Clinical and serological associations of autoantibodies to the Ku70/Ku80 heterodimer determined by a novel chemiluminescent immunoassay

BACKGROUND

Autoantibodies targeting Ku, an abundant nuclear protein with DNA helicase activity, have been reported in patients with systemic autoimmune rheumatic diseases. Little is known about the clinical associations of anti-Ku antibodies, especially when novel diagnostic technologies are used. The objective of the present study was to analyse the prevalence of anti-Ku antibodies in different medical conditions using a novel chemiluminescent immunoassay.

PATIENTS AND METHODS

Serum samples from adult patients with systemic lupus erythematosus (SLE, n=305), systemic sclerosis (SSc, n=70) and autoimmune myositis patients (AIM, n=109) were the primary focus of the study. Results were compared with disease controls (rheumatoid arthritis, RA, n=30; infectious diseases, n=17) and healthy individuals (n=167). In addition, samples submitted for routine autoantibody testing from patients referred to a rheumatology clinic (n=1078) were studied. All samples were tested for anti-Ku antibodies by QUANTA Flash Ku chemiluminescent immunoassay (research use only, Inova Diagnostics, San Diego, USA) using full length recombinant human Ku. SLE patient samples were also tested for other autoantibodies. Clinical data of anti-Ku antibody positive patients (high titres) were obtained by retrospective chart review.

RESULTS AND FINDINGS

In the disease cohorts, 30/305 (9.8%) SLE, 3/70 (4.3%) systemic sclerosis and 4/109 (3.7%) autoimmune myositis (AIM) patients were positive, respectively. The four positive AIM patients had an overlap myositis syndrome that included two patients with SLE. The three systemic sclerosis (SSc) positive samples had diagnoses of SSc/SLE overlap, diffuse cutaneous SSc, and early edematous phase SSc. In the control cohorts, 2/170 (1.2%) healthy individuals (all low titre), 0/30 (0.0%) (RA) and 0/17 (0.0%) infectious disease patients were positive. The area under the curve values were: 0.75 for SLE vs. controls, 0.68 for SSc vs. controls and 0.37 for AIM vs.

CONTROLS

In the rheumatology clinic referral cohort, 12/1078 (1.1%) were positive for anti-Ku antibodies, nine showing low and three high titres. The diagnoses of the three high positive anti-Ku positive patients were: probable SLE, mixed connective tissue disease (MCTD) and ANA positive RA.

CONCLUSION

Anti-Ku antibodies detected by chemiluminescent immunoassay are most prevalent in SLE. When found in AIM and SSc, they were associated with overlap syndrome and early SSc.

Breast cancer in systemic lupus erythematosus

OBJECTIVE

Evidence points to a decreased breast cancer risk in systemic lupus erythematosus (SLE). We analyzed data from a large multisite SLE cohort, linked to cancer registries.

METHODS

Information on age, SLE duration, cancer date, and histology was available. We analyzed information on histological type and performed multivariate logistic regression analyses of histological types according to age, SLE duration, and calendar year.

RESULTS

We studied 180 breast cancers in the SLE cohort. Of the 155 cases with histology information, 11 were referred to simply as 'carcinoma not otherwise specified'. In the remaining 144 breast cancers, the most common histological type was ductal carcinoma (n = 95; 66%) followed by lobular adenocarcinoma (n = 11; 8%), 15 cancers were of mixed histology, and the remaining ones were special types. In our regression analyses, the independent risk factors for lobular versus ductal carcinoma was age [odds ratio (OR) 1.07, 95% confidence interval (CI) 1.01-1.14] and for the 'special' subtypes it was age (OR 1.06, 95% CI 1.01-1.10) and SLE duration (OR 1.05, 95% CI 1.00-1.11).

CONCLUSIONS

Generally, up to 80% of breast cancers are ductal carcinomas. Though our results are not definitive, in the breast cancers that occur in SLE, there may be a slight decrease in the ductal histological type. In our analyses, age and SLE duration were independent predictors of histological status.

Disseminated Histoplasma capsulatum infection presenting with panniculitis and focal myositis in rheumatoid arthritis treated with etanercept

We report the case of a patient with rheumatoid arthritis (RA) on etanercept who presented with panniculitis and focal myositis as manifestations of disseminated histoplasmosis. Systematic search of the literature showed 11 additional case reports of disseminated histoplasmosis with tumour necrosis factor-alpha (TNFalpha) blockade therapy (infliximab, n = 8; etanercept, n = 3). Although disseminated histoplasmosis may manifest with classical symptoms of fever and respiratory complaints, it may also present atypically, such as with panniculitis and focal myositis. This review illustrates and emphasizes the importance of being highly suspicious for infection, including by opportunistic organisms, and to exclude such process in patients treated with a TNFalpha inhibitor when faced with unusual complications, even when an alternative aetiology appears plausible.

SLE patients with renal damage incur higher health care costs

OBJECTIVES

To compare costs and quality of life (QoL) between SLE patients with and without renal damage.

METHODS

Seven hundred and fifteen patients were surveyed semi-annually over 4 yrs on health care use and productivity loss and annually on QoL. Cumulative direct and indirect costs (2006 Canadian dollars) and QoL (average annual change in SF-36) were compared between patients with and without renal damage [Systemic Lupus International Collaborating Clinics/ACR Damage Index (SLICC/ACR DI)] using simultaneous regressions.

RESULTS

At study conclusion, for patients with the renal subscale of the SLICC/ACR DI = 0 (n = 634), 1 (n = 54), 2 (n = 15) and 3 (n = 12), mean 4-yr cumulative direct costs per patient (95% CI) were $20,337 ($18,815, $21,858), $27,869 ($19,230, $36,509), $51,191 ($23,463, $78,919) and $99,544 ($57,102, $141,987), respectively. In a regression where the renal subscale of the SLICC/ACR DI was a single indicator variable, on average (95% CI), each unit increase in renal damage was associated with a 24% (15%, 33%) increase in direct costs. In a regression where each level in the renal subscale was an indicator variable, patients with end-stage renal disease incurred 103% (65%, 141%) higher direct costs than those without renal damage. Cumulative indirect costs and annual change in the SF-36 summary scores did not differ between patients.

CONCLUSIONS

SLE patients with renal damage incurred higher direct costs, but did not experience a poorer QoL. QoL may be more influenced by concurrent renal activity than accumulated renal damage, which can occur at any time and patients may gradually habituate to their compromised health state.

Mortality related to cerebrovascular disease in systemic lupus erythematosus

The objective of this study was to examine mortality rates related to cerebrovascular disease in systemic lupus erythematosus (SLE) compared to the general population. Our sample was a multisite Canadian SLE cohort (10 centres, n = 2688 patients). Deaths due to cerebrovascular disease were ascertained by vital statistics registry linkage using ICD diagnostic codes. Standardized mortality ratio (SMR, ratio of deaths observed to expected) estimates were calculated. The total SMR for death due to cerebrovascular disease was 2.0 (95% confidence interval [CI] 1.0, 3.7). When considering specific types of events, the category with the greatest increased risk was that of ill-defined cerebrovascular events (SMR 44.9 95% CI 9.3, 131.3) and other cerebrovascular disease (SMR 8.4, 95% CI 2.3, 21.6). Deaths due to cerebral infarctions appeared to be less common than hemorrhages and other types of cerebrovascular events. Our data suggest an increase in mortality related to cerebrovascular disease in SLE patients compared to the general population. The large increase in ill-defined cerebrovascular events may represent cases of cerebral vasculitis or other rare forms of nervous system disease; alternately, it may reflect diagnostic uncertainty regarding the etiology of some clinical presentations in SLE patients. The suggestion that more deaths are attributed to cerebral hemorrhage, as opposed to infarction, indicates that inherent or iatrogenic factors (eg, thrombocytopenia or anticoagulation) may be important. In view of the paucity of large-scale studies of mortality attributed to neuropsychiatric outcomes in SLE, our findings highlight the need for additional research in large SLE cohorts.

Mortality in systemic lupus erythematosus

OBJECTIVE

To examine mortality rates in the largest systemic lupus erythematosus (SLE) cohort ever assembled.

METHODS

Our sample was a multisite international SLE cohort (23 centers, 9,547 patients). Deaths were ascertained by vital statistics registry linkage. Standardized mortality ratio (SMR; ratio of deaths observed to deaths expected) estimates were calculated for all deaths and by cause. The effects of sex, age, SLE duration, race, and calendar-year periods were determined.

RESULTS

The overall SMR was 2.4 (95% confidence interval 2.3-2.5). Particularly high mortality was seen for circulatory disease, infections, renal disease, non-Hodgkin's lymphoma, and lung cancer. The highest SMR estimates were seen in patient groups characterized by female sex, younger age, SLE duration <1 year, or black/African American race. There was a dramatic decrease in total SMR estimates across calendar-year periods, which was demonstrable for specific causes including death due to infections and death due to renal disorders. However, the SMR due to circulatory diseases tended to increase slightly from the 1970s to the year 2001.

CONCLUSION

Our data from a very large multicenter international cohort emphasize what has been demonstrated previously in smaller samples. These results highlight the increased mortality rate in SLE patients compared with the general population, and they suggest particular risk associated with female sex, younger age, shorter SLE duration, and black/African American race. The risk for certain types of deaths, primarily related to lupus activity (such as renal disease), has decreased over time, while the risk for deaths due to circulatory disease does not appear to have diminished.

An international cohort study of cancer in systemic lupus erythematosus

OBJECTIVE

There is increasing evidence in support of an association between systemic lupus erythematosus (SLE) and malignancy, but in earlier studies the association could not be quantified precisely. The present study was undertaken to ascertain the incidence of cancer in SLE patients, compared with that in the general population.

METHODS

We assembled a multisite (23 centers) international cohort of patients diagnosed as having SLE. Patients at each center were linked to regional tumor registries to determine cancer occurrence. Standardized incidence ratios (SIRs) were calculated as the ratio of observed to expected cancers. Cancers expected were determined by multiplying person-years in the cohort by the geographically matched age, sex, and calendar year-specific cancer rates, and summing over all person-years.

RESULTS

The 9,547 patients from 23 centers were observed for a total of 76,948 patient-years, with an average followup of 8 years. Within the observation interval, 431 cancers occurred. The data confirmed an increased risk of cancer among patients with SLE. For all cancers combined, the SIR estimate was 1.15 (95% confidence interval [95% CI] 1.05-1.27), for all hematologic malignancies, it was 2.75 (95% CI 2.13-3.49), and for non-Hodgkin's lymphoma, it was 3.64 (95% CI 2.63-4.93). The data also suggested an increased risk of lung cancer (SIR 1.37; 95% CI 1.05-1.76), and hepatobiliary cancer (SIR 2.60; 95% CI 1.25, 4.78).

CONCLUSION

These results support the notion of an association between SLE and cancer and more precisely define the risk of non-Hodgkin's lymphoma in SLE. It is not yet known whether this association is mediated by genetic factors or exogenous exposures.

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.

The cytoplasmic linker protein CLIP-170 is a human autoantigen

The purpose of this study was to identify autoantigens that are recognized by human sera and are associated with a speckled cytoplasmic fluorescent staining pattern on tissue culture cells, and to determine clinical features associated with specific autoantibodies. A serum from a patient with systemic lupus erythematosus was used to identify a 3.7-kb cDNA insert from a HeLa cell expression library. The purified cDNA (VLK2.1) encoded a peptide of 1051 amino acids that shared 98.4% similarity with the carboxyl terminal portion of a previously reported 170 kD protein named cytoplasmic linker protein-170 (CLIP-170). Antibodies affinity purified with the recombinant CLIP-170 protein, the prototype human serum and a monoclonal antibody raised against CLIP-170 exhibited identical speckled staining of the cytoplasm in HEp-2 cells. The human autoantibodies reacted with the purified recombinant protein in a Western immunoblot and immunoprecipitated the in vitro translated recombinant protein. Three additional human sera also immunoprecipitated the recombinant CLIP-170 protein. The clinical diagnoses in these patients were limited scleroderma, glioblastoma and idiopathic pleural effusion. This is the first report that identifies CLIP-170 as a human autoantigen.

Living with lupus: a prospective pan-Canadian study

OBJECTIVE

To portray life with lupus for women affected by this disease and to identify predictors of fatigue, a common symptom that compromises patients' quality of life.

METHODS

A sample of 120 female patients (mean age 42.5 yrs) with systemic lupus erythematosus (SLE) from 9 rheumatology clinics across Canada were followed prospectively for 15 months. Assessments of psychosocial functioning took place at baseline, and at 3, 9, and 15 months. Physician examinations were conducted at baseline and 15 months.

RESULTS

Significant time effects were found for: global psychological distress (p < 0.001), stress (p < 0.01), emotion-oriented coping (p < 0.001), physical health status (p < 0.001), and fatigue (p < 0.001), indicating that patients improved from baseline to 15 months. Disease activity worsened for 40.3%, improved for 50.8%, and remained the same for 8.8% of the patients from baseline to 15 months. Controlling for baseline disease activity and fatigue, and considering sleep problems, decreases in stress and depression predicted less fatigue at 15 months (p < 0.001; adjusted R2 = 0.43).

CONCLUSION

Despite fluctuations in disease activity, patients with SLE, as a group, cope adequately with their disease over time. There is, nonetheless, a subset of patients (about 40%) who remain distressed and who may benefit from psychosocial interventions.

Traditional Framingham risk factors fail to fully account for accelerated atherosclerosis in systemic lupus erythematosus

OBJECTIVE

The frequency of coronary heart disease (CHD) and stroke are increased in systemic lupus erythematosus (SLE), but the extent of the increase is uncertain. We sought to determine to what extent the increase could not be explained by common risk factors.

METHODS

The participants at two SLE registries were assessed retrospectively for the baseline level of the Framingham study risk factors and for the presence of vascular outcomes: nonfatal myocardial infarction (MI), death due to CHD, overall CHD (nonfatal MI, death due to CHD, angina pectoris, and congestive heart failure due to CHD), and stroke. For each patient, the probability of the given outcome was estimated based on the individual's risk profile and the Framingham multiple logistic regression model, corrected for observed followup. Ninety-five percent confidence intervals (95% CIs) were estimated by bootstrap techniques.

RESULTS

Of 296 SLE patients, 33 with a vascular event prior to baseline were excluded. Of the 263 remaining patients, 34 had CHD events (17 nonfatal MIs, 12 CHD deaths) and 16 had strokes over a mean followup period of 8.6 years. After controlling for common risk factors at baseline, the increase in relative risk for these outcomes was 10.1 for nonfatal MI (95% CI 5.8-15.6), 17.0 for death due to CHD (95% CI 8.1-29.7), 7.5 for overall CHD (95% CI 5.1-10.4), and 7.9 for stroke (95% CI 4.0-13.6).

CONCLUSION

There is a substantial and statistically significant increase in CHD and stroke in SLE that cannot be fully explained by traditional Framingham risk factors alone.

Absence of antiphospholipid/co-factor antibodies in Takayasu arteritis

There are anecdotal reports and small series describing the presence of anticardiolipin antibodies in patients with Takayasu Arteritis. This communication describes a systematic study searching for non-organ specific autoantibodies which includes antinuclear antibodies, anticardiolipin and anti-beta(2) GP(1) antibodies in a cohort of 28 Mexicans with angiographic definitive diagnostic of Takayasu Arteritis.

MATERIAL AND METHODS

Twenty-eight consecutive patients, who fulfilled classification and diagnostic criteria for Takayasu Arteritis and had a diagnostic panaortogram, were bled to study the presence of circulating autoantibodies in a cross-sectional design.

RESULTS

There were no antinuclear antibodies, although a few sera had faint cytoplasm fluorescent deposit and reacted with cell extract. We did not recognize a distinct pattern. Also, there was no IgG nor IgM anticardiolipin antibodies nor anticofactor antibodies of clinical interest.

DISCUSSION AND CONCLUSIONS

The presence of circulating non-organ specific autoantibodies is not a characteristic feature in Takayasu Arteritis when strict diagnostic criteria are applied. The occasional presence of such immune markers could be due to technical differences in sample management, less strict diagnosis or biological variability in certain cases, but has no diagnostic value.

The use of alternative medical therapies in patients with systemic lupus erythematosus. Trination Study Group

OBJECTIVE

As part of an ongoing study of health resource utilization and diminished productivity in patients with systemic lupus erythematosus (SLE), the use of alternative medical therapies was assessed.

METHODS

A cohort of 707 patients with SLE from 3 countries completed questionnaires on demographics, social support, health status (using the Short Form 36 health survey), satisfaction with health care, health resource utilization (conventional resources and alternative therapies), and time losses in labor market and non-labor market activities. Annual direct and indirect costs (1997 Canadian dollars) were calculated and compared for users and nonusers of alternative medical therapies.

RESULTS

Among the 707 patients, 352 (49.8%) were found to use alternative therapies and at similar rates across Canada, the United States, and the United Kingdom. Users were younger and better educated than nonusers, exhibited poorer levels of self-rated health status and satisfaction with medical care, and had minimal to no objective evidence of worse disease (according to the revised Systemic Lupus Activity Measure instrument). The mean of log direct medical costs for conventional resources was higher for users of select alternative therapies compared with nonusers. In a logistic regression, neither the number of alternative therapies used nor the individual therapy increased the probability of incurring indirect costs.

CONCLUSION

The use of alternative medical therapies is common in patients with SLE. Users of many alternative medical therapies accrue greater conventional medical costs compared with nonusers. The use of alternative medical therapy may be a marker for care-seeking behavior associated with higher consumption of conventional medical resources in the absence of demonstrable additional morbidity and should be considered in future cost analyses of patients with SLE.

Determinants of health status in fibromyalgia: a comparative study with systemic lupus erythematosus

OBJECTIVE

To compare perceived health status in women with fibromyalgia (FM) and systemic lupus erythematosus (SLE) using the Medical Outcomes Study (MOS) Short Form Health Survey (SF-36); and to identify determinants of physical and mental health in each patient group.

METHODS

A cross sectional study of 46 women with FM (mean age 48.13 yrs, SD 9.40) and 59 women with SLE (mean age 42.36 yrs, SD 11.31). Patients with FM were recruited from a rheumatology clinic and a rheumatology practice, while patients with SLE were recruited from 4 rheumatology clinics. Clinical examination determined disease activity (by Systemic Lupus Activity Measure) in SLE and a tender point count was used for FM. Patients completed questionnaires assessing health status (SF-36), stress (Hassles), social support (Social Support Questionnaire 6), and coping (Coping Inventory for Stressful Situations).

RESULTS

Patients with FM reported more impairment on the following SF-36 subscales: physical function (p < 0.001), role physical (p < 0.001), bodily pain (p < 0.001), and vitality (p < 0.001). Physical component summary scores were also significantly lower (p < 0.001) for the FM group. Four hierarchical regression analyses were computed to determine factors related to physical and mental health in each patient group, with the following variables in the equation: age, income, disease activity (Step 1), hassles (Step 2), emotional and task coping, and social support (Step 3). Better physical health in FM was related to higher income (R2 = 0.17, p < 0.05). In the SLE group, better physical health was associated with younger age, less disease activity, and lower hassles (R2 = 0.37, p < 0.0001). Worse mental health among women with FM was associated with more hassles, more emotional coping, and less satisfaction with social support (R2 = 0.64, p < 0.0001), while lower income, higher hassles, and more emotional coping were linked to worse mental health in SLE (R2 = 0.46, p < 0.0001).

CONCLUSION

Health related quality of life (HRQL) is impaired among women with FM and SLE, with FM patients reporting greater impairment along several dimensions. Enhancing the HRQL of patients with FM and SLE requires targeting specific modifiable psychosocial factors.

Quality of life in systemic lupus erythematosus patients during more and less active disease states: differential contributors to mental and physical health

OBJECTIVE

To identify determinants of mental and physical health as a function of disease state in patients with systemic lupus erythematosus (SLE).

METHODS

A sample of 129 SLE patients (mean age 42.01 years; SD 11.09) was recruited from 9 immunology/rheumatology clinics across Canada. Patients completed questionnaires assessing psychological distress, social support, coping, stress, and health-related quality of life. Physicians rated disease activity (using the revised Systemic Lupus Activity Measure; SLAM-R) and damage (using the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index). Mental and physical health composite scores were derived from the Medical Outcomes Study Short Form 36. Patients were subdivided into more active (SLAM-R > or = 10; n = 38) or less active disease states (n = 91).

RESULTS

Better mental health was predicted by more education and less emotion-oriented coping in the patients in a more active disease state (P = 0.0001; R2 = 0.46). Better mental health was predicted by less stress, less emotion-oriented coping and more task-oriented coping in patients during a less active disease state (P = 0.0001; R2 = 0.45). Better physical health was predicted by more emotion-oriented coping in patients in a more active disease state (P = 0.04; R2 = 0.11). Better physical health was predicted by less stress and younger age in patients during a less active disease state (P = 0.0001; R2 = 0.20).

CONCLUSION

The positive association between emotion-oriented coping and better physical health in patients during a more active disease state suggests that this style of coping may be more adaptive in situations that are considered uncontrollable (e.g., SLE flare). Predictors of mental health were similar to those found in the literature, especially for SLE patients in a less active disease state.

Early endosome antigen. 1: An autoantigen associated with neurological diseases

BACKGROUND

We have identified 36 human sera sent for autoantibody analyses that produce a unique vesicular staining pattern of the cytoplasm of tissue culture cells. The purpose of this study was to identify the autoantigens that are recognized by the sera that produce this staining pattern and determine if the patients have common clinical features.

METHODS

A serum from one of the patients (MS) with rapidly progressive demyelinating polyneuropathy was used to isolate a approximately 4.5 kb cDNA insert from a HeLa expression library. The purified cDNA (MS-5.1) was characterized by a poly A tail and an open reading frame that encoded 1329 amino acids. The derived amino acid sequence was found to be 99% identical to a 180 kd peripheral endosomal protein named early endosome antigen (EEA1).

RESULTS

Antibodies from rabbits immunized with the recombinant protein and the prototype human serum produced an identical distinctive speckled cytoplasmic staining pattern. These sera also precipitated the in vitro translated recombinant protein and reacted with the isolated recombinant protein in a Western immunoblot. Of the 36 sera that produced an identical staining pattern as the prototype and immune rabbit sera, 8 (22%) had IgG antibodies that recognized the recombinant EEA1 protein when tested by immunoblotting and immunoprecipitation assays. Of the 8 patients with anti-EEA1 antibodies 4 were females, 4 were males, and the mean age was 69 years (range 48 to 86 years).

CONCLUSIONS

Diagnoses included: polyneuropathy, lower motor neuron disease, pigmented retinitis, seronegative polyarthritis, interstitial pulmonary fibrosis, Raynaud's phenomenon, Wegener's granulomatosis, and proteinuria. Three of the eight patients with EEA1 autoantibodies died within 1 year after EEA1 antibodies were identified.

Strong association of autoantibodies to human nuclear lamin B1 with lupus anticoagulant antibodies in systemic lupus erythematosus

OBJECTIVE

To determine the frequency and clinical significance of high titers of IgG autoantibodies to nuclear lamin B1 in a large number of unselected and well-characterized systemic lupus erythematosus (SLE) patients, disease controls, and normal healthy controls.

METHODS

A cross-sectional study of anti-lamin B1 autoantibodies, as measured by enzyme-linked immunosorbent assay using human recombinant lamin B1 autoantigen, was performed on serum samples obtained at first evaluation of 238 consecutive French Canadian adults: 61 healthy control subjects, 20 patients with osteoarthritis, 22 with ankylosing spondylitis, 11 with autoimmune hepatitis, 30 with rheumatoid arthritis, and 94 with SLE. SLE patients were studied for 57 disease manifestations. A case-control study was performed to analyze the relationship between anti-lamin B1 status and thrombotic manifestations between SLE onset and last followup.

RESULTS

High titers of anti-lamin B1 were strikingly restricted to a subset of 8 SLE patients (8.5%). The mean anti-lamin B1 titer was higher in this subset than in the other SLE patients or any control group (P<0.001). By univariate analysis and stepwise multiple logistic regression, the most striking association of anti-lamin B1 was with lupus anticoagulant (LAC) antibodies (P = 0.00001). Although LAC were significantly associated with thrombosis in our SLE patients, anti-lamin B1 was not. The frequency of thrombosis in SLE patients expressing both LAC and anti-lamin B1 was similar to that in patients without LAC (P = 1.0). However, patients expressing LAC without anti-lamin B1 had a greater frequency of thrombosis (P = 0.018).

CONCLUSION

High titers of IgG anti-lamin B1 autoantibodies are highly specific for a subset of SLE patients whose clinical characteristics include the presence of LAC and other laboratory manifestations of the antiphospholipid syndrome. The presence of LAC without anti-lamin B1 may define a subset of SLE patients at greater risk for thrombosis.

Severe mixed connective tissue disease in a woman with pure gonadal dysgenesis: estrogens do not influence disease expression

Mixed connective tissue disease (MCTD) is more prevalent in women during the child bearing years, suggesting that estrogens may play a role in disease expression. We describe a woman who developed MCTD despite pure gonadal dysgenesis, i.e., a disease associated with permanently very low plasma levels of estrogens. The onset of MCTD and subsequent life threatening disease course over 15 years occurred while she declined exogenous hormonal replacement therapy. Concurrent presence of estrogens is not necessary for onset, persistence, or exacerbation of severe MCTD.

Anticentromere autoantibodies in patients without Raynaud's disease or systemic sclerosis

Anticentromere autoantibodies (ACA) are associated with Raynaud's disease and systemic sclerosis (SSc). ACA usually bind at least one of three major centromere proteins (CENPs), particularly CENP-B. We identified 16 patients with ACA who do not have Raynaud's disease or SSc. The objective of this study was to determine whether these 16 ACA differ in antigenic specificity from the ACA found in patients with Raynaud's disease or SSc. Binding of these serum ACA was tested using competition experiments with recombinant CENP-B, and native centromere proteins from HEp-2 cells and HeLa nuclear extracts in ELISAs, immunoblots, and indirect immunofluorescence assays. The ACA from these 16 patients are strikingly different from those obtained from patients who have Raynaud's disease or SSc. Only 5 of the 16 index sera (31.25%) bound CENP-B from two or more different sources by at least two methods. Six of these 16 sera (37.5%) did not bind CENP-B on ELISA, and 8 of 16 (43.75%) did not bind CENP-B on immunoblots. Three sera did not bind CENP-B either by ELISA or immunoblots. Of the 13 sera that bound CENP-B, their patterns of binding to CENP-B strongly suggested that they bind different epitopes within the CENP-B antigen. Independently of their binding to CENP-B, these sera reacted mainly with minor CENP antigens detected by HeLa nuclear extracts. We have identified unusual ACA not associated with Raynaud's disease or SSc.

A long-term study of hydroxychloroquine withdrawal on exacerbations in systemic lupus erythematosus. The Canadian Hydroxychloroquine Study Group

The ability of antimalarials to moderate severe disease activity in systemic lupus erythematosus (SLE) is plausible but undemonstrated. We evaluated the long-term effectiveness of maintaining treatment with hydroxychloroquine sulphate (HCQ) to prevent major flares in quiescent SLE. Forty-seven patients with quiescent SLE who had been randomized to take HCQ (n = 25) or placebo (n = 22) as part of a 24-week withdrawal trial were evaluated for an additional 3 years. The primary outcome was time to a major flare of SLE which resulted in either the institution of or an increase in the current dosage of prednisone of 10 mg/day or more, or institution of therapy with immunosuppressive agents. Secondary outcomes included the specific subtype of these major flares (glomerulonephritis, vasculitis or other) and hospitalization for an exacerbation of SLE. An intent-to-treat analysis was conducted. Over the 42 months of study, 11 of 22 (50%) patients randomized initially to placebo, and seven of 25 (28%) patients randomized to continue treatment experienced a major flare. The relative risk of major flare for those randomized to continue HCQ compared with controls was 0.43 (95% CI: 0.17, 1.12). The relative risks for subtypes of flares were 0.26 (95% CI: 0.03, 2.54) for nephritis, 0.51 (95% CI: 0.09, 3.08) for vasculitis and 0.65 (95% CI: 0.17, 2.41) for flares characterized by other symptoms. The relative risk of hospitalization for major flare for patients randomized to continue hydroxychloroquine was 0.58 (95% CI: 0.13, 2.60). While the results are not statistically significant, they are compatible with the clinical belief that HCQ has a long-term protective effect against major disease flares in SLE and suggest that on average, HCQ use reduces major flares by 57% (95% CI: 83% reduction to 12% increase).

Analysis of IgG subclasses of human antitopoisomerase I autoantibodies suggests chronic B cell stimulation

Antitopoisomerase I autoantibodies are highly specific of scleroderma and are mainly IgG. The present study was designed to evaluate the prevalence of each IgG antitopoisomerase I subclass. An ELISA for the detection of IgG antitopoisomerase I subclasses was standardized and used to study the antibodies from 49 antitopoisomerase I-positive patients identified from a total of 541 patients. Correlations and multivariate analysis were performed to determine the frequency of associations between the IgG antitopoisomerase I subclasses. All IgG antitopoisomerase I subclasses were found. Twelve patients (24.5%) had all four IgG antitopoisomerase I subclasses, 13 (26.5%) had three, 16 (32.7%) had two, and 7 (14.3%) had only one antitopoisomerase I subclass. The presence of all four IgG antitopoisomerase I subclasses suggests that this specific B-cell is the target of multiple activation pathways which indicate that there is a complex T-cell-cytokine-driven process. Together with the absence of other autoantibodies in these sera, our results support the concept of a multiple but highly selected and chronic B-cell activation in scleroderma patients with antitopoisomerase I.

Risk factors for adult Still's disease

OBJECTIVE

To assess risk factors for adult Still's disease (ASD).

METHODS

A matched case-control study of 60 patients with ASD and 60 same sex siblings closest in age was conducted. Subjects were recruited from cohorts in Eastern Canada, Pittsburgh, and the Arthritis, Rheumatism, and Aging, Medical Information Systems (ARAMIS). A questionnaire was used to obtain data on demographic characteristics, education, income, occupation, exposure to toxic substances, stress, and medical history.

RESULTS

116 patients with ASD were identified, of which 104 participated. 86 identified same sex siblings, of which 60 replied. When compared to same sex siblings, ASD patients were similar with respect to education and occupation but had a trend to higher median income. There were no significant associations of ASD with smoking, alcohol consumption, individual toxic substances, vaccination, blood transfusion, minor or major surgery, pregnancy, or diet in the year preceding disease onset. There were no significant associations with tonsillectomy or adenoidectomy, appendectomy, asthma, hay fever, allergy shots, or pregnancy at any time preceding the onset of disease. There was a statistically nonsignificant increase in a history of exposure to coal dust [odds ratio (OR) 3.0; 95% confidence interval (CI) 0.30 to 28.84], in allergy preceding the onset of disease (OR 2.67; 95% CI 0.71 to 10.05), and in oral contraceptive use in the year preceding onset (OR 2.00; 95% CI 0.18 to 22.06). Stressful life events (OR 2.56; 95% CI 1.18 to 5.52) in the year preceding onset was significantly associated with increased risk for ASD. This positive association should be treated with caution unless confirmed by a separate study.

CONCLUSION

This exploratory study of risk factors for ASD draws attention to stress as a potentially important risk factor, while likely excluding a considerable number of others.

Autosplenectomy in systemic lupus erythematosus

Autosplenectomy in systemic lupus erythematosus (SLE) is associated with a high mortality rate due to Streptococcus pneumoniae sepsis. We describe 2 patients who developed autosplenectomy in the setting of an acute SLE exacerbation. Followup of both patients 12 and 5.5 years after the initial diagnosis of autosplenectomy revealed persistent absence of the spleen. Pneumococcal vaccine was given to both patients. In contrast with reports describing life threatening infections in 46.7% of asplenic patients with SLE, none developed during prolonged followup of our patients. Our data and review of 13 other patients with SLE with autosplenectomy suggest that the 23-valent pneumococcal vaccine should be given promptly to patients with SLE when a diagnosis of autosplenectomy is established.

CD4-reactive antibodies in systemic lupus erythematosus

An important place in the immune network is reserved for specific interactions between regulatory antibodies (Ab) and their ligands on T and B lymphocytes. Several lines of evidence indicate that the CD4 glycoprotein may be recognized by such Ab. High levels of CD4-reactive Ab occur in approximately 10-20% of HIV-infected patients. Moreover, between 20 and 30% SLE patients have Ab preferentially reactive with the CD4+ T cells. In relation to this, we have done studies aimed at demonstrating the existence and characteristics of Ab directly targeting CD4 in patients with SLE in comparison with rheumatoid arthritis and normal controls. Assessment of the CD4-reactive Ab by different approaches revealed a several-fold increase in serum concentration of anti-CD4 Ab restricted to a subset of SLE patients (n = 15/87, 17.2%). Enhanced binding was shown to occur specifically both on native CD4 (by immunofluorescence) and on recombinant CD4 (by ELISA and Western blot). Anti-CD4 Ab belonged to IgM and/or IgG isotypes. The overall binding of immunoglobulins to the CD4 molecule was not significantly contributed by DNA/anti-DNA and other circulating immune complexes, and there was no restriction in the usage of kappa and lambda light chains. Clinically, high CD4 reactivity occurred in SLE patients with active disease, as measured by the SLEDAI, and was associated with particular clinical manifestations, including neuropsychiatric disease and lymphopenia.

Distinctive features of idiopathic inflammatory myopathies in French Canadians

This is the first report on idiopathic inflammatory myopathies (IIM) in French Canadians. We reviewed retrospectively 30 French Canadian adults (20 women and 10 men) with IIM seen consecutively over 12 years. The median age at diagnosis was 45 years. The IIM were 8 (27%) primary polymyositis (PM), 9 (30%) primary dermatomyositis (DM), 5 (17%) IIM with neoplasia (lymphoma, breast, esophageal, colonic, and skin cancer) and 8 (27%) IIM with a connective tissue disease (4 with systemic sclerosis, 2 with mixed connective tissue disease, and 2 with rheumatoid arthritis). The most common presenting symptom was proximal muscle weakness (n = 10,33%). Of the remaining 20 patients, 6 (20%) had the onset of their weakness within 1 month of the presenting symptom. Only 3 (10%) patients did not have proximal muscle weakness. Twenty-six (87%) patients had weakness in the pelvic girdle, 25 (83%) in the shoulder girdle, and 7 (23%) in the neck muscles. Other common symptoms included dyspnea on exertion and dysphagia, each present in 13 (43%) patients. Gottron's papules and the heliotrope rash were the most common skin lesions documented in 11 (37%) and 10 (33%) patients, respectively. The serum creatine kinase (CK) level was between 171 and 1,000 U/L in 13 (43%) patients and between 1,001 and 6,000 U/L in 13 (43%) patients. Antinuclear antibodies (ANA) on HEp-2 cells were positive in 16 (53%) patients, of which 2 (13%) expressed autoantibodies to nuclear pore complexes. Autoantibody specificities were anti-La (n = 4, 13%), anti-U1RNP (n = 3, 10%), and anti-Ro (n = 2, 7%). None of the patients expressed anti-Jo-1, anti-topoisomerase I, or anticentromere antibodies. Twenty-eight (93%) patients received corticosteroid therapy, and 8 (27%) patients responded to prednisone alone. Thirteen (43%) patients were treated with methotrexate, and 9 (69%) responded. The mean follow-up was 62 months: 23 (77%) had their disease controlled, 3 (10%) patients were lost to follow-up, and 4 (13%) died (no death occurred because of IIM or its treatment). Therapy was discontinued because of remission in 5 (17%) patients. Cumulative survival rates at 2, 5, and 10 years were 89%, 89%, and 85%, respectively. The presence of autoantibodies to nuclear pore complexes and anti-La autoantibodies, the rare occurrence of anti-Jo-1 autoantibodies, the response to conventional therapies, and a high survival rate may distinguish IIM in French Canadians from that of other reported series.

Focal myositis presenting as pseudothrombophlebitis of the neck in a patient with mixed connective tissue disease

This report describes a case of focal myositis in a patient with mixed connective tissue disease. The patient presented with diffuse neck swelling and pseudothrombophlebitis of the left internal jugular vein. Other clinical features included a high fever, elevated erythrocyte sedimentation rate, and prompt improvement after administration of high-dose intravenous corticosteroid therapy. Criteria for polymyositis were absent, serum levels of creatine kinase remained normal, and there was no sign of recurrence during 3 years of followup. Results of immunoprecipitation for anti-Jo-1 and other myositis-specific autoantibodies remained negative in serial serum samples obtained before, during, and after the episode.

A novel anti-microfilament antibody, anti-135 kD, is associated with Raynaud's disease, undifferentiated connective tissue disease and systemic autoimmune diseases

We report herein the characterization of a human IgG antibody reactive with a nonmuscle 135 kD microfilament-associated protein, anti-135 kD. Using nonmuscle epithelial PtK2 cells as substrate in indirect immunofluorescence, we identified a distinctive pattern of reactivity with microfilaments in sera from 12 of 165 (7.3%) patients investigated for systemic autoimmune diseases and in only 2 of 171 (1.2%) normal and rheumatic disease controls (P < 0.006, 95% Cl 1.46 to 30.1). An association between anti-135 kD and Raynaud's phenomenon (n = 12/14, 85.7%) with or without an associated systemic autoimmune disease was noted. The anti-135 kD specificity was established by several criteria. (1) The fluorescence was periodically distributed along microfilaments and concentrated at focal adhesions for all sera (n = 14). (2) On immunoblots, the 14 sera reacted with a PtK2 polypeptide of 135 kD. (3) IgG purified by blot-affinity from the 135 kD band (alpha-135) reproduced the fluorescent pattern of the original sera while IgG purified from other bands did not. (4) Double immunofluorescence with alpha-135 and anti-alpha-actinin mAb indicated absence of antibody fluorescence at ruffling membranes where a-actinin was distributed. (5) IgG subclass analysis of anti-135 kD revealed that 12 (85.7%) sera are of IgG3 isotype and 2 (14.3%) are of IgG1 isotype while the light chain expression was kappa restricted. This is the first report of an antibody to a 135 kD microfilament protein. Anti-135 kD expand the repertoire of anti-microfilament and anticytoskeletal antibodies in human sera.

Localization of the Ran-GTP binding protein RanBP2 at the cytoplasmic side of the nuclear pore complex

A partial cDNA clone coding for the mouse homologue of the human Ran-GTP binding protein, RanBP2, has been isolated by screening of a murine expression library with antibodies to nup180, a previously identified nuclear pore complex protein (nucleoporin). Whether the antibodies cross-reacted with the polypeptide encoded by the cDNA clone or, alternatively, nup180 is proteolytically related to RanBP2, has not been determined. The 3795-bp open reading frame of the cDNA encodes a polypeptide consisting of 1265 amino acids with three Ran-GTP binding domains (RanBD) that are almost identical with published partial amino acid sequences of human RanBP2 as deduced from several partial cDNA clones of other authors. Sequence analysis further revealed that murine RanBP2 contains tandemly repeated zinc fingers of Cys2-Cys2 type and multiple copies of the FXFG nucleoporin "signature" motif clustered in regions preceding the RanBDs. Antibodies raised against a synthetic peptide of the derived amino acid sequence decorated the cytoplasmic rings of nuclear pore complexes (NPCs) as shown by immunogold electron microscopy. We suggest that the cytoplasmically disposed nucleoporin RanBP2 provides docking sites for import substrate-receptor complexes and, further, that the affinity of these sites to the transport substrate is modulated in a Ran-dependent fashion.

Characterization of a novel human antibody xenoreactive with fibronectin

Recent reports have used bovine fibronectin (Fn) as source of antigen to study human anti-Fn autoantibodies. We have characterized a novel human antibody (Ab) reactive with bovine and marsupial Fn, but not with human Fn. Indirect immunofluorescence, wet cleaving and protein adherence assays, immunoblotting, blot-affinity purification, a cell adhesion inhibition assay, and competitive experiments with synthetic peptides were used to characterize the anti-Fn Ab in serum from a patient with an undifferentiated connective tissue disease. A characteristic Fn-like network was observed by indirect immunofluorescence on bovine MDBK and marsupial PtK2 cells, but not on various human cell lines. Double immunofluorescence revealed colocalization of the Ab with a mouse monoclonal anti-Fn Ab. A reactive polypeptide of 240 kDa corresponding to the M(r) of Fn was identified by immunoblotting using MDBK and PtK2 total cell lysates. The Ab reacted with the 240-kDa band of purified bovine Fn with an endpoint titer of 1:64,000, while no reactivity was observed with human cellular or plasma Fn. Blot-affinity purification of the Ab from the 240-kDa PtK2 region confirmed that the Fn-like fluorescent pattern observed was due to reactivity with the 240-kDa band and not with other regions of the blot. The Ab affinity-purified from the 240-kDa region also reacted with purified bovine Fn by immunoblotting. Functional analysis disclosed specific inhibition of PtK2 and MDBK cell adhesion by the affinity-purified anti-Fn Ab. Competitive experiments with synthetic peptides demonstrated that the epitope is located in the decapeptide RGDSPASSKP containing the cell-binding domain of Fn. Longitudinal analysis of the Ab revealed its persistence over 6 years. Bovine and marsupial Fn can be the focus of a highly specific and persistent human immune response. Reactivity of a human Ab with bovine Fn does not imply cross-reactivity with human Fn. In light of recent reports using bovine Fn to characterize human anti-Fn "autoantibodies," future studies on human anti-Fn should specifically employ purified human Fn as antigen.

Onset of rheumatoid arthritis after surgical treatment of Cushing's disease

We describe a patient with Cushing's disease who, shortly after trans-sphenoidal surgical resection of an adrenocorticotropic hormone secreting pituitary microadenoma and specifically at the time of normalization of her serum cortisol level, developed a subacute episode of symmetric polyarticular synovitis. This episode lasted for one month; however, it did not resolve completely and progressed after 3.5 years of diffuse arthralgias and morning stiffness to seropositive and erosive rheumatoid arthritis (RA). Review of the literature revealed 3 additional patients with RA with a similar course. These patients may represent a natural illustration of the antiinflammatory effects of supraphysiological levels of endogenous glucocorticoids.

Antibodies to fibrin bound tissue type plasminogen activator in systemic sclerosis

OBJECTIVE

Abnormalities of tissue type plasminogen activator (tPA) and plasminogen activator inhibitor have been described in some patients with systemic sclerosis (SSc). We studied 128 unselected SSc sera for the presence of autoantibodies to fibrin bound tPA.

METHODS

A solid phase fibrin-tPA immunoassay utilized 500 IU/ml tPA bound to solid phase fibrin. Sera diluted 1/50 were incubated with the fibrin bound tPA, the plates were washed, and bound immunoglobulins were detected using polyvalent peroxidase labelled goat antihuman immunoglobulins. Controls included plates coated with fibrin alone or tPA passively adsorbed to the plastic. Sera were considered positive when the A490/630 was above the mean + 2 SD (> 0.055) obtained with normal human serum in 2 independent tests.

RESULTS

25/128 (20%) SSc sera demonstrated antibody reactivity with fibrin bound tPA (mean A490/630 = 0.112). Detailed clinical data were available on 117/128 patients with SSc and on 21/25 anti-tPA positive patients. The mean age of the anti-tPA positive group was 51 yrs and of the anti-tPA negative group 49.6 yrs. Within the anti-tPA positive group there was a significantly higher proportion (p > 0.05) of patients with the CREST (calcinosis, Raynaud's esophageal dysmotility, sclerodactyly, telangiectasias) variant of SSc (7/25 = 28% vs 11/103 = 11%) and pulmonary hypertension (5/21 = 24% vs 6/96 = 6%).

CONCLUSION

Our study demonstrates that 20% of unselected patients with SSc have anti-tPA antibodies and that there is a higher representation of patients with CREST syndrome in this subgroup. The high frequency of pulmonary hypertension in the anti-tPA positive group suggests that these autoantibodies may play a pathogenic role in certain patients with SSc.

Hypergammaglobulinemic purpura in systemic autoimmune rheumatic diseases: predictive value of anti-Ro(SSA) and anti-La(SSB) antibodies and treatment with indomethacin and hydroxychloroquine

OBJECTIVE

To define the clinical manifestations, autoantibody associations, optimal treatment, and prognosis of hypergammaglobulinemic purpura associated with systemic autoimmune rheumatic diseases.

METHODS

Of 303 consecutive patients with systemic autoimmune rheumatic diseases evaluated over 5 years, 17 French Canadian patients with hypergammaglobulinemic purpura with systemic lupus erythematosus (SLE) (n = 12) or another systemic autoimmune rheumatic disease (n = 5) were identified and followed prospectively. Mild secondary Sjörgren's syndrome developed in 9 (53%) patients.

RESULTS

Sixteen (94.1%) patients were women. Attacks of hypergammaglobulinemic purpura occurred in the pretibial (76.5%) or perimalleolar (70.5%) areas or the dorsal aspect of the feet (52.9%). Triggering factors included walking, prolonged standing, and alcohol intake. The mean duration of attacks was 6.1 days. Systemic manifestations consistent with a flare of the underlying systemic autoimmune rheumatic diseases accompanied hypergammaglobulinemic purpura attacks in 15 (88%) patients. Arthralgias (n = 13, 86.6%), arthritis (n = 9, 69.2%), and periarthritis were characterstically localized adjacent to the purpura. Anti-Ro antibodies were expressed in all (100%) patients with hypergammaglobulinemic purpura with SLE, but in only 11 (28.9%) of 38 consecutive patients with SLE without hypergammaglobulinemic purpura (P < 0.000001, odds ratio 84, 95% confidence interval 4.6, 1525). The positive predictive values for hypergammaglobulinemic purpura in SLE were: anti-Ro plus anti-La 73%, anti-La 57%, and anti-Ro 52%. The negative predictive value of anti-Ro was 100%. Although 11 (92%) patients with SLE with anti-Ro expressed anti-52 kDa Ro [4 (36.3%) of whom also expressed anti-60 kDa Ro], this frequency was not greater than in anti-Ro positive patients with SLE without hypergammaglobulinemic purpura. The effects of indomethacin or hydroxychloroquine were assessed over 6 months in 8 patients with recurrent incapacitating hypergammaglobulinemic purpura. Complete (n = 4) or partial (n = 4) remission of hypergammaglobulinemic purpura occurred. In 5 additional patients with severe hypergammaglobulinemic purpura, attacks stopped with prednisone 25 to 60 mg daily. The mean duration of hypergammaglobulinemic purpura followup was 5.4 years (range 1-6 years). At last followup, hypergammaglobulinemic purpura had resolved in 11 (64.7%) patients despite persistently abnormal serology.

CONCLUSION

In the absence of anti-Ro antibodies, a presumptive diagnosis of hypergammaglobulinemic purpura secondary to SLE should be questioned. Prednisone should be used only in severe hypergammaglobulinemic purpura. Indomethacin and hydroxychloroquine are of value in the treatment of milder hypergammaglobulinemic purpura.

A controlled study of the long-term prognosis of adult Still's disease

PURPOSE

To assess the long-term prognosis of patients with adult Still's disease for physical and psychological disability, pain, social functioning, social support, medication use, formal education, occupation, time lost from work, and family income, and to contrast these results with those of same-sex sibling controls.

PATIENTS AND METHODS

Patients were recruited from medical center-based cohorts in Pittsburgh and Eastern Canada and from a national survey of rheumatologists. Patients and same-sex sibling controls completed the Health Assessment Questionnaire for physical disability, the psychological and social function domains of the Arthritis Impact Measurement Scales, and the Interpersonal Skills Evaluation List questionnaire for social support, and replied to questions on medication use, formal education, occupation, time lost from work, and family income.

RESULTS

One hundred four of 111 eligible adult Still's patients (94%) provided data. They identified 86 same-sex sibling controls, of whom 60 (70%) participated. The mean duration of adult Still's disease was 10 years. Approximately half of patients continued to require medication even 10 years after diagnosis. Patients had significantly higher levels of pain, physical disability, and psychological disability when compared with the controls. However, the levels of pain and physical disability were low compared to patients with other rheumatic diseases. Educational achievement, occupational prestige, social functioning and support, time lost from work, and family income were similar for both patients and controls.

CONCLUSIONS

Despite causing disability, pain, and, in many, the need for long-term medication, patients with adult Still's disease are resilient. The disease did not interfere with educational attainment, occupational prestige, social functioning and support, time lost from work, or family income.

Anti-microfilament IgG antibodies in normal adults and in patients with autoimmune diseases: immunofluorescence and immunoblotting analysis of 201 subjects reveals polyreactivity with microfilament-associated proteins

We have investigated IgG antibodies to microfilament-associated proteins in sera from 29 normal controls and from 172 patients with autoimmune diseases such as rheumatoid arthritis (n = 45), systemic lupus erythematosus (n = 43), polymyositis/dermatomyositis (n = 36), systemic sclerosis (n = 35), and autoimmune chronic active hepatitis (CAH, n = 13). We observed, by indirect immunofluorescence, a staining pattern in which the fluorescence was continuously distributed along microfilaments by using several animal and human cell lines as substrate. Because no reactivity with individual bands or specific combinations of bands was observed by immunoblotting using different cell lines, we further characterized our sera by immunoblotting using a panel of the purified microfilament-associated proteins filamin, myosin, alpha-actinin, actin, tropomyosin, and myosin light chain. Results shows that normal as well as autoimmune sera are polyreactive with microfilament proteins. The specificity of reactivity against a particular microfilament-associated protein was demonstrated by inhibition experiments with the specific protein. No correlation was observed between immunoblot and immunofluorescence results. Of the 201 sera, 40 (20%), 42 (21%), 31 (15%), 26 (13%), 34 (17%), 24 (12%), 4 (2%), and 0 (0%) reacted, respectively, by immunoblotting with 0, 1, 2, 3, 4, 5, 6, or 7 of the microfilament-associated proteins. Furthermore, 57 different profiles of reactivity with the panel proteins were observed. All autoimmune CAH sera reacted with at least 3 proteins. This result was strikingly unique to this group. Anti-actin antibodies were as common in normal as in CAH sera. Anti-alpha-actinin antibodies were strikingly more frequent in CAH than in any group. We conclude that a remarkable diversity of anti-microfilament antibodies is present in normal as well as in autoimmune sera and that a continuous microfilament fluorescent pattern is not restricted simply to anti-actin antibodies. Furthermore, sera negative by immunofluorescence react with several miocrofilament-associated proteins by immunoblotting. Reactivity with multiple (> or = 3) microfilament-associated proteins including alpha-actinin distinguishes CAH sera from normal and other autoimmune sera.

Characterization of a novel human IgG antibody reactive with a Ca(2+)-sensitive cell-cell adhesion epitope of PtK2 epithelial cells

We have characterized a human IgG antibody present in the serum of a patient with an autoimmune undifferentiated connective tissue disease and reactive with PtK2 epithelial cell-cell adhesions. The fluorescent staining pattern is observed only at cell-cell contacts whether cells are permeabilized or not. The serum reacts with polypeptides of 90, 48 and 45 kD by immunoblotting. IgG affinity-purified from these bands failed to reproduce the original immunofluorescence staining pattern. Treatment with cycloheximide did not abolish the staining pattern suggesting that the recognized antigen is not a newly expressed protein. However, when EGTA was used for chelating calcium ions in the culture medium the original staining pattern observed at cell-cell adhesions was affected although some fluorescence was still present at cell periphery. This was reversible when cells were reincubated with fresh medium containing Ca2+. The recognized antigen colocalizes at cell-cell adhesions with actin, the microfilament-associated proteins vinculin, alpha-actinin and myosin light chain, and with Triton-insoluble uvomorulin (E-cadherin) material. We conclude that the antibody reacts with, at least, an extracellular portion of a Ca(2+)-dependent PtK2 antigen. The characterization of this antibody based on (1) its localization at cell-cell adhesions, (2) its sensitivity to EGTA-treatment and (3) its colocalization with the epithelial cellular adhesion molecule (CAM) uvomorulin, strongly suggest that the recognized Ag is a CAM or a CAM-associated protein.

Anticentromere autoantibodies. Evaluation of an ELISA using recombinant fusion protein CENP-B as antigen

OBJECTIVE

To evaluate an enzyme-linked immunosorbent assay (ELISA) for anticentromere autoantibodies (ACA).

METHODS

Sera from 611 patients with scleroderma, CREST (calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, telangiectasias), Raynaud's disease, and connective tissue disease control patients were studied by ELISA using the fusion protein CENP-B, by immunofluorescence on dividing HEp-2 cells, and by immunoblotting on chromosomes and CENP-B.

RESULTS

Compared with immunofluorescence, the CENP-B ELISA sensitivity was 94% and the specificity was 93%. In 19.7% of the cases, there was a probability of a false-positive result and in 1.9%, a probability of a false-negative result, yielding positive and negative predictive values of 0.80 and 0.98, respectively.

CONCLUSION

The CENP-B ELISA is a sensitive and specific assay for ACA.

Nup180, a novel nuclear pore complex protein localizing to the cytoplasmic ring and associated fibrils

Using an autoimmune serum from a patient with overlap connective tissue disease we have identified by biochemical and immunocytochemical approaches an evolutionarily conserved nuclear pore complex (NPC) protein with an estimated molecular mass of 180 kD and an isoelectric point of approximately 6.2 which we have designated as nup180. Extraction of isolated nuclear envelopes with 2 M urea and chromatography of the solubilized proteins on WGA-Sepharose demonstrated that nup180 is a peripheral membrane protein and does not react with WGA. Affinity-purified antibodies yielded a punctate immunofluorescent pattern of the nuclear surface of mammalian cells and stained brightly the nuclear envelope of cryosectioned Xenopus oocytes. Nuclei reconstituted in vitro in Xenopus egg extract were also stained in the characteristic punctate fashion. Immunogold EM localized nup180 exclusively to the cytoplasmic ring of NPCs and short fibers emanating therefrom into the cytoplasm. Antibodies to nup180 did not inhibit nuclear protein transport in vivo nor in vitro. Despite the apparent lack of involvement in NPC assembly or nucleocytoplasmic transport processes, the conservation of nup180 across species and its exclusive association with the NPC cytoplasmic ring suggests an important, though currently undefined function for this novel NPC protein.

Lambda light chain deposition disease presenting as an amyloid-like arthropathy

We describe a case of lambda light chain deposition disease (LCDD) which presented with symmetric, seronegative, nonerosive arthritis associated with skin nodules and widespread, progressive soft tissue induration. Multiple biopsies disclosed Congo red nonbirefringent deposits which stained strongly with lambda light chain antiserum, allowing distinction from amyloid arthropathy. This is the first report of musculoskeletal involvement in LCDD.