Statin-Associated Autoimmune Myopathy: A Systematic Review of 100 Cases

Management of immune-mediated necrotizing myopathy

The immune-mediated necrotizing myopathies (IMNM) are autoimmune myositides clinically characterized by proximal predominant weakness and elevated creatine kinase (CK). They may be associated with autoantibodies (anti-HMGCR, anti-SRP), triggered by statin use (e.g., anti-HMGCR myopathy), associated with cancer, or may be idiopathic. Immunotherapy is required to improve strength and decrease the CK level, but no therapies are currently approved by the U.S. Food and Drug Administration for the treatment of IMNM. The optimal treatment strategy for IMNM is currently unknown and wide practice variation exists in the management of this condition. However, observational studies and expert opinion suggest that certain therapies may be more effective for the different serological subtypes of IMNM. HMGCR IMNM often responds favorably to intravenous immunoglobulin (IVIG) even as monotherapy. Signal recognition peptide and seronegative IMNM typically require combination immunotherapy, most often consisting of an oral immunosuppressant, corticosteroids, and IVIG or rituximab. Patients often remain on immunotherapy for years and relapse is common during tapering of immunotherapy. Further studies are needed to guide the optimal management of these patients.

Statin-Associated Autoimmune Myopathy Masquerading As Recurrent Falls in an Older Adult

Statins are widely prescribed in clinical practice. Statin-induced myopathy is relatively common, benign, and resolves after statin withdrawal. However, statin-associated autoimmune myopathy is an exceptionally rare and devastating complication that can occur any time after statin initiation. It is characterized by persistent muscle weakness and elevated creatine kinase levels that persist after statin withdrawal. Herein, we present a challenging case of a statin-associated autoimmune myopathy that developed after a decade of atorvastatin use that resulted in debilitating weakness. It is important to recognize cases of myopathies wherein statin discontinuation and aggressive immunosuppressive therapy can reduce morbidity and mortality.

Dysphagia: A Case Report of an Atypical Presentation of Statin-Induced Necrotizing Myositis

Statin medications act by inhibiting the enzyme hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase (HMGCR), thus decreasing hepatic cholesterol synthesis. They are considered the mainstay treatment of hypercholesterolemia due to their tremendous efficacy and mortality benefit. Although generally well tolerated, statins may adversely affect skeletal muscle resulting in side effects ranging from mild myalgia to life-threatening necrotizing myositis. Statin-induced necrotizing autoimmune myositis is a rare yet devastating adverse effect that may occur shortly after initiation of therapy or after several years of use. Unfortunately, medication discontinuation has shown no impact on prevention or alleviation of symptoms. Though there is currently no definitive guidance for the treatment of this condition, corticosteroids are generally considered to be first line, via high-dose oral prednisone or intravenous methylprednisolone. In this case report, we discuss the case of a 72-year-old male with an unusual presentation of statin-induced necrotizing autoimmune myositis: dysphagia, weakness, and weight loss. His diagnosis was confirmed by muscle biopsy indicating necrotizing myositis and his serum was found to be strongly positive for anti-HMG-CoA reductase antibodies. This patient had a very brief history of statin use, but his primary care provider discontinued the medication a couple of months prior to symptom onset due to elevated liver function tests. He was treated with aggressive intravenous fluid hydration and intravenous corticosteroids during an extended inpatient hospital stay. He was discharged to a rehabilitation facility. This report demonstrates the importance of creating a wide differential for patients who present with fatigue, generalized weakness, and dysphagia. It is essential to always consider statin-induced necrotizing myositis if a patient has a history of statin use, even if the statin has been discontinued. Necrotizing myositis demands timely diagnosis and management to improve mortality.

Statin-induced autoimmune myositis: a proposal of an "experience-based" diagnostic algorithm from the analysis of 69 patients

Statin-induced autoimmune myositis (SIAM) represents a rare clinical entity that can be triggered by prolonged statin treatment. Its pathogenetic substrate consists of an autoimmune-mediated mechanism, evidenced by the detection of antibodies directed against the 3-hydroxy-3-methylglutaryl-coenzyme A reductase (anti-HMGCR Ab), the target enzyme of statin therapies. To facilitate the diagnosis of nuanced SIAM clinical cases, the present study proposes an "experience-based" diagnostic algorithm for SIAM. We have analyzed the clinical data of 69 patients diagnosed with SIAM. Sixty-seven patients have been collected from the 55 available and complete case records regarding SIAM in the literature; the other 2 patients represent our direct clinical experience and their case records have been detailed. From the analysis of the clinical features of 69 patients, we have constructed the diagnostic algorithm, which starts from the recognition of suggestive symptoms of SIAM. Further steps provide for CK values dosage, musculoskeletal MR, EMG/ENG of upper-lower limbs and, Anti-HMGCR Ab testing and, where possible, the muscle biopsy. A global evaluation of the collected clinical features may suggest a more severe disease in female patients. Atorvastatin proved to be the most used hypolipidemic therapy.

Management of patients with statin intolerance

Atherosclerotic cardiovascular disease is a leading cause of morbidity and mortality, and statins have become a cornerstone in its treatment and prevention. Despite the well-documented benefits of statins, many patients stop taking them, with adverse muscle symptoms being a commonly cited reason. Although some statin-associated adverse muscle effects are real, some can be attributed to the nocebo effect, which is the patient's perception of harm. The purpose of this article is to review the literature on statin safety, particularly that related to muscle, to analyze adverse effects, and to propose various treatment strategies for the statin intolerant patient.

Correlates of Myopathy in Diabetic Patients Taking Statins

Diabetes is one of the most common chronic ailments; its incidence has reached epidemic proportions in the 21st century. Diabetes significantly increases micro and macrovascular complications, which are effectively managed with statins. Therefore, statins' pharmacokinetics, pharmacodynamics, and pharmacogenetics have been extensively studied. Although statins act as a keystone in preventing cardiovascular complications, at the same time, they pose a threat to the quality of life of diabetics due to the resulting muscular side effects. This article summarizes the prevalence, clinical manifestations, pathophysiology, and risk factors of statin-induced myopathy in diabetic patients. Among the diverse predisposing risk factors, the primary variables identified for causing myopathy in diabetic patients include age, gender, ethnicity, duration and severity of illness, comorbid conditions, level of physical activity, alcohol use, cholecalciferol (vitamin D3) levels, type and dose of statins, and anti-diabetic drugs or other drugs used concomitantly. In addition, cardiovascular risk quotients also potentially impact diabetic patients making them more vulnerable to developing myopathy from statins. Therefore, this study highlights the importance of managing statin-associated myopathic side effects by providing consensus guidelines on diagnostic, monitoring, and treatment strategies. We also discussed statins' prognostic value in reducing cardiovascular events in diabetic individuals.

Statin-associated immune-mediated necrotizing myositis in Native Americans

OBJECTIVES

Statin-associated immune-mediated necrotizing myopathy (IMNM) and idiopathic inflammatory myositis (IIM) are myopathies with overlapping features. This study compared the manifestations of IMNM to IIM in Native Americans.

METHOD

Twenty-one Native American patients with inflammatory myopathy (IM) were characterized as to diabetes mellitus, hyperlipidaemia, statin exposure, myopathy diagnosis, muscle histology, autoimmune and myositis-specific autoantibodies, therapy and outcome.

RESULTS

IM consisted of 52.4% IMNM, 42.9% IIM and 4.8% metabolic myopathy. IMNM vs IIM patients were older [61.6 years (s.d. 9.8) vs 39.8 (14.3)], diabetes mellitus (100% vs 55.6%), hyperlipidaemia (100% vs 33.3%), statin-exposure (100% vs 22.2%), creatine kinase [CK; 11 780 IU (s.d. 7064) vs 1707 (1658)], anti-3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) antibodies (85.7% vs 11.1%) and necrotizing IM (81.8% vs 11.1%), but shorter disease duration [26.2 months (s.d. 395) vs 78.4 (47.9)], RP (9.1% vs 55.6%), cutaneous manifestations (0% vs 55.6%), ANA (18.2% vs 66.7%) or any autoantibody (18.2% vs 88.9%) (all P < 0.05). MRI abnormalities, histologic IM, myositis-specific autoantibodies, pulmonary hypertension, oesophageal dysfunction, interstitial lung disease, disability and persistently elevated CK were similar. IMNM vs IIM was treated more with IVIG (72.7% vs 11.1%; P = 0.009) and less with antimetabolites (45.5% vs 88.9%; P = 0.05) and rituximab (18.2% vs 55.6%; P = 0.09).

CONCLUSIONS

IMNM may occur in Native Americans and is associated with diabetes mellitus, hyperlipidaemia, statin use and older age and is characterized by marked CK elevation, necrotizing myopathy and anti-HMGCR antibodies with few cutaneous or vascular manifestations.

Pearls & Oy-sters: Managing Cholesterol in a Patient With Statin Intolerance Due to Anti-HMG-CoA Reductase-Associated Myopathy

Statins are the first line of treatment for hypercholesterolemia and of prevention of atherosclerotic cardiovascular disease (ASCVD). It is estimated that 1 in 4 Americans over the age of 40 years use statins. In rare cases, patients may develop an autoimmune myopathy associated with antibodies against 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR). Anti-HMGCR-associated myopathy requires immediate discontinuation of statins plus initiation of immunosuppressive therapy. Suspension of statin treatment worsens low-density lipoprotein-cholesterol (LDL-C) control, leading to an increased risk of ASCVD and necessitating commencement of another treatment for dyslipidemia. Unfortunately, the management of dyslipidemia in these patients is still unclear. In this study, we describe the case of a 65-year-old woman with dyslipidemia treated with atorvastatin, who consulted for long-standing muscle pain associated with symmetrical proximal weakness. Laboratory tests showed elevated levels of creatine kinase and anti-HMGCR antibodies. She was diagnosed with an anti-HMGCR-associated myopathy and was successfully treated with corticosteroids and azathioprine as immunosuppressive therapy, followed by ezetimibe for LDL-C reduction. We present key findings for early recognition and treatment of anti-HMGCR-associated myopathy and give recommendations on how to manage hypercholesterolemia in a patient with statin intolerance due to this disease.

Statin-Induced Myositis with Concomitant Myocarditis

Statins are commonly prescribed medications that provide many significant cardiovascular benefits for both primary and secondary prevention in patients with and without coronary artery disease. Known adverse effects of these medications include varying degrees of muscle toxicity, including myalgia, myopathy, and rare cases of necrotizing myositis, hepatic dysfunction, and central nervous system changes. Despite known adverse effects, statins are rarely associated with myocarditis. Statins can cause skeletal muscle myopathy and myositis by upregulating HMG-CoA reductase (HMGCR) in muscle tissue, resulting in antibody-mediated inflammation. A similar proposed mechanism is likely possible within cardiac myocytes. We present a rare case of statin-induced necrotizing myositis with concomitant cardiac involvement. Severe skeletal muscle myositis was confirmed by lower extremity MRI and biopsy findings. In association, elevated and plateaued high-sensitivity troponin without evidence of cardiac ischemia warranted cardiac MRI, which further confirmed myocarditis due to inflammation within a non-vascular distribution. Given its rare presentation, the treatment for statin-induced cardiac toxicity is unclear; however, the patient in this case report was treated with pulse-dose intravenous steroids and indefinite discontinuation of statin medications.

Alopecia Universalis after Treatment with Simvastatin and Ezetimibe: Affects on Family

A alopecia areata (AA) é uma doença autoimune que se desenvolve no couro cabeludo ou em outras partes do corpo. A alopecia universal, que é uma forma rara de alopecia areata, é caracterizada pela perda de pelos que afeta todo o corpo. Nos dois pacientes apresentados, o tratamento com atorvastatina foi iniciado com o diagnóstico de hipercolesterolemia, mas, quando as metas de valores não foram alcançadas, foi iniciado o tratamento com uma combinação de sinvastatina e ezetimiba. Depois de um período de tratamento com sinvastatina e ezetimiba, o distúrbio de AA, o qual começou com a perda de cabelo no couro cabeludo, espalhou pelo corpo todo e se transformou em alopecia universal. Embora as estatinas possam causar alopecia com reações autoimunes, elas geralmente são utilizadas no tratamento da alopecia, por seus efeitos imunomoduladores.

Safety of Statins and Nonstatins for Treatment of Dyslipidemia

This article reviews the safety of statins and non-statin medications for management of dyslipidemia. Statins have uncommon serious adverse effects: myopathy/ rhabdomyolysis, which resolve with statin discontinuation, and diabetes, usually in people with risk factors for diabetes. The CVD benefit of statins far exceeds the risk of diabetes. Statin myalgia, without CK elevation, is likely caused by muscle symptoms with another etiology, or the nocebo effect. Notable adverse effects of non-statin medicines include injection site reactions (alirocumab, evolocumab, inclisiran), increased uric acid and gout (bempedoic acid), atrial fibrillation/flutter (omega-3-fatty acids), and myopathy in combination with a statin (gemfibrozil).

Statin-Associated Autoimmune Myopathy: Review of the Literature

OBJECTIVE

Statin-associated autoimmune myopathy (SAAM) is a rare adverse event characterized by progressive muscle symptoms despite discontinuation, requiring immunosuppressive therapy for remission. The objective of this review was to characterize SAAM, for timely detection, while examining the literature for effective treatment considerations.

METHODS

PubMed search was conducted from 2010 to 2020 was for relevant case series and studies of at least 8 patients displaying muscle discomfort or weakness, anti-HMGCR antibodies, exposure to statins, and biopsies consistent with SAAM.

RESULTS

Three case series and 3 case cohort studies identified 199 patients with SAAM. Exhibiting a mean age of 63.74 years, patients were more likely Caucasian (81%) and female (1.2X), and required a mean duration of 4.75 years before symptomatic. The presentation involved proximal muscle weakness (94%), myalgias (37%) and dysphagia (23%), accompanied by a mean creatinine kinase of 6383 IU/L. Most patients (57%) required 2 or more immunosuppressive (IMS) agents to achieve 62% remission. After 2 years of treatment, 15% of patients without remission reported symptomatic improvement, while another 12% were refractory to treatment.

CONCLUSION

Delayed onset of SAAM greater than 4 years from statin initiation may create a low index of suspicion. However, progression of symptoms beyond 2 months from statin discontinuation and positive anti-HMGCR antibodies requires immunosuppressive agents. Data and expert opinion support use of at least two IMS medications upon diagnosis for a minimum of 2 years. Therapy success depends on timely recognition and initiation of IMS combinations to achieve earlier remission and symptomatic improvement.

[Subacute Flaccid Tetraparesis]

Subacute Flaccid Tetraparesis Abstract. The patient presented herself with a subacute flaccid tetraparesis. After clinical examination, laboratory analysis, EMG, MRI and muscle biopsy we diagnosed a statin-associated immune-mediated necrotizing myopathy. Neurorehabilitation and prednisolone therapy as well as immunomodulatory therapy with azathioprine did not result in remission. After two cycles of Privigen®, the patient was almost symptom-free and no longer restricted in everyday life; the CK fell to 400U/l.

Immune-Mediated Myopathy in a Patient Presenting for Melanoma Resection and Sentinel Lymph Node Biopsy

Statin-induced necrotizing autoimmune myopathy (SINAM) is a rare side effect in people who are taking a class of drugs called statins. Patients with SINAM will present with subacute severe symmetric proximal muscle weakness. In contrast to more common myopathies, SINAM may not spontaneously resolve with statin discontinuation. These patients may require long-term immunotherapy to limit further disease progression. In this case study, we report a 74-year-old female with SINAM who presented for radical excision of a right upper back melanoma and sentinel lymph node biopsy at an outpatient facility. An anesthetic plan was crafted with the use of a supraglottic airway device without neuromuscular blockade.

A Case Series of Statin-Induced Necrotizing Autoimmune Myopathy

The use of statins has been increasing over the past decade for the primary and secondary prevention of cardiovascular disease worldwide. Subsequently, various side effects have also been unfolding. Muscle-related side effects secondary to statins range from myalgia to rhabdomyolysis and need close monitoring for early detection. Statin-induced necrotizing autoimmune myopathy (SINAM) in particular is unique given its pathophysiology, trigger factor, genetic predisposition, and aggressive management strategy. We present two cases of SINAM and discuss the clinical aspects of diagnosis, investigation, and management. Statin-induced necrotizing autoimmune myopathy usually presents with proximal myopathy along with increased creatinine kinase (CK) levels which do not resolve with only statin discontinuation. Diagnosis should be made with biopsy and 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) antibody detection. The investigation should also be directed to rule out other etiology of proximal myopathy. In most cases, rechallenge with a statin is unsuccessful and immunosuppressive treatment is essential.

Effect of statins use on risk and prognosis of breast cancer: a meta-analysis

The findings regarding the association between statins use and breast cancer are inconsistent. Given the widely and long-term use of statins as first choice drug for dyslipidemia, we conducted this meta-analysis for better understanding the associations between statins use and the risk and prognosis of breast cancer. Articles regarding effect of statins use on risk, prognosis of breast cancer and published before January 2021 were searched in the following databases: Web of Science, PubMed, EMBASE, Medline and Google Scholar. Odds ratios (ORs)/relative risks (RRs) or hazard ratios (HRs) and their 95% confidence intervals (CIs) were computed to generate a pooled effect size and 95% CI. The meta-analysis showed no significant association between statins use and risk of breast cancer (OR/RR = 1.02; 95% CI, 0.97-1.08; I2 = 76.1%; P < 0.001). The meta-analysis showed that statins use was associated with lower breast cancer recurrence, all-cause mortality and disease-specific mortality (breast cancer recurrence: HR = 0.75; 95% CI, 0.67-0.84; I2 = 31.7%; P = 0.154; all-cause mortality: HR = 0.82; 95% CI, 0.77-0.89; I2 = 67.5%; P < 0.001; and disease-specific mortality: HR = 0.82; 95% CI, 0.72-0.93; I2 = 83.6%; P < 0.001). Overall, in this report we demonstrated that the use of statins can improve the prognosis of breast cancer patients including lower risks of breast cancer recurrence, all-cause and cancer-specific mortality, though statins therapy may not have an impact on reducing the risk of breast cancer.

Combined Central Retinal Vein and Cilioretinal Artery Occlusion in the Setting of Intravenous Immunoglobulin Administration

Purpose:

This work reports a case of combined vascular occlusion in the setting of intravenous immunoglobulin (IVIg) administration.

Methods:

The authors describe a case of combined central retinal vein and cilioretinal artery that occurred in the setting of IVIg administration.

Results:

A 52-year-old White man presented with a unilateral subjective scotoma that began during IVIg administered for the treatment of statin-induced necrotizing autoimmune myopathy. Examination and optical coherence tomography imaging revealed a combined nonischemic central retinal vein and cilioretinal artery occlusion.

Conclusions:

To the authors’ review and knowledge, this is the first reported case of combined central retinal vein and cilioretinal artery occlusion occurring in the setting of IVIg administration. This rare adverse effect is an entity to be considered in patients who are treated with IVIg.

Statin-Associated Necrotizing Myopathy Leading to Acute Kidney Injury: A Case Report

Statins or 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors are a mainstay of cardiovascular disease therapy. In addition to their lipid-lowering capabilities, they exhibit several pleiotropic effects. Their adverse reactions such as myalgias are not uncommon, but in rare cases, the resulting rhabdomyolysis can be fatal. Recently, more insight has been brought into the pathogenesis of statin-induced rhabdomyolysis, and immune-mediated necrotizing myopathies are diagnosed more frequently. We present a case of a female patient who was on chronic rosuvastatin therapy and developed necrotizing myopathy. The disease progressed to acute kidney and liver injury. We discontinued the drug, started supportive measures, and initiated renal replacement therapy with a high cutoff dialysis membrane once. Her recovery was prompt, with a normal control electromyography 2 weeks after discharge.

Statin-induced necrotising autoimmune myopathy: a rare complication of statin therapy

Statin-induced necrotising autoimmune myopathy (SINAM), a rare complication of statin use, presents with significant proximal muscle weakness and raised creatine kinase (CK) levels (50-100 times). This is different from other musculoskeletal conditions caused by statin use. Anti-hydroxy-methyl-glutaryl-coenzyme A reductase (HMG-CoA) reductase antibody is usually positive in SINAM and it generally indicates good response to immunosuppressive medications. We report a case of a 52-year-old man who presented with a 2-month history of significant upper and lower extremity proximal muscle weakness and a CK level of >10 000. He was started on atorvastatin for myocardial infarction 3 years ago. MRI pelvis, including proximal thigh, showed diffuse muscle oedema to all muscle groups. Muscle biopsy was suggestive of necrotising myopathy. His HMG-CoA reductase antibody was also positive. His treatment regimen consisted of immunosuppressants, including steroids. He also required extensive physiotherapy and showed response to treatment when reviewed in the outpatient clinic 9 months later.

Statin-Induced Triad of Autoimmune Myocarditis, Myositis, and Transaminitis

Despite well-established cardiovascular benefits, statins have been associated with myopathic side effects ranging from myalgias to rhabdomyolysis and autoimmune necrotizing myositis. Statins have not been previously shown to cause myocarditis. Our case highlights this rare entity.

Neurological complications of cardiovascular drugs

Cardiovascular drugs are used to treat arterial hypertension, hyperlipidemia, arrhythmias, heart failure, and coronary artery disease. They also include antiplatelet and anticoagulant drugs that are essential for prevention of cardiogenic embolism. Most neurologic complications of the cardiovascular drugs are minor or transient and are far outweighed by the anticipated benefits of treatment. Other neurologic complications are more serious and require early recognition and management. Overtreatment of arterial hypertension may cause lightheadedness or fatigue but often responds readily to dose adjustment or an alternative drug. Other drug complications may be more troublesome as in myalgia associated with statins or headache associated with vasodilators. The recognized bleeding risk of the antithrombotics requires careful calculation of risk/benefit ratios for individual patients. Many neurologic complications of cardiovascular drugs are well documented in clinical trials with known frequency and severity, but others are rare and recognized only in isolated case reports or small case series. This chapter draws on both sources to report the adverse effects on muscle, nerve, and brain associated with commonly used cardiovascular drugs.

Challenges in Treating Statin-Associated Necrotizing Myopathy

Myalgia and mild elevation in muscle enzymes are common side effects of statin therapy. While these symptoms are generally self-limited, in rare cases, statin use is associated with an immune-mediated necrotizing myopathy caused by development of autoantibodies against HMG-CoA reductase. The primary presenting symptom of this condition is progressive symmetric proximal weakness that does not abate or worsens even after cessation of statin therapy and is associated with markedly elevated creatine kinase (CK) levels. To date, no randomized controlled trials have been conducted to identify the most effective treatment for statin-associated autoimmune myopathy. Treatment recommendations involve a combination of steroids and immunosuppressive drugs. This single-center case series highlights the clinicopathologic features diagnostic for statin-associated autoimmune myopathy as well as treatment challenges for the patient population. The series highlights a range of potential presentations, from mildly symptomatic despite highly elevated CK, to severe muscle weakness including dysphagia. Multiple patients required several immunosuppressant medications as well as intravenous immunoglobulin (IVIG) to achieve disease control. In this case series, marked improvement was noted in several diabetic patients with IVIG.

Atorvastatin-Induced Necrotizing Myopathy and its Response to Combination Therapy

Atorvastatin is the most commonly used statin medication to decrease cholesterol levels and prevent atherosclerosis. Myopathy is a reported side effect of atorvastatin which can happen even after more than six months after starting the medication. The side effect on the muscle tissue can range from simple reversible myalgia to respiratory muscle compromise. Here we present a 46-year-old male who presented with myopathy after taking atorvastatin for two years. Biopsy proved immune-mediated necrotizing myopathy which responded to a combination of Rituximab and intravenous immunoglobulin therapy.

A case of statin-associated immune-mediated necrotizing myopathy with atypical biopsy features

Statin-associated immune-mediated necrotizing myopathy (IMNM) is a rare presentation of a statin-associated myopathy. Patients usually present with muscle weakness and pain in the setting of statin use with elevated creatine kinase (CK) levels and a positive anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (anti-HMGCR) antibody. Muscle biopsies typically show necrosis, CD68+ macrophages, and minimal lymphocytes. We present a case of a 67-year-old woman who had 2 months of progressive weakness and bilateral lower extremity pain after initiating atorvastatin therapy with symptoms persisting after statin cessation. She was found to have high anti-HMGCR antibody titers, and the biopsy of the rectus femoris muscle showed a prominent endomysial inflammatory cell infiltrate with necrotic and regenerative fibers and an atypical extensive inflammatory infiltrate composed of both CD4+ helper T cells and CD8+ cytotoxic T cells. She showed symptom resolution and normalization of CK levels and inflammatory markers with treatment involving a prolonged prednisone taper and a brief course of azathioprine, which was stopped because of the adverse effects.

Treatment of Statin-Induced Necrotizing Autoimmune Myopathy With Glucocorticoid Monotherapy

Statins are widely prescribed medications to prevent cardiovascular events such as myocardial infarction and stroke. Both myalgia and myopathy are well-known potential side effects of statins. However, a rare and severe form of statin-induced necrotizing autoimmune myopathy (SINAM) has recently been described and can lead to debilitating weakness, often requiring immunosuppressive therapy. We report a case of a 73-year-old male who made a complete recovery from SINAM following a three-month course of prednisone monotherapy.

Efficacy and Safety of High-Dose Immunoglobulin-Based Regimen in Statin-Associated Autoimmune Myopathy: A Multi-Center and Multi-Disciplinary Retrospective Study

Statin-associated autoimmune myopathy is a rare muscle disorder, characterized by autoantibodies against HMGCR. The anti-HMGCR myopathy persists after statin, and often requires immunosuppressive therapy. However, there is not a standardized therapeutic approach. The purpose of this study is to report the effectiveness of the immunosuppressive treatment employed in a multi-center and multi-disciplinary cohort of patients affected by anti-HMGCR myopathy, in which an immunoglobulin (IVIG)-based treatment strategy was applied. We collected 16 consecutive patients with a diagnosis of anti-HMGCR myopathy, between 2012 and 2019, and recorded data on clinical and laboratory presentation (i.e., muscle strength, serum CK levels, and anti-HMGCR antibody titer) and treatment strategies. Our results highlight the safety and efficacy of an induction therapy combining IVIG with GCs and/or methotrexate to achieve persistent remission of the disease and steroid-free maintenance. Under IVIG-based regimens, clinical improvement and CK normalization occurred in more than two thirds of patients by six months. Relapse rate was low (3/16) and 2/3 relapses occurred after treatment suspension. Nearly 90% of the patients who successfully discontinued GCs were treated with a triple immunosuppressive regimen. In conclusion, an IVIG-based regimen, which particularly includes high-dose immunoglobulin, GCs and methotrexate, can provide a fast remission achievement with GC saving.

Weakness Due to Anemia? Go Fish! Melena as a Red Herring in the Diagnosis of Statin-Induced Myopathy

Statins are a ubiquitous medication class in the primary care setting where they provide effective primary and secondary prevention of coronary artery disease by lowering cholesterol. While statins are mostly safe, muscle-related adverse events are well described. Very rarely patients can actually develop elevated creatine kinase (CK) consistent with myonecrosis. We present a case of progressive anti-hydroxymethylglutaryl coenzyme A reductase (anti-HMGCR) inflammatory myopathy, which was misdiagnosed for many months. Our patient was a 67-year-old gentleman sent to the ER by the Internal Medicine Clinic for profound weakness and melena. He had recently undergone esophagogastroduodenoscopy (EGD) for evaluation of progressive dysphagia and was found to be significantly anemic. Repeat EGD demonstrated a bleeding ulcer, and his weakness was attributed to anemia; however, careful examination demonstrated objective muscle weakness which could not be attributed to anemia alone. Subsequent work-up demonstrated myositis due to HMGCR antibody. Statin cessation and treatment with steroids and intravenous immunoglobulin (IVIG) led to a nearly full recovery in strength and resolution of dysphagia over the next several months.

Statin Associated Autoimmune Myonecrosis: Case Report With Delayed Onset and Treatment Challenges

PURPOSE

A case of delayed statin associated autoimmune myopathy (SAAM) is presented along with review of clinical findings and treatment strategies.

SUMMARY

A 54 year old male presented with proximal extremity weakness, difficulty ambulating, and dysphagia. Symptoms began when restarting atorvastatin 40 mg daily for a recent NSTEMI, following 10 years of statin use, interrupted after diagnosis of NASH. Relevant labs included CK of 13,618 IU/L, ALT/ AST of 568/407 IU/L, while additional liver, renal, and toxicology tests were normal. Following treatment response to prednisone 40 mg daily for 3 days, outpatient testing for anti-HMGCR antibodies was ordered.Twelve days from discharge, the patient was readmitted for myalgia and dysphagia, CK = 6042 IU/L, ALT/AST = 360/112 IU/L, and positive anti-HMGCR antibodies. Newly diagnosed with SAAM, symptoms improved with methylprednisolone and intravenous immunoglobulin (IVIG), continuing outpatient as daily prednisone and monthly IVIG. Four days later, the patient relapsed with worsened weakness and dysphagia, CK = 5812 IU/L, and ALT/AST = 647/337 IU/L. After response to methylprednisolone and rituximab, the patient was discharged on a corticosteroid taper, biweekly rituximab, and monthly IVIG. Two weeks later, a final admission involved a syncopal episode and fall, with a CK = 1461 IU/L. Treatment included IVIG, rituximab, and corticosteroid taper, which lead to remission for greater than 6 months.

CONCLUSION

Statin associated autoimmune myopathy occurred when restarting atorvastatin, following 10 years of statin use. Clinical findings and positive anti-HMGCR antibodies confirmed the diagnosis. Recurrent relapses required triple combination therapy including addition of rituximab to achieve remission.

Optical Clearing of Skeletal Muscle Bundles Engineered in 3-D Printed Templates

Many techniques for engineering and interrogating three-dimensional (3-D) muscle bundles from animal- or patient-derived myoblasts have recently been developed to overcome the limitations of existing in vitro and in vivo model systems. However, many approaches for engineering 3-D muscle bundles rely on specialized and time-consuming techniques, such as photolithography for fabrication and cryosectioning for histology. Cryosectioning also limits visualization to a single plane instead of the entire 3-D structure. To address these challenges, we first implemented a consumer-grade 3-D-printer to rapidly prototype multiple templates for engineering muscle bundles. We then employed our templates to engineer 3D muscle bundles and identify template geometries that promoted bundle survival over three weeks. Subsequently, we implemented tissue clearing, immunostaining, and confocal imaging to acquire z-stacks of intact muscle bundles labelled for myogenic markers. With this approach, we could select the imaging plane on-demand and visualize the intact 3-D structure of bundles. However, tissue clearing did cause some tissue degradation that should be considered. Together, these advances in muscle tissue engineering and imaging will accelerate the use of these 3-D tissue platforms for disease modeling and therapeutic discovery.

Severe statin-induced autoimmune myopathy successfully treated with intravenous immunoglobulin

Statin-induced autoimmune necrotising myopathy causes a severe progressive muscle weakness even when the statins are discontinued. First-line treatment is usually with high dose steroids followed by immunosuppressants, but this is often ineffective and there is a high risk of side effects. We describe a diabetic patient who had a very severe statin-induced autoimmune myopathy. He made a full recovery with regular intravenous immunoglobulin (IVIg) infusion in relatively low dose (55 g the first day followed by 50 g/day the second and third day, subsequently he was given 50 g/day for 3 days every 6 weeks). His symptoms relapsed when the IVIgs were discontinued for 28 weeks but remitted again following recommencement of IVIg infusions (50 g/day for 3 days every 7 weeks). Our case suggests IVIgs are an effective and well tolerated alternative to steroids and immunosuppressants.

Immune mediated necrotizing myopathy: A rare complication of statin therapy

Immune mediated necrotizing myopathy (IMNM) is part of the inflammatory myopathies group of diseases and presents with muscle weakness, myalgias and elevated serum creatine phosphokinase (CPK). Statin-induced IMNM is a rare complication. We present a patient with IMNM secondary to simvastatin use. The patient presented with proximal myopathy, dysphagia, and elevated creatinine kinase levels, and was subsequently found to have anti-3- hydroxy-3-methylglutaryl-CoA reductase (HMGCR) autoantibodies with a necrotizing process on muscle biopsy. This patient’s case was further complicated by sequelae of multiple disease processes, ultimately leading to deterioration of his health.

A Rare Case of Statin-induced Immune-mediated Necrotizing Myopathy

Statin-associated myopathy comprises of a spectrum of conditions ranging from benign myalgias to statin-induced immune-mediated necrotizing myopathy. Statin-induced immune-mediated necrotizing myopathy is an autoimmune condition wherein there is a destruction of normal skeletal muscular architecture that can be severely debilitating if not recognized promptly. Given its rarity, management is a challenge. We present one such case that was managed with aggressive immunosuppression.

A Rapidly Progressive Case of Statin-induced Necrotizing Autoimmune Myopathy

Statins are one of the most commonly used medications to lower cholesterol and have been known to cause various side effects including myalgias, myopathies, and rhabdomyolysis. Statin-induced necrotizing autoimmune myopathy (SINAM), a subtype of inflammatory myopathy, is an exceedingly rare but severe side effect of statin use that manifests as progressive muscle weakness. We describe a rapidly progressive case of SINAM in a 66-year-old Haitian female who developed debilitating symptoms after one month of statin use. Despite aggressive treatment with steroids and immunosuppressants, she failed to regain muscle strength and functional status, and remains on therapy. Given the widespread use of statins, it is important for clinicians to be aware of this condition and its presenting symptoms in order to initiate prompt treatment. 

Statin-induced necrotizing autoimmune myopathy: an extremely rare adverse effect from statin use

Statins are widely prescribed medications to prevent cardiovascular events. While self-limited statin myopathy is relatively common, statin-induced necrotizing autoimmune myopathy (SINAM) is extremely uncommon, with incidence of two cases per million per year. We present a case of SINAM after a decade of atorvastatin use, leading to debilitating weakness. A 71-year-old male presented with recurrent falls due to extreme bilateral lower-extremity weakness without pain or sensory changes. No fever, chills, rash, joint pain, recent infection or medication changes were reported. Reported taking atorvastatin 80 mg daily for 10 years. Physical examination revealed significant muscle wasting on right deltoid and proximal muscle weakness in all extremities. Lab tests included elevated creatinine kinase, aldolase, ESR, CRP and transaminases. Anti-HMGCR antibody was significantly elevated. TSH, serum protein electrophoresis and RPR were unremarkable. ANA, Anti-Jo-1, anti-Mi2, anti-SRP, anti-ds-DNA, anti-SSA and anti-SSB antibodies were negative. MRI of thigh revealed diffuse myositis. Electromyogram revealed an acute myopathic process. Muscle biopsy showed muscle necrosis and C5b-9 sarcolemmal deposits on non-necrotic fibers without rimmed vacuoles. He was diagnosed with SINAM. Statin was discontinued, and steroid, immunoglobulins and azathioprine were started with gradual improvement. Unlike the self-limiting statin myopathy, SINAM is more severe and is associated with significant proximal muscle weakness, markedly elevated CK and persistent symptoms despite statin discontinuation. Anti-HMGCR antibodies are present in 100% of cases. Immunosuppressants are the mainstay of treatment, and statin rechallenge should never be done in these cases. Although relatively rare, physicians should be cognizant of SINAM.

Statin-induced anti-HMGCR antibody-related immune-mediated necrotising myositis achieving complete remission with rituximab

Statin-induced immune-mediated necrotising myopathy (IMNM) is a rare but increasingly recognised myositis. Many cases have positive antibodies to 3-hydroxy-3-methylglutaryl coenzyme A reductase (anti-HMGCR). The current treatment is ceasing the statin, but often immunosuppressive therapy is required as the antibodies persist, causing muscle necrosis. Despite the use of immunosuppressive medications, most commonly prednisolone, methotrexate, plasma exchange and/or intravenous immunoglobulin, some patients do not respond. We report the successful treatment with rituximab therapy for three patients with IMNM with positive anti-HMGCR antibodies. All three patients with statin-induced IMNM were elderly, with a disease history of 7-9 years, and had failed several immunosuppressive agents. They responded well to rituximab (induction and maintenance) therapy. They remain in remission with no symptoms and normal creatine kinase. One patient had normalisation of anti-HMGCR antibody level, and one patient's antibody level reduced significantly. Rituximab is an effective immunosuppressive treatment for patients with refractory IMNM.

Detection of Anti-mitochondrial Antibodies Accompanied by Drug-induced Hepatic Injury due to Atorvastatin

A 44-year-old Japanese woman was admitted to our hospital with fatigue and an altered liver function. She had been receiving atorvastatin treatment for 10 months. Although no jaundice was seen, the patient's serum alkaline phosphatase and γ-glutamyl transpeptidase levels were markedly elevated. Based on the results of a drug-induced lymphocyte-stimulation test, her liver disease was diagnosed as atorvastatin-induced hepatic injury. Subsequently, anti-mitochondrial antibodies (AMAs) were detected in her serum; however, a liver biopsy specimen did not show the characteristic features of primary biliary cholangitis. We herein report the detection of AMAs accompanied by drug-induced hepatic injury caused by atorvastatin.

Statin-induced delayed rhabdomyolysis

An elderly woman with a history of hypertension, hypothyroidism, mesenteric vein thrombosis, depression and hyperlipidaemia on statins for >9 years presented with new-onset leg weakness, falls, dark-coloured urine, transaminitis and rhabdomyolysis (creatinine phosphokinase 12 896 U/L; aldolase 45.9 (normal <7.7 U/L). Workup for autoimmune myositis was negative. The patient had clinical and laboratory improvement with discontinuation of statins with the return of clinical strength and creatinine phosphokinase back to baseline levels (51 U/L) within 2 weeks.

Autoimmune necrotizing myopathy after statin discontinuation

We report a case of autoimmune necrotizing myopathy related to statin use in a 70-year-old woman who came to the hospital because of progressive lower extremity weakness. Laboratory, electromyography and muscle biopsy results were consistent with autoimmune necrotising myopathy. The patient was treated with intravenous immunoglobulin with improvement in muscle strength.

Toxic myopathies

PURPOSE OF REVIEW

Our aim is to highlight major advances reported in the last few years in drug-induced muscle toxicity.

RECENT FINDINGS

Our focus is on myopathies induced by statins and immune checkpoint inhibitors with a brief overview of rare steroid myopathies. Statin muscle injury is frequently because of direct toxicity rather than an autoimmune mechanism. Laboratory testing and muscle pathologic features distinguish these two conditions. Statin-associated necrotizing autoimmune myopathy (SANAM) is associated with an autoantibody in 66% of cases targeting the HMGCR enzyme. The later autoantibody is a marker for necrotizing autoimmune myopathy, regardless of statin exposure. In SANAM, MHC-I antigens are expressed on the surface of intact muscle fibers. Genetic HLA loci predispose patients exposed to statins to immunologic toxicity. SANAM requires long-term therapy with multiple immunosuppressive therapies. Immune checkpoint inhibitors are powerful emerging therapies for advanced cancer that pause a novel therapeutic challenge.

SUMMARY

This review is focused on statins, the most prevalent myotoxic drug class. In addition, we examine the accumulating body of evidence of muscle injury and its management with immune checkpoint inhibitors. We anticipate the reader to become more knowledgeable in recent discoveries related to these myotoxic drugs, and their mechanisms of action and management.