MM and encephalopathy

 Q: 59 years old male with recently diagnosed multiple myeloma (MM) is admitted to ICU with encephalopathy. Ammonia level is noted to be high. The most likely cause of encephalopathy in this patient is liver failure. 

A) True

B) False

Answer:  B

The objective of this question is to highlight the fact that there are many other reasons besides liver insufficiency for hyperammonemia. Many of these causes are well known and many remain undiagnosed. It includes multiple myeloma, acute leukemia, infections, unmasked urea cycle defects in stressful situations, and drugs. 

Myeloma cell lines produce high ammonia, and chemotherapy resolves the pathology.

#metabolism

References:

1. Kwan L, Wang C, Levitt L. Hyperammonemic encephalopathy in multiple myeloma. N Engl J Med 2002; 346:1674. 

2. Upadhyay R, Bleck TP, Busl KM. Hyperammonemia: What Urea-lly Need to Know: Case Report of Severe Noncirrhotic Hyperammonemic Encephalopathy and Review of the Literature. Case Rep Med. 2016;2016:8512721. 

3. Talamo G, Cavallo F, Zangari M, et al. Hyperammonemia and encephalopathy in patients with multiple myeloma. Am J Hematol 2007; 82:414.