

We confirm the SLC17A1 locus as the third associated with gout at a genome-wide level of significance.

Methotrexate pneumonitis in rheumatoid arthritis: increased prevalence with increasing latitude: an epidemiological study of trends in new zealand

BACKGROUND

There is an association between increasing prevalence and increasing latitude for some autoimmune diseases, including rheumatoid arthritis (RA). Furthermore, in RA patients, a geographical variation in methotrexate pneumonitis has been suggested at a regional level in New Zealand.

OBJECTIVE

The objective of the study was to determine if there is an increased incidence of methotrexate pneumonitis with increasing latitude in New Zealand.

METHODS

A search was conducted using the NZ Ministry of Health's National Minimum Data Set for patients with discharge codes for RA (M05, M06) or history of RA and drug-induced lung disease (J702, J703, J704) or other (J189, J680, J90, J984) and methotrexate (Y431), for the period July 1, 1999, to June 30, 2008. Anonymous data were provided by the Ministry of Health for the 43 patients fulfilling these coding criteria and also the latitude and population of each domicile code. A Poisson regression analysis was undertaken with latitude as a continuous variable, adjusting for the total population at different latitudes.

RESULTS

The incidence rate ratio for methotrexate pneumonitis shows a 16% increase per 1 degree of latitude (95% confidence interval, 7%-27%; P = 0.02).

CONCLUSIONS

There was a latitudinal gradient seen in the rate of patient discharges for methotrexate pneumonitis, in the defined period. This supports the hypothesis that there is a latitude-dependent risk factor for this disorder and raises questions regarding possible environmental cofactors. It also supports the growing pool of evidence that certain immune-mediated conditions are more common at higher latitudes.

Validation of the Dudley Inflammatory Bowel Symptom Questionnaire for the assessment of bowel symptoms in axial SpA: prevalence of clinically relevant bowel symptoms and association with disease activity

OBJECTIVES

To validate the Dudley Inflammatory Bowel Disease Questionnaire (DISQ) for determining the presence and severity of bowel symptoms in axial SpA.

METHODS

Seventy-seven SpA patients were assessed for disease activity using the BASDAI. All participants, including 32 healthy controls and 29 patients with Crohn's Disease (CD), completed the DISQ and an assessment of stool form and frequency. Validation of the DISQ was undertaken in accordance with OMERACT criteria.

RESULTS

Validity of the DISQ for measuring bowel symptoms in SpA was confirmed (Cronbach's α 0.79). Mean DISQ scores (s.d.) were: controls 2.6 (2.6), SpA 8.7 (6.1) and CD 17.1 (10.2). Differences were significant between controls and SpA, and SpA and CD, and correlated with disease activity (ρ 0.27, P = 0.02). In SpA, DISQ scores of those taking NSAIDs (n = 59) did not differ from those not taking NSAIDs (n = 18) (P = 0.31). Stool form and frequency differed significantly between SpA patients and healthy controls (P < 0.001). Using the DISQ the prevalence of clinically relevant bowel symptoms in SpA is 31%, and 7.8% experience bowel symptoms equivalent to active CD.

CONCLUSION

The DISQ is a valid measure of bowel symptoms in SpA. Bowel symptoms are prevalent in SpA and correlate with disease activity. Symptoms do not relate to treatment with NSAIDs. We conclude that bowel symptoms should be included as a domain in the clinical assessment of patients with SpA and that the DISQ has potential as an outcome measure in clinical trials.

The SLC2A9 nonsynonymous Arg265His variant and gout: evidence for a population-specific effect on severity

Introduction

The C allele of the nonsynonymous Arg265His (rs3733591) variant of SLC2A9 confers risk for gout in Han Chinese, Solomon Island and Japanese samples, with a stronger role in tophaceous gout. There is no evidence for an association with gout in Caucasian populations. In the present study, we tested rs3733591 for association with gout in New Zealand (NZ) Māori, Pacific Island and Caucasian samples.

Methods

Rs3733591 was genotyped across gout patients (n = 229, 232 and 327 NZ Māori, Pacific Island and Caucasian samples, respectively) and non-gout controls (n = 343, 174 and 638 Māori, Pacific Island and Caucasian samples, respectively). Further Caucasian sample sets consisting of 67 cases and 4,712 controls as well as 153 cases and 6,969 controls were obtained from the Framingham Heart Study and the Atherosclerosis Risk in Communities study, respectively. The Polynesian samples were analyzed according to Eastern and Western Polynesian ancestry.

Results

No evidence for risk conferred by the C allele of rs3733591 with gout was found in the sample sets of NZ Māori (odd ratio (OR) = 0.98, P = 0.86), Eastern Polynesians (OR = 0.99, P = 0.92), Western Polynesians (OR = 1.16, P = 0.36) or combined Caucasians (OR = 1.15, P = 0.13). The C allele was significantly overrepresented in Māori tophaceous cases compared to cases without tophi (OR = 2.21, P = 0.008), but not in the other ancestral groupings.

Conclusions

Noting that our study's power was limited for detecting weak genetic effects, we were unable to replicate associations of rs3733591 with gout in Eastern Polynesian, Western Polynesian and Caucasian samples. However, consistent with a previous study of Han Chinese and Solomon Island populations, our data suggest that rs3733591 could be a marker of severe gout in some populations. Our results also suggest that the effect of this variant is population-specific, further confirming population heterogeneity regarding the association of SLC2A9 with gout.

The PTPN22 locus and rheumatoid arthritis: no evidence for an effect on risk independent of Arg620Trp

Objectives

The Trp⁶²⁰ allotype of PTPN22 confers susceptibility to rheumatoid arthritis (RA) and certain other classical autoimmune diseases. There has been a report of other variants within the PTPN22 locus that alter risk of RA; protective haplotype ‘5’, haplotype group ‘6–10’ and susceptibility haplotype ‘4’, suggesting the possibility of other PTPN22 variants involved in the pathogenesis of RA independent of R620W (rs2476601). Our aim was to further investigate this possibility.

Methods

A total of 4,460 RA cases and 4,481 controls, all European, were analysed. Single nucleotide polymorphisms rs3789607, rs12144309, rs3811021 and rs12566340 were genotyped over New Zealand (NZ) and UK samples. Publically-available Wellcome Trust Case Control Consortium (WTCCC) genotype data were used.

Results

The protective effect of haplotype 5 was confirmed (rs3789607; (OR = 0.91, P = 0.016), and a second protective effect (possibly of haplotype 6) was observed (rs12144309; OR = 0.90, P = 0.021). The previously reported susceptibility effect of haplotype 4 was not replicated; instead a protective effect was observed (rs3811021; OR = 0.85, P = 1.4×10⁻⁵). Haplotypes defined by rs3789607, rs12144309 and rs3811021 coalesced with the major allele of rs12566340 within the adjacent BFK (B-cell lymphoma 2 (BCL2) family kin) gene. We, therefore, tested rs12566340 for association with RA conditional on rs2476601; there was no evidence for an independent effect at rs12566340 (P = 0.76). Similarly, there was no evidence for an independent effect at rs12566340 in type 1 diabetes (P = 0.85).

Conclusions

We have no evidence for a common variant additional to rs2476601 within the PTPN22 locus that influences the risk of RA. Arg620Trp is almost certainly the single common causal variant.

A strong role for the ABCG2 gene in susceptibility to gout in New Zealand Pacific Island and Caucasian, but not Māori, case and control sample sets

Genetic variation in ABCG2 (rs2231142, Q141K), encoding a uric acid transporter, is associated with gout in diverse populations. The aim of this study was to examine a role for ABCG2 in gout susceptibility in New Zealand Māori, Pacific Island and Caucasian samples. Patients (n = 185, 173 and 214, for Māori, Pacific Island and Caucasian, respectively) satisfied the American College of Rheumatology gout classification criteria. The comparison samples comprised 284, 129 and 562 individuals, respectively, without gout. rs2231142 was genotyped and stratification accounted for using genomic control markers. Association of the minor allele of rs2231142 with gout was observed in the Pacific Island samples (OR = 2.80, P(STRAT) < 0.001 after accounting for effects of population structure), but not in the Māori samples (OR = 1.08, P(STRAT)= 0.70), with heterogeneity in association evident between the Māori and Pacific Island datasets (P(HET) = 0.001). A similar dichotomy in association was observed when samples were stratified into Western (Tonga, Samoa, Niue, Tokelau) versus Eastern Polynesian (Māori, Cook Island) origin (OR = 2.59, P(STRAT) < 0.001; OR = 1.12, P(STRAT)= 0.48, respectively; P(HET) = 0.005). Association with gout was observed in the Caucasian samples (OR = 2.20, P = 3.2 × 10(-8)). Unlike SLC2A9, which is a strong risk factor for gout in both Māori and Pacific Island people, ABCG2 rs2231142 has a strong effect only in people of Western Polynesian ancestry. Our results emphasize the need to account for sub-population differences when undertaking biomedical genetic research in a group defined by a geographical region and shared ancestry but characterized by migratory events that create bottlenecks and altered genetic structure in the founder populations.

The effects of an orally administered probiotic on sulfasalazine metabolism in individuals with rheumatoid arthritis: a preliminary study

AIM

To carry out a pilot study to investigate the effect of short-term oral probiotic administration on the metabolism of sulfasalazine (SSZ) in patients with rheumatoid arthritis (RA) stabilized on SSZ.

METHODS

Twelve subjects with RA taking stable doses of SSZ for a minimum of 3 months prior to the study, received a probiotic preparation contained three strains of bacteria (1.8 x 10(9) CFU/day) twice daily for 1 week. Single point blood and 12-h urine samples were taken before and after probiotic treatment and 3 weeks following discontinuation of probiotics, for determination of SSZ and its metabolites. The presence of the probiotic bacteria in the feces of patients was investigated by denaturing gradient gel electrophoresis (DGGE).

RESULTS

Adverse events recorded were three instances of gastrointestinal disturbance and one flare of RA. Plasma and urinary levels of SSZ and its metabolites showed no statistically significant changes after probiotic administration and the incidence of gastrointestinal disturbance did not appear to be ascribed to higher sulfapyridine plasma levels. Probiotic-specific DGGE bands were detected in the feces of some patients after the treatment period.

CONCLUSIONS

Short-term treatment of RA patients with a multi-strain probiotic did not significantly influence SSZ metabolism as has been demonstrated in animal models.

Only one independent genetic association with rheumatoid arthritis within the KIAA1109-TENR-IL2-IL21 locus in Caucasian sample sets: confirmation of association of rs6822844 with rheumatoid arthritis at a genome-wide level of significance

INTRODUCTION

The single nucleotide polymorphism (SNP) rs6822844 within the KIAA1109-TENR-IL2-IL21 gene cluster has been associated with rheumatoid arthritis (RA). Other variants within this cluster, including rs17388568 that is not in linkage disequilibrium (LD) with rs6822844, and rs907715 that is in moderate LD with rs6822844 and rs17388568, have been associated with a number of autoimmune phenotypes, including type 1 diabetes (T1D). Here we aimed to: one, confirm at a genome-wide level of significance association of rs6822844 with RA and, two, evaluate whether or not there were effects independent of rs6822844 on RA at the KIAA1109-TENR-IL2-IL21 locus.

METHODS

A total of 842 Australasian RA patients and 1,115 controls of European Caucasian ancestry were genotyped for rs6822844, rs17388568 and rs907715. Meta-analysis of these data with published and publicly-available data was conducted using STATA.

RESULTS

No statistically significant evidence for association was observed in the Australasian sample set for rs6822844 (odds ratio (OR)=0.95 (0.80 to 1.12), P=0.54), or rs17388568 (OR=1.03 (0.90 to 1.19), P=0.65) or rs907715 (OR=0.98 (0.86 to 1.12), P=0.69). When combined in a meta-analysis using data from a total of 9,772 cases and 10,909 controls there was a genome-wide level of significance supporting association of rs6822844 with RA (OR=0.86 (0.82 to 0.91), P=8.8x10(-8), P=2.1x10(-8) including North American Rheumatoid Arthritis Consortium data). Meta-analysis of rs17388568, using a total of 6,585 cases and 7,528 controls, revealed no significant association with RA (OR=1.03, (0.98 to 1.09); P=0.22) and meta-analysis of rs907715 using a total of 2,689 cases and 4,045 controls revealed a trend towards association (OR=0.93 (0.87 to 1.00), P=0.07). However, this trend was not independent of the association at rs6822844.

CONCLUSIONS

The KIAA1109-TENR-IL2-IL21 gene cluster, that encodes an interleukin (IL-21) that plays an important role in Th17 cell biology, is the 20th locus for which there is a genome-wide (P Collapse

Key Words Collapse

MESH Headings

• Aged
• Aged, 80 and over
• Alleles
• Arthritis, Rheumatoid/ethnology
• Arthritis, Rheumatoid/genetics
• Australia
• Case-Control Studies
• Female
• GTPase-Activating Proteins/genetics
• Genetic Predisposition to Disease/genetics
• Genotype
• Humans
• Interleukin-2/genetics
• Interleukins/genetics
• Male
• Microtubule-Associated Proteins/genetics
• Middle Aged
• New Zealand
• Polymorphism, Single Nucleotide/genetics
• White People/ethnology
• White People/genetics

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Grants

• 076113 Wellcome Trust

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Association of variation in Fcgamma receptor 3B gene copy number with rheumatoid arthritis in Caucasian samples

OBJECTIVE

There is increasing evidence that variation in gene copy number (CN) influences clinical phenotype. The low-affinity Fcgamma receptor 3B (FCGR3B) located in the FCGR gene cluster is a CN polymorphic gene involved in the recruitment to sites of inflammation and activation of polymorphonuclear neutrophils (PMNs). Given recent evidence that low FCGR3B CN is a risk factor for systemic but not organ-specific autoimmune disease and the potential importance of PMN in the pathophysiology of rheumatoid arthritis (RA), the authors hypothesised that FCGR3B gene dosage influences susceptibility to RA.

METHODS

FCGR3B CN was measured in 643 cases of RA and 461 controls from New Zealand (NZ), with follow-up analysis in 768 cases and 702 controls from the Netherlands and 250 cases and 211 controls from the UK. All subjects were of Caucasian ancestry.

RESULTS

Significant evidence for an association between CN <2 and RA was observed in the Dutch cohort (OR 2.01 (95% CI 1.37 to 2.94), p=3 x 10-4) but not in the two smaller cohorts (OR 1.45 (95% CI 0.92 to 2.26), p=0.11 and OR 1.33 (95% CI 0.58 to 3.02), p=0.50 for the NZ and UK populations, respectively). The association was evident in a meta-analysis which included a previously published Caucasian sample set (OR 1.67 (95% CI 1.28 to 2.17), p=1.2 x 10-4).

CONCLUSIONS

One possible mechanism to explain the association between reduced FCGR3B CN and RA is the reduced clearance of immune complex during inflammation. However, it is not known whether the association between RA and FCGR3B CN is aetiological or acts as a proxy marker for another biologically relevant variant. More detailed examination of genetic variation within the FCGR gene cluster is required.

PCR detectable Y chromosome-specific DNA but no intact Y chromosome-bearing cells in polymyositis biopsies of two women with male offspring

AIMS

Pregnancy-related and idiopathic adult polymyositis are inflammatory myopathies of unknown aetiology in which CD8 positive T cells are found in close association with the up-regulation of human leukocyte antigen (HLA) class I on affected muscle cells. A similar polymyositis can also occur in patients with chronic graft versus host disease, wherein graft lymphocytes may be involved in the myositis. We investigated whether polymyositis that was temporally related to pregnancy, contained Y chromosome-bearing cells or signals using polymerase chain reaction (PCR) in biopsies of lesional muscle from two women who had given birth to sons. Furthermore, if Y chromosome material was present, we investigated whether it was contained in the intact inflammatory cells (CD8 positive lymphocytes for example), fetal macrophages, or differentiated fetal stem cells engrafted in the lesional skeletal muscle, and thus whether fetal cells played a role in the pathogenesis of the myositis.

METHODS

PCR analysis was used for the Y chromosome in lesional tissue and fluorescence in situ hybridisation (FISH) for intact cells carrying the Y chromosome.

RESULTS

Small amounts of Y chromosome material were detected on second round PCR in fresh frozen tissue. No Y chromosome-bearing intact cells of lymphocytic, macrophage or muscle lineage were detected.

CONCLUSION

Our results suggest that microchimeric fetal cells are not found in the lesional tissue of pregnancy-related polymyositis.

Role of the urate transporter SLC2A9 gene in susceptibility to gout in New Zealand Māori, Pacific Island, and Caucasian case-control sample sets

OBJECTIVE

To examine the role of genetic variation in the renal urate transporter SLC2A9 in gout in New Zealand sample sets of Māori, Pacific Island, and Caucasian ancestry and to determine if the Māori and Pacific Island samples could be useful for fine-mapping.

METHODS

Patients (n= 56 Māori, 69 Pacific Island, and 131 Caucasian) were recruited from rheumatology outpatient clinics and satisfied the American College of Rheumatology criteria for gout. The control samples comprised 125 Māori subjects, 41 Pacific Island subjects, and 568 Caucasian subjects without arthritis. SLC2A9 single-nucleotide polymorphisms rs16890979 (V253I), rs5028843, rs11942223, and rs12510549 were genotyped (possible etiologic variants in Caucasians).

RESULTS

Association of the major allele of rs16890979, rs11942223, and rs5028843 with gout was observed in all sample sets (P = 3.7 x 10(-7), 1.6 x 10(-6), and 7.6 x 10(-5) for rs11942223 in the Māori, Pacific Island, and Caucasian samples, respectively). One 4-marker haplotype (1/1/2/1; more prevalent in the Māori and Pacific Island control samples) was not observed in a single gout case.

CONCLUSION

Our data confirm a role of SLC2A9 in gout susceptibility in a New Zealand Caucasian sample set, with the effect on risk (odds ratio >2.0) greater than previous estimates. We also demonstrate association of SLC2A9 with gout in samples of Māori and Pacific Island ancestry and a consistent pattern of haplotype association. The presence of both alleles of rs16890979 on susceptibility and protective haplotypes in the Māori and Pacific Island sample is evidence against a role for this nonsynonymous variant as the sole etiologic agent. More extensive linkage disequilibrium in Māori and Pacific Island samples suggests that Caucasian samples may be more useful for fine-mapping.

A comparison of fatigue correlates in rheumatoid arthritis and osteoarthritis: disparity in associations with disability, anxiety and sleep disturbance

OBJECTIVES

To investigate correlates of fatigue among individuals with RA and OA, including mood, sleep, disease activity and radiographic damage.

METHODS

Fatigue was assessed using the Multidimensional Assessment of Fatigue-Global Fatigue Index (MAF-GFI) in 103 patients with RA and 103 with OA. Sleep disturbance and pain were assessed using a visual analogue scale anxiety and depression using the Hospital Anxiety and Depression scale and disability using the HAQ. In the RA cohort, the disease activity score-28 joint count (DAS-28) and the Van der Heijde modified Sharp score were calculated, and in the OA cohort, the Kellgren-Lawrence score and the WOMAC score calculated.

RESULTS

The MAF-GFI scores were higher in the OA cohort (P = 0.02). This was not significant after controlling for disability (P = 0.59). OA participants reported greater pain, disability, depression and sleeplessness than those with RA (all P < 0.01). The strongest correlates of fatigue in the RA cohort were depression (P < 0.001) and anxiety (P < 0.001). There was no significant association with pain (P = 0.43), DAS-28 (P = 0.07), HAQ (P = 0.10) or Sharp score (P = 0.78). In OA, the correlates of fatigue were older age (P = 0.02), sleep disturbance (P = 0.03), depression (P = 0.04), disability (P = 0.04) and lower CRP (P = 0.001).

CONCLUSIONS

Fatigue is common and severe in both RA and OA. In RA, fatigue had no significant association with pain, disease activity, disability or erosions, but was associated with depression and anxiety. The disparity in correlates indicates that generalizing the experience of fatigue between OA and RA is not appropriate. Fatigue is an important domain in the assessment of disease impact.

The ITGAV rs3738919 variant and susceptibility to rheumatoid arthritis in four Caucasian sample sets

INTRODUCTION

Angiogenesis is an important process in the development of destructive synovial pannus in rheumatoid arthritis (RA). The ITGAV +gene encodes a cell cycle-associated antigen, integrin alphanubeta 3, which plays a role in RA angiogenesis. Previously, two independent studies identified an association between the major allele of the ITGAV single-nucleotide polymorphism (SNP) rs3738919 and RA. We therefore tested this association in an independent study using New Zealand (NZ) and Oxford (UK) RA case control samples.

METHODS

We compared genotype frequencies in 740 NZ Caucasian RA patients and 553 controls genotyped for rs3738919, using a polymerase chain reaction-restriction fragment length polymorphism assay. A TaqMan genotyping SNP assay was used to type 713 Caucasian RA patients and 515 control samples from Oxford for the rs3738919 variant. Association of rs3738919 with RA was tested in these two sample sets using the chi-square goodness-of-fit test. The Mantel-Haenszel test was used to perform a meta-analysis, combining the genetic results from four independent Caucasian case control cohorts, consisting of 3,527 cases and 4,126 controls. Haplotype analysis was also performed using SNPs rs3911238, rs10174098 and rs3738919 in the Wellcome Trust Case Control Consortium, NZ and Oxford case control samples.

RESULTS

We found no evidence for association between ITGAV and RA in either the NZ or Oxford sample set (odds ratio [OR] = 0.88, P(allelic) = 0.11 and OR = 1.18, P(allelic) = 0.07, respectively). Inclusion of these data in a meta-analysis (random effects) of four independent cohorts (3,527 cases and 4,126 controls) weakens support for the hypothesis that rs3738919 plays a role in the development of RA (OR(combined) = 0.92, 95% confidence interval 0.80 to 1.07; P = 0.29). No consistent haplotype associations were evident.

CONCLUSIONS

Association of ITGAV SNP rs7378919 with RA was not replicated in NZ or Oxford case control sample sets. Meta-analysis of these and previously published data lends limited support for a role for the ITGAV in RA in Caucasians of European ancestry.

Monocyte derived interleukin (IL)-23 is an important determinant of synovial IL-17A expression in rheumatoid arthritis

OBJECTIVE

To demonstrate gene expression of interleukin (IL)-17A, IL-23, and IL-12 and to determine the proximity of IL-17A and IL-23 producing cells in rheumatoid synovial tissue.

METHODS

Total RNA was isolated from 25 synovial membranes obtained from 20 patients with rheumatoid arthritis (RA). Quantitative real-time polymerase chain reaction was used to measure IL-17A, IL-12p35, IL-23p19, p40, and GAPDH expression. Immunohistochemistry was utilized to determine cell type and proximity of IL-17A, IL-12, and IL-23 in rheumatoid synovium.

RESULTS

IL-17A was present in 13/25 synovia. IL-12p35 was present in all samples while IL-23p19 was present in 23/25. p40 was present in 23/25 samples. Of the 2 p40- samples both were IL-23p19 and IL-12p35 positive. Mean expression of IL-23p19 was significantly higher in the IL-17A+ versus IL-17A- synovia (0.10 +/- 0.02 ng vs 0.05 +/- 0.01 ng; p < 0.05). There was no difference in IL-12p35 expression between IL-17A+ and IL-17A- synovia (0.5 +/- 0.21 ng vs 0.38 +/- 0.24 ng; p = 0.2). All IL-17A+ cells were in the vicinity of IL-23+ cells. IL-12+ cells were both close to and removed from IL-17A+ cells. Only a proportion of CD3+T cells appeared to produce IL-17A.

CONCLUSION

IL-17A gene expression occurs in only a subset of rheumatoid synovial membranes. IL-23 gene expression is higher in IL-17A+ versus IL-17A- membranes. In keeping with this, IL-17A+ and IL-23+ cells colocalize in synovial membranes. IL-17 is not an absolute requirement in RA but may be important in amplifying the inflammatory response. Anti-IL23 therapies may have a role in those patients with IL-17A expression.

Evidence for association of an interleukin 23 receptor variant independent of the R381Q variant with rheumatoid arthritis

OBJECTIVE

The rare allele of a non-synonymous interleukin 23 receptor (IL23R) single nucleotide polymorphism (SNP) rs11209026 (p.Arg381Gln) confers strong protection against Crohn disease (CD) and psoriasis. Other IL23R variants also exhibit association with CD, genetically independent of rs11209026. In rheumatoid arthritis (RA), IL23 is an important determinant of the production of IL17A, a cytokine of consequence in inflammation and bone destruction. While there is no previous support for strong association of IL23R with RA, the possibility of a weaker role for IL23R variants in the aetiology of RA cannot be eliminated.

METHODS

A New Zealand RA cohort was tested for association with six IL23R SNPs and the resulting data combined with a reanalysis of the Wellcome Trust Case Control Consortium data and a previously published Spanish data set. The combined data set totals over 3000 Caucasian cases and 3800 controls, which has sufficient power to detect a risk of as low as odds ratio (OR) = 1.2.

RESULTS

Our data emphasise the lack of association of rs11209026 with RA (OR 1.01, 95% confidence interval (CI) 0.88 to 1.16, p = 0.86). However there was some evidence for association of rs1343151 with RA (OR 1.14, 95% CI 1.06 to 1.22, p = <0.001).

CONCLUSIONS

While requiring further replication, these data further support a role for the IL17A/IL23 pathway in RA. Understanding how different variants of IL23R associate, at varying levels of strength, with contrasting groups of immune-mediated diseases (CD, psoriasis, ankylosing spondylitis, RA) will enhance knowledge on the aetiology of these diseases.

Outpatient follow-up for patients with rheumatoid arthritis in relation to New Zealand Rheumatology Association guidelines at Dunedin Hospital

AIM

Current treatment for rheumatoid arthritis (RA) involves the use of various disease-modifying anti-rheumatic drugs (DMARDs) and biologic response agents which require ongoing medical supervision. An audit was undertaken to assess the adequacy of outpatient specialist follow-up for supervision of treatment in patients with RA in the Otago region.

METHODS

The Rheumatology Service database was used to assess time between follow-up for the penultimate and last visit to rheumatology outpatient clinic for all patients who made at least two visits between 1 October 2001 and 30 September 2006. Other recorded data included demographic information and clinician expectations for the timing of the next outpatient visit. Comparisons were made between actual follow-up intervals, those indicated by specialists and the follow-up intervals recommended by the New Zealand Rheumatology Association Guidelines. Patients were characterised according to four groups specified in the guidelines: Group A: patients newly started on DMARDs; Group B: patients with some change in disease management: Group C: patient stable on potent medications: Group D: patients stable on less severe medication.

RESULTS

According to the guidelines only 40% of patients were followed up within the recommended intervals. Groups A and B (76.9% and 70.6% respectively) had a significantly greater proportion of patients with follow-up at variance to guideline recommendations compared to groups C and D (50% and 45.3% respectively) (p<0.001). There were marked discrepancies between the guideline recommended follow-up intervals and those suggested by the clinicians. Compared with guideline recommendations clinicians advised less frequent follow-up for groups A and B but more frequent for patients in Groups C and D. However, an assessment of the quality of life scores amongst the patients suggested that follow-up was still appropriately targeted to those patients with lower quality of life.

CONCLUSION

Discrepancies in follow-up were most marked in the patient groups potentially most at risk of medication-related problems in whom guidelines suggested more intensive monitoring. Additional strategies to promote guideline-based follow-up arrangements may be indicated. Further work should examine the relationships between guideline recommended, physician intended and actual follow-up among rheumatology patients in other regions in order to assess whether modifications should occur to clinician behaviour or guideline content.

Alendronate-induced synovitis

We describe 7 cases of synovitis or arthritis occurring after commencement of alendronate for treatment of osteoporosis. These were cases from our practice or notified to the New Zealand Pharmacovigilance Centre, Dunedin, New Zealand. There was no evidence of rheumatoid arthritis, pyrophosphate arthropathy, or seronegative arthritis in any patient. Symptoms recurred on rechallenge in 5 of the cases. We conclude alendronate should be considered as a possible cause of synovitis or polyarthritis in patients treated with it in the absence of any other pathology.

Evidence for an influence of chemokine ligand 3-like 1 (CCL3L1) gene copy number on susceptibility to rheumatoid arthritis

OBJECTIVE

There is increasing evidence that gene copy-number variation influences phenotypic variation. Chemokine ligand 3-like 1 (CCL3L1) is encoded by a variable copy-number gene, and binds to several pro-inflammatory cytokine receptors, including chemokine receptor 5 (CCR5). Considering lymphocyte recruitment by beta-chemokines is a feature of autoimmunity, and that the CCR5Delta32 variant is associated with protection to rheumatoid arthritis (RA), we hypothesised that CCL3L1 copy-number influences susceptibility to RA and type 1 diabetes (T1D).

METHODS

We measured CCL3L1 copy-number in 1136 RA cases from New Zealand (NZ) and the UK, 252 NZ T1D cases and a total of 1470 controls. All subjects were ancestrally Caucasian.

RESULTS

A copy-number higher than 2 (the most common copy number) was a risk factor for RA in the NZ cohort (odds ratio (OR) 1.34, 95% CI 1.08-1.66, p = 0.009) but not the smaller UK RA cohort (OR 1.09, 95% CI 0.75-1.60, p = 0.643). There was evidence for association in the T1D cohort (OR 1.46, 95% CI 0.98-2.20, p = 0.064) and in the combined RA/T1D cohort (OR 1.30, 95% CI 1.00-1.54, p = 0.003). Genetic interaction between CCL3L1 dosage and CCR5 genotype was found; the increased genetic risk conferred by higher CCL3L1 copy-number was ablated by a dysfunctional CCR5 (CCR5Delta32).

CONCLUSIONS

These data suggest that increased CCL3L1 expression may enhance inflammatory responses and increase the chance of autoimmune disease. Genetic interaction data were consistent with a biologically plausible model; CCR5Delta32 protects against RA and T1D by blocking signalling through the CCR5 pathway, mitigating the pro-inflammatory effects of excess CCL3L1.

Multicentric carpal-tarsal osteolysis with nephropathy treated successfully with cyclosporine A: a case report and literature review

Multicentric carpal-tarsal osteolysis is a rare skeletal disorder characterized by osteolysis of the metacarpal, carpal, and tarsal bones and leading to crippling joint deformities. Progressive nephropathy occurs in more than half the cases. All previously reported series with renal biopsies showed only end-stage renal disease on histological examination because of the late presentation to nephrologists. Accurate diagnosis of the underlying renal pathological state therefore has not been possible. We report the first case in which early and sequential renal biopsies were performed. These show the renal lesion to be focal and segmental glomerulosclerosis, which was treated successfully with cyclosporine A.

Rationale for a trial of immunosuppressive therapy in acute schizophrenia

Schizophrenia is a debilitating, costly, socially disruptive, life-threatening disease in which available treatments are largely palliative and empirical, and produce significant short- and long-term side effects. Therefore, a strong case can made for exploring alternative treatments with a rational basis for use in this disease. Considerable evidence indicates that autoimmune processes may be involved in some forms of schizophrenia, including altered risk of certain autoimmune diseases in patients and their relatives, shared epidemiological features, and apparent involvement of genes known to influence the immune response repertoire. Attempts to provide direct evidence for autoimmune processes have proven elusive, possibly due to the technical difficulty inherent in accessing autoantibodies with high affinity for brain cell-surface receptors. In view of this impasse, we argue for a well-designed trial in schizophrenia of immunosuppressive therapy, which is now the mainstay of therapy for many autoimmune diseases. Analysis of disease states in which immunosuppression has been effectively used over many decades provides guidelines necessary for a meaningful trial.

Pulmonary rheumatoid nodules demonstrating features usually associated with rheumatoid synovial membrane

OBJECTIVES

To describe the unusual immunohistological characteristics of two pulmonary rheumatoid nodules showing ectopic lymphoid follicles and the features normally associated with rheumatoid synovial membrane, and to discuss the implications of this novel observation.

METHODS

Two formalin-fixed wax-embedded pulmonary rheumatoid nodules were processed for immunohistology.

RESULTS

The central structure of the pulmonary nodules was typical of that uniformly expected in a rheumatoid nodule with central necrosis surrounded by a palisade of macrophages. However, a feature not previously observed in nodules was the presence of lymphoid aggregates containing B lymphocytes and, in some cases, showing characteristic features of lymphoid follicles.

CONCLUSIONS

The presence of B lymphocytes and the development of ectopic lymphoid follicles in rheumatoid nodules have not been described previously. It is similar to synovial membrane, and contrasts with the expected structure of subcutaneous nodules where B cells and lymphoid follicles are normally absent. These observations establish that the morphology of rheumatoid nodules can vary in different tissues. They further suggest that the inflammatory process in the nodule and synovial membrane are likely to be similar, and that the characteristics of different tissues may be an important determinant of apparent differences between inflammatory lesions in synovial membrane and extra-articular nodules in rheumatoid arthritis.

Genomic DNA pooling for whole-genome association scans in complex disease: empirical demonstration of efficacy in rheumatoid arthritis

A pragmatic approach that balances the benefit of a whole-genome association (WGA) experiment against the cost of individual genotyping is to use pooled genomic DNA samples. We aimed to determine the feasibility of this approach in a WGA scan in rheumatoid arthritis (RA) using the validated human leucocyte antigen (HLA) and PTPN22 associations as test loci. A total of 203 269 single-nucleotide polymorphisms (SNPs) on the Affymetrix 100K GeneChip and Illumina Infinium microarrays were examined. A new approach to the estimation of allele frequencies from Affymetrix hybridization intensities was developed involving weighting for quality signals from the probe quartets. SNPs were ranked by z-scores, combined from United Kingdom and New Zealand case-control cohorts. Within a 1.7 Mb HLA region, 33 of the 257 SNPs and at PTPN22, 21 of the 45 SNPs, were ranked within the top 100 associated SNPs genome wide. Within PTPN22, individual genotyping of SNP rs1343125 within MAGI3 confirmed association and provided some evidence for association independent of the PTPN22 620W variant (P=0.03). Our results emphasize the feasibility of using genomic DNA pooling for the detection of association with complex disease susceptibility alleles. The results also underscore the importance of the HLA and PTPN22 loci in RA aetiology.

Pneumonitis associated with leflunomide: a profile of New Zealand and Australian reports

BACKGROUND

Pneumonitis has very rarely been observed in patients taking leflunomide in clinical trials. Evidence is emerging that it is more frequent in clinical practice.

AIM

The aim of this study was to investigate voluntary reports of suspected respiratory reactions to leflunomide held by the New Zealand Pharmacovigilance Centre (NZPhvC) and the Australian Adverse Drug Reactions Unit (ADRU) to ascertain if they fulfilled the criteria for pneumonitis and to define characteristics of this reaction.

METHOD

Reports of respiratory adverse reactions attributed to leflunomide and received by the NZPhvC and the ADRU were analysed to identify those that were likely to be pneumonitis based on the criteria of Searles and McKendry. Features of these reports were examined to provide further information about this adverse reaction.

RESULTS

The NZPhvC and the ADRU received 14 reports considered to be pneumonitis occurring in patients taking leflunomide. Two case reports fulfilled the Searles and McKendry criteria for definite or probable hypersensitivity pneumonitis. The patients in the remaining reports had radiological evidence of pulmonary infiltrates, an acute respiratory illness and no evidence of precipitating infection. In two cases the patients were taking leflunomide alone; one improved when it was withdrawn. In the other 12 cases, patients were taking leflunomide in combination with methotrexate. In nine of these 12 patients pneumonitis occurred after leflunomide was added to methotrexate, usually within 12-20 weeks. One of the two patients who died had possible previous methotrexate pneumonitis. Leflunomide washout with cholestyramine was used to treat three patients, one with life-threatening illness, with good results.

CONCLUSION

This case series supports observations that leflunomide can cause pneumonitis either as monotherapy or in combination with methotrexate. The case histories indicate that prompt recognition is important to avoid life-threatening disease and support the use of cholestyramine to remove leflunomide.

The use of the hand anatomic index to assess deformity and impaired function in systemic sclerosis

To determine the "hand anatomic index" (HAI--a quantitative measure of hand deformity) in systemic sclerosis (scleroderma) and to compare it with the other measures of hand deformity and functional impairment. The HAI (measure of open hand span minus closed hand span/lateral height of hand) was determined in 30 patients with scleroderma and compared with hand deformity (as assessed by two independent rheumatologists) and with the Health Assessment Questionnaire (mHAQ), hand strength and prehensile gripability data. The HAI was confirmed as a reliable measure which clearly distinguished patients with increasing hand deformity and separated patients with diffuse scleroderma (n=12) from limited scleroderma (n=18), P=0.005. The HAI correlated significantly with measures of global functional impairment (as measured by the mHAQ) r=-0.46, P=0.01, hand strength r=0.51, P=0.0001 and prehensile gripability, r=-0.37, P=0.05 but neither with disease duration r=-0.16, P=NS nor age at disease onset r=0.20, P=NS. It was estimated that the HAI accounts for ~25% of the total global disability (as measured by HAQ). Measurement of the HAI in scleroderma provides a reliable and objective measure reflecting variable degrees of hand deformity and functional impairment and might provide a valid clinical outcome measure in patients with this disabling disorder.

Clinical characteristics of an anatomical hand index measured in patients with rheumatoid arthritis as a potential outcome measure

OBJECTIVES

To determine the clinical characteristics of an anatomical hand index previously reported as a potential measure of joint deformity and outcome in patients with rheumatoid arthritis.

METHODS

The hand index (open hand span - closed hand span/lateral height of the hand) was measured in a cross-sectional study of 145 out-patients with rheumatoid arthritis with disease durations 0-55 yr. Subsets of patients were restudied at mean follow-ups of approximately 9 months and 4 yr.

RESULTS

The hand index fell gradually with disease duration. Correlations were demonstrated with the Sharp index (r = - 0.39, P = 0.000) and to a lesser extent with disease activity score (r = - 0.28, P = 0.001). At 260 +/- 115 days the hand index worsened by 0.09 units (P = 0.09, NS). At 51.6 +/- 5.4 months the index showed a fall from 1.96 +/- 0.73 to 1.61 +/- 0.65 (P = 0.000). During the same interval the Sharp index increased from 60 +/- 68 to 80 +/- 71 (P = 0.000).

CONCLUSIONS

Measurement of simple hand dimensions can demonstrate worsening of hand deformity with time in patients with rheumatoid arthritis. We suggest that more sophisticated analysis of digital hand images, as used in our original study, might yield additional information and increase the sensitivity of an anatomical hand index as an outcome measure in rheumatoid arthritis.