Proteins interacting with the 26S proteasome

The 26S proteasome is the multi-protein protease that recognizes and degrades ubiquitinylated substrates targeted for destruction by the ubiquitin pathway. In addition to the well-documented subunit organization of the 26S holoenzyme, it is clear that a number of other proteins transiently associate with the 26S complex. These transiently associated proteins confer a number of different roles such as substrate presentation, cleavage of the multi-ubiquitin chain from the protein substrate and turnover of misfolded proteins. Such activities are essential for the 26S proteasome to efficiently fulfill its intracellular function in protein degradation.

Hormonal exposures and breast cancer in a sample of women with systemic lupus erythematosus

OBJECTIVES

To determine if breast cancer risk in women with SLE is modified by a history of exposure to hormone replacement therapy (HRT) or oral contraceptives (OC), after adjusting for other risk factors.

METHODS

Data were pooled from SLE cohorts at three centres. For each female cohort member (n = 871), the probability of developing breast cancer was estimated from factors (age, parity, age at first live birth, age of menarche, personal history of benign breast disease, family history) in the Gail model, an established tool for predicting breast cancer risk. From these probabilities, the expected number of breast cancers for the cohort was estimated. Actual occurrence of cases was determined by linkage with regional cancer registries. Standardized incidence ratios (SIRs; ratio of cancers observed to expected) were calculated, with subgroup analyses according to HRT and OC exposure.

RESULTS

In the cohort, 15 breast cancers occurred vs 7.2 predicted [SIR 2.1, 95% confidence interval (CI) 1.1, 3.5]. When controlling for Gail model risk factors, estimates were similar for women never exposed to HRT vs those exposed to HRT. Adjusted SIR estimates appeared similar also for women exposed or not exposed to OC.

CONCLUSIONS

Although not definitive, the data suggest that the breast cancer experience in this sample is not completely explained by factors such as reproductive and family history, or by exogenous hormonal exposures. Other determinants, including medication exposures or genetic factors (possibly related to oestrogen receptors or metabolism) may be important. Variations in these factors might explain why an elevated risk of breast cancer has not been apparent in all SLE populations.

EULAR randomised controlled trial of pulse cyclophosphamide and methylprednisolone versus continuous cyclophosphamide and prednisolone followed by azathioprine and prednisolone in lupus nephritis

OBJECTIVE

To compare the efficacy and side effects of intermittent pulse cyclophosphamide plus methylprednisolone with continuous oral cyclophosphamide plus prednisolone, followed by azathioprine, in patients with proliferative glomerulonephritis caused by systemic lupus erythematosus (SLE).

METHODS

A multicentre randomised controlled trial was conducted between June 1992 and May 1996 involving eight European centres. All patients satisfied the American College of Rheumatology criteria for SLE and had biopsy proven proliferative lupus nephritis. All received corticosteroids in addition to cytotoxic drugs, as defined in the protocol, for two years. The trial was terminated after four years as recruitment was disappointing.

RESULTS

32 SLE patients with lupus nephritis were recruited: 16 were randomised to intermittent pulse cyclophosphamide and 16 to continuous cyclophosphamide plus azathioprine. Mean duration of follow up was 3.7 years in the continuous group (range 0 to 5.6) and 3.3 years in the pulse group (range 0.25 to 6). Three patients were excluded from the pulse therapy group as they were later found to have pure mesangial glomerulonephritis. Two patients in the continuous therapy group developed end stage renal failure requiring dialysis, but none in the intermittent pulse therapy (p = 0.488; NS). There were similar numbers of side effects and withdrawals from treatment in both groups. There were three deaths: two in the intermittent pulse therapy group and one in the continuous therapy group.

CONCLUSIONS

There was no statistically significant difference in efficacy and side effects between the two regimens. Infectious complications occurred commonly, so careful monitoring is required during treatment.

The systemic lupus erythematosus Tri-nation Study: absence of a link between health resource use and health outcome

OBJECTIVE

Health consumption and health status in SLE in three countries with different health funding structures were compared.

METHODS

Seven hundred and fifteen SLE patients (Canada 231, USA 269, UK 215) were surveyed semi-annually over 4 yr for health resource utilization and health status. Cross-country comparisons of (i) cumulative health expenditure (calculated by applying 2002 Canadian prices to resources in all countries) and (ii) disease damage (Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index, SLICC/ACR DI) at study conclusion were performed after adjustment. Missing expenditure and damage data were managed through multiple imputation using best predictive regressions with all available data from all patients as potential covariates.

RESULTS

Four hundred and eighty-five patients provided data at study entry and conclusion and at least four resource questionnaires (Canada 162, USA 157, UK 166); 41 died (Canada 13, USA 18, UK 10); 189 withdrew, were lost to follow-up or provided data at entry and conclusion but fewer than four resource questionnaires (Canada 56, USA 94, UK 39). At conclusion, after imputation, in Canada, the USA and the UK respectively, mean cumulative costs per patient over 4 yr [95% confidence interval (CI)] were $15,845 (13,509, 18,182), $20,244 (17,764, 22,724) and $17,647 (15,557, 19,737) and mean changes in SLICC/ACR DI were 0.49 (0.39, 0.60), 0.63 (0.52, 0.74) and 0.48 (0.39, 0.57). After adjustment for baseline differences, on average (95% CI), Canadian and British patients utilized 20% (8%, 32%) and 13% (1%, 24%) less resources than patients in the USA respectively, but experienced similar health outcomes.

CONCLUSION

Despite patients in the USA incurring higher health expenditures, they did not experience superior health outcomes.

Measuring systemic lupus erythematosus activity during pregnancy: validation of the lupus activity index in pregnancy scale

OBJECTIVE

To validate the Lupus Activity Index in Pregnancy (LAI-P) scale as a diagnostic tool for lupus flares during pregnancy and the puerperium.

METHODS

The LAI-P is a modified activity scale specific for pregnancy. Thirty-eight pregnant women with systemic lupus erythematosus (SLE) were prospectively followed in 3 clinics specific for lupus in pregnancy. On each visit, LAI-P was calculated. A modified physician global assessment (m-PGA) scale was used as gold standard (0 = no activity, 1 = mild-moderate activity, 2 = severe activity). A change > or = 0.25 in LAI-P was predefined as a flare according to previous studies in nonpregnant patients. For the purposes of the study, each visit was considered as an independent case.

RESULTS

During the study period, 158 visits took place for a total 621 patient-weeks. Sensitivity to change was high (standardized response mean for LAI-P = 1.6). We found a significant association between LAI-P and m-PGA (P < 0.002 in all regression models performed). Sensitivity, specificity, and positive and negative predictive values were 0.93, 0.98, 0.88, and 0.99. Positive and negative likelihood ratios were 49 and 0.07, respectively.

CONCLUSIONS

LAI-P has a high sensitivity to changes in lupus activity, a significant correlation with m-PGA, and high sensitivity, specificity, predictive values, and likelihood ratios for diagnosing SLE flares during pregnancy and the puerperium.

Influence of groundwater characteristics on the survival of enteric viruses

AIMS

This study was undertaken to further understand the processes affecting the persistence of enteric viruses in groundwater.

METHODS AND RESULTS

Varying temperature, oxygen and nutrient levels were tested in the presence and absence of groundwater micro-organisms to determine which of the factors tested had dominant influence on the decay of Escherichia coli, the bacteriophage MS2, poliovirus and coxsackievirus. The results indicated that the most influential factor affecting the decay of the viruses and E. coli was the presence of groundwater micro-organisms. The results also implied that temperature, the presence of oxygen and nutrient levels indirectly influence viruses and E. coli decay by influencing the activity of the groundwater micro-organisms.

CONCLUSIONS

E. coli and the viruses displayed maximum decay under aerobic conditions, at 28 degrees C without the addition of nutrients in the presence of groundwater micro-organisms.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results suggest that if the mode of action of the groundwater micro-organisms could be determined then the decay of viral pathogens in recharged waters may be more easily predicted.

Definition and treatment of lupus flares measured by the BILAG index

OBJECTIVES

The BILAG index is a clinical measure of lupus disease activity. It is valid, reliable and sensitive to change. Scoring in the BILAG index is based upon the physician's intention to treat. A flare of active lupus is defined as a new A or B score in at least one system. The main aim of this study was to determine whether patients with a lupus flare are treated as expected from the principles upon which the scoring system was devised. Secondly we wanted to establish whether patients with a new B score preceded by a C should be considered to have flared, as with patients scoring B following a D or E score.

METHODS

Over a 12-month period, 250 patients regularly attending lupus clinics in Birmingham and London were assessed using the BILAG index at each visit.

RESULTS

A new A or B score was observed in 154 (61.6%) patients. An A flare was observed in 26 (10.4%) patients. A B flare (in which the B score was preceded by a D or E score) was observed in 65 (26.0%) patients. There were 63 (25.2%) patients in whom there was a B score in a system in which a C score was previously recorded. Steroids were started or increased in 20 (77%) patients with an A flare. Almost all (92%) patients with a new A score had some increase in therapy. For the patients with new B scores, 53 (41%) had some increase in therapy, but multiple reasons were found for no change in therapy in 75 (59%) of these patients. There was no difference in the treatment of new B scores arising after a previous C score compared with previous D or E scores. Non-Caucasians were more likely to have a lupus flare than Caucasians.

CONCLUSIONS

These results are consistent with the principles upon which the BILAG index was devised and suggest that a moderate disease flare can be defined as a new B score following a C, D or E score according to the BILAG index.

Ultrasound guidance allows accurate needle placement and aspiration from small joints in patients with early inflammatory arthritis

OBJECTIVES

To compare the accuracy of palpation-guided and high frequency ultrasound-guided needle placement in small joints and to develop a technique to obtain synovial fluid from these joints for diagnosis and research.

METHODS

The accuracy of needle placement during palpation-guided proximal interphalangeal (PIP) or metacarpophalangeal (MCP) joint injection was assessed. This was compared with the accuracy of ultrasound-guided needle placement. A joint lavage technique was developed to obtain synovial fluid from these joints.

RESULTS

Needle positioning was intra-articular in 59% of palpation-guided injections (6/12 PIP and 4/5 MCP joints). No fluid could be aspirated prior to injection. With ultrasound guidance, initial needle placement was intra-articular in 96% of cases (24/26 PIP and 27/27 MCP joints). Synovial fluid cells were lavaged from 63% of joints (19/25 PIP and 14/27 MCP joints). In only one case was a large effusion seen and this was aspirated directly.

CONCLUSIONS

The use of high frequency ultrasound to guide needle placement within a small joint allows for significantly greater accuracy than a palpation-guided approach. When followed by lavage, synovial fluid cells and diluted synovial fluid can be obtained from the majority of small joints. This has important clinical and research implications.

Cardiovascular risk in systemic lupus erythematosus--evidence of increased oxidative stress and dyslipidaemia

OBJECTIVES

Systemic lupus erythematosus (SLE) is associated with severe and premature cardiovascular disease, which is not explained by traditional risk factors alone. This study aimed to investigate markers of oxidative stress, lipid metabolism and inflammation as potential cardiovascular risk factors in women with SLE.

METHODS

Venous blood samples were taken from 53 female Caucasian patients with SLE and from healthy age- and sex-matched controls. Samples were analysed for markers of oxidative stress, lipid metabolism [including low-density lipoprotein (LDL) subfraction profile] and C-reactive protein (CRP).

RESULTS

Female SLE patients had an atherogenic lipid profile characterized by raised total cholesterol and triglycerides, and the presence of small, dense LDL subfractions compared with healthy controls. These changes were associated with increased oxidative damage and a moderately raised CRP.

CONCLUSIONS

The results provide evidence for free radical and inflammatory activity in SLE and suggest potential targets to reduce the risk of cardiovascular disease in these patients.

Development and assessment of a World Wide Web site for systemic lupus erythematosus patient information

Patient education is an important component of the management of chronic diseases such as SLE. We have investigated the value of the World Wide Web as a medium for delivery of SLE patient information. Volunteers recruited from the clinic and from the website completed interviews and questionnaires aimed at defining their information needs. A new website was then established and its impact on users tested using knowledge questionnaires. The new website was used extensively (20-30 users each day) over the 24 month period of study until April 2001. A total of 510 participants completed an online questionnaire that showed that for some users it was their first use of the internet to gather lupus information, but the majority (58.9%) accessed it at least monthly for this purpose. We also found that, while most users (56.9%) found current disease information was at an appropriate level, 37.5% thought it was too basic. Knowledge questionnaires from 42 participants before and after using the site showed a significant rise in users' knowledge of the areas covered by the site. As far as we are aware this study is the first to show that a patient-oriented website can have a positive effect on disease knowledge. The relative ease with which good quality information can be disseminated via the web suggests that this medium is likely to be less costly and perhaps more educationally effective than printed information, and so is likely to become a primary vehicle for patient education. The website tested can be found at: www.rheumatology.bham.ac.uk/lupus/intro.html.

Association of damage with autoantibody profile, age, race, sex and disease duration in systemic lupus erythematosus

OBJECTIVE

To determine if there is any association between autoantibody profile and damage in a cohort of patients with systemic lupus erythematosus (SLE).

METHODS

A prospective cohort of SLE patients attending two SLE clinics in Birmingham was analysed. All patients fulfilled ARA criteria for SLE. Detailed clinical and serological information was recorded at each visit. Damage according to the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SLICC/ACR DI) was recorded 6-monthly and the last score in the year 2000 or prior to death was used in the analysis. Univariate analysis was performed with the chi(2) test, Fisher's exact test or univariate analysis of variance. Multivariate analysis was done with binary logistic regression.

RESULTS

A total of 348 patients (326 females) were studied, comprising 208 Caucasians, 65 Afro-Caribbeans, 59 Asians, four Orientals and 12 others. There were 32 (9.2%) deaths and 156 (44.8%) patients had damage recorded during follow-up. The presence of damage showed no significant association with race, sex or anti-cardiolipin, anti-Ro, anti-La, anti-Sm, anti-RNP and anti-dsDNA antibodies. Only age, disease duration and other antibodies to extractable nuclear antigens (ENA) were found to be associated with the presence of damage. When individual organ damage was analysed, the only significant associations were of anti-Ro with ocular damage and of other anti-ENA antibodies (anti-Scl-70 and/or anti-Jo-1) with premature gonadal failure. Other autoantibodies were not predictive of damage in individual organs.

CONCLUSIONS

Although autoantibodies are useful in diagnosis and predicting disease activity in SLE, they do not appear to be useful in predicting damage in SLE.

Unilateral varicella zoster virus ophthalmicus and contralateral acute retinal necrosis

We report two patients who developed varicella zoster virus (VZV) ophthalmicus complicated by ipsilateral keratouveitis, and within 4 weeks developed acute retinal necrosis (ARN) in the contralateral eye. The ipsilateral retina was spared in each case. One patient had systemic lupus erythematosus (SLE) and the other Hodgkin's disease. Both patients were in remission at the time of presentation.

Management of pregnancy in women with pulmonary hypertension secondary to SLE and anti-phospholipid syndrome

Pulmonary hypertension is found in about 10% of patients with systemic lupus erythematosis (SLE). Pulmonary hypertension may be present at the time of diagnosis or may develop after the diagnosis of SLE or anti-phospholipid syndrome (APS). It often presents in the reproductive years and has a significant impact on pregnancy outcome, being a significant cause of indirect maternal deaths. In our observational case series of three patients there were two deaths (66%). In cases 1 and 2 the pulmonary hypertension developed during pregnancy and deteriorated rapidly with markedly abnormal mean pulmonary artery pressures of 80 and 70 mmHg respectively prior to death. Both patients died within 48 hours of delivery. In case 3 the pulmonary hypertension was milder and was diagnosed very early in pregnancy. The patient received multidisciplinary care from the first trimester and the management of the pregnancy, delivery and the early puerperium was planned. Careful epidural anaesthesia was used and the patient had invasive monitoring on the intensive therapy unit (ITU) for 72 hours. Women with pulmonary hypertension need to be aware of the high risk of maternal mortality associated with pregnancy but we believe that an improvement in outcome can be achieved by careful assessment and the use of a multidisciplinary approach from early in pregnancy.

The intracellular localization of the proteasome

In summary, localization of proteasomes does appear to be important in the regulation of proteolysis. In yeast, a discrete localization is observed at the nuclear periphery for cells undergoing mitotic growth. This localization is clearly important as degradation by the ubiquitin/proteasome pathway is impaired in mutants that mislocalize proteasomes. In mammalian cells, proteasomes are present throughout the cell. However, the proteasome does appear to be enriched at the MTOC upon aggresome formation. The inhibition of the ubiquitin/proteasome pathway in aggresome-containing cells could provide an explanation for the pathogenicity of a number of neurodegenerative diseases.

Immune responses to native beta(2)-glycoprotein I in patients with systemic lupus erythematosus and the antiphospholipid syndrome

OBJECTIVE

To identify HLA class II associations with anti beta(2)-glycoprotein I (beta2GPI) antibodies in a cohort of Caucasian patients with systemic lupus erythematosus (SLE) and to determine whether these HLA genotypes act as restriction elements for lymphocyte proliferation to native human beta2GPI in vitro.

METHODS

Anti-beta2GPI antibodies were detected in patient sera using enzyme-linked immunosorbent assays (ELISAs). HLA class II alleles (DRB1, DQB1) were determined by polymerase chain reaction-based DNA genotyping. In vitro peripheral blood mononuclear cell (PBMC) responses to native human beta2GPI were measured in a 7-day proliferation assay.

RESULTS

We identified three groups of Caucasian SLE patients using these ELISAs. In group 1, 16 out of 18 SLE patients (89%) with anti-beta2GPI antibodies were positive for HLA-DRB1*0401/4/8, DR11 or DRB1*1302 (P=0.001 vs controls) compared with 23 out of 53 patients (43%) in group 2 with anti-cardiolipin antibodies only, 57 out of 151 patients (38%) in group 3 (SLE patients without anticardiolipin antibodies) and 109 out of 225 controls (48%). Fourteen patients with anti-beta2GPI antibodies had greater median stimulation indices to beta2GPI in vitro compared with the 15 controls studied (P=0.04).

CONCLUSION

The HLA class II and PBMC proliferation data suggest that beta2GPI may be both a T- and B-cell autoantigen in SLE.

Proteins containing the UBA domain are able to bind to multi-ubiquitin chains

The UBA domain is a motif found in a variety of proteins, some of which are associated with the ubiquitin-proteasome system. We describe the isolation of a fission-yeast gene, mud1+, which encodes a UBA domain containing protein that is able to bind multi-ubiquitin chains. We show that the UBA domain is responsible for this activity. Two other proteins containing this motif, the fission-yeast homologues of Rad23 and Dsk2, are also shown to bind multi-ubiquitin chains via their UBA domains. These two proteins are implicated, along with the fission-yeast Pus1(S5a/Rpn10) subunit of the 26 S proteasome, in the recognition and turnover of substrates by this proteolytic complex.

Phasic activities of rapid eye movement sleep in vegetative state patients

STUDY OBJECTIVES

To assess the phasic components of rapid eye movement (REM) sleep in patients in vegetative state and to evaluate the possible relationship of these activities to patient outcome.

SETTING

Sleep disorders unit at a major rehabilitation hospital.

DESIGN

Comparative control study.

PATIENTS

Eleven patients in vegetative state (10 males and 1 female) aged 17-53 years.

INTERVENTIONS

Continuous 24-hour polysomnographic recording.

MEASUREMENTS AND RESULTS

All the patients had REM sleep periods during the 24-hr recording session. Mean total REM sleep time for the whole session was 66.5 +/- 34.9 min, and for the nocturnal hours only, 37.3 +/- 19.7 min. Comparison with the control group (79.2 +/- 11.5 min) yielded a significant difference only for nocturnal REM sleep time (p<0.0003). The duration of the REM sleep periods was significantly shorter in the patients than the controls for the whole 24-hr session (10.9 +/- 6.0 vs.19.6 +/- 4.9 min, p<0.008), but not for the nocturnal period alone. Compared to controls, the density of rapid eye movements (REMs) (p=0.001), chin twitches (p=0.002), and leg muscle twitches (p=0.023) was significantly lower in the patient group. The density of the sawtooth waves was also lower in the patients, but the difference did not reach significance (p=0.069). Similar results were obtained when the comparison was done only for the nocturnal period. There was no significant difference for any of the REM sleep characteristics or REM sleep phasic activities (24-hr, nocturnal and diurnal periods) between the patients who recovered consciousness and those who did not.

CONCLUSIONS

The present study shows that patients in vegetative state have a significant reduction in the phasic activities of REM sleep. However, the amount of these activities is unrelated to recovery from the clinical condition. These findings may reflect possible damage to the pedunculopontine tegmentum cholinergic mechanisms in vegetative state.

IgG subclass distribution of antibodies against beta(2)-GP1 and cardiolipin in patients with systemic lupus erythematosus and primary antiphospholipid syndrome, and their clinical associations

OBJECTIVES

To determine the immunoglobulin G (IgG) subclass distribution of anticardiolipin (aCL) and anti-beta(2)-glycoprotein 1 (beta(2)-GP1) antibodies (abeta(2)-GP1), and to examine possible associations between the different abeta(2)-GP1 and aCL subclasses and the main clinical manifestations of the antiphospholipid syndrome (APS).

METHODS

We studied 130 patients with systemic lupus erythematosus and 35 patients with primary APS. We used enzyme-linked immunosorbent assays to measure IgG aCL and abeta(2)-GP1 and to determine the IgG subclass distribution of these two autoantibodies.

RESULTS

When the number of patients positive for each subclass was examined, IgG(3) and IgG(2) aCL were more frequent (63.5 and 54.1% of patients were positive for the two subclasses, respectively), while for abeta(2)-GP1 IgG(2) was the most prevalent subclass (81.8% of patients were positive). IgG(2) aCL was significantly associated with arterial thrombosis (P=0.023) and fetal loss (P=0.013), and IgG(3) aCL was significantly associated with arterial thrombosis (P=0.0003) and fetal loss (P=0.045). IgG(2) abeta(2)-GP1 was associated with venous thrombosis (P=0.012) and IgG(3) abeta(2)-GP1 was associated with venous thrombosis (P=0.036) and fetal loss (P=0.024).

CONCLUSIONS

The IgG(2) predominance of abeta(2)-GP1 suggests that the antibody response against beta(2)-GP1 may be T-cell-independent. As IgG(2) and IgG(3) differ in their effector functions, their association with the same clinical manifestations (i.e. thrombosis and fetal loss) suggests that more than one mechanism may be involved in the pathogenesis of thrombosis and fetal loss in APS.