Lora-Tamayo Jaime, Palom Xavier, Sarrá José, Gasch Oriol, Isern Virginia, Fernández de Sevilla Alberto, Pujol Ramón
Department of Internal Medicine, Hospital Universitario de Bellvitge, c/ Feixa Llarga s/n, L'Hospitalet de Llobregat, Barcelona, Spain.
Clin Lymphoma Myeloma. 2008 Dec;8(6):363-9. doi: 10.3816/CLM.2008.n.054.
Hyperammonemic encephalopathy is a rarely reported complication of multiple myeloma (MM). We describe an illustrative case of hyperammonemia in the setting of an immunoglobulin (Ig) D-lambda MM, and perform a systematic review of the English-written literature. Our search yielded 26 more cases. Median age was 64 years, and 54% of patients were male. All presented with progressive impairment of their level of consciousness. Median ammonium concentration was 109 micromol/L (interquartile range, 73-149 micromol/L). Most were IgA type (10 cases), and there were 2 cases of IgD type. Most cases were aggressive or chemotherapy-resistant forms of MM. Eight patients were diagnosed with MM at the same time as the episode of hyperammonemia. Only 1 patient had signs of portal hypertension as a result of concomitant hyperdynamic heart failure. Determination of amino acid in 10 patients showed high levels of glycine, low levels of tyrosine, and a low Fischer ratio. Two patients did not receive chemotherapy and died. Twenty-two out of 25 patients who received chemotherapy against MM showed a decrease in ammonium blood concentration, and of those, 15 survived the episode (68%). Overall mortality was 44%. In conclusion, hyperammonemia is a severe complication of MM, associated with a high mortality. It should be considered in any patient with MM and a low level of consciousness. Chemotherapy directed against MM seems to be the most effective measure in order to achieve normal ammonium levels and clinical improvement.
高氨血症性脑病是多发性骨髓瘤（MM）一种鲜有报道的并发症。我们描述了一例免疫球蛋白（Ig）D-λ型MM患者发生高氨血症的典型病例，并对英文文献进行了系统回顾。我们的检索又发现了26例病例。患者中位年龄为64岁，54%为男性。所有患者均出现意识水平进行性损害。中位血氨浓度为109微摩尔/升（四分位间距，73 - 149微摩尔/升）。多数为IgA类型（10例），IgD类型有2例。多数病例为侵袭性或化疗耐药型MM。8例患者在高氨血症发作时同时被诊断为MM。仅1例患者因合并高动力性心力衰竭出现门静脉高压体征。10例患者的氨基酸测定显示甘氨酸水平升高、酪氨酸水平降低以及费舍尔比值降低。2例患者未接受化疗死亡。25例接受MM化疗的患者中，22例血氨浓度下降，其中15例在发作后存活（68%）。总体死亡率为44%。总之，高氨血症是MM的一种严重并发症，死亡率高。对于任何患有MM且意识水平低下的患者都应考虑到这一情况。针对MM的化疗似乎是使血氨水平恢复正常并实现临床改善的最有效措施。
