Analysis of L-asparaginase induced elevation of blood ammonia and hepatic encephalopathy / 中华血液学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To summarize the incidence of various adverse reactions in the clinical application of L-asparaginase (L-Asp), and to analyze the cause of hepatic encephalopathy in three cases.</p><p><b>METHODS</b>The complete data of 23 patients in our department from December 2009 to December 2010 were collected. Their blood ammonia levels, transaminase, serum albumin and blood coagulation function before, during and after the L-Asp application were assayed.</p><p><b>RESULTS</b>(1) All patients had elevated blood ammonia level after the L- Asp application. This occurred 2 days after the beginning of treatment and the median time to reach peak level (ranged from 194 to 446 μmol/L, with a median value of 300 μmol/L) was 4 days. It returned to normal level after a median time of 5 days (ranged 3-7 days) with drug withdrawal. Of the 23 patients studied, 3 developed hepatic encephalopathy. (2) All patients appeared lower blood fibrinogen, 10 cases (43.5%) with lower fibrinogen only, while 13 cases (56.5%) with both prolonged APTT and lower fibrinogen. The lowest level of fibrinogen was detected at 1 week after drug application. Of the 23 patients, 14 (60.9%) had mild lower blood fibrinogen (1-2 g/L), and 9 (39.1%) had significantly lower fibrinogen (0-1 g/L). (3) Six cases (26.1%) had slightly elevated level of transaminase (<2 times the upper limits of normal), 8 (34.8%) appeared hypoalbuminemia.</p><p><b>CONCLUSION</b>As the incidence of elevated blood ammonia levels was high in the application of L-Asp, the level of blood ammonia should be closely monitored to avoid the occurrence of hepatic encephalopathy, especially in elderly patients and patients with previous liver disease or long-term heavy drinking. L-Asp can also lead to low fibrinogen level, hypoalbuminemia and abnormal transaminase. Monitoring the blood coagulation function and liver function is required and, if necessary, plasma infusion and liver protection therapy are required.</p>