How does Intravenous Immunoglobulin (IVIG) treatment for rhabdomyolysis or autoimmune necrotizing myositis relate to elevated liver function tests and anemia?

From the Guidelines

Rhabdomyolysis and autoimmune necrotizing myositis with elevated liver function tests and anemia are treated with IVIG at a dosage of 1 to 2 g/kg of ideal body weight, usually given over 2 consecutive days, once a month for 1 to 6 months, as this approach has shown improvement in muscle strength, rash, and activities of daily living (ADL) in patients with dermatomyopathy (DM) 1. The treatment of these conditions involves a multifaceted approach addressing both the primary muscle damage and secondary complications. IVIG therapy is used to modulate the immune response, neutralize pathogenic autoantibodies, and reduce inflammation. Key considerations in the treatment include:

• Monitoring of serum IgA level before administering IVIG to avoid infusion reactions and anaphylaxis in patients with IgA deficiency 1
• Use of IVIG preparations with reduced IgA levels in patients with IgA deficiency
• Administration of IVIG over 3 to 5 days at 0.4 g/kg if the dose is higher than 80 g
• Combination of IVIG with corticosteroids, such as prednisone, and sometimes steroid-sparing agents like mycophenolate mofetil (MMF) 1
• Supportive care, including aggressive IV hydration, monitoring of electrolytes, and treatment of anemia with iron supplementation or erythropoietin if needed The elevated liver function tests often seen in these conditions result from either direct liver involvement or from muscle enzyme spillover, while anemia may develop from inflammatory processes or autoimmune hemolysis. It is essential to reserve the use of cyclophosphamide (CYC) for severe organ manifestations, due to its association with cytopenias, hemorrhagic cystitis, premature ovarian failure, sterility, severe infections, nausea, and vomiting 1.

From the Research

Treatment of Rhabdomyolysis and Autoimmune Necrotizing Myositis

• Rhabdomyolysis is a clinical condition characterized by destruction of skeletal muscle with release of intracellular contents into the bloodstream, which can lead to systemic complications such as elevated liver function tests and anemia 2.
• The treatment of rhabdomyolysis remains controversial, but aggressive intravenous fluid resuscitation (IVFR) is conditionally recommended to improve outcomes of acute renal failure (ARF) and lessen the need for dialysis 3.
• Autoimmune necrotizing myopathy (NAM) is a distinct clinical entity that can be associated with statin therapy, cancer, or connective tissue disease, and is characterized by necrotic muscle fibers with absent or minimal inflammation 4.
• The use of intravenous immunoglobulin (IVIG) has been reported in the treatment of NAM, particularly in cases that are refractory to other immunosuppressive therapies 5.

Relationship between IVIG Treatment and Elevated Liver Function Tests and Anemia

• There is limited evidence on the specific relationship between IVIG treatment and elevated liver function tests and anemia in patients with rhabdomyolysis or NAM.
• However, it is known that IVIG can cause changes in liver function tests, and anemia can be a complication of chronic inflammation and muscle damage in NAM 4, 5.
• Further research is needed to fully understand the relationship between IVIG treatment and these complications in patients with rhabdomyolysis or NAM.

Management of Rhabdomyolysis and NAM

• The management of rhabdomyolysis and NAM requires a multidisciplinary approach, including aggressive fluid resuscitation, immunosuppressive therapy, and close monitoring of liver function tests and hematologic parameters 4, 2, 3.
• Early recognition and treatment of these conditions are crucial to prevent long-term complications and improve patient outcomes 5, 6.