Is NAM autoimmune necrotizing myopathy treatable

Statins can rarely cause necrotizing autoimmune myopathy. But the muscle complaints are not always attributable to the drug. One patient apparently overdid her healthy diet.

In rare cases, necrotizing myopathy can occur as a complication of statin therapy. Autoantibodies against the enzyme HMG-CoA reductase, which is inhibited by statins, can often be detected in these patients.

In an unusual case report, however, such lipid-lowering therapy could not have been the cause of the muscle complaints.

Doctors around Dr. Ariane Barbacki from Davis Jewish General Hospital in Montreal reported on a 57-year-old patient who had suffered from severe progressive myalgia and muscle weakness for two weeks. The muscle complaints concerned the shoulder muscles as well as the hip and neck flexors. The muscle biopsy showed severe fiber necrosis and moderate lymphocyte inflammation.

Laboratory diagnostics suggest statins as the cause

According to laboratory diagnostics, statin therapy is a possible cause of the necrotizing myopathy. The serum creatine kinase value was significantly increased at 161.2 µkat / L (9,672 U / L); a value between 0.4 and 4.0 µkat / L (24–240 U / L) would be normal. HMG-CoA reductase antibodies could be detected in an enzyme immunoassay. The tests for other myositis-specific autoantibodies were negative.

However, the woman had not taken any statins or any other suspicious food supplements such as red mold rice or other substances. Red mold rice has a cholesterol-lowering effect because it contains monacolin K, the ingredient in lovastatin.

Looking at the menu is suspicious

Then what was the cause of the woman's discomfort? A look at the menu made the doctors treated suspicious. The woman has eaten two cups of red rice from the Camargue every day for the past few months, not to be confused with the red mold rice, which is usually not eaten as food.

Barbacki and colleagues estimate that the patient had ingested around 2 grams of phytosterols per day from consuming such amounts of travel. Phytosterols are the main component of plant cell membranes and are similar in structure to cholesterol. They are said to have a slight cholesterol-lowering effect, presumably due to the competitive inhibitory effect on cholesterol absorption in the intestine.

Such a supply of phytoterines could lower the LDL cholesterol level by 10 to 15%, report the doctors. They therefore suspect that the woman's diet was the cause of the necrotizing autoimmune myopathy.

Rule out statin therapy as the cause of the disease in around 65% of affected patients with a positive detection of HMG-CoA reductase antibodies. According to Canadian doctors, the remaining cases may be due to a special diet. As far as you know, this is the first case in which this connection has shown itself so clearly.

The woman was initially treated with prednision 60 mg / day and subsequently with immunoglobulins 2 g / kg body weight every 4 weeks, which relieved her muscle complaints.