The efficacy and safety of tacrolimus in patients with dermatomyositis/polymyositis: A meta-analysis and systematic review

OBJECTIVE

To evaluate the efficacy and safety of tacrolimus for dermatomyositis (DM) and polymyositis (PM) treatment.

METHODS

We searched the Embase, PubMed, the Cochrane Central Register of Controlled Trials, and China National Knowledge Infrastructure were used as searching tools from inception up to October 2022. Two authors independently selected studies. The available studies were comprehensively reviewed and investigated.

RESULTS

A total of 9 studies, including 350 patients, were analysed. Pooled results showed a higher overall survival rate in tacrolimus therapy group. Creatine kinase (CK) levels and forced vital capacity (FVC) showed significant improvement after tacrolimus therapy. The incidence of adverse events including infection and renal dysfunction showed no significant differences between the tacrolimus therapy group and conventional therapy group.

CONCLUSION

The results of this meta-analysis indicated that GC therapy in combination with tacrolimus therapy could help improving overall survival rate, pulmonary function and had similar safety outcomes compared to conventional therapy in DM and PM patients.

Triggers of inflammatory myopathy: insights into pathogenesis

The inflammatory myopathies, which include dermatomyositis, polymyositis, and the immune-mediated necrotizing myopathies, are a heterogeneous group of autoimmune diseases that manifest with muscle, skin, or lung damage. Collectively, these autoimmune diseases result from loss of tolerance to a select group of self-antigens, although the precise mechanism through which this occurs is not known. Infection, malignancy, and certain medications including statins and the immune checkpoint inhibitors used in cancer therapy have been identified as potential immunologic triggers of the inflammatory myopathies. Some of these triggers are classically associated with specific myositis-specific autoantibodies (MSAs). The strong association between certain triggers and MSAs provides insights into how an immunologic event can lead to loss of tolerance to specific self-antigens, resulting in autoimmune disease. In this review, we discuss the proposed triggers of the inflammatory myopathies and their associations with MSAs, and provide insights into how these triggers may result in the inflammatory myopathies.

Progressive hypoventilation due to mixed CD8+ and CD4+ lymphocytic polymyositis following tremelimumab - durvalumab treatment

BACKGROUND

The combination of CTLA-4 and PD-L1 inhibitors has a manageable adverse effect profile, although rare immune-related adverse events (irAE) can occur.

CASE PRESENTATION

We describe an autoimmune polymyositis following a partial response to combination tremelimumab and durvalumab for the treatment of recurrent lung adenocarcinoma. Radiography revealed significant reduction in all metastases; however, the patient developed progressive neuromuscular hypoventilation due to lymphocytic destruction of the diaphragmatic musculature. Serologic testing revealed a low level of de novo circulating antibodies against striated muscle fiber. Immunohistochemistry revealed type II muscle fiber atrophy with a mixed CD8+ and CD4+ lymphocyte infiltrate, indicative of inflammatory myopathy.

CONCLUSIONS

This case supports the hypothesis that muscle tissue is a target for lymphocytic infiltration in immune checkpoint inhibitor-associated polymyositis. Further insights into the autoimmune mechanism of PM will hopefully contribute to the prevention and treatment of this phenomenon.

Statin-associated polymyositis following omeprazole treatment

Statins are an extensively used class of drugs, and myopathy is an uncommon, but well-described side effect of statin therapy. Inflammatory myopathies, including polymyositis, dermatomyositis, and necrotizing autoimmune myopathy, are even more rare, but debilitating, side effects of statin therapy that are characterized by the persistence of symptoms even after discontinuation of the drug. It is important to differentiate statin-associated inflammatory myopathies from other self-limited myopathies, as the disease often requires multiple immunosuppressive therapies. Drug interactions increase the risk of statin-associated toxic myopathy, but no risk factors for statin-associated inflammatory myopathies have been established. Here we describe the case of a man, age 59 years, who had been treated with a combination of atorvastatin and gemfibrozil for approximately 5 years and developed polymyositis after treatment with omeprazole for 7 months. Symptoms did not resolve after discontinuation of the atorvastatin, gemfibrozil, and omeprazole. The patient was treated with prednisone and methotrexate followed by intravenous immunoglobulin, which resulted in normalization of creatinine kinase levels and resolution of symptoms after 14 weeks. It is unclear if polymyositis was triggered by interaction of the statin with omeprazole and/or gemfibrozil, or if it developed secondary to long-term use of atorvastatin only.

Characterization of pathogenic T cells and autoantibodies in C-protein-induced autoimmune polymyositis

Although autoimmune processes may take place in human polymyositis, little is known with regard to its pathogenesis due to the lack of appropriate animal models. In the present study, we developed experimental autoimmune myositis (EAM) in Lewis rats by immunization with recombinant skeletal C-protein and examined the role of pathogenic T cells and autoantibodies. Using recombinant proteins and synthetic peptides, we demonstrated that skeletal C-protein Fragment 2 (SC2) has the strongest myositis-inducing ability and that myositis-inducing epitope(s) reside within the residues 334-363 of SC2 (SC2P3). However, immunization with SC2P3 induced only mild EAM compared with SC2 immunization. Characterization of T cells and antisera revealed that SC2P3 and SC2P7 contain the B cell epitope, while the T cell epitope resides in SC2P5. Furthermore, anti-SC2, but not anti-SC2P3, antisera contained antibodies against the conformational epitope(s) in the SC2 molecule. However, SC2P3 or SC2P5 immunization plus anti-SC2 antibody transfer aggravated the disease only slightly. These findings suggest that C-protein-induced EAM is formed by activation of C-protein-specific T cells along with antibodies against conformational epitopes in C-protein but that there are undetermined factors related to the disease progression. Further analysis of C-protein-induced EAM will provide useful information to elucidate the pathomechanisms of human polymyositis.

Increased exposure to statins in patients developing chronic muscle diseases: a 2-year retrospective study

OBJECTIVE

Case reports have suggested that lipid-lowering drugs (LLDs), especially statins, could induce or reveal chronic muscle diseases. We conducted a study to evaluate the association between chronic muscle diseases and prior exposure to LLDs.

METHOD

This was a retrospective study of chronic primary muscle disease cases newly diagnosed at the Toulouse University Hospitals between January 2003 and December 2004 among patients living in the Midi-Pyrénées area, France. All patients remained symptomatic for more than 1 year after drug withdrawal, or required drugs for inflammatory myopathy. Data on the patient's exposure to LLDs and to other drugs were compared with that of matched controls (5/1) selected through the Midi-Pyrénées Health Insurance System database.

RESULTS

A total of 37 patients were included in the study. Of those, 21 (56.8%) suffered from dermatomyositis (DM) or polymyositis (PM), 12 (32.4%) from genetic myopathy, and 4 (10.8%) from an unclassified disease. The prevalence of exposure to statins was 40.5% in patients and 20% in controls (odds ratio (OR) 2.73, 95% confidence interval (CI) 1.21-6.14; p<0.01). There was a significant positive interaction between statins and proton pump inhibitors exposure (weighted OR 3.3, 95% CI 1.37-7.54; p = 0.02). Statin exposure rate was 47.6% among patients with DM/PM (OR 3.86, 95% CI 1.30-11.57; p<0.01). There was no difference between patients and controls for exposure to fibrates.

CONCLUSION

Patients who developed chronic muscle diseases after the age of 50, including DM/PM, had a higher than expected frequency of prior exposure to statins. Further studies are needed to confirm this association and the role of proton pump inhibitors.

Myopathy including polymyositis: a likely class adverse effect of proton pump inhibitors?

OBJECTIVE

Polymyositis occurring in patients treated with omeprazole has been signalled as a possible adverse drug reaction (ADR) by the New Zealand Intensive Medicines Monitoring Programme (IMMP) and the WHO Collaborating Centre for International Drug Monitoring: the Uppsala Monitoring Centre (UMC). Polymyositis and other myopathies have also been reported in post-marketing data and in the medical literature in association with proton pump inhibitor (PPI) use. We wished to follow-up these signals and investigate the evidence of causality for the association of polymyositis and other myopathy with PPI use.

METHODS

Spontaneously reported ADRs from national monitoring centres are sent to the WHO ADR database (VigiBase). VigiBase was searched for case reports of the PPIs, omeprazole, pantoprazole, lansoprazole, esomeprazole and rabeprazole, with terms indicative of myopathy, and further information was elicited from the national centres to help establish causality. Literature sources were reviewed for the occurrence of the above terms in combination with PPIs.

RESULTS

In total, there were 292 reports of various myopathies with PPIs, excluding 868 cases of 'myalgia'. In this analysis, 69 patients recovered when the drug was withdrawn and, in 15 patients, the reaction re-occurred when the drug was reinstated. In one-third of the 292 cases, the PPI was the single administered drug, and the PPI was the single suspected drug by the reporter in 57% of reports where concomitant medication was used. In this analysis, three index cases are documented. One involves the same patient taking three different PPIs (lansoprazole, esomeprazole and rabeprazole) at different time periods, with myalgia and muscle weakness occurring with all three drugs. In the two other index cases, myopathies with esomeprazole and omeprazole were reported with positive rechallenge, and causality was assessed as 'possible' and 'certain' by the reporting centres. In 27 cases myositis or polymyositis was reported. Other myopathies were reported, including 35 cases with rhabdomyolysis. In 9 of these cases, the PPI was withdrawn and the reaction abated. The PPI was reinstated in one patient, but the reaction did not re-occur. Time to onset was given in 17 of the rhabdomyolysis cases, rhabdomyolysis occurred with the first week in 9 cases, and in 3 cases the reaction occurred between 14 days to 3 months of treatment. In 12 of these patients, an HMG-CoA reductase inhibitor (statin) was taken concomitantly.

CONCLUSION

Case reports from the WHO ADR database, including index cases involving four out of five PPIs, along with evidence of a possible mechanism, provide compelling evidence that there is a causal association between members of the PPI drug class and myopathy including polymyositis. Evidence was also obtained to support the view that PPI use may be associated with occurrence of other myopathies, including the serious reaction rhabdomyolysis.

Acute polymyositis during treatment of acute hepatitis C with pegylated interferon alpha-2b

Hepatitis C virus is not cleared after primary infection in 50-85% of subjects exposed to hepatitis C virus. Anti-viral treatment during the early phase of infection significantly enhances the likelihood of a sustained clearance of hepatitis C virus. Although, a variety of autoimmune-related side effects have been observed during interferon therapy for chronic hepatitis, immuno-mediated adverse reactions have not been reported during treatment of acute hepatitis C. We describe the case of a patient who developed acute hepatitis C virus infection and, while receiving pegylated interferon alpha-2b monotherapy, developed a severe polymyositis. This case illustrates the potential risk of autoimmunity by interferon, also for acute hepatitis, and underlines the importance of a prompt diagnosis and a rapid discontinuation of interferon treatment for an improvement of clinical outcomes.

Safety of statins: focus on clinical pharmacokinetics and drug interactions

Statin monotherapy is generally well tolerated, with a low frequency of adverse events. The most important adverse effects associated with statins are myopathy and an asymptomatic increase in hepatic transaminases, both of which occur infrequently. Because statins are prescribed on a long-term basis, however, possible interactions with other drugs deserve particular attention, as many patients will typically receive pharmacological therapy for concomitant conditions during the course of statin treatment. This review summarizes the pharmacokinetic properties of statins and emphasizes their clinically relevant drug interactions.

Polymyosites induites ou associées aux traitements hypolipémiants ?

PURPOSE

Rhabdomyolysis and myositis are rare, dose-related complications of statins and fenofibrates. The outcome is favorable as a rule with rapid regression after stopping the responsible drug. Recently, various auto-immune disease with evidence of hypersensitivity to HMG-CoA reductase inhibitors or fibrates drugs have been reported. Less than ten cases of dermatomyositis and polymyositis due to cholesterol-lowering drugs (CLD) have been previously reported. Five more cases polymyositis associated with CLD are reported.

METHODS

Symptoms were compatible with diagnosis of polymyositis according to Bohan and Peter and with previous reported criteria for drug-induced myopathy in all cases. None of these patients had previous other connective tissue disorders.

RESULTS

Five patients (median age 68 [54-78], female N =4) with CLD treatment (statin N =4, fenofibrates N =1) have developed iatrogenic polymyositis. All of them presented both proximal muscular weakness and increased muscle enzyme levels. One patient had iatrogenic antisynthetase syndrome characterized by mechanic's hand, Raynaud's phenomenon and anti JO1 antibodies. One other had sclerodermic hand oedema. Antinuclear antibodies were positive in 4 cases and muscle biopsy revealed polymyositis infiltrate in 4 cases. CLD treatment was discontinued with partial clinical improvement in 3 cases. Clinical remission was obtained with corticosteroid (N =5) in association with immunosuppresive agents in 3 cases.

CONCLUSION

Muscular symptoms in patient with CLD treatment could be the first symptom of a polymyositis revealed or increased by this treatment and must encourage physician with antinuclear antibodies screening especially in case of proximal muscular weakness and increased muscle enzyme levels.

[Pravastatin-associated polymyositis, a case report]

A 69 year old man complained of general myalgia, arthralgia and muscle weakness in two weeks after he started to take 10 mg per day pravastatin. Symptoms progressed at least for 3 months after withdrawal of the medication. The muscle weakness was more in distal upper extremities and the iliopsoas muscle. Serum CK was 943IU/L. The anti-nuclear and Jo-1 antibody were positive. EMG examinations disclosed fibrillation potentials at rest and myopathic discharges by a voluntary contractor. Symptoms as well as serum CK values improved promptly by treatment with prednisolone. From these clinical and laboratory results, it was speculated that this patient suffered from subacute polymyositis, although pathological studies were not performed. Because of continuing hypercholesterolemia, the patient was retreated with atorvastatin, presenting similar, but less serious symptoms. So far, three cases of statin-associated polymyositis or dermatomyositis were reported. Statins could influence the immune system, but it is still unsettled if statins cause autoimmune polymyositis. This problem warrants further study.

[Severe polymyositis with simvastatin use]

INTRODUCTION

Myotoxicity is the most common adverse reaction of statins, being its frequency less than 0.5%. Mild myopathy reversible after statin withdrawal is the most common event. We present a case of severe polymyositis which was likely to be induced by simvastatin.

CASE REPORT

75 years old man with hypercholesterolemia treated with simvastatin 20 mg/day for 6 months started previous 2 months with proximal limb weakness, dysphagia and myalgias during exercise that did not release after simvastatin withdrawal. Laboratory findings showed increased creatinin kinase (6,010 UI/L), raised aldolase (51 UI/L) and lactic acid dehydrogenase (1,406 UI/L). Muscular biopsy showed abundant inflammatory cell infiltration in perivascular areas, muscle fibre necrosis with miofagocitosis and considerable variation in fibre size, some of them reaching 210 mm. Treatment with cortico esteroids was started and 4 months later clinical remission and nomalization of creatinin kinase was observed.

DISCUSSION

Mechanisms of statins induced myotoxicity are not well known. Studies in rats suggest a muscle membrane defect (increased membrane fluidity) and abundant signs of damage (fiber necrosis, hipercontraction) but no cellular infiltrates were seen, pointing to a non inflammatory myopathy which was dose dependent. In our case, and Giordano s et al, the remission of the disease with cortico esteroid therapy and the finding of abundant inflammatory cell infiltration suggest the implication of immunological mechanism and not only a muscle membrane defect.

[Generalized muscle pain in a 67-year-old patient. Myalgia/myositis in therapy with Zocor]

Der Nutzen des Einsatzes der Statine konnte in mehreren multizentrischen und internationalen Studien eindeutig nachgewiesen werden: Die kardiovaskuläre Morbidität und Mortalität sowie die Gesamtmortalität kann bei Männern und Frauen selbst ohne manifeste koronare Herzkrankheit durch die Behandlung mit Statinen gesenkt werden [1,6]. Bei hoher Effektivität haben diese Medikamente generell eine sehr gute Verträglichkeit. Muskuläre Komplikationen sind insgesamt sehr selten, allerdings gibt es einige zu Myopathien prädisponierende Risikofaktoren, welche vor Beginn einer Behandlung zu beachten sind. Insbesondere gilt es bei gleichzeitiger Verabreichung verschiedener Medikamente oder bei multimorbiden Patienten Vorsicht walten zu lassen. Patienten sollten über das Myopathierisiko aufgeklärt und dazu angehalten werden, allfällige muskuläre Symptome wie Schmerzen, Schwäche oder Druckempfindlichkeit unverzüglich zu melden. Die Statintherapie soll in einem solchen Falle sofort sistiert werden. Muskelsymptome und eine CK-Erhöhung über das Zehnfache der Norm sind diagnostisch für eine Myositis, welche nach sofortigem Absetzen der Therapie meist zurückgeht. Generell gilt die Empfehlung, vor Beginn der Therapie Lipidprofil, Leberwerte und CK zu bestimmen, sie dann nach drei und nach sechs Wochen und schliesslich jährlich nachzukontrollieren.

A case of polymyositis with anti-histidyl-t-RNA synthetase (Jo-1) antibody syndrome following extensive vinyl chloride exposure

Occupational exposure to vinyl chloride monomers is known to induce Raynaud's phenomenon, periportal fibrosis, liver angiosarcoma and scleroderma-like syndrome. We report the first case of occupational polymyositis in a 58-year-old man exposed to vinyl chloride. A dysimmune process was strongly suspected as having induced vinyl chloride disease. Our patient had an anti-histidyl-t-RNA-synthetase (Jo1) antibody, which has never to our knowledge been reported in this occupational disease.

A case of polymyositis with dilated cardiomyopathy associated with interferon alpha treatment for hepatitis B

Polymyositis is a rare complication of interferon alpha treatment as a result of immune-modulating role of the drug itself. In this case, interferon alpha induced polymyositis and cardiomyopathy is diagnosed in a 33-yr-old male patient with history of chronic hepatitis B. To treat hepatitis B, interferon alpha was administered until the proximal muscle weakness developed. Thereafter, sixteen cycles of immunoglobulin treatment (400 mg/kg) along with corticosteroids were instituted and led to an improvement in subjective symptoms with decreases in level of CPK and LDH. However, dilated cardiomyopathy has not improved in spite of the cessation of interferon treatment. Unlike the persistently elevated serum HBV DNA level, the serum ALT and AST levels have gradually decreased. Our case shows that clinical symptoms of polymyositis improved with steroid and immunoglobulin treatment without deterioration of the hepatitis B. To our knowledge, this is the first case of polymyositis associated with dilated cardiomyopathy after the administration of interferon in a patient with hepatitis B.

Polymyositis occurring during alpha-interferon treatment for malignant melanoma: a case report and review of the literature

Polymyositis is a systemic autoimmune disorder characterised by proximal muscle weakness which most frequently involves the limbs, neck and trunk. Alpha interferon is an antiviral molecule with well-known immunomodulatory and antiproliferative effects, but its use is often associated with a variety of side effects, in particular autoimmune phenomena. We report the occurrence of polymyositis during treatment with alpha-interferon in a patient affected by malignant melanoma. Indirect evidence suggests that in this case the patient's myositis was not linked to her neoplasia, since the melanoma was confirmed to be in remission both at the time of the diagnosis of the muscle disease and again after more than one year of follow-up.

Polymyositis with respiratory muscle weakness requiring mechanical ventilation in a patient with metastatic thymoma treated with octreotide

Although most patients with thymoma present with a mediastinal mass amenable to surgical resection, some patients develop metastatic disease requiring systemic therapy. The majority of thymomas express somatostatin receptors as demonstrated by octreotide scanning, an observation which has prompted the clinical use of octreotide in patients with this disease. Many patients with thymoma exhibit autoimmune paraneoplastic syndromes, most frequently myesthenia gravis. We report here the case of a patient with metastatic thymoma who developed a profound autoimmune polymyositis and lupus-like syndrome that flared following treatment with octreotide and was associated with a clinical response to this agent. No evidence for myesthenia gravis was discovered. The severity of the myopathy necessitated mechanical ventilation for 12 weeks. The natural history of thymoma, treatment options including recent combination chemotherapy regimens, and potential mechanisms for flaring of autoimmune paraneoplastic syndromes triggered by therapy of thymoma are discussed.

[Polymyositis induced by tiopronine]

BACKGROUND

D-penicillamine-induced muscle disorders are well-known, tiopronine-induced disorders are less often reported.

CASE REPORT

A 62-year-old patient, given tiopronine for rheumatoid arthritis, developed severe polymyositis with characteristic clinical and pathology features. The course was favorable after tiopronine withdrawal and substitution with methotrexate.

DISCUSSION

Clinicians should be aware of the side-effects of tiopronine, particularly muscle disorders, and implement careful surveillance to achieve early diagnosis and appropriate therapy.

[D-penicillamine-induced pemphigus, polymyositis and myasthenia]

BACKGROUND

D-penicillamine can induce autoimmune disease, particularly in patients with associated immune disorders.

CASE REPORT

A 67-year old woman who had been taking D-penicillamine for 15 months for rheumatoid arthritis was hospitalized due to the development of a bullous eruption and proximal muscle deficiency. Search for intercellular antisubstance antibodies in serum was negative. The skin biopsy histology revealed intra-epidermal cleavage in the mucosal body and direct immunofluorescence revealed epidermal frame-marking with anti-IgG and anti-C3 antibodies. Other tests revealed muscular cytolysis, and anti-acetylcholine receptor antibodies. The electromyogram showed neuromuscular block without muscle deficiency and muscle biopsy showed moderate myositis. D-penicillamine was interrupted and was followed by cure of the pemphigus and aggravation of the myositis, requiring high-dose systemic corticosteroid therapy.

DISCUSSION

This patient developed D-penicillamine induced pemphigus, a rather frequent observation. The desmoglein immunolabelling favored drug-induced pemphigus and the course was rapidly favorable after withdrawal. Pemphigus had developed simultaneously with signs of myasthenia and polymyositis. Polymyositis and myasthenia are also known complications of D-penicillamine therapy. The association of these three complications suggests that D-penicillamine can unmask certain antigens or have an immunomodulator effect.

Polymyositis developing after prolonged injections of pentazocine

Pentazocine is a frequently used analgesic drug. Numerous complications have been reported in association with its use, including skin fibrosis, skin ulceration, abnormal skin pigmentation and symmetrical myopathy. Fibrous myopathy is a rare but conspicuous complication of prolonged pentazocine injection. However, inflammatory myopathy has not previously been related to this substance abuse. We describe a patient who developed polymyositis after 13 months of pentazocine injections.

The first case of polymyositis associated with interferon therapy

A 54-year-old man with renal cell carcinoma was treated with interferon (IFN)-gamma for 3 weeks soon after nephrectomy. Three months later he received IFN-alpha therapy for 8 weeks due to chronic active hepatitis C. He subsequently contracted polymyositis (PM): proximal muscle weakness, an elevation of muscle enzymes, myogenic patterns on the electromyograph and histologically specific findings in biopsied muscle specimens. After discontinuation of IFN his muscular weakness gradually recovered.

Is there an association between injectable collagen and polymyositis/dermatomyositis?

OBJECTIVE

Recent case reports have raised the possibility that use of injectable bovine collagen may be associated with polymyositis/dermatomyositis (PM/DM). Because the number of collagen users is high, PM/DM would be expected to occur in some for reasons unrelated to the collagen use. A central issue is whether the number of observed cases exceeds the number expected on the basis of background rates alone. The present study was undertaken to investigate this.

METHODS

The number of observed cases was determined by review of the medical records of collagen users who had reported illnesses consistent with PM/DM: Because of the uncertainty about diagnosis of PM/DM, population incidence rates, number of patients treated with collagen, and duration of followup after treatment, we examined a range of estimates of each of these factors that would affect the expected number of cases.

RESULTS

From reports among collagen users, 7 probable or definite cases of PM/DM were confirmed. In contrast, 13 cases would be expected based on the best estimates of relevant factors. Under the most conservative estimates for factors that influence the number of expected cases, 12 cases would be expected, while worst-case assumptions would yield an expected 130 cases.

CONCLUSION

The consistent finding of fewer-than-expected PM/DM cases among collagen users suggests that collagen use is not associated with the development of PM/DM:

D-penicillamine induced polymyositis causing complete heart block

We describe a 63-year-old female patient with rheumatoid arthritis who developed complete heart block and features of polymyositis within a few weeks of starting treatment with D-penicillamine. We believe she is one of only three published patients in whom complete heart block accompanies penicillamine-induced polymyositis. The literature on penicillamine myositis is reviewed with special emphasis on cardiac problems. Patients taking D-penicillamine who develop features suggestive of polymyositis may develop insidious, but potentially life-threatening cardiac involvement and must be carefully monitored.

D-penicillamine and polymyositis: the significance of the anti-Jo-1 antibody

A 57-yr-old lady developed polymyositis whilst taking D-penicillamine for RA. D-Penicillamine-induced polymyositis occurs in RA with a greater frequency than idiopathic polymyositis. Anti-acetyl choline receptor antibodies and ANA were positive, consistent with drug-induced disease. Anti-Jo-1 antibodies are considered specific for idiopathic myositis, and their presence was unexpected. Following withdrawal of the drug, the disappearance of the anti-Jo-1 and other antibodies coincident with clinical improvement, suggested that D-penicillamine was responsible for inducing antibody production.

Idiopathic polymyositis complicated by arthritis and mesangial proliferative glomerulonephritis: case report and review of the literature

A 56-yr-old male developed a systemic illness while receiving cyclical oral etidronate therapy for idiopathic osteoporosis. The illness, characterized by fever, proximal myopathy and inflammatory synovitis, was associated with interstitial lung disease and mesangial proliferative glomerulonephritis. Elevated plasma creatine phosphokinase level and inflammatory muscle biopsy findings confirmed a diagnosis of polymyositis (PM). Antibodies to Jo-1 were also detected. A review of the literature reveals that mesangial proliferation is the commonest glomerular lesion and suggests a possible association between arthritis and glomerulonephritis in PM. The prognosis of this renal lesion appears to be good, although only limited data is available.

A case of polymyositis in a patient with primary biliary cirrhosis treated with D-penicillamine

Although D-penicillamine has been used for many rheumatologic diseases, toxicity limits its usefulness in many patients. Polymyositis/dermatomyositis can develop as one of the autoimmune complications of D-penicillamine treatment, but its exact pathogenesis remains unclear. We report a patient with primary biliary cirrhosis, who developed polymyositis while receiving D-penicillamine therapy. We described the special clinical course of the patient. Patients receiving D-penicillamine therapy should be followed carefully for the development of autoimmune complications like polymyositis/dermatomyositis.

Inflammatory and toxic myopathies

The major advances in the immunopathogenesis and treatment of inflammatory myopathies, and the main criteria that distinguish polymyositis (PM) from dermatomyositis (DM) or inclusion-body myositis (IBM) are presented. The origin and implications of the amyloid and ubiquitin deposits found within the vacuolated fibers of patients with IBM are considered. The pathogenesis of human immunodeficiency virus (HIV) and human T-cell lymphotrophic virus (HTLV)-I-associated PM is presented, and the role of retroviruses in triggering PM, even in the absence of detectable viral genome within the muscle fibers, is discussed. In addition, three toxic myopathies with distinct morphologic, biochemical, or molecular characteristics, caused by zidovudine [azidothymidine (AZT) myopathy], the cholesterol-lowering-agent myopathy (CLAM), and the combination of blocking agents with corticosteroids are presented.