OP0162 EFFICACY AND SAFETY OF LENABASUM IN THE PHASE 3 DETERMINE TRIAL IN DERMATOMYOSITIS

Background

Safe and effective treatments are of significant unmet need in DM. Lenabasum, a CB2 agonist that activates resolution of inflammation, improved skin disease, patient-reported outcomes, and biomarkers in a Phase 2 study of DM patients with active skin disease.

Objectives

To evaluate the efficacy and safety of lenabasum in a Phase 3 double-blind study in DM.

Methods

DM patients ≥ 18 years old with active skin with or without muscle involvement were enrolled in 55 sites in North America, Europe, and Asia-Pacific. Stable doses of background immunosuppressants were allowed. Subjects were randomized 2:1:2 to lenabasum 20 mg BID, lenabasum 5 mg BID, or placebo BID for 52 weeks, with visits ≤ 8 weeks apart. The study was stopped after all subjects completed Week 28. Some subjects had completed Week 52 by then. The primary efficacy endpoint was Total Improvement Score (TIS) at Week 28 and a secondary efficacy endpoint was TIS at Week 52, for lenabasum 20 mg BID vs placebo.

Results

175 subjects (69 lenabasum 20 mg BID, 35 lenabasum 5 mg BID, 71 placebo BID) received study drug; 167 completed Week 28, and 103 completed Week 52. The most common reasons for study discontinuation were study stopped by Sponsor (34.3%), withdrawal of consent (4.5%), and adverse events (AEs, 3.9%), with similar rates among groups. Baseline demographics and disease measurements were similar among groups and in total subjects were (mean or %): age 52.0 years; 81.1% female, 75.4% White; MMT-8 133.3; CDASI activity score 23.4; HAQ-DI 0.84, MDGA 5.55, EMGA 5.23; and PtGA 5.12. Corticosteroids were used by 48.1% and 38.0%, immunoglobulins by 5.8% and 7.0%, and other immunosuppressives by 51.0% and 54.9%, and monoclonal antibodies by 8.7% and 7.0% of lenabasum and placebo groups at baseline, respectively. The primary efficacy endpoint was not met - mean (SD) TIS score was 28.3 (19.75) vs 27.2 (19.23) at Week 28 for lenabasum 20 mg BID vs placebo, p = 0.3311, MMRM. Week 52 values were 40.6 (16.88) vs 34.8 (19.94), p = 0.2290. When analyses were restricted to subjects with muscle weakness at baseline (MMT8 < 142), TIS scores and treatment differences were greater and reached nominal statistical significance at Week 40, p = 0.0172. Mean (SD) improvements in CDASI activity score were numerically greater but not statistically different between lenabasum 20 mg BID group vs placebo at Week 28 [-7.1 (7.76) vs -5.8 (8.88) points, p = 0.2775] and Week 52 [-10.0 (9.45) vs -6.2 (12.8) points, p = 0.0932]. When restricting analysis of participants without muscle weakness (MMT-8 = 150), improvement in CDASI activity score was greater in the lenabasum 20 mg BID group vs placebo at Week 28, p = 0.0461, and Week 52 p = 0.0059.

Treatment-emergent AEs (TEAEs) occurred in 87.0%, 85.7%, and 87.3% of lenabasum 20 mg BID, lenabasum 5 mg BID, and placebo groups, with no deaths. Related TEAEs leading to withdrawal of study product were infrequent, occurring in 1.4%, 0%, and 2.0% of subjects in the same groups. Serious TEAEs occurred in 11.6%, 8.6%, and 4.2% of subjects in the lenabasum 20 mg BID, lenabasum 5 mg BID, and placebo groups. No serious TEAE preferred term occurred in more than 1 subject in any group. TEAE occurring in ≥ 10% of lenabasum 20 mg BID subjects were (% lenabasum vs % placebo): dermatomyositis (flare) 27.5% vs 40.8%; diarrhea 14.5% vs 8.5%; dizziness 13.0% vs 4.2%; nausea 11.6% vs 4.2%; headache 10.1% vs 14.1%; and arthralgia 10.1% vs 2.8%.

Conclusion

Although, primary or secondary endpoints were not met in the study, subgroup analysis of patients with muscle weakness and without muscle weakness, showed improvement in muscle strength and rash, respectively in lenabasum 20 mg BID group vs placebo. Lenabasum was administered safely and was well-tolerated in this study.

Disclosure of Interests

Victoria Werth Speakers bureau: University of Pennsylvania, who own the copyright for the CLASI and SDASI, Consultant of: AbbVie, Amgen, Argenx, AstraZeneca, Biogen, BMS, Celgene, Chrysalis, CSL Behring, Cugene, Eli Lilly, EMD Serono, Genentech, GSK, Incyte, Idera, Janssen, Kirin, Medimmune, Medscape, Nektar, Octapharma, Pfizer, Principa, Regeneron, Resolve, and Viela Bio, Grant/research support from: AstraZeneca, Biogen, Celgene, Corbus Pharmaceuticals, Genentech, Gilead, Janssen, Pfizer, Syntimmune, and Viela Bio, Barbara White Shareholder of: Corbus Pharmaceuticals, Employee of: Previous employee of Corbus Pharmaceuticals, Nancy Dgetluck Shareholder of: Corbus Pharmaceuticals, Employee of: Corbus Pharmaceuticals, Kathleen Hally Shareholder of: Corbus Pharmaceuticals, Employee of: Corbus Pharmaceuticals, Scott Constantine Shareholder of: Corbus Pharmaceuticals, Employee of: Corbus Pharmaceuticals, Rohit Aggarwal Consultant of: For Abbvie, Q32, Alexion, AstraZeneca, BMS, Boehringer Ingelheim, Corbus, Csl Behring, EMD Serono, Galapagos, Janssen, Kezar, Jubliant, Kyverna, Mallinckrodt, Merck, Novartis, Octapharma, Pfizer, Octazyme, Roivant, Scipher., Grant/research support from: BMS, Mallinkrodt, EMD Serono, Q32, Pfizer, David Fiorentino Consultant of: Corbus Pharmaceuticals, Grant/research support from: Corbus Pharmaceuticals, Ingrid E. Lundberg Shareholder of: Roche and Novartis., Consultant of: Corbus Pharmaceuticals Inc, Astra Zeneca, Bristol Myer´s Squibb, Corbus Pharmaceutical, EMD Serono Research & Development Institute, Argenx, Octapharma, Kezaar, Orphazyme, and Janssen, Grant/research support from: Astra Zeneca, Chester V Oddis Consultant of: Corbus Pharmaceuticals

OP0008 A RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED PHASE III TRIAL OF IVIG 10% IN PATIENTS WITH DERMATOMYOSITIS. THE PRODERM STUDY: RESULTS ON EFFICACY AND SAFETY

Background:

Dermatomyositis (DM) is a rare chronic systemic autoimmune disease with characteristic skin rash and progressive proximal muscle weakness. Current therapies encompass corticosteroids and other immunosuppressants and intravenous immunoglobulins (IVIg), however, none of these therapies are proven by randomized controlled phase 3 studies. There have been no large randomized clinical trials supporting the efficacy and safety of IVIg in DM.

Objectives:

The ProDERM study aimed to evaluate the efficacy and safety/tolerability of IVIg in DM patients in a double-blind, randomized, placebo-controlled, international multi-center, phase III clinical trial.

Methods:

The trial consisted of a double-blind, placebo-controlled First Period (16 weeks), in which adult patients with definite or probable DM (according to Bohan and Peter criteria) were randomized 1:1 to either high dose IVIg (2g/kg every 4 weeks) or placebo. Patients on placebo and patients without clinical worsening while on IVIg treatment entered the open label Extension Period (24 weeks) and received 2g/kg IVIg infusions every 4 weeks. To be included, subjects must have active disease with a manual muscle testing-8 (MMT-8) score < 142/150. Patients who showed clinical worsening (defined according to Oddis et al, 2013 - with slight adaptation) at 2 consecutive visits between week 8 and week 16 were switched to the alternate treatment arm.

Primary endpoint was the proportion of responders in the IVIg vs. placebo arm at week 16, where response was defined per 2016 ACR/EULAR Myositis response criteria of at least minimal improvement [Total Improvement Score (TIS) ≥ 20 points)] and without clinical worsening at 2 consecutive visits up to week 16.

Results:

A total of 95 adult DM patients (mean age: 53 years; 75% females; 92% Caucasian) were enrolled, with 47 and 48 randomized to IVIg and placebo, respectively. Baseline clinical characteristics (including medical history and prior DM medication) were balanced between the 2 arms.

The study met the primary endpoint at week 16, with the proportion of responders being significantly higher in the IVIg group (37/47; 78.7%) as compared to the placebo group (21/48; 43.8%; p-value 0.0008; Table 1).

Table 1.

Total Improvement Score – Analysis of Proportion of Responders at Week 16 (Full Analysis Set, N=95)

TIS Responseoctagam 10%N=47PlaceboN=48Difference octagam 10% – placeboNumber (%) of responders37 (78.72%)21 (43.75%)Difference in response rates34.97[95% CI] p-valuea[16.70, 53.24] 0.0008

aCochran-Mantel-Haenszel TestCI=confidence interval; N=number of patients; TIS=total improvement score

In the analysis of responders per improvement category at Week 16, a 45.2% higher response rate for at least moderate improvement (TIS ≥n40 points; p < 0.0001) and a 23.6% higher response rate for at least major improvement (TIS ≥060 points; p < 0.0062) was observed in the IVIG group as compared to the placebo group.

The mean (SD) TIS was significantly higher in IVIg group [48.4 (24.4)] than in placebo arm [21.6 (20.2)] at week 16 (Fig 1).

Figure 1.

After switching to IVIG in the Extension Period the placebo group attained a similar response rate at Week 40 as did the IVIg treated patients at Week 16, i.e approx. 70% for minimal improvement.

In line with the overall primary endpoint, secondary end points including all of the sub-components of TIS except muscle enzyme (MMT-8, MD global, Extramuscular global, patient global, HAQ,) as well as CDASI (Cutaneous Dermatomyositis Disease Area and Severity Index), also showed statistically significant improvement under IVIg treatment compared to placebo treatment.

The safety and tolerability profile of IVIg was consistent with previously reported safety outcomes for IVIg administration.

Conclusion:

This is the first large international phase III randomized, placebo-controlled trial demonstrating the efficacy and safety of IVIg as a treatment for patients with DM.

References:

[1]Oddis, C. V. et al. Arthritis Rheum (2013), 65, 314–324

Acknowledgements:

Acknowledgments to all participating investigators, centers and patients and their families

Disclosure of Interests:

Rohit Aggarwal Consultant of: Q32, Alexion, Argenx, AstraZeneca, BMS, Boehringer Ingelheim, Corbus, Csl Behring, EMD Serono, Janssen, Kezar, Mallinckrodt, Kyverna, Octapharma, Orphazyme, Pfizer., Grant/research support from: BMS, Mallinckrodt, Pfizer, EMD Serono, Christina Charles-Schoeman Consultant of: Pfizer, Abbvie, Octapharma, Gilead, Regeneron-Sanofi, Grant/research support from: Bristol Myers Squibb, Pfizer, Abbvie, Octapharma, Joachim Schessl Speakers bureau: Octapharma, Grifols, CSL Behring, Consultant of: Octapharma, Zsuzsanna Bata-Csorgo Speakers bureau: Novartis, Sanofi-Genzyme, Ewopharma, Consultant of: Sanofi-Genzyme, Novartis, Ewopharma, Mazen Dimachkie Consultant of: ArgenX, Catalyst, Cello, CSL-Behring, EcoR1, Kezar, Momenta, NuFactor, Octapharma, RaPharma/UCB, RMS Medical, Sanofi Genzyme, Shire Takeda, Spark Therapeutics and UCB Biopharma., Grant/research support from: Alexion, Alnylam Pharmaceuticals, Amicus, Biomarin, Bristol-Myers Squibb, Catalyst, Corbus, CSL-Behring, GlaxoSmithKline, Genentech, Grifols, Kezar, Mitsubishi Tanabe Pharma, Novartis, Octapharma, Orphazyme, Ra Pharma/UCB, Sanofi Genzyme, Sarepta Therapeutics, Shire Takeda, Spark Therapeutics, UCB Biopharma, Viromed/Healixmith., Zoltán Griger Speakers bureau: Abbvie, CSL-Behring, Eli-Lilly, Roche, Boehringer Ingelheim, Consultant of: Octapharma, Sergey Moiseev: None declared, Chester V Oddis Consultant of: EMD Serono; Alexion Pharmaceuticals, Inc, Grant/research support from: Genentech (Clinical trial support); Bristol Myers Squibb (Clinical trial support), Elena Schiopu Consultant of: Octapharma, Grant/research support from: Octapharma, Janssen (Johnson & Johnson), BMS, Pfizer, Abbvie, Jirˇí Vencovský Speakers bureau: Abbvie, Biogen, MSD, Pfizer, Roche, Sanofi, UCB, Consultant of: Abbvie, Boehringer, Eli Lilly, Octapharma, Gilead, Irene Beckmann Employee of: Octapharma, Todd Levine Shareholder of: Corinthian Reference Labs, CND Life Sciences, Consultant of: Grifols, Octapharma, Alexion, Elisabeth Clodi Employee of: Octapharma PPG, Vienna Austria, and the ProDERM Investigators: None declared

Anti-hydroxy-3-methylglutaryl-coenzyme A reductase (anti-HMGCR) antibody in necrotizing myopathy: treatment outcomes, cancer risk, and role of autoantibody level

Objective: To evaluate clinical associations of anti-hydroxy-3-methylglutaryl-coenzyme A reductase (anti-HMGCR) antibody (Ab) and statin exposure in necrotizing myopathy (NM) patients. Methods: NM without a known myositis-specific autoantibody (MSA) was ascertained from a large single-centre myositis database between 1985 and 2012. A comparison NM cohort included 32 anti-SRP⁺ autoantibody patients, and other control groups included 74 non-NM myositis patients and 21 non-myositis controls. Sera from all cases and controls were tested using a validated anti-HMGCR enzyme-linked immunosorbent assay. Clinical features including statin use and anti-HMGCR Ab status were compared between cases and controls. Results: Of the 256 NM muscle biopsies reviewed, only 48 subjects with available sera were identified as traditional MSA-negative NM. Anti-HMGCR positivity was significantly (p < 0.001) associated with MSA-negative NM [48% (23/48)] compared to all of the myositis and non-myositis controls [5% (6/127)]. Most anti-HMGCR Ab-positive NM patients had high titres of anti-HMGCR (83%) and a history of statin exposure (78%), along with severe muscle weakness, high creatine kinase (CK) levels (90% ≥ 5000 IU/L), a paucity of other organ manifestations, and the need for immunosuppression with prednisone and methotrexate, but generally favourable outcomes. Anti-HMGCR serum levels were associated with baseline CK levels but not muscle weakness. Conclusion: HMGCR Ab-positive NM patients are associated with statin exposure, have severe muscle weakness and high CK at presentation, lack other organ manifestations, and generally have favourable outcomes from immunosuppression. Anti-HMGCR Abs should be assessed in MSA-negative NM patients, particularly those with a history of statin exposure.

Update on the pharmacological treatment of adult myositis

The management of patients with idiopathic inflammatory myopathy (IIM) remains a challenge given the systemic features beyond active myositis. That is, recognizing the inflammatory arthropathy, varying dermatomyositis rashes, and overt and occult features of interstitial lung disease in addition to myositis adds to the complexity of diagnosis and treatment of IIM. However, clinicians now have available many more immunosuppressive drugs as well as biologic agents for use in patients with myositis and other autoimmune diseases. Here, the use of these agents is reviewed and support based on available published literature is provided even though many studies have been small and results somewhat anecdotal. Glucocorticoids remain the initial treatment of choice in most instances and methotrexate and azathioprine are often used early in the treatment course. These agents are followed by other immunosuppressive drugs, for example mycophenolate mofetil, tacrolimus, cyclosporine and cyclophosphamide, some of which are used alone while combinations of these agents also provide an effective option. There is more rationale for the use of biologic agents such as rituximab from a mechanistic perspective and, given the incorporation of validated core set measures in assessing myositis patients, we can look forward to better designed clinical trials in the future.

Autoantibodies to a 140-kd protein in juvenile dermatomyositis are associated with calcinosis

OBJECTIVE

The identification of novel autoantibodies in juvenile dermatomyositis (DM) may have etiologic and clinical implications. The aim of this study was to describe autoantibodies to a 140-kd protein in children recruited to the Juvenile DM National Registry and Repository for UK and Ireland.

METHODS

Clinical data and sera were collected from children with juvenile myositis. Sera that recognized a 140-kd protein by immunoprecipitation were identified. The identity of the p140 autoantigen was investigated by immunoprecipitation/immunodepletion, using commercial monoclonal antibodies to NXP-2, reference anti-p140, and anti-p155/140, the other autoantibody recently described in juvenile DM. DNA samples from 100 Caucasian children with myositis were genotyped for HLA class II haplotype associations and compared with those from 864 randomly selected UK Caucasian control subjects.

RESULTS

Sera from 37 (23%) of 162 patients with juvenile myositis were positive for anti-p140 autoantibodies, which were detected exclusively in patients with juvenile DM and not in patients with juvenile DM-overlap syndrome or control subjects. No anti-p140 antibody-positive patients were positive for other recognized autoantibodies. Immunodepletion suggested that the identity of p140 was consistent with NXP-2 (the previously identified MJ autoantigen). In children with anti-p140 antibodies, the association with calcinosis was significant compared with the rest of the cohort (corrected P < 0.005, odds ratio 7.0, 95% confidence interval 3.0-16.1). The clinical features of patients with anti-p140 autoantibodies were different from those of children with anti-p155/140 autoantibodies. The presence of HLA-DRB1*08 was a possible risk factor for anti-p140 autoantibody positivity.

CONCLUSION

This study has established that anti-p140 autoantibodies represent a major autoantibody subset in juvenile DM. This specificity may identify a further immunogenetic and clinical phenotype within the juvenile myositis spectrum that includes an association with calcinosis.

The protein tyrosine phosphatase N22 gene is associated with juvenile and adult idiopathic inflammatory myopathy independent of the HLA 8.1 haplotype in British Caucasian patients

OBJECTIVE

To examine single-nucleotide polymorphisms (SNPs) of the protein tyrosine phosphatase N22 gene (PTPN22) and to study the relationship between PTPN22 and the HLA region in patients with idiopathic inflammatory myopathies (IIMs).

METHODS

PTPN22 SNPs were assessed in a large, cross-sectional, case-control study from the UK involving patients with adult or juvenile IIM, comprising patients with polymyositis (PM) (n=114), dermatomyositis (DM) (n=102), myositis associated with another connective tissue disease (myositis-CTD overlap syndrome) (n=64), or juvenile DM (n=101), in comparison with 748 control subjects. Seventeen PTPN22 SNPs were genotyped using the Sequenom MassArray iPLEX platform. Serotyping for myositis-specific/myositis-associated autoantibodies (MSAs/MAAs) was performed by radioimmunoprecipitation.

RESULTS

A significant association was noted between the R620W variant (rs2476601) and IIM (corrected P [Pcorr]=0.0009 versus controls), and specifically with the clinical subgroup of PM (Pcorr=0.003 versus controls). A weaker association was noted with juvenile DM (Pcorr=0.009 versus controls). No significant associations were noted after stratification by serologic subgroups. The association with the R620W variant was independent of alleles forming the HLA 8.1 haplotype. No other PTPN22 SNPs were associated with IIM. The PTPN22 haplotype containing the R620W T allele was the only haplotype significantly associated with IIM.

CONCLUSION

The R620W variant is a significant risk factor for IIM, independent of the HLA 8.1 haplotype. Unlike that in the HLA region, risk is not increased in individuals possessing MSAs/MAAs. These results are further evidence that the PTPN22 gene confers autoimmune susceptibility.

Tumour necrosis factor-alpha single nucleotide polymorphisms are not independent of HLA class I in UK Caucasians with adult onset idiopathic inflammatory myopathies

OBJECTIVE

To investigate haplotype tagging single nucleotide polymorphisms (SNPs) in the tumour necrosis factor alpha (TNF-alpha) gene, in UK Caucasian idiopathic inflammatory myopathy (IIM) patients.

METHODS

A cross-sectional, case-control study of four TNF-alpha SNPs was undertaken, comparing cases of polymyositis (PM) (n = 121), dermatomyositis (DM) (n = 109) and myositis overlapping with other connective tissue diseases (CTD-overlap) (n = 73) with normal subjects (n = 177). Subgroup analyses were undertaken after stratifying for myositis specific/associated antibodies.

RESULTS

The TNF-308A allele demonstrated a strong association with each myositis disease subgroup vs controls [PM, odds ratio (OR) 2.8, 95% confidence interval 1.9-4.3; DM, OR 2.5, 1.6-3.8; CTD-overlap, OR 3.3, 2.1-5.1]. The TNF-308GA/AA genotype frequency was significantly increased vs controls (PM, OR 3.7, 2.1-6.3; DM, OR 3.2, 1.8-5.5; CTD-overlap, OR 5.0, 2.6-9.6) suggesting a dominant model. The association was strongest in patients possessing anti-aminoacyl transfer RNA synthetase (anti-synthetase) (OR 5.1, 3.3-8.0) or -PM-Scl (OR 5.0, 2.7-8.9) antibodies. The -1031T allele was also a significant risk factor in DM (OR 2.2, 1.4-3.6), anti-synthetase (OR 2.9, 1.6-5.3) and -PM-Scl (OR 5.6, 1.9-6.4) antibody positive patients. The TNF-308A association was lost after adjusting for HLA-B*08, but remained independent of HLA-DQB1*02 (both are alleles forming part of the common ancestral haplotype). The HLA-B*08/TNF-308A/DRB1*03/DQA1*05/DQB1*02 haplotype was a risk factor in all myositis subgroups vs controls (OR 3.0, 1.8-5.3).

CONCLUSIONS

TNF-308A and -1031T alleles are significant risk factors in the IIMs. In the IIMs, the TNF-308A allele is part of the common ancestral haplotype, but is not independent of HLA-B*08.

Monocyte chemotactic protein-1 single nucleotide polymorphisms do not confer susceptibility for the development of adult onset polymyositis/dermatomyositis in UK Caucasians

OBJECTIVES

Polymyositis (PM) and dermatomyositis (DM) form part of the idiopathic inflammatory myopathies (IIMs). The chemokine monocyte chemotactic protein-1 (MCP-1) is expressed at sites of the T cell inflammatory response in the IIMs. We thus investigate whether genetic markers in the MCP-1 gene confer disease susceptibility for the development of PM and DM.

METHODS

DNA samples were analysed from a group of 195 UK Caucasian IIM patients, comprising 103 PM and 92 DM. Their results were compared with those of 162 ethnically matched controls. The polymorphic positions of three single nucleotide polymorphisms (SNPs) and one insertion-deletion sequence within regions coding for MCP-1 were tested. The SNPs examined were located in intron 1 (rs2857657, C/G), exon 2 (rs4586, A/G) and the 3 ' untranslated region (rs13900, C/T). The insertion-deletion sequence was located in intron 1 (rs3917887, AGCTCCTCCTTCTC/-). Each SNP was tested for Hardy-Weinberg equilibrium and allelic/genotypic associations. Haplotype frequencies were estimated using the Expectation/Maximization algorithm.

RESULTS

There was strong linkage disequilibrium present between three out of these four markers. The majority of controls were in Hardy Weinberg equilibrium. No allelic, genotypic or haplotypic associations were detected when comparing PM or DM cases to controls, or when PM and DM were compared with each other.

CONCLUSIONS

Genetic markers in the MCP-1 gene do not demonstrate significant genetic associations with the IIMs, and do not discriminate PM from DM in a UK Caucasian population.

Current approach to the treatment of polymyositis and dermatomyositis

Although corticosteroids remain the mainstay of treatment for the inflammatory myopathies, their use is complicated by many side effects. Other immunosuppressive agents, alone or in combination, are being increasingly used for patients with other severe disease or treatment-related complications. Pulmonary disease remains a serious source of morbidity and mortality in myositis patients. Cyclophosphamide, cyclosporine, and tacrolimus are efficacious in patients with interstitial lung disease. Intravenous immunoglobulin is not only effective for the cutaneous complications of dermatomyositis but has been helpful in other extramuscular manifestations.

Myositis-specific and -associated autoantibodies: a review from the clinical perspective

Twenty-five percent to 50% of patients with polymyositis (PM) and dermatomyositis (DM) have autoantibodies that are specific for or associated with the presence of myositis. Because of a relatively low sensitivity for the diagnosis of PM or DM, these autoantibodies are inadequate as a screening test for PM or DM in patients with suspected inflammatory myopathy. However, they may be used to support the diagnosis of myositis, and they help exclude the diagnosis of inclusion body myositis in which autoantibodies are infrequent. In addition, these antibodies are associated with homogeneous syndromes with the following reproducible clinical features and prognosis: (I) the antisynthetases generally occur with moderately severe myositis, often in association with interstitial lung disease. Raynaud's phenomenon, and arthropathy; (2) anti-SRP is a marker of severe PM with associated cardiac disease and high mortality; (3) anti-Mi-2 occurs in generally corticosteroid-responsive DM associated with a potentially severe rash; and (4) the myositis-associated autoantibodies anti-PM-ScI and anti-Ku portend a moderately favorable prognosis. Anti-PH-Scl occurs in systemic sclerosis, often in association with arthropathy and Raynaud's syndrome. Anti-Ku occurs in systemic sclerosis and other connective tissue diseases with or without myositis. Thus, both myositis-specific and -associated antibodies have clinical use in the diagnosis of PM and DM and are predictive of certain clinical syndromes and responses to treatment.

Sensory Neuropathy With Sjögren's Syndrome, Thymoma, and Hypogammaglobulinemia

We report a 63-year-old woman with common variable immunodeficiency (CVID) and an indolent distal sensory neuropathy. Despite having negative serologic tests for Sjögren's syndrome, evaluation of the neuropathy led to a new diagnosis of Sjögren's syndrome based on the presence of sicca symptoms, an abnormal Schirmer's test, and histologic evidence of sialadenitis. In addition, a thymoma was discovered. We conclude that the occurrence of thymoma, CVID, and Sjogren's syndrome reflect a state of systemic autoimmune dysregulation in this patient. We also reiterate the diagnostic importance of salivary gland biopsy in patients with sicca symptoms and sensory neuropathy.

Dermatomyositis with erosive arthropathy: association with the anti-PL-7 antibody

We describe a patient with dermatomyositis and inflammatory polyarthritis with erosive wrist arthropathy who was found to have the anti-PL-7 autoantibody directed against threonyl-tRNA synthetase.

Acute onset of colchicine myoneuropathy in cardiac transplant recipients: case studies of three patients

Colchicine causes both muscle and peripheral nerve toxicity of subacute onset in patients with renal insufficiency. We report three cardiac transplant recipients, treated with colchicine for cyclosporin A (CyA)-induced gout, who developed acute weakness due to colchicine myoneuropathy. The onset of disabling weakness occurred over a 1-2 week period. All three patients had concomitant renal insufficiency and an elevated serum creatine kinase and two elevated CyA levels at the time of presentation. Electromyography revealed features of myopathy and motor axonal neuropathy in all three patients. Two underwent muscle biopsy which confirmed the presence of sarcoplasmic vacuoles characteristic of colchicine-induced myopathy. All patients rapidly improved with either colchicine dose reduction or drug discontinuation. In conclusion, cardiac transplant recipients treated with CyA and colchicine may be at increased risk of developing colchicine-induced myoneuropathy especially in the setting of concurrent renal insufficiency. In patients with post-transplantation gouty arthritis, other treatment modalities are suggested; and if colchicine is administered, the dose should be reduced, CyA levels should be monitored closely and patients should be assessed for signs of neuromuscular toxicity.

Classification criteria for the idiopathic inflammatory myopathies

Inasmuch as the clinical features of the idiopathic inflammatory myopathies are not easily differentiated from those of other similar rheumatic and neurologic conditions, diagnosis is often difficult. Various classification criteria for polymyositis and dermatomyositis have been suggested by a number of investigators. The most commonly accepted and used criteria include symmetric proximal muscle weakness, serum elevations of muscle enzymes, the classic electromyographic and muscle biopsy findings of inflammatory myopathy, and the typical skin rash of dermatomyositis. Although these criteria are clinically useful, they can result in misdiagnoses and inappropriate therapies. They also result in heterogeneous patient groups being selected for clinical and laboratory studies. Furthermore, they do not include recent findings related to the myositis-specific autoantibodies and magnetic resonance imaging of muscle that have been found to be important adjuncts in assessing patients with muscle weakness or elevations of muscle enzymes. A modification to the Bohan and Peter criteria is proposed to include myositis-specific autoantibodies and magnetic resonance imaging. This proposal could initiate productive discussions and investigations of the sensitivity and specificity of new classification criteria for myositis and could ultimately enhance our treatment capabilities.

Beta-adrenergic regulation of constitutive nitric oxide synthase in cardiac myocytes

Nitric oxide (NO) has been implicated in endogenous control of myocardial contractility. However, NO release has not yet been demonstrated in cardiac myocytes. Accordingly, endogenous NO production was measured with a porphyrinic microsensor positioned on the surface of individual neonatal or adult rat ventricular myocytes (n > 6 neonatal and adult cells per experiment). In beating neonatal myocytes, there was no detectable spontaneous NO release with each contraction. However, norepinephrine (NE; 0.25-1 microM) elicited transient NO release from beating neonatal (149 +/- 11 to 767 +/- 83 nM NO) and noncontracting adult (157 +/- 13 to 791 +/- 89 nM NO) cells. NO was released by adrenergic agonists with the following rank order of potency: isoproterenol (beta1beta2) > NE (alpha/beta1) > dobutamine (beta1) approximately epinephrine (alpha/beta1beta2) > tertbutylene (beta2); NO was not released by phenylephrine (alpha). NE-evoked NO release was reversibly blocked by N(G)-monomethyl-L-arginine, trifluoperazine, guanosine 5'-O-(2-thiodiphosphate), and nifedipine but was enhanced by 3-isobutyl-1-methylxanthine (0.5 mM = 14.5 +/- 1.6%) and BAY K 8644 (10 microM = 11.9 +/- 1%). NO was also released by A-23187 (10 microM = 884 +/- 88 nM NO), guanosine 5'-O-(3-thiotriphosphate) (1 microM = 334 +/- 56 nM NO), and dibutyryl adenosine 3',5'-cyclic monophosphate (10-100 microM = 35 +/- 9 to 284 +/- 49 nM NO) but not by ATP, bradykinin, carbachol, 8-bromoguanosine 3',5'-cyclic monophosphate, or shear stress. This first functional demonstration of a constitutive NO synthase in cardiac myocytes suggests its regulation by a beta-adrenergic signaling pathway and may provide a novel mechanism for the coronary artery vasodilatation and enhanced diastolic relaxation observed with adrenergic stimulation.

Percutaneous needle muscle biopsy in the evaluation of patients with suspected inflammatory myopathy

OBJECTIVE

To determine the usefulness of a unique method of percutaneous needle muscle biopsy (NMB) in patients with suspected idiopathic inflammatory myopathy (IIM).

METHODS

The yield of percutaneous NMB was studied in 55 patients who were found to have a combination of clinical, laboratory, or electromyographic features of IIM.

RESULTS

A diagnosis of IIM was confirmed histopathologically in 29 patients (53%), other specific myopathies were found in 5 (9%), nonspecific myopathic changes were present in 11 (20%), and a neurogenic process was diagnosed in 3 (5%). Nonspecific changes or no abnormalities were present in 7 patients (13%). Followup of the 18 patients with nonspecific histopathologic findings disclosed that only 3 had a subsequent disease course compatible with IIM.

CONCLUSION

Percutaneous NMB is a safe, convenient, and relatively inexpensive method of muscle biopsy, with a high diagnostic yield for the pathologic confirmation of IIM. It should be considered as a primary method of acquiring muscle for histopathologic examination in the evaluation of suspected IIM.

Incidence of systemic sclerosis in Allegheny County, Pennsylvania. A twenty-year study of hospital-diagnosed cases, 1963-1982

OBJECTIVE

To determine the incidence of hospital-diagnosed systemic sclerosis (SSc) among residents of Pittsburgh and Allegheny County, PA, from 1963 through 1982.

METHODS

Medical records from all Allegheny County hospitals were searched using International Classification of Diseases codes for patients diagnosed with SSc. Each case was reviewed and verified by a physician, according to specified criteria. Age-adjusted incidence rates were computed for race and sex, and results were expressed as new cases per million population per year, with the 1970 Allegheny County population serving as the standard.

RESULTS

Four hundred forty-four cases of SSc were identified during this 20-year survey, for a total annual incidence of 13.9 per million population. Overall, the incidence rate doubled during 1973-1982 compared with the first time interval of the study, with the greatest increase occurring in women. Among the younger population (ages 15-24), black women had the highest incidence of SSc (21.2 per million population). Overall, the female-to-male incidence ratio was 3:1, and was slightly higher (3.4:1) during the childbearing years (ages 15-44). Men under age 35 and children infrequently developed SSc.

CONCLUSION

The incidence of SSc reported in this study increased with time. Although this trend was most likely due to improved detection and medical record techniques, the incidence rate stability in men compared with women suggests that there may have been a true increase in the incidence of SSc in this population, particularly in women.

Cytokines and nitric oxide synthase inhibitor as mediators of adrenergic refractoriness in cardiac myocytes

We have previously proposed that pro-inflammatory cytokines and nitric oxide (NO) contributed to reversible myocardial depression in patients with sepsis and congestive heart failure. Sepsis and heart failure are also associated with refractoriness to beta-adrenoceptor agonists. Therefore, the chronotropic effects of cytokines and the NO synthase inhibitor, NG-methyl-L-arginine (NMA), on beta-adrenoceptor stimulation of neonatal cardiac myocytes were studied. Tumor necrosis factor alpha, interleukin-1 beta and interleukin-6 but not interleukin-4 or interleukin-5 significantly enhanced spontaneous beating rates compared to untreated myocytes in serum-free media for 48 h (P < 0.01; n = 12 for each). NMA also significantly enhanced spontaneous beating rates (P < 0.01; n = 12 for each). Only interleukin-1 beta treatment resulted in significant nitrite production, immunohistochemical staining for inducible nitric oxide synthase and detection of inducible NO synthase messenger RNA by reverse transcriptase-polymerase chain reaction (RT-PCR). However, tumor necrosis factor alpha, interleukin-1 beta, interleukin-6, and NMA each completely blocked the positive chronotropic effects of the beta-adrenoceptor agonist, isoproterenol (P < 0.01; n = 12 for each). These findings are most consistent with an inducible NO synthase-independent effect of cytokines and NMA on the chronotropic responses of neonatal cardiac myocytes to beta-adrenoceptor stimulation. This effect of cytokines and NMA on adrenergic signaling may involve a myocardial constitutive NO synthase or an NO-independent mechanism.

Glucose and pyruvate regulate cytokine-induced nitric oxide production by cardiac myocytes

Metabolic requirements for the production of nitric oxide (NO) by cytokine-stimulated neonatal rat cardiac myocytes (CM) were studied. CM were cultured for 48 h in media containing interleukin-1 beta (IL-1 beta) and free fatty acids. Removal of glucose from the media partially inhibited IL-1 beta-stimulated nitrite (NO2-) production [8.1 +/- 0.3 vs. 4.4 +/- 0.6 nmol.(1.25 X 10(5) cells)-1.48 h-1; P < 0.01; n = 12]. The glycolytic inhibitor 2-deoxy-D-glucose (2-DG) completely inhibited IL-1 beta-stimulated NO2- production [0.7 +/- 0.5 nmol.(1.25 X 10(5) cells)-1.48 h-1; P < 0.01; n = 12]. The addition of the glycolytic end product, pyruvate, completely blocked the 2-DG inhibition of IL-1 beta-stimulated NO2- production [7.4 +/- 0.4 nmol.(1.25 X 10(5) cells)-1.48 h-1; P < 0.01; n = 12]. Pyruvate alone did not significantly enhance NO2- production in the presence or absence of glucose (n = 12). The inactive analogue 3-O-methylglucose had no effect on NO2- production (n = 12). Reverse transcription-polymerase chain reaction revealed that pyruvate blocked 2-DG inhibition of inducible NO synthase mRNA expression. Neither 2-DG nor pyruvate had any effect on GTP-cyclohydrolase I mRNA expression in CM. We report for the first time that optimal IL-1 beta-stimulated NO production by CM requires both glucose and the glycolytic end product pyruvate.

Anti-U5 small nuclear ribonucleoprotein (snRNP) antibodies: a rare anti-U snRNP specificity

We surveyed for autoantibodies to the U small nuclear ribonucleoproteins (snRNPs) in sera from 1171 patients with various connective tissue diseases by immunoprecipitation assay. We found serum, termed LaJ, which principally recognized the U5 snRNP from one patient with systemic sclerosis-polymyositis overlap syndrome. Anti-LaJ serum immunoprecipitated predominantly U5 snRNA from a 32PO4-labeled HeLa cell extract and at least five U5-specific proteins as well as the Sm core proteins from a [35S]methionine-labeled extract. Anti-LaJ serum immunoprecipitated both U5 snRNA and these five proteins in identical fractions at 15-20S by parallel sucrose gradient, suggesting physical association of these two components. Thus, we concluded that anti-LaJ serum contained antibody specific to the U5 snRNP. Antibodies specific to U5 snRNP were found in a single serum; in contrast, the prevalence of anti-U1 snRNP and anti-Sm antibody was considerably higher. Thus, the specific proteins of the U5 snRNP are rare targets for autoantibodies in patients with connective tissue disease.

Significance of anti-nuclear matrix antibodies in patients with in vivo speckled antinuclear antibody staining

OBJECTIVE

Evidence suggests that patients with in vivo speckled antinuclear antibody (ANA) patterns have high titers of circulating ANA, specifically anti-U1 RNP antibody. A small percentage of patients with high titers of anti-U1 RNP antibody have anti-nuclear matrix antibodies, and some also demonstrate in vivo ANA. This study was designed to screen for the presence of anti-nuclear matrix antibodies in patients with in vivo ANA.

METHODS

Anti-nuclear matrix antibodies were detected by indirect immunofluorescence on HCI-extracted HEp-2 cell substrate, by enzyme-linked immunosorbent assay, and by immunoblot analysis.

RESULTS

All 10 patients with in vivo ANA were found to have anti-nuclear matrix antibody demonstrated using HCI-extracted HEp-2 cell substrate, and all exhibited antibody activity to a 36-kd protein from nuclear matrix antigen.

CONCLUSION

These results suggest that anti-nuclear matrix antibodies are a major factor in the development of in vivo ANA.

Protein kinase A activation is required for IL-1-induced nitric oxide production by cardiac myocytes

We have previously reported that interleukin-1 beta (IL-1) alone induced the transcription of inducible nitric oxide synthase (iNOS) mRNA and nitric oxide (NO) production by isolated neonatal rat cardiac myocytes (CM). The present studies were undertaken to explore the signal transduction pathways involved in IL-1-induced NO production by CM. The addition of IL-1 to CM resulted in a peak rise in both adenosine 3',5'-cyclic monophosphate (cAMP) and protein kinase A (PKA) activities by 10 min followed by rapid declines and return to basal levels within 60 min. The PKA inhibitor KT-5720 completely blocked NO-2 production by IL-1-stimulated CM (P < 0.01; n = 12). The protein kinase C (PKC) inhibitor, calphostin C, had no effect on NO2- production by IL-1 stimulated CM [P = not significant (NS); n = 12]. The addition of PKA+cAMP to cytosols derived from IL-1-treated CM did not directly enhance iNOS enzyme activity (P = NS; n = 3). CM treated with IL-1 alone stained positively for iNOS protein by immunohistochemistry. iNOS staining was absent in CM treated with IL-1+KT-5720. KT-5720 resulted in an earlier disappearance of iNOS mRNA from IL-1-treated CM, as detected by semiquantitative reverse transcriptase-polymerase chain reaction. We report for the first time that PKA (but not PKC) activation is required for IL-1-induced NO production by CM.

NF-kappa B and GTP cyclohydrolase regulate cytokine-induced nitric oxide production by cardiac myocytes

We previously reported that interleukin-1 beta (IL-1) alone stimulated nitric oxide (NO) production by neonatal rat cardiac myocytes (CM) in culture. The present studies were undertaken to explore the signal transduction pathways involved in IL-1-induced NO production by CM. Translocation from the cytosol to the nucleus of nuclear factor-kappa B (NF-kappa B) and activation of guanosine 5'-triphosphate (GTP) cyclohydrolase [rate-limiting enzyme in tetrahydrobiopterin (BH4) synthesis] have been implicated in IL-1 signaling. Accordingly, the effects of the NF-kappa B inhibitor pyrolidine dithiocarbamate (PDTC) and the GTP cyclohydrolase inhibitor 2,4-diamino-6-hydroxypyrimidine (DAHP) on IL-1-induced NO production by CM were studied. PDTC and DAHP inhibited IL-1-induced NO2-production by CM (6.7 +/- 0.6 vs. 0.9 +/- 0.3 and 0.3 +/- 0.1 nmol. 1.25 x 10(5) cells(-1).48 h-1, respectively, P < 0.01, n = 12 for each). Immunohistochemical staining revealed that PDTC blocked IL-1-stimulated nuclear translocation of NF-kappa B. The membrane-permeable analogue of the NO synthase cofactor BH4, methyl-BH4 (mBH4), only partially reversed DAHP inhibition of NO2- formation (6.7 +/- 0.6 vs. 2.4 +/- 0.3 nmol. 1.25 x 10(5) cells-1.48 h-1, P < 0.01, n = 12). Semiquantitative reverse transcription polymerase chain reaction revealed no inducible NO synthase (iNOS) mRNA production in cells treated with IL-1 + PDTC.CM treated with IL-1 + DAHP did express iNOS mRNA. We report for the first time that nuclear translocation of NF-kappa B is essential for II-1-induced iNOS mRNA expression and GTP cyclohydrolase activity is required in addition in addition to BH4 for optimal NO production by CM.

Inotropic, chronotropic, and radioligand binding characteristics of leukotriene B4 in cardiac myocyte, papillary muscle, and membrane preparations

Cardioprotective effects of dietary fish oil consumption have been attributed to the substitution of eicosapentaenoic acid (EPA) for arachidonic acid (AA) in cellular membranes. This substitution blocks the formation of leukotriene B(4) (LTB(4)) which is elaborated locally in the area of ischemic myocardium. We studied the in vitro inotropic, chronotropic, and radioligand binding characteristics of LTB(4) to gain potentially important insights into the mechanisms involved in the cardioprotective effect of EPA. LTB(4) was a concentration-dependent and reversible negative inotrope in isolated papillary muscle preparations. LTB(4) significantly blocked the positive inotropic effect of Bay K 8644 (BK) (calcium channel regulator) on papillary muscles and the positive chronotropic effect of BK on spontaneously beating neonatal cardiac myocytes. LTB(4) had no direct effect on [(3)H]PN200-110 binding to cardiac sarcolemmal L-type calcium channels or [3H]ryanodine binding to cardiac SR calcium release channels. These studies support a potentially important indirect effect of LTB(4) on myocardial E-C coupling.

New perspectives on osteoarthritis

Osteoarthritis (OA) is the most common rheumatologic disease, afflicting tens of millions of U.S. citizens. It is not an inevitable consequence of aging; rather, it is a degenerative process acquired because of metabolic, mechanical, genetic, and other influences. It is characterized by progressive loss of cartilage and bony overgrowth. Because cartilage is not innervated, the pain of OA arises from secondary effects, such as joint capsule distention, stretching of periosteal nerve endings, and, possibly, synovial inflammation. Psychologic factors, including stress and depression, may influence the perception of pain by OA patients. The risk of OA apparently is not increased by normal joint use, but persons who participate in competitive sports or who play with abnormal or injured joints are at increased risk. Obesity increases OA risk, and weight loss has been found to decrease it. Some forms of premature OA appear to be inherited. The objective diagnosis of OA is made on the basis of radiography. However, many individuals with radiographic evidence of OA are asymptomatic in the affected joint. It is essential to ensure that pain in the affected joint is attributable to OA and not another cause. The management of OA should include physical medicine measures such as heat or cold therapy and often neglected environmental measures, such as reducing chair height and using shoe orthotics. Therapeutic exercise is beneficial for many patients and includes an initial warm-up with range of motion, muscle strengthening, and aerobic activity (such as swimming). A major question in the pharmacologic management of OA is whether nonsteroidal anti-inflammatory drugs (NSAIDs) are superior to analgesics in terms of symptomatic relief; studies indicate that they are not. The question is relevant because of the adverse effects of NSAID use, particularly in the elderly population.

cAMP enhances inducible nitric oxide synthase mRNA stability in cardiac myocytes

The effects of adenosine 3',5'-cyclic monophosphate (cAMP) on cardiac myocyte nitric oxide (NO) production were studied. Maximal nitrite (NO2(-)) production by cultured neonatal rat cardiac myocytes was achieved with 500 U/ml interleukin-1 beta (IL-1 beta) for 48 h (4.6 +/- 0.3 nmol/1.25 x 10(5) cells; n = 12). Cardiac myocytes exposed to 500 U/ml IL-1 beta for 48 h stained positively for inducible nitric oxide synthase (iNOS) by immunohistochemistry. Forskolin (FSK; adenylate cyclase stimulator) or dibutyryl cAMP (DBcAMP; membrane-permeable cAMP analogue) administration alone had no effect on NO2(-) production. The addition of FSK or DBcAMP to IL-1 beta significantly increased NO2-) levels vs. IL-1 beta alone (9.7 +/- 0.6 and 10.9 +/- 0.8 vs. 4.6 +/- 0.3 nmol/1.25 x 10(5) cells per 48 h, respectively; P < 0.01; n = 12). Semiquantitative reverse transcriptase-polymerase chain reaction revealed increased iNOS mRNA in myocytes treated with FSK+IL-1 beta or DBcAMP+IL-1 beta vs. those treated with IL-1 beta alone. The addition of FSK or DBcAMP to IL-1 beta increased iNOS mRNA half-life over IL-1 beta treatment alone (10.6, 11.7 vs. 2.4 h, respectively). Cardiac myocytes do not express iNOS in response to cAMP alone. Rather, cAMP enhances iNOS mRNA stability following cytokine exposure.

Regulation of constitutive nitric oxide synthase activity by the human heart

We and others have provided indirect evidence for the presence of a constitutive nitric oxide synthase (cNOS) in the mammalian heart. We now provide more direct evidence for the regulation of a myocardial cNOS in the hearts of patients undergoing elective cardiopulmonary bypass (CPB). cNOS enzyme activity was demonstrable in both cytosolic (8.3 +/- 0.02 pmol/min/mg) and membrane (11.1 +/- 0.4 pmol/min/mg) preparations derived from human atrial pectinate muscles obtained at the time of CPB (n = 6). Plasma nitrite (NO2-) + plasma nitrate (NO3-) levels from the beating hearts of patients before bypass were reduced from 146 +/- 33 to 5.1 +/- 50 pmol/min/g after cardiac arrest during CPB (n = 23; p < 0.002 by Student's t test). Thus, the human myocardium constitutively produces nitric oxide that is regulated by the contractile state of the heart.

Adult respiratory distress syndrome in polymyositis patients with the anti-Jo-1 antibody

We report 3 patients with polymyositis and the anti-Jo-1 antibody who developed fatal adult respiratory distress syndrome (ARDS). Other than the presence of the anti-Jo-1 antibody, there were no other consistent clinical features at the onset of disease that were predictive of ARDS development.

A longitudinal study of functional disability in a national cohort of patients with polymyositis/dermatomyositis

OBJECTIVE

To analyze changes in functional status and the factors contributing to disability in a national inception cohort of 257 patients with polymyositis/dermatomyositis (PM/DM).

METHODS

Data were gathered from patients' self-reports on questionnaires: one concerning disease- and treatment-related complications, and the other concerning disability, as reflected by a disability index (DI) derived from the Health Assessment Questionnaire (HAQ).

RESULTS

Based on certain characteristics that differentiated disability patterns, 3 groups of patients were identified. Group 1 patients (n = 153) were < or = 60 years old and never had avascular necrosis (AVN) or a vertebral compression fracture (CF), Group 2 patients were > 60 and never had AVN or a vertebral CF, and Group 3 patients reported AVN or a vertebral CF irrespective of age. As measured by the HAQ DI, disability increased very gradually over time in Group 1 patients and more rapidly in Group 2 and Group 3 patients. The increase in disability in patients experiencing AVN was greater than that in patients with similar pre-AVN disease characteristics who did not develop AVN (P = 0.003).

CONCLUSION

In this prospective study of disease course and iatrogenic factors related to functional disability in PM/DM, the HAQ DI increased with disease duration. Corticosteroid-related morbidity, as reflected by the development of AVN or CF, significantly contributed to patient-reported functional disability.

Cytokine-stimulated nitric oxide production inhibits mitochondrial activity in cardiac myocytes

We have previously proposed that cytokine-stimulated nitric oxide (NO) production is responsible for reversible myocardial depression in sepsis, trauma and ischemia. NO previously has been found to inhibit mitochondrial activity in other cell types. Accordingly, we sought to determine if cytokine-stimulated NO production inhibited cardiac myocyte mitochondrial activity. Treatment of neonatal rat cardiac myocytes with interleukin-beta (IL-1) resulted in the expression of mRNA for inducible NO synthase (iNOS) and stained positively for iNOS protein by immunohistochemistry. No iNOS staining was detected in untreated cells. IL-1 treatment resulted in significant nitrite levels vs control over 48 hrs (4.2 +/- 0.7 vs 0.3 +/- 0.2 nmol/1.25 x 10(5) cells, respectively) (n = 12) that was inhibited by 1mM NMA (0.3 +/- 0.2 nmoles; p < .01; n = 12). Mitochondrial activity was assessed by the MTT colorimetric assay using (3-4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and OD 570-630. Mitochondrial activity was significantly inhibited by IL-1 vs control cells (0.436 +/- 0.01 vs 0.608 +/- 0.03) and reversed by 1mM NMA (0.549 +/- 0.03) or removal of IL-1 (0.662 +/- 0.02) (p < .01; n = 12 for each). These data strongly suggest that cytokine-stimulated NO production by cardiac myocytes results in reversible inhibition of mitochondrial activity.

Inflammatory myopathies

New information regarding myositis specific autoantibodies, histopathologic analysis of muscle biopsy specimens, and immunogenetic features of the different serologic subsets of disease has greatly increased our understanding of the pathogenesis of the inflammatory myopathies. The clinical descriptions of inclusion body myositis and 'amyopathic dermatomyositis' (Euwer and Sontheimer, 1993) are examples of our expanded descriptive capabilities in the evaluation of patients with myopathy. Finally, newer techniques such as cytokine analysis and magnetic resonance imaging may help in the ongoing assessment of disease activity in patients with myositis. The combination of these recently described clinical and laboratory parameters are enough to force a reconsideration of the previously described classification and diagnostic criteria in the inflammatory myopathies.

Cytokine induction during cardiac surgery: analysis of TNF-alpha expression pre- and postcardiopulmonary bypass

Cytokines are soluble mediators that possess both intra- and intercellular signaling properties. Their function has been investigated most thoroughly in the context of immune reactions. Cytokines, however, form an important component of the inflammatory response to trauma and are found in elevated concentrations following cardiopulmonary bypass (CPB). We were, therefore, interested in studying mRNA expression for the cytokine tumor necrosis factor alpha (TNF-alpha) in patients undergoing cardiac surgery. White cells isolated from the circulation of seven patients before and after CPB were assayed for the expression of mRNA with TNF-alpha specific primers using the polymerase chain reaction. Message for TNF-alpha was found in all patients, with the highest values demonstrated in patients whose CPB times exceeded 1 1/2 hours. Enhanced message expression was seen as early as 1 hour after the start of CPB. Genes responsible for cytokine (TNF-alpha) expression and production are activated during cardiac surgery.

Nitric oxide synthase inhibitor alters papillary muscle force-frequency relationship

We provide evidence for an immediate effect of NG-monomethyl-L-arginine (L-NMMA) on the force-frequency relationship in isolated hamster papillary muscles. L-NMMA (competitive inhibitor of nitric oxide synthase) reversed the force-frequency relationship (staircase effect) in isolated hamster papillary muscles from negative to positive (P < .01; ANOVA; n = 6). The addition of L-arginine (substrate for nitric oxide synthase) blocked the L-NMMA effect (P < .01; ANOVA; n = 6). The addition of the nitric oxide (NO) donor, sodium nitroprusside (NTP), significantly increased the level of cGMP in the tissue bath (P < .01; test; n = 6) and reversed the positive inotropic effect of L-NMMA on staircase (P < .01; ANOVA; n = 6). The addition of 8-Br-cGMP to the bath resulted in a concentration-dependent decrease in tension generated by the papillary muscles (n = 6). Methylene blue (known inhibitor of cGMP) mimicked the effect of L-NMMA on staircase (P < .01; ANOVA; n = 6). L-NMMA also significantly blunted the negative inotropic effect of ryanodine (SR calcium release channel regulator) (P < .01; ANOVA; n = 6). The positive inotropic effect of Bay K 8644 (sarcolemmal, L-type calcium channel regulator) was not affected by L-NMMA (P = NS; ANOVA; n = 6). L-NMMA had no effect on either [3H]ryanodine or [3H]PN200-110 (sarcolemmal, L-type calcium channel regulator) binding to cardiac membranes. These findings support a cGMP-dependent role for endogenous NO in myocardial E-C coupling.

Chronotropic effects of cytokines and the nitric oxide synthase inhibitor, L-NMMA, on cardiac myocytes

We and others have proposed that cytokine-stimulated nitric oxide (NO) production is responsible for reversible myocardial depression in sepsis, trauma and ischemia. An effect of NO on cardiac sarcolemmal L-type calcium channels has also recently been proposed. The spontaneous beating rate of neonatal cardiac myocytes is regulated by the sarcolemmal L-type calcium channel. Accordingly, we sought to determine if cytokine-stimulated NO production could also regulate beating rates of neonatal cardiac myocytes. Treatment of neonatal rat cardiac myocytes with TNF, IL-1, IL-6, 10(-5)M NMA, or 10(-3)M NMA significantly enhanced spontaneous beating rates compared to untreated myocytes in serum-free media for 48 hours (p < or = .01; n = 12 for each). Only IL-1 treatment resulted in significant nitrite levels vs. control over 48 hours (4.2 +/- 0.7 vs. 0.3 +/- 0.2 nmoles/1.25 x 10(-5) cells, respectively) (n = 12). Nitrite production by IL-1 was inhibited by 10(-3)M NMA but not 10(-5)M NMA (0.3 +/- 0.2 vs. 4.1 +/- 0.6 nmoles; p < .01; n = 12). The addition of 10(-5)M NMA to TNF, IL-1, and IL-6 did not alter the effect of the cytokines on the spontaneous beating rates of the cardiac cells (p < or = .01; n = 12 for each). These results strongly suggest that cytokines and NMA affect cardiac myocyte spontaneous beating rates through mechanisms independent of NO.

Therapy of inflammatory myopathy

The management of the muscular and extramuscular manifestations of the inflammatory myopathies remains a challenge for the practicing rheumatologist. Although corticosteroids remain the first line of therapy, their side effects often limit their usefulness. Paradoxically, one of the side effects of steroids, muscle weakness, is the very symptom at which therapy is aimed. Other immunosuppressive agents are of proven benefit alone or in combination with corticosteroids. The identification of characteristic autoantibodies that identify poor prognostic outcomes and the availability of newer immunosuppressive regimens should contribute to a more aggressive but perhaps safer therapeutic approach to the patient with myositis.

Catalytic conversion of L-arginine to nitrate by platinum electrodes

Platinum electrodes (PLE) have been used recently to study the physiologic effects of the enzymatic conversion of L-arginine (L-arg) to nitric oxide (NO) by nitric oxide synthase (NOS). We sought to determine if PLE alone could catalytically convert L-arg to NO without NOS. Accordingly, NO2- + NO3- levels (NOx) were measured by HPLC from a physiologic Tyrode's buffer in the presence and absence of electrical stimulation with PLE or silver chloride electrodes (SCE) for 10 min (n = 6 for each condition). PLE stimulated at 1Hz produced 24 +/- 0.7 and 15.4 +/- 2.8 microM NOx from D-arg and L-arg (100mM) respectively. PLE + L-arg stimulated from 0 to 5 Hz produced increasing NOx (2.9 +/- 0.27;15.4 +/- 2.8;19.7 +/- 4;32 +/- 5;37 +/- 6.2;43 +/- 7 microM). SCE+L-arg showed no increase in NOx above background. The addition of 1% BSA to the Tyrode's buffer further increased NOx levels. NO2- levels were undetectable, indicating all NOx levels were NO3-. We conclude that PLE can catalytically convert L-Arg to NO3- via electron transfer without NOS.

A potential role for nitric oxide in myocardial stunning

Nitric oxide (NO) production by the human heart has been demonstrated in patients undergoing cardiac surgery. Similar to what has been described in other species, a basal production of NO by the human heart is seen (126 +/- 42 pmol/min per gram). Following reperfusion, at the end of the procedure, the level of NO production increases significantly reaching concentrations of 1430 +/- 330 pmol/min per gram. Increased activity for the enzyme NO synthase (NOS) (8.0 +/- 1.2 pmol/mg prebypass vs 26.4 +/- 4.8 pmol/mg postbypass) coincides with changes in NO production and occurs at a time when myocardial stunning is clinically detectable. The significance of these findings is discussed and suggest a role for NO in the pathophysiology of myocardial stunning.

Therapy for myositis

The management of inflammatory myopathy is a challenge. Although corticosteroids remain the initial therapeutic choice in most instances, their side effects and lack of efficacy are such that alternative modes of therapy are frequently sought. The identification of serum autoantibodies associated with more severe forms of myositis has prompted new classification schemes and has led to more aggressive approaches with combination therapy, using corticosteroids, immunosuppressive drugs, or other immune-modulating agents. Non-corticosteroid agents that provide some benefit include methotrexate, azathioprine, chlorambucil, and perhaps cyclophosphamide. Cyclosporine has been increasingly studied with encouraging results, and intravenous immunoglobulin has demonstrated some benefit for myositis patients. Plasma exchange and leukapheresis were of no proven benefit in a randomized, double-blind trial.

Verapamil regulation of a defective SR release channel in the cardiomyopathic Syrian hamster

The Bio 14.6 Cardiomyopathic Syrian Hamster (CMH) has an autosomal recessive disease characterized by intracellular calcium overload, cardiac and skeletal myopathies and premature death from congestive heart failure. Early treatment of these animals with the calcium antagonist, verapamil (V), prevents the development of the disease. We have previously provided evidence supporting a specific defect in the ryanodine-sensitive SR calcium release channel (SRCRC) in CMH. We now provide physiologic and biochemical evidence that V modulates SRCRC. Papillary muscles prepared from F1B control hamsters (F1B) revealed an enhanced inotropic responsiveness to V and ryanodine (R) with age, not seen with CMH. CMH papillary muscles demonstrated paradoxical positive inotropic effects of V and R not shared with F1B. The positive inotropic effects of V and R were not additive. V enhanced the affinity (decreased KD) of [3H]ryanodine binding to cardiac membranes. Thus, V may prevent the overt manifestations of genetic disease in CMH by modulating a defective ryanodine-sensitive SR release channel.

Positive inotropic effect of acetylcysteine in cardiomyopathic Syrian hamsters

Several laboratories have provided indirect evidence that the myocardium of the cardiomyopathic Syrian hamster (CMH) is chronically ischemic on the basis of microvascular spasm. We previously reported evidence supporting a defect in the ryanodine-sensitive sarcoplasmic reticulum calcium release channel (SRCRC) in CMH. A relation between alterations in SRCRC and chronic ischemia has not yet been explored. A potential mechanism could be the effects of changes in redox state on thiol groups. Thiol reagents have previously been shown to regulate calcium release from SRCRC. Accordingly, we studied the inotropic effects of the sulfhydryl donors, acetylcysteine (AC), cysteine, and cystine in CMH. AC was a positive inotrope in isolated papillary muscles prepared from CMH, but not F1B controls (F1B) (p < 0.01). No significant differences were noted in inotropic responses to cysteine or cystine. AC blunted the response of CMH > F1B control papillary muscle preparations to stimulation frequency (p < 0.01). The actual tension generated (in mg/mm2) by CMH was no longer different than F1B with addition of AC (10(-3) M), ryanodine (10(-8) M), or verapamil (5 x 10(-7) M). These findings are consistent with a defect in SRCRC in CMH. This defect may be primary or may provide a novel mechanism for hibernating myocardium owing to chronic ischemia.

Serum autoantibody to the nucleolar antigen PM-Scl. Clinical and immunogenetic associations

OBJECTIVE

The inflammatory myopathies are characterized by distinctive autoantibodies that are associated with certain clinical features and immunogenetic patterns. Anti-PM-Scl is one such antibody and is found in pure myositis, myositis in overlap, and systemic sclerosis (SSc). Our purpose was to describe the clinical and immunogenetic associations of the anti-PM-Scl antibody.

METHODS

Serum samples from 617 patients with various connective tissue diseases were screened for anti-PM-Scl antibody by indirect immunofluorescence and Ouchterlony double immunodiffusion. Patients with anti-PM-Scl were serologically typed for HLA-DR and DQ, and the genes encoding DQ alpha and DQ beta were characterized by hybridization of sequence-specific oligonucleotide to amplified genomic DNA.

RESULTS

Twenty-three patients (4%) had serum anti-PM-Scl. Sixteen had either pure myositis or myositis in overlap, 6 had SSc alone, and 1 had SSc and rheumatoid arthritis. Twenty of the antibody-positive patients had serologic HLA typing performed; 15 (75%) were HLA-DR3 positive, and 17 (85%) expressed the DQw2 allele. None of the 5 DR3 negative patients shared a unique DR or DQ antigen with the DR3 positive patients, and further DNA analysis of 10 patients (4 of whom were DR3 negative) did not reveal any unique DQ alleles.

CONCLUSION

Anti-PM-Scl identifies a subset of patients with myositis, SSc, or an overlap of the two disorders, and this antibody has a strong but not exclusive immunogenetic association with the HLA-DR3 antigen.