PET Quantification of [18F]VAT in Human Brain and Its Test-Retest Reproducibility and Age Dependence

Molecular imaging of brain vesicular acetylcholine transporter provides a biomarker to explore cholinergic systems in humans. We aimed to characterize the distribution of, and optimize methods to quantify, the vesicular acetylcholine transporter-specific tracer (-)-(1-(8-(2-[18F]fluoroethoxy)-3-hydroxy-1,2,3,4-tetrahydronaphthalen-2-yl)-piperidin-4-yl)(4-fluorophenyl)methanone ([18F]VAT) in the brain using PET. Methods: Fifty-two healthy participants aged 21-97 y had brain PET with [18F]VAT. [3H]VAT autoradiography identified brain areas devoid of specific binding in cortical white matter. PET image-based white matter reference region size, model start time, and duration were optimized for calculations of Logan nondisplaceable binding potential (BPND). Ten participants had 2 scans to determine test-retest variability. Finally, we analyzed age-dependent differences in participants. Results: [18F]VAT was widely distributed in the brain, with high striatal, thalamic, amygdala, hippocampal, cerebellar vermis, and regionally specific uptake in the cerebral cortex. [3H]VAT autoradiography-specific binding and PET [18F]VAT uptake were low in white matter. [18F]VAT SUVs in the white matter reference region correlated with age, requiring stringent erosion parameters. Logan BPND estimates stabilized using at least 40 min of data starting 25 min after injection. Test-retest variability had excellent reproducibility and reliability in repeat BPND calculations for 10 participants (putamen, 6.8%; r > 0.93). We observed age-dependent decreases in the caudate and putamen (multiple comparisons corrected) and in numerous cortical regions. Finally, we provide power tables to indicate potential mean differences that can be detected between 2 groups of participants. Conclusion: These results validate a reference region for BPND calculations and demonstrate the viability, reproducibility, and utility of using the [18F]VAT tracer in humans to quantify cholinergic pathways.

Diagnosis and subtyping of idiopathic inflammatory myopathies: caution required in the use of myositis autoantibodies

Detection of myositis autoantibodies (MAs) has utility in both the diagnosis and subtyping of idiopathic inflammatory myopathies (IIMs). Multiplex assays such as the Euroimmun line immunoassay (LIA) have significant limitations in rare diseases like IIM. A retrospective cohort study was performed on positive MA detected on LIA in 171 patients using the manufacturer's recommended cut-off. Only 16.7% were deemed true positive after clinical correlation. Autoantibody-specific cut-offs were created and applied to the original cohort, along with generically applied higher cut-offs. Positive predictive value (PPV) improved, but there was variable increase in false negatives. False positive MA results are common using LIA, but locally derived cut-offs can improve performance. Clinicians must be aware of the limitations of LIA, which is the commonest method for MA detection in Australasia.

Relationship Between Adalimumab Concentrations, Antidrug Antibodies, and Disease Activity in Rheumatoid Arthritis: A Cross-Sectional Observational Study

OBJECTIVES

To determine the influence of patient characteristics and disease activity on adalimumab (ADA) concentrations; to assess the relationships between ADA concentrations, the presence of antidrug antibodies (ADAb), and disease activity in rheumatoid arthritis (RA); and to determine the association between cytokine concentrations and ADA concentrations.

METHODS

A cross-sectional study of people with RA receiving ADA for at least 4 weeks was undertaken. Disease activity was assessed by the Disease Activity Score in 28 joints (DAS28), with responders defined as DAS28 ≤ 3.2. Serum and plasma were obtained for ADA concentrations and ADAb, and a panel of cytokines were obtained for a subgroup. ADA concentrations were compared between demographic and clinical subgroups using ANOVA. The independent associations between clinical and demographic features were analyzed using a general linear model. Variables significantly associated with ADA concentrations from the univariate analyses were entered into multivariate analyses.

RESULTS

Of the 156 participants, 69.2% were female and the mean age was 57.4 (SD 12.7) years. Multivariate analysis revealed that higher C-reactive protein (P < 0.001) and higher weight (P < 0.004) were independently associated with lower ADA concentrations. ADA concentrations were higher in those with DAS28 ≤ 3.2 compared to those with DAS28 > 3.2 (median 10.8 [IQR 6.4-20.8] mg/L vs 7.1 [IQR 1.5-12.6] mg/L, P < 0.001). There was a significant negative correlation between interleukin 6 (IL-6) and ADA concentrations (r = -0.04, P < 0.01).

CONCLUSION

ADA concentration correlates negatively with markers of inflammatory disease activity in RA, including IL-6. ADA concentration in the range 5 to 7 mg/L over the dose interval are associated with better disease control.

Four-year review of New Zealand laboratory infliximab and adalimumab concentration results indicating potential for improved dosing

A review of laboratory results across New Zealand for therapeutic drug monitoring (TDM) of infliximab and adalimumab concentrations and antidrug antibodies (ADAs) over 4 years was completed. Of 6591 results, the median serum concentration for infliximab was 5.7 mg/L and for adalimumab was 5.5 mg/L. Subtherapeutic drug concentrations (<7 mg/L) were measured in 54% of samples. Drug concentrations <2 mg/L were measured in 23% of samples, with ADAs detected in 51% of these. The high number of samples with subtherapeutic drug concentrations and common ADA detection is consistent with failing therapy but could also suggest that standard dosing is frequently too low for patients. These results reinforce the value of antitumour necrosis factor drug TDM in making decisions to adjust dosing or switch agents in patients taking infliximab and adalimumab.

Proteinopathy and Longitudinal Cognitive Decline in Parkinson Disease

BACKGROUND AND OBJECTIVES

People with Parkinson disease (PD) commonly experience cognitive decline, which may relate to increased α-synuclein, tau, and β-amyloid accumulation. This study examines whether the different proteins predict longitudinal cognitive decline in PD.

METHODS

All participants (PD: n = 152; controls: n = 52) were part of a longitudinal study and completed a lumbar puncture for CSF protein analysis (α-synuclein, total tau (tau), and β-amyloid-42 (β-amyloid)), a β-amyloid PET scan, and/or provided a blood sample for ApoE genotype (ε4+, ε4-), which is a risk factor for β-amyloid accumulation. Participants also had comprehensive, longitudinal clinical assessments of overall cognitive function and dementia status as well as cognitive testing of attention, language, memory, visuospatial and executive function. We used hierarchical linear growth models to examine whether the different protein metrics predict cognitive change and multivariate Cox proportional hazard models to predict time to dementia conversion. Akaike Information Criterion was used to compare models for best fit.

RESULTS

Baseline measures of CSF β-amyloid predicted decline for memory (p = .04) and overall cognitive function (p = .01). ApoE genotypes showed a significant group (ε4+, ε4-) effect, such that ε4+ declined faster than ε4- in visuospatial function (p = .03). Baseline β-amyloid PET significantly predicted decline in all cognitive measures (all p ≤ .004). Neither baseline CSF α-synuclein nor tau predicted cognitive decline. All three β-amyloid-related metrics (CSF, PET, ApoE) also predicted time to dementia. Models with β-amyloid PET as a predictor fit the data the best.

DISCUSSION

Presence or risk of β-amyloid accumulation consistently predicted cognitive decline and time to dementia in PD. This suggests β-amyloid has high potential as a prognostic indicator and biomarker for cognitive changes in PD.

Incidence of anti-neutrophil cytoplasmic antibody-associated vasculitis before and after the February 2011 Christchurch Earthquake

BACKGROUND

It has been suggested that environmental pollution from an earthquake might be associated with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV).

AIM

To determine the incidence of AAV during the 3-year period before (period 1), and the 3 years following (period 2), the earthquake that occurred on 22 February 2011 in Christchurch, New Zealand.

METHODS

All ANCA tests performed in the Canterbury region for 3 years before the earthquake (period 1, 2007-2010), and for 3 years after the earthquake (period 2, 2011-2014) were examined. AAV was defined according to The European Medicines Agency classification algorithm. Medical records were reviewed and cases were included if they were newly diagnosed within the study period. Incidence was calculated using population data from the 2013 New Zealand census.

RESULTS

A total of 52 new cases of AAV was identified. The incidence in period 1 was 1.87/100 000/annum (95% C.I. 1.23-2.72), and for period 2 was 1.73/100 000/annum (95% C.I. 1.12-2.55). There was no statistically significant difference in incidence between the two study periods. There was no difference when analysing by myeloperoxidase (MPO) or proteinase-3 status, or restricting the analyses to those residing in an urban environment. The mean age at diagnosis for MPO AAV was significantly younger in period 2 than period 1 (61 years vs 71 years, P = 0.05). There were no other clinically important differences between the two groups.

CONCLUSION

This study does not support the hypothesis that an environmental agent, caused by dust pollution related to earthquake damage, has a causative role in the pathogenesis of AAV.

Management of Gout in a Hospital Setting: A Lost Opportunity

OBJECTIVE

Management of gout is frequently suboptimal. The aim of this study was to determine the proportion of patients presenting to Christchurch Hospital for a gout flare and to determine whether management for both acute flares and urate lowering was in accordance with international recommendations.

METHODS

A retrospective audit was undertaken of all admissions to Christchurch Hospital from June 1, 2013, to May 31, 2014, in which gout was coded as a primary or secondary discharge diagnosis. Information including demographics, comorbidities, concomitant medications, treatment of acute gout, and urate lowering was collected.

RESULTS

A total of 235 acute admissions for gout in 216 individuals were identified. Eleven individuals had 2 admissions and 4 individuals had 3 admissions. In 95/235 admissions (40.4%), gout was the primary diagnosis. Gout accounted for 95/77,321 (0.12%) of acute admissions. The treatment of acute gout was prednisone monotherapy in 170/235 (72.3%) of admissions. Serum urate was measured at some point during 123/235 (52.3%) of admissions, with only 19/123 (15.4%) at target urate level (< 0.36 mmol/l). At 60 of the 235 admissions, urate-lowering therapy was already being prescribed. Nine out of 175 patients (5.1%) not treated with urate-lowering therapy at admission commenced allopurinol and 32/174 (18.4%) had commencement of urate-lowering therapy recommended in the discharge plan.

CONCLUSION

Rates of admission for gout are similar to that observed in other studies. Failure to initiate, change, or recommend alterations in urate-lowering therapy to achieve target urate in people with gout admitted to hospital represents a significant lost opportunity to improve longterm gout management.

Association between environmental exposures and granulomatosis with polyangiitis in Canterbury, New Zealand

Introduction

Granulomatosis with polyangiitis (GPA) is a rare systemic vasculitis. While aetiology is unknown the prominent respiratory involvement suggests inhaled antigens may be involved. The aim of this study was to identify environmental risk factors associated with GPA in Canterbury, New Zealand.

Methods

A case-controlled study was undertaken. All GPA cases fulfilled American College of Rheumatology (ACR), Chapel Hill Consensus Criteria (CHCC) or the European Medicines Agency (EMA) criteria. Each case was gender matched with four controls - 2 musculoskeletal (osteoarthritis or fracture) and 2 respiratory (asthma or chronic obstructive pulmonary disease). One musculoskeletal control and one respiratory control were age matched with the case at the time of the interview (interview) and the remaining two controls were age matched at the time their case experienced the first symptom of vasculitis (index). A structured questionnaire to assess potential environmental agents was administered without blinding for case/control status. Data were analyzed using conditional logistic regression to allow for the individual matching of cases and controls to assess for association between environmental factors and GPA.

Results

49 cases and 196 controls were recruited. 53 % were male and the mean ± standard deviation (SD) age of the cases was 64.9 ± 12.4 years, interview controls 65.1 ± 12.4.years and index controls 53.9 ± 14.5 years. Any reported exposure to dust (specifically silica and grain dust) was associated with GPA, odds ratio (OR) 3.6 (95 % confidence interval (CI); 1.5–8.3, p = 0.003). Occupation as a farm worker was associated with GPA OR 3.43 (1.5–7.5, p = 0.002). Specific gardening activities were associated with GPA including digging (OR 3.2; 1.4–7.0; p = 0.003), mowing (OR 2.7; 1.3–5.8; p = 0.008) and planting (OR 2.6; 1.2–5.5; p = 0.013).

Conclusion

We have replicated findings from northern hemisphere studies identifying dust exposure as well as farm exposure as risk factors for the development of GPA. We have shown activities associated with exposure to inhaled antigens, in particular those related to farming or gardening activities may increase the risk of GPA.

Clinically insignificant effect of supplemental vitamin C on serum urate in patients with gout: a pilot randomized controlled trial

OBJECTIVE

Studies in human volunteers have shown that vitamin C reduces serum urate (SU) levels. The aim of this study was to determine the effects of vitamin C on SU levels in patients with gout.

METHODS

Patients with gout and an SU level >0.36 mmoles/liter (6 mg/dl) were recruited. Twenty patients already taking allopurinol were randomized to receive an increase in the dose of allopurinol or to commence taking vitamin C (500 mg/day). Twenty patients who had not been taking allopurinol were randomized to start receiving either allopurinol (up to 100 mg/day) or vitamin C (500 mg/day). Levels of plasma ascorbate, creatinine, and SU were measured on day 0 and week 8.

RESULTS

There was no significant difference in the baseline SU level or estimated glomerular filtration rate (eGFR) between those who received vitamin C and those who did not (for SU, mean ± SEM 0.50 ± 0.11 mmoles/liter [8.4 ± 1.8 mg/dl] versus 0.50 ± 0.09 mmoles/liter [8.4 ± 1.5 mg/dl]; for eGFR, mean ± SEM 65.5 ± 3.5 ml/minute/1.73 m(2) versus 67.9 ± 4.6 ml/minute/1.73 m(2) ). Among the randomized patients, 30% in the vitamin C group and 25% in the no vitamin C control group were receiving diuretics. In the patients receiving vitamin C, there was a significant increase between day 0 and week 8 in the plasma ascorbate level. The reduction in SU level over 8 weeks was significantly less in those patients receiving vitamin C compared to those who started or increased the dose of allopurinol (mean reduction 0.014 mmoles/liter [0.23 mg/dl] versus 0.118 mmoles/liter [1.9 mg/dl]; P < 0.001).

CONCLUSION

A modest dosage of vitamin C (500 mg/day) for 8 weeks had no clinically significant urate-lowering effects in patients with gout, despite the fact that plasma ascorbate levels increased. These results differ from previous findings in healthy control subjects with hyperuricemia. The uricosuric effect of modest-dose vitamin C appears to be small in patients with gout, when administered as monotherapy or in combination with allopurinol.

Cardiovascular morbidity in rheumatoid arthritis patients in North Canterbury, New Zealand 1999-2008

AIM

Cardiovascular disease is a substantial contributor to increased morbidity and mortality in rheumatoid arthritis (RA). The aim of this audit was to determine the rate of cardiovascular events in a cohort of newly diagnosed RA patients.

METHOD

The inpatient clinical database from Christchurch Hospital, Christchurch, New Zealand, was searched using the International Classification of Diseases 9th Revision (ICD9) and 10 codes representing RA and cardiovascular disease between 1 January 1999 and 31 December 2008. Notes were reviewed with additional demographic and medication data sought. Outpatient data for RA patients was collated from the Rheumatology Department's letter database.

RESULTS

Four hundred and six patients were identified with combined ICD9 or 10 codes for RA and ischemic heart disease, of whom 194 had a confirmed myocardial event. Of these, 34 were diagnosed with RA between January 1999 and December 2008 prior to their myocardial event. Kaplan-Meier analysis showed risk of a cardiovascular event at 1 and 10 years was 0.64% and 9.4%, respectively. There were 26 confirmed deaths in the study period. The risk of death at 1 and 10 years was 0.48% and 8.16%, respectively.

CONCLUSION

We have shown a relatively low prevalence of cardiovascular events in this RA population diagnosed within a 10 year period. This is consistent with other reports and likely reflects the short follow-up period. Prospective longer-term studies will be required to further investigate the relative contribution of disease activity and other parameters to cardiovascular events in patients with early RA.

Effects of changing from oral to subcutaneous methotrexate on red blood cell methotrexate polyglutamate concentrations and disease activity in patients with rheumatoid arthritis

OBJECTIVE

To determine the effects of changing from oral to subcutaneous (SC) methotrexate (MTX) in patients with rheumatoid arthritis (RA) on red blood cell MTX polyglutamate (RBC MTXGlu(n)) concentrations, disease activity, and adverse effects.

METHODS

Thirty patients were changed from oral to SC MTX. Trough RBC MTXGlu(n) concentrations were measured for 24 weeks and concentrations fitted to a first-order accumulation model. Disease activity was assessed by 28-joint Disease Activity Score (DAS28).

RESULTS

MTXGlu(3), MTXGlu(4), and MTXGlu(5) concentrations, but not MTXGlu(1) and MTXGlu(2), increased significantly over 24 weeks, reaching 90% of new steady-state concentrations by about 40 weeks. A decrease in DAS28 was associated with increased RBC MTXGlu(5) (p = 0.035) and RBC MTXGlu(3-5) (p = 0.032). No change in adverse effect frequency occurred.

CONCLUSION

Changing to SC MTX results in increased long-chain MTXGlu(n). However, it takes at least 6 months for RBC steady-state concentrations to be achieved. Increased long-chain MTXGlu(n) concentrations were significantly associated with reduced disease activity.

Methotrexate polyglutamate concentrations are not associated with disease control in rheumatoid arthritis patients receiving long-term methotrexate therapy

OBJECTIVE

There are limited data suggesting that methotrexate polyglutamate (MTXGlu) concentrations can guide MTX dosing in patients with rheumatoid arthritis (RA). The aim of this study was to define a therapeutic range of red blood cell (RBC) MTXGlu(n) concentrations (where n refers to the number of glutamate groups), including threshold values for efficacy and adverse effects in patients receiving long-term oral MTX treatment.

METHODS

A cross-sectional study of 192 patients receiving oral MTX was undertaken. Disease activity was assessed by the swollen and tender joint counts, the C-reactive protein level, and the Disease Activity Score in 28 joints (DAS28). High disease activity was defined as a DAS28 of >3.2. A standardized questionnaire regarding common MTX adverse effects was completed.

RESULTS

The MTX dosage was significantly higher in patients in whom the swollen joint count and DAS28 were higher. The MTXGlu(4), MTXGlu(5), MTXGlu(3-5), and MTXGlu(1-5) concentrations were significantly higher in patients with high disease activity. After correction for age, the estimated glomerular filtration rate, and the MTX dosage, the association remained significant for MTXGlu(5). RBC folate concentrations were significantly higher in the group with high disease activity. There was no association between any MTXGlu(n) concentration and adverse effects.

CONCLUSION

In contrast to other studies, the results of the present study did not show a relationship between the MTXGlu(n) concentration and reduced disease activity in patients with RA who were receiving long-term MTX therapy. However, disease activity was influenced by the RBC folate level, which may be a more important factor than MTXGlu(n) concentrations for disease control. In accordance with the findings of previous studies, we were unable to show a relationship between MTXGlu(n) concentrations and adverse effects. Prospective studies will be important to determine whether there is a role for measuring MTXGlu(n) concentrations in patients receiving long-term treatment with MTX.

Lack of association between elevated mean red cell volume and haematological toxicity in patients receiving long-term methotrexate for rheumatoid arthritis

AIMS

It has been suggested that elevated mean red cell volume (MCV) may be a predictor of haematological toxicity in rheumatoid arthritis (RA) patients receiving methotrexate (MTX). We wished to identify whether there was an association between MCV, red cell folate and haematological toxicity in patients on MTX monotherapy for the long-term management of RA.

METHODS

Evidence of haematological toxicity was sought by note review of patients recruited in a cross-sectional study of MTX monotherapy in RA. Retrospective data included MCVs from before MTX initiation and after 3 and 6 months of treatment. Data were collected prospectively every 6 months for up to 2 years after enrolment. Any record of cytopenia or the development of haematological malignancy was recorded from commencement of MTX until the present day. Red cell folate concentrations were tested on enrolment to the study.

RESULTS

A total of 165 patients was included, 74.5% female, median disease duration 7 years (range 3 months-57 years). The median duration of MTX treatment was 74.9 months (range 10-241 months) giving 1030.2 patient-years of MTX exposure. Twenty-four patients (14.5%) had a MCV > 98 fL on study entry. Evidence of haematological abnormality was found in six patients (3.6%); chronic lymphocytic leukaemia (1), persistent lymphocytosis (1), persistent monocytosis (1) and neutropenia (3). There was no association between red cell folate or MCV and haematological toxicity.

CONCLUSION

Neutropenia and pancytopenia are rare side-effects of MTX therapy in this cohort. Elevated MCV or low mean red cell folate does not appear to be associated with haematological malignancy or toxicity in this cohort of patients on long-term MTX therapy.

Determinants of red blood cell methotrexate polyglutamate concentrations in rheumatoid arthritis patients receiving long-term methotrexate treatment

OBJECTIVE

Methotrexate (MTX) is the most commonly used disease-modifying antirheumatic drug (DMARD) in the management of rheumatoid arthritis (RA). MTX is transported into cells, where additional glutamate moieties are added and it is retained as MTX polyglutamates (MTXGlu [referred to as a group as MTXGlun]). There is large interpatient variability in MTXGlun concentrations. This study was undertaken to determine nongenetic factors that influence red blood cell (RBC) MTXGlun concentrations in patients receiving long-term stable low-dose oral MTX.

METHODS

One hundred ninety-two patients receiving long-term oral MTX for the treatment of RA were recruited. Trough MTXGlun concentrations were measured by high-performance liquid chromatography. Univariate analysis was performed to determine variables influencing MTXGlun concentrations. Backward stepwise multivariate regression analysis was done to determine variables that affect individual MTXGlun concentrations; variables with P values of <0.1 in the univariate analysis for any MTXGlun were included.

RESULTS

Univariate analysis revealed that increased age, lower estimated glomerular filtration rate (GFR), higher MTX dosage, longer duration of MTX treatment, and use of prednisone were associated with significantly higher MTXGlun concentrations. Smokers had significantly lower concentrations of MTXGlu3, MTXGlu3-5, and MTXGlu1-5. Sex, rheumatoid factor and anti-cyclic citrullinated peptide status, RBC folate level, and body mass index had no significant effect on MTXGlun levels. Concomitant use of other DMARDs was associated with lower MTXGlu2 levels, and treatment with nonsteroidal antiinflammatory drugs was associated with lower MTXGlu3 and MTXGlu1-5 concentrations. Multivariate regression analysis revealed that age, MTX dosage, and estimated GFR were the major determinants of MTXGlun concentrations.

CONCLUSION

Large interpatient variability in MTXGlun concentrations can be explained, at least in part, by a combination of factors, particularly age, MTX dosage, and renal function. There are complex interactions between smoking, RBC folate levels, and concentrations of MTXGlun.

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.

Leflunomide-associated infections in rheumatoid arthritis

OBJECTIVE

To determine the prevalence of severe infections in patients with rheumatoid arthritis (RA) prescribed leflunomide in North Canterbury, New Zealand.

METHODS

A case-note audit of all Christchurch Hospital patients with RA prescribed leflunomide between 2002 and 2006 was performed. The criterion for severe infection was inpatient hospitalization. Relevant reports to the national Pharmacovigilance Centre were also examined.

RESULTS

Since January 2002, 171 patients with RA have commenced taking leflunomide. Ninety-nine of 171 (57.9%) patients were also prescribed prednisone. Combination disease modifying antirheumatic drug therapy was common, with 82/171 (48.0%) taking methotrexate (MTX), 15/171 (8.8%) hydroxy-chloroquine, 11/171 (6.4%) sulfasalazine, and 8/171 (4.7%) anti-tumor necrosis factor therapy. Eleven patients developed infection requiring hospitalization while taking leflunomide including: lower respiratory tract infections (3), cellulitis (2), disseminated herpes zoster (2), probable TB liver (1), abdominal sepsis (1), mycotic aneurysm (1) and gastroenteritis (1). Nine of the 11 patients were also taking corticosteroids or corticosteroids with MTX. The 171 patients were treated for a total of 4005 months, giving an incidence for severe infection of 3.30/100 patient-years (95% CI 1.65-5.90). Patients at increased risk were those with severe disease and taking concomitant MTX and corticosteroids. The NZ Pharmacovigilance Centre has received 7 additional reports of severe infections in patients with RA taking leflunomide. Reported cases include probable pulmonary TB (1), pneumocystis pneumonia (1), other pulmonary infection (2), and septicemia (3) including a case of infective endocarditis. Four occurred in combination with MTX, one with adalimumab. All 5 patients were also taking -corticosteroids.

CONCLUSION

We believe this observed rate of serious infection is acceptable in the context of optimally treating active RA. Patients with severe disease and taking combination MTX and corticosteroids are at greatest risk. In our experience, once established, infections may rapidly progress in patients with RA taking leflunomide, and early cholestyramine washout is strongly recommended.

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.

Wegener's granulomatosis in New Zealand: evidence for a latitude-dependent incidence gradient

BACKGROUND

The aim of the study was to determine whether there was evidence for a geographic gradient in the incidence of Wegener's granulomatosis (WG) and WG-like disease in New Zealand (NZ).

METHODS

The National Minimum Dataset of the Ministry of Health, NZ was searched for individual patient discharges coded by the International Classification of Diseases 10th Revision, Australian Modification as either M301 (polyarteritis with lung involvement, including Churg Strauss and allergic granulomatous angiitis) or M313 (WG, necrotizing respiratory granulomatosis) for the period 1 January 1999 to 31 December 2003. Data were standardized using the 2001 NZ census.

RESULTS

One hundred and ninety-five patients (95 men) were given a first-time discharge code of either M301 (40 patients) or M313 (155 patients). No gender bias was seen. The rate among Europeans was twice that of NZ Maoris or Asians. The rate of disease peaked in the age band 70-79 years and during winter months. A significant positive north-south geographic gradient was present for M313. No difference in the rate of readmission or time to relapse between geographic regions was found for M313.

CONCLUSION

A north-south gradient in the rate of patient discharges given a diagnostic code of M313 (WG, necrotizing respiratory granulomatosis) was present in NZ. This finding supports the hypothesis that there is a latitude-dependent risk factor(s) for WG possibly common to both global hemispheres.

Emerging therapies in the long-term management of hyperuricaemia and gout

Gout is a common chronic arthritis that can lead to significant disability. Gout is one of the few rheumatological conditions that can be diagnosed with certainty, has a known cause and can be cured with appropriate therapy. Hypouricaemic agents reduce uric acid concentrations through inhibiting uric acid production (allopurinol) or enhancing uric acid excretion (probenecid, benzbromarone). Allopurinol is the most commonly used hypouricaemic agent but at recommended doses often fails to reduce adequately uric acid concentrations and prevent acute attacks of gout. The use of probenecid is limited by lack of efficacy in renal impairment. In the last few years, new agents in the management of hyperuricaemia and gout have become available. Febuxostat, a new xanthine oxidase inhibitor, is an effective hypouricaemic agent although further data are required for patients with renal impairment and other significant medical conditions. Rasburicase, a recombinant uricase (which catalyses the conversion of uric acid to the more readily excreted allantoin) is available for prevention of tumour lysis syndrome. However, its repeated use, as would be required in chronic gout, is limited by antigenicity. A less antigenic PEGylated uricase can rapidly reduce serum uric acid concentrations and promote resorption of tophi. However, further information with regard to the long-term risks and benefits of these agents is required. These agents may ultimately be used in the short term to rapidly deplete urate stores (induction therapy) followed by long-term therapy with an alternative hypouricaemic agent to prevent subsequent accumulation of uric acid (maintenance therapy).

Antineutrophil cytoplasmic antibody measurement: advantages and disadvantages of a capture PR3 ELISA and a direct PR3 ELISA

AIM

To compare the performance of a capture proteinase 3 enzyme linked immunosorbent assay (PR3 ELISA) with a direct PR3 ELISA in the measurement of PR3 antineutrophil cytoplasmic antibodies (ANCA).

METHOD

The performance of both assays systems was compared using two sets of sera. Sera from patients (n = 49) suffering from Wegener's granulomatosis (WG) and fulfilling the American College of Rheumatology classification criteria (or a modification of those criteria that allowed for ANCA positivity) were used along with sera from a group of patients (n = 48) considered to have a clinically false positive PR3 ANCA result when measured by routine direct ELISA.

RESULTS

Using the assay specific cut-offs, the direct ELISA gave a positive result in 92% on repeat testing and the capture ELISA a positive result in 84% of sera from patients with WG. The capture ELISA was negative in 75% of patients considered to have a false positive PR3 ANCA on initial testing by direct ELISA (27% were negative on repeat testing by direct ELISA). The mean concentration of PR3 ANCA in WG patient sera measured by the capture ELISA was significantly higher than that measured by the direct ELISA. The capture PR3 ELISA had a broader analytical range which was also reflected in PR3 ANCA concentrations measured in serial serum samples from WG patients.

CONCLUSION

In this study the direct PR3 ELISA performed better as a screening test for PR3 ANCA compared with the capture PR3 ELISA, mainly because the cut-off for the capture ELISA needed to be set higher to avoid non-specific binding. In contrast, the improved analytical range of the capture ELISA made it a potentially more useful method for monitoring serial PR3 ANCA concentrations. In specific serum samples the capture ELISA was better able to discriminate 'false positive' PR3 ANCA.

Soluble human leukocyte antigen: A diagnostic indicator of rheumatoid arthritis?

Early stage rheumatoid arthritis (RA) is often difficult to diagnose because initial symptoms are non-specific. To aid diagnosis, suitable serological diagnostic markers are sought. Elevated levels of soluble MHC class II (soluble human leukocyte antigen; sHLA-DR) in human serum have been associated with rheumatoid and 'rheumatoid-like' autoimmune diseases. As a result, sHLA-DR has been suggested as a specific marker of RA. However, reported levels of sHLA-DR in sera of healthy donors vary significantly and the mechanism of release of HLA-DR into serum is poorly understood. Investigations into the diagnostic potential of this molecule necessitate the development of a sensitive and specific sHLA-DR assay. We have investigated multiple ELISA setups to develop such an assay and false positive signal has been carefully removed using a combination of isotype-matched controls and immuno-depletion. sHLA-DR levels in sera of RA patients were not significantly different from those in healthy donors which suggests sHLA-DR has limited utility in the diagnosis of RA. In RA patients, we detected high levels of sHLA-DR in aspirated synovial fluid (SF), but this did not correlate with sHLA-DR levels in serum.

Unicentric Castleman's disease: a surprising neck mass

BACKGROUND

We present the case of a 36-year-old female with a three-week history of a pulsatile, tender mass in the anterior triangle of the neck.

METHODS

Radiology demonstrated that this was a vascular tumour deep to the sternocleidomastoid muscle.

RESULTS

Pre-operative embolisation and complete surgical resection was performed. Histology revealed Castleman's disease.

CONCLUSION

Unicentric hyaline vascular Castleman's disease is an unusual cause of neck mass. Surgical resection remains the best chance for cure in unicentric disease. Long term follow-up is necessary as the risk of subsequent malignancy exists.

Levels of the soluble forms of CD80, CD86, and CD83 are elevated in the synovial fluid of rheumatoid arthritis patients

The release of soluble forms of CD80 (sCD80), CD86 (sCD86), and CD83 (sCD83) provide a potentially powerful immunoregulatory mechanism. We therefore investigated the potential presence and relative levels of these molecules in the synovial fluid (SF) and serum of patients with rheumatoid arthritis (RA) and osteoarthritis (OA). Serum and SF levels were measured by enzyme-linked immunosorbent assay. Serum levels of sCD80, sCD86, and sCD83 in RA and OA patients were similar to those present in normal donor serum (NDS) and the SF of OA patients. In contrast, when compared with NDS and OA SF levels, almost all RA SF samples had elevated sCD83 levels (32/35, >0.63 ng/ml) and a substantial proportion had elevated sCD80 (13/29, >0.22 ng/ml) or sCD86 (16/33, >2.31 ng/ml) levels. Analysis of matched pairs of serum and SF from RA patients demonstrated that the SF/serum ratio for sCD80 (95% CI = 1.7-3), sCD86 (95% CI = 1.5-3.1), and sCD83 (95% CI = 3.6-7.8) levels was >1 in almost all patients. In conclusion, this study shows that the SF from almost all RA patients contain elevated levels of sCD83 and the majority of these samples also contain elevated levels of sCD80 and/or sCD86. These molecules may play a role in modulating immune responses within the rheumatoid joint.

The epidemiology of Wegener's granulomatosis and microscopic polyangiitis in a Southern Hemisphere region

OBJECTIVE

To determine the prevalence of Wegener's granulomatosis (WG) and microscopic polyangiitis (MPA) in the province of Canterbury, New Zealand.

METHOD

Three hospital clinical databases and the immunology laboratory database were searched and case notes reviewed for patients fulfilling either the 1990 American College of Rheumatology (ACR) criteria for WG or a modification of those criteria that allowed for antineutrophil cytoplasmic antibody (ANCA) positivity in the absence of granulomatous vasculitis. MPA was defined by the Chapel Hill consensus definition; however, in the absence of histological evidence of pauci-immune glomerulonephritis, ANCA positivity in association with evidence of active glomerular disease was included as a criterion. The point prevalence at 31 December 2003 and the 5-yr period prevalence for the interval 1 January 1999 to 31 December 2003 were calculated.

RESULTS

Seventy-three patients with WG and 28 patients with MPA fulfilled the inclusion criteria. A 5-yr period prevalence of 152 WG cases/million [95% confidence interval (CI) 117-186] and 58 MPA cases/million (95% CI 37-80) was calculated using 2001 census data as denominator. Nineteen patients with WG died and 10 patients with MPA died during the study period, resulting in a point prevalence for survivors at 31 December 2003 of 112 cases/million (95% CI 82-142) and 37 cases/million (95% CI 20-55), respectively. Using unmodified ACR criteria the 5-yr period and point prevalence for WG were 131/million (95% CI 99-163) and 93.5/million (95% CI 66-121), respectively. Apart from respiratory tract involvement, which formed part of the case definition of WG, organ involvement was similar in both diseases.

CONCLUSION

The prevalence of WG and MPA in Canterbury is the highest reported to date. Restricting the case definition of WG to the ACR classification criteria we found a prevalence equivalent to that described in northern Norway. The clinical severity and serological characteristics were similar to descriptions in other WG and MPA patient cohorts. Studies of disease prevalence in other Southern Hemisphere centres will determine if the observed north-south negative disease gradient in the Northern Hemisphere is reciprocated.

Prioritizing health-care funding

In the face of limited resources, on what basis should we prioritize health-care funding? The most influential consideration should be the knowledge that an intervention does something beneficial for the person who receives it. Rather than using imposed knowledge or knowledge obtained by grace, modern medicine uses knowledge obtained by rational thought. Traditionally, two philosophical schools of rational thought support medical interventions: empiricism and rationalism. Empiricist knowledge underpins the treatment of risk, while rationalist knowledge underpins the treatment of disease. To introduce reasoned order into the rationing process we must understand the limitations inherent in the application of these two forms of knowledge. Why are screening programmes for breast and uterine cervical cancer supported while severe restrictions are placed on treatments for chronic arthritis? Can the benefits of cholesterol-lowering drugs be measured? Empiricism has achieved an unchallenged ascendancy in modern health-care delivery. Is this ascendancy justified? There is a need for reference criteria to compare the benefits of competing interventions across disciplines. As a starting point for debate we propose that interventions should be given a priority based on how closely they fulfil five criteria: knowledge of disease pathophysiology, measurability of short-term and long-term benefits, incidence of serious adverse effects and affordability. It is only by using and refining such funding criteria that better public understanding of the rationing process will be achieved and political interference minimized.

Adult-onset inflammatory myopathy: North Canterbury experience 1989-2001

AIM

To perform a clinical audit of all patients diagnosed with inflammatory myopathy in the North Canterbury region.

METHODS

A retrospective case note audit of patients with a discharge diagnosis of inflammatory myopathy from June 1989 to June 2001 was performed. The audit was based at Christchurch Hospital, New Zealand, which services a population of 430,000.

RESULTS

Of 77 case notes reviewed, 44 patients were identified who were considered to fulfil clinical criteria for inflammatory myopathy. There was a female preponderance (80% female, 20% male). Diagnostic categories in descending order of frequency included: dermatomyositis (41%), polymyositis (39%), inclusion body myositis (IBM) (14%) and overlap syndromes (6%). Malignancy-associated myositis occurred in 20% overall (dermatomyositis 11%, polymyositis 9%). Delays in diagnosis and late age at presentation (average 72 years) were seen in the IBM group. Proximal limb weakness was common, but not universal at presentation (80%). A muscle biopsy was performed in all patients and electromyography in 82%. All were treated with high dose prednisone (0.5-1 mg/kg) of whom 29% were maintained on prednisone alone. Immunosuppressives/immunomodulators used included: azathioprine (58%), methotrexate (31%), intravenous immunoglobulin (13%), chlorambucil (13%), and cyclophosphamide (9%). Thirteen patients (42%) required more than one agent, with three trialling five agents. There were 59 relapses in 20 patients (45%), with mean time to first relapse of 7.8 months. At audit completion, 33% had deceased with malignancy and respiratory failure the main causes.

CONCLUSION

Inflammatory myopathy is a challenging condition in both diagnosis and management. Our audit has shown delays in the diagnosis of IBM, a relatively high incidence of malignancy and a notable risk of relapse and mortality.

HLA-B27 associated spondyloarthropathy, vasculitis, and amyloid enteropathy: response to infliximab

In 2000 we described a patient with HLA-B27 associated spondyloarthropathy (SpA) and severe ascending aortitis requiring surgical intervention. Despite continued immunosuppressive therapy she developed narrowing of the distal part of the right subclavian artery and proximal axillary artery secondary to active vasculitis. In addition, biopsy-proven amyloid gastroenteropathy developed causing persistent diarrhea and iron deficiency anemia. Treatment with infliximab resulted in resolution of joint symptoms and rapid improvement in laboratory markers of inflammation. Diarrhea settled more gradually, such that her bowel habit had normalized 16 months after therapy commenced.

Synovial fluid transforming growth factor beta inhibits dendritic cell-T lymphocyte interactions in patients with chronic arthritis

OBJECTIVE

To examine whether rheumatoid synovial fluid (SF) inhibits dendritic cell (DC) expression of the CD80 and CD86 costimulator molecules and contributes to SF T lymphocyte hyporesponsiveness.

METHODS

Cell-free rheumatoid SF was tested for its effect on DC-stimulated autologous/allogeneic mixed lymphocyte reactions and for its effect on DC surface antigen expression, as assessed by flow cytometry. Blocking monoclonal antibodies were used to identify the SF cytokines that inhibited DC-T lymphocyte interactions.

RESULTS

Low concentrations of SF (2.5%) could inhibit DC-mediated autologous and allogeneic T lymphocyte proliferation. This inhibitory effect could be reversed by neutralizing transforming growth factor beta (TGFbeta) and interleukin-2 (IL-2), but not by IL-12, in the SF. Hyaluronic acid, IL-6, IL-10, and tumor necrosis factor alpha were not associated with SF inhibition. In vitro culture alone and crosslinking with the CD40 ligand up-regulated DC CD80/CD86 expression and costimulator function, and this was not affected by inclusion of SF. In the presence of SF, DC clustered with autologous T lymphocytes showed decreased CD80 and CD86 expression, and variable CD80/CD86 decreases were observed on DC clustered with allogeneic T lymphocytes.

CONCLUSIONS

TGFbeta in SF appears to suppress T lymphocyte function, which may affect both signaling to DC and the induction of DC costimulator function.

Prolonged remission of longstanding systemic lupus erythematosus after autologous bone marrow transplant for non-Hodgkin's lymphoma

We describe a patient with longstanding steroid-dependent systemic lupus erythematosus (SLE) in whom clinical and serological remission was achieved following high-dose therapy and autologous bone marrow rescue for high-grade non-Hodgkin's lymphoma. However, 3 years later, autoimmune disease re-presented in the form of immune thrombocytopenia (ITP), which had not previously been a feature of the SLE, necessitating reintroduction of steroid immunosuppression. Relapse of SLE is most likely, although de novo ITP post-BMT is also a possibility. The case suggests that severe long-standing autoimmune disease may be controlled by high-dose therapy and autologous stem cell reconstitution. However, further studies are required to determine the mechanism of re-emergence of autoimmunity and to evaluate optimal regimens and the potential value of such therapy in severe autoimmune diseases.

Expression and function of CD80 and CD86 costimulator molecules on synovial dendritic cells in chronic arthritis

OBJECTIVE

To examine CD86 expression on dendritic cells isolated from the synovial fluid (SFDC) of patients with chronic arthritis, and to determine the importance of both CD80 and CD86 molecules in SFDC-T lymphocyte interactions.

METHODS

CD86 messenger RNA (mRNA) and surface expression were analyzed in SFDC using reverse transcriptase-polymerase chain reaction and flow cytometry, respectively. The costimulator activity of the SFDC CD80 and CD86 molecules was determined by allogeneic mixed lymphocyte reaction (MLR). CD80 and CD86 induction on SFDC during in vitro culture was also examined.

RESULTS

Fresh SFDC either lacked or showed very weak surface expression of CD86 molecules (as shown previously for CD80), yet contained CD86 mRNA. CD80 antibodies minimally inhibited an allogeneic MLR, whereas CD86 antibodies and CTLA-4 Ig showed significant inhibition. Both CD80 and CD86 molecules were inconsistently induced on SFDC following culture in either media, interferon-gamma, or granulocyte-macrophage colony-stimulating factor.

CONCLUSION

SFDC may be defective antigen-presenting cells in vivo. The ability of CD80 and CD86 molecules to be induced and become functional on SFDC in vitro implies the presence of a negative regulatory compound(s) in the synovial environment.

Prostaglandin E2 content in herniated lumbar disc disease

STUDY DESIGN

A prospective series of biochemical assays for prostaglandin E2 content in symptomatic herniated lumbar disc specimens.

OBJECTIVES

To help clarify the pathogenesis of lumbar radiculopathy.

SUMMARY OF BACKGROUND DATA

Three recent studies have shown elevated levels of prostaglandin E2 in intervertebral disc herniations. None of these studies correlated symptoms with prostaglandin E2 levels.

METHODS

Twenty-four disrupted disc samples were purified by a standard solid phase extraction method and analyzed for prostaglandin E2 with an enzyme-linked immunosorbent assay. Clinical and anatomic correlations were sought with analysis of variance and t test.

RESULTS

Sequestered discs tended to be associated with a higher prostaglandin E2 content than extruded discs, which in turn, tended to be associated with higher prostaglandin E2 content than protruded ones. A positive straight leg raising test appeared to be associated with a higher prostaglandin E2 content than a negative test.

CONCLUSIONS

Prostaglandin E2 appears to mediate some of the inflammatory effects of lumbar disc herniation. An intact anulus may provide some protection against this stimulus.

Monocyte-macrophage antigen expression on chondrocytes

OBJECTIVE

To characterize chondrocytes in normal and arthritic joints and compare their phenotype to that of synovial macrophages present in rheumatoid joints.

METHODS

Using an immunoperoxidase staining technique, we examined the presence and distribution of a number of leukocyte activation and differentiation antigens on samples of cartilage obtained from resected joints of normal controls and subjects with rheumatoid arthritis or osteoarthritis.

RESULTS

Chondrocytes in each group were CD14+, CD68+, Thy-1+, CD11a+, CD18+, MAX.3-, and MAX.24-. Staining was variable for MAX.1 and CD45. HLA-DR and CD71 were expressed only on cells located in the superficial layer of rheumatoid cartilage. We found lower levels of expression of CD14 on chondrocytes in arthritic joints, whereas CD58 was expressed at higher levels. Surface expression of CD14 was confirmed on normal chondrocytes using flow cytometry and further supported by the detection of CD14 mRNA by polymerase chain reaction.

CONCLUSION

Our findings demonstrate that chondrocytes express several antigens that are also found on monocytes and macrophages.

Dendritic cells in synovial fluid of chronic inflammatory arthritis lack CD80 surface expression

Dendritic cells (DC) act as potent primary antigen-presenting cells in many immune responses and therefore may have a role in the initiation and perpetuation of the synovial inflammation in chronic inflammatory arthritis. To examine their function, it is important to isolate fresh DC from arthritic joints without aberrant activation. We have developed a technique using minimal cell manipulation to isolate DC from the synovial fluid of chronic arthritic patients. Using this method, DC were shown to be potent allostimulatory cells, with 63-90% of cells lacking lineage-specific markers (lin-), but positive for MHC class II molecules. Two morphologically distinct populations of these cells were identified in 10 out of 13 DC preparations. Both populations expressed CD40, intercellular adhesion molecule-1 (ICAM-1), ICAM-2, ICAM-3 and leucocyte function associated antigen-3 (LFA-3), but the predominant population, which was larger and more typical of cultured blood DC, had a higher density of these antigens compared with the minor population, which were smaller and morphologically similar to lymphocytes. Two new MoAbs which label activated human blood DC, HB15 (CD83) and CMRF-44, were tested. CD83 labelled very weakly or not at all, whereas CMRF-44 was positive on the larger cells only. Likewise, the costimulator molecule, B7/BB1 (CD80), was not detected on the surface of either synovial lin- cell population, reverse transcriptase polymerase chain reaction (RT-PCR) showed little or no CD80 mRNA, and no binding of the CTLA-4Ig fusion protein was found. These results suggest that synovial DC are not, despite the inflammatory environment, in a fully activated state.

Co-expression of the CD45RA and CD45RO antigens on T lymphocytes in chronic arthritis

The site of T lymphocyte activation in chronic arthritis is unknown. Peripheral blood (PB) lymphocytes from chronic arthritis patients are in a 'naive' or non-activated state, as defined by expression of the CD45RA antigen and lack of HLA class II expression. In contrast, most synovial fluid (SF) T lymphocytes express a 'memory' or activated phenotype, as defined by the CD45RO antigen and high HLA class II expression. Following stimulation, naive cells lose CD45RA and gain CD45RO expression to become memory cells with a transitional stage of dual CD45RA, CD45RO antigen expression. To localize where this change in phenotype occurs we used dual colour immunofluorescence labelling to compare the percentage of dual CD45RA, CD45RO-positive T lymphocytes in PB and SF from chronic arthritic patients and from normal PB, assuming this population would be increased at the primary site of T lymphocyte activation. Expression of the intermediate and late activation marker, HLA-DR, was also analysed using dual colour immunofluorescence labelling. The percentage of dual positive T lymphocytes was similar between arthritic PB, SF, and normal PB, as was the density of both CD45RA and CD45RO antigens. Thus, CD45 isoform expression did not indicate where T lymphocytes were activated. However, we identified a previously unreported population of CD45RA+ CD45RO+ HLA-DR- T lymphocytes in arthritic and normal PB. In SF, this population was absent, but a substantial number of dual CD45RA, CD45RO-positive HLA-DR+ T lymphocytes were identified. This population would not be predicted by the current model of T lymphocyte activation. Division of T lymphocytes into functional groups on the basis of CD45 isoform expression is likely to be more complicated than previously thought. Based on our findings we propose an alternative model of T lymphocyte differentiation.

Adenocarcinoma of the colon and associated necrotizing vasculitis of mesenteric arteries

Vasculitis associated with malignancy is uncommon, with the most well-known association being that between hairy cell leukaemia and polyarteritis nodosa. The less common association of vasculitis and solid tumours usually involves a cutaneous leukocytoclastic vasculitis. We report a patient with Duke's C adenocarcinoma of the sigmoid colon with associated necrotizing vasculitis of the mesenteric arteries and postulate that local factors may predominate in its pathogenesis.

Dual CD45RA, CD45RO positive T-lymphocytes within rheumatoid arthritic joints

This report documents the presence of an expanded population of dual CD45RA, CD45RO positive T cells (up to 91% of T cells) in the rheumatoid joint. Cells from peripheral blood (PB) and synovial fluid (SF) were analysed by dual immunofluorescence labelling. Synovium from a separate patient population was analysed by single and dual immunoenzyme staining of serial sections. Dual CD45RA, CD45RO positive T cells were found in PB (up to 74%), SF (up to 91%) and synovium. This was associated with a lack of early activation antigens (4F2, interleukin-2 receptor, transferrin receptor) but increased HLA-Class II antigens (HLA-DR, -DP, -DQ) in SF compared with PB. This intermediate activation phenotype may support the hypothesis that T cell activation or reactivation occurs within the rheumatoid joint.

Respiratory failure in Wegener's granulomatosis: response to pulse intravenous methylprednisolone and cyclophosphamide

We describe a patient with respiratory failure due to Wegener's granulomatosis (WG) who obtained a dramatic and sustained response to pulse intravenous methylprednisolone and cyclophosphamide. Discussion includes a review of the literature with respect to the relative merits of daily oral cyclophosphamide versus pulse intravenous cyclophosphamide in WG and other vasculitides. While the combination of daily oral steroids and daily oral cyclophosphamide dramatically improves the outcome of WG, this therapy is not without serious side effects. Pulse therapy may be equally as effective and may lessen the frequency of serious side effects.

Rheumatoid pleural effusion: response to intrapleural corticosteroid

The management of a patient with a large symptomatic rheumatoid pleural effusion is described. Thoracentesis and bed rest gave only short term modest benefit. A more lasting and beneficial response was obtained with an intrapleural injection of (120 mg) depomethylprednisolone acetate. This treatment is a useful interim measure until disease suppressive therapy gives systemic control.

Possible mechanism for mianserin induced neutropenia associated with saturable elimination kinetics

Two cases of mianserin induced neutropenia associated with prolonged elimination of the drug were studied. In each case the pharmacokinetic profile suggested saturable elimination kinetics, and the temporal relation of mianserin concentrations and the neutrophil count suggested a direct toxic effect of mianserin on the bone marrow. Until further studies are carried out the plasma mianserin concentration and neutrophil count should be measured in any patient who develops an infection while taking this drug.

Health care in early infancy

The pattern of illness and of health care during the first 16 weeks of life in a cohort of 1210 infants was examined. Children from families in the lower social strata had a significantly increased risk of respiratory illness and gastrointestinal disturbance and received less routine well baby care than children from more socially advantaged backgrounds. A number of policy changes which might improve the distribution of health care resources are examined.