Related Experiment Video
Updated: Apr 30, 2026

Detection of Anti-MDA5 Autoantibodies Using HeLa Cells and Immunocytochemistry with Light Microscopy
Published on: October 31, 2025
Anti-HMGCR autoantibodies in European patients with autoimmune necrotizing myopathies: inconstant exposure to statin
Yves Allenbach1, Laurent Drouot, Aude Rigolet
1From the AP-HP, Hôpital Pitié-Salpêtrière, Department of Internal Medicine 1 and Inflammation-Immunopathology-Biotherapy Department (I2B), East Paris Neuromuscular Diseases Reference Center, Inserm U974, Université Pierre et Marie Curie, Paris 6, Paris (YA, AR, SH, O. Benveniste); Inserm, U905, Immunology Department, Normandie Univ, IRIB and Rouen University Hospital (LD, FJ, JM, O. Boyer); AP-HP, Hôpital Pitié-Salpêtrière, Department of Immunochemistry, Université Pierre et Marie Curie, Paris 6, Paris (JLC, LM); AP-HP, Hôpital Pitié-Salpêtrière, Institute of Myology, Unite de Morphologie Musculaire, CNRS-UMR7215, Paris (NBR); AP-HP, Hôpital Pitié-Salpêtrière, Department of Neuropathology, Université Pierre et Marie Curie, Paris 6, Paris (TM, OD); AP-HP, Hôpital Pitié-Salpêtrière, Department of Neurology, East Paris Neuromuscular Diseases Reference Center, Université Pierre et Marie Curie, Paris 6, Paris (AB, PL, TS, BE); AP-HP, Hôpital Cochin Centre de Référence Maladies Auto-Immunes et Systémiques Rares, Service de Médecine Interne Pôle Médecine, Université René Descartes Paris V, Paris (NCC, BT); APHM, Hôpital la Timone, Centre de Référence des Maladies Neuromusculaires, Marseille (ECS); Clermont-Ferrand University Hospital, Department of Rheumatology, Clermont-Ferrand (AT); AP-HP, Hôpital Necker, Department of Paediatric Rheumatology, Paris (BBM); AP-HP, Hôpital Bicêtre, Department of Paediatric Rheumatology, Kremlin-Bicêtre, Paris (IKP); CHU Strasbourg, Department of Rheumatology, Strasbourg (JS); Hôpital Pitié-Salpêtrière, Institute of Myology, Paris (LS); AP-HP, Hôpital Jean Verdier, Department of Internal Medicine, La Seine-Saint-Denis (OF); AP-HP, Hôpital Avicenne, Department of Internal Medicine, Bobigny (CL); CHRU Tours, Department of Internal Medicine, Tours (ED); Fondation A. de Rothschild, Department of Neurology, Paris (RDP); AP-HP, Hôpital Bichat, Department of Internal Medicine, Paris (AD); CHU Rennes, Department of Neurology, Rennes (DM); Centre Hospitalier de la Region d'Annecy, Department of Internal Medicine, Annecy (CM); Hôpital Pierre Oudot, Department of Internal Medicine, Bourgouin (MR); Hôpital du Haut Levêque, Department of Neurology, Bordeaux (XF); CHU Rennes, Department of Internal Medicine, Rennes (SB, BG); CHU Fort de France, Department of Neurology, Fort de France (RM); AP-HP, Hôpital Pitié-Salpêtrière, Departement Hospitalo-Universitaire I2B, UPMC Univ Paris 06, UMR 7211, INSERM, UMRS 959, Department of Internal Medicine 2, Paris (PC, LA); France.
Abstract:
Necrotizing autoimmune myopathy (NAM) is a group of acquired myopathies characterized by prominent myofiber necrosis with little or no muscle inflammation. Recently, researchers identified autoantibodies (aAb) against 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) in patients with NAM, especially in statin-exposed patients. Here we report what is to our knowledge the first European cohort of patients with NAM.The serum of 206 patients with suspicion of NAM was tested for detection of anti-HMGCR aAb using an addressable laser bead immunoassay. Forty-five patients were found to be anti-HMGCR positive. Their mean age was 48.9 ± 21.9 years and the group was predominantly female (73.3%). Statin exposure was recorded in 44.4% of patients. Almost all patients had a muscular deficit (97.7%), frequently severe (Medical Research Council [MRC] 5 ≤3 in 75.5%). Subacute onset (<6 mo) was noted for most of them (64.4%). Nevertheless, 3 patients (6.6%) had a slowly progressive course over more than 10 years. Except for weight loss (20%), no extramuscular sign was observed. The mean CK level was high (6941 ± 8802 IU/L) and correlated with muscle strength evaluated by manual muscle testing (r = -0.37, p = 0.03). Similarly, anti-HMGCR aAb titers were correlated with muscular strength (r = -0.31; p = 0.03) and CK level (r = 0.45; p = 0.01). Mean duration of treatment was 34.1 ± 40.8 months, and by the end of the study no patient had been able to stop treatment.This study confirms the observation and description of anti-HMGCR aAb associated with NAM. The majority of patients were statin naive and needed prolonged treatments. Some patients had a dystrophic-like presentation. Anti-HMGR aAb titers correlated with CK levels and muscle strength, suggesting their pathogenic role.
Related Concept Videos
Myasthenia Gravis: Overview and Treatment
These antibodies interfere with the function of the nicotinic receptors in three ways: by binding to the receptor and disrupting acetylcholine binding; by causing cross-linking of receptors which...
Myasthenia Gravis: Diagnostic Tests
The edrophonium test is a diagnostic tool for myasthenia gravis. It involves...
Myasthenia Gravis ll: Pathophysiology
Lipid-Lowering Drugs: Statins and Miscellaneous Agents
Myocarditis III: Medical Management
Autoimmune Disorders
Concept and Mechanism of Autoimmune Diseases
The immune...

