For the past 4 months, Ms. Thu had been receiving treatment for elevated liver enzymes at a hospital. Recently, she experienced fatigue, weight loss, proximal muscle weakness in her shoulders and hips, difficulty rising from a chair, and quick exhaustion when raising her arms. She sought care at Tam Anh Cau Giay General Clinic. Blood tests revealed liver enzyme levels three times higher than normal, and muscle enzyme (CK) levels over 5,000 units, significantly above the normal range of 26-140 units for women. Electromyography showed her arm strength reduced to 4/5 and leg strength to 3/5. Further tests confirmed Ms. Thu was positive for HMGCR antibody, a specific autoantibody for immune-mediated necrotizing myopathy (IMNM).

Doctor Mai Thi Minh Tam, Head of the Department of Musculoskeletal Medicine, stated that the patient's elevated liver enzyme levels were not due to liver damage but rather immune-mediated necrotizing myopathy. This autoimmune muscle disease affects approximately two out of 100,000 people. It occurs when the immune system attacks muscles, causing widespread destruction of muscle cells. This process leaks substances, including ALT and AST enzymes, into the bloodstream, resulting in consistently high levels of these indicators in patients.

If not detected and treated promptly, immune-mediated necrotizing myopathy can lead to muscle necrosis, reduced mobility, and rapid progression to disability.

Ms. Thu walks more steadily after days of treatment. *Photo: Tam Anh General Hospital*.

Ms. Thu was admitted to the hospital and began early treatment to prevent severe complications. Following treatment with anti-inflammatory drugs, high-dose corticosteroids, and immunosuppressants, her liver enzyme levels decreased, and muscle enzyme (CK) levels gradually returned to normal. Her limb strength improved, and she was discharged to continue maintenance treatment at home with regular follow-up appointments.

Medical staff perform immune assays in the diagnosis of autoimmune diseases. *Photo: Tam Anh General Hospital*.

Doctor Tam advised that patients with elevated liver enzyme levels not caused by liver damage should be alert to autoimmune muscle diseases such as: dermatomyositis, polymyositis, and immune-mediated necrotizing myopathy. Severe progression of the disease can damage respiratory muscles like the diaphragm and intercostal muscles, leading to respiratory paralysis; pharyngeal muscles, causing difficulty swallowing; and the heart muscle, resulting in heart failure.

Patients with immune-mediated necrotizing myopathy require monthly monitoring of muscle enzyme (CK) levels during the first 6 months and regular disease management to prevent relapse.

Thanh Long