Letter: Salicylate-induced hepatic injury

Human ES and iPS cells display less drug resistance than differentiated cells, and naïve-state induction further decreases drug resistance

Pluripotent stem cells (PSCs) possess unique characteristics that distinguish them from other cell types. Human embryonic stem (ES) cells are recently gaining attention as a powerful tool for human toxicity assessment without the use of experimental animals, and an embryonic stem cell test (EST) was introduced for this purpose. However, human PSCs have not been thoroughly investigated in terms of drug resistance or compared with other cell types or cell states, such as naïve state, to date. Aiming to close this gap in research knowledge, we assessed and compared several human PSC lines for their resistance to drug exposure. Firstly, we report that RIKEN-2A human induced pluripotent stem (iPS) cells possessed approximately the same sensitivity to selected drugs as KhES-3 human ES cells. Secondly, both ES and iPS cells were several times less resistant to drug exposure than other non-pluripotent cell types. Finally, we showed that iPS cells subjected to naïve-state induction procedures exhibited a sharp increase in drug sensitivity. Upon passage of these naïve-like cells in non-naïve PSC culture medium, their sensitivity to drug exposure decreased. We thus revealed differences in sensitivity to drug exposure among different types or states of PSCs and, importantly, indicated that naïve-state induction could increase this sensitivity.

Hepatotoxicity associated with choline magnesium trisalicylate: case report and review of salicylate-induced hepatotoxicity

A case of a 21-year-old woman who had developed mild hepatotoxicity while receiving choline magnesium trisalicylate therapy is described. She presented with fever and mild hepatic enzyme elevations before salicylate therapy was instituted. Liver function tests (LFT) returned to normal within five days of hospitalization but she continued to develop daily fevers. Blood, urine, and throat cultures were negative. An acute viral illness or reactivation of systemic lupus erythematosus were the suspected diagnoses. Choline magnesium trisalicylate was then administered in an effort to control her fever, and was successful. After three days of salicylate therapy her LFT values began to rise. They continued to rise for five more days before salicylate hepatotoxicity was suspected. Choline magnesium trisalicylate was discontinued after eight days and the patient's LFT quickly returned to normal. The source of fever was never identified, although infection with cytomegalovirus was considered the most likely cause. Salicylate-induced hepatotoxicity is reviewed.

Hepatotoxicity following the therapeutic use of antipyretic analgesics

The potential for hepatic injury associated with the therapeutic use of salicylates and acetaminophen has recently attracted considerable attention. About 300 cases have been reported in which elevated transaminase levels or other evidence of hepatic injury developed following treatment with salicylates. Review of the spectrum of abnormalities reveals a group of patients (4 percent) with symptomatic liver damage in whom progressive or chronic liver disease is a possibility with continued use of the drug. In a few patients in this group, jaundice developed; several had abnormal prothrombin times; 11 (70 percent) had transaminase values in excess of 500 units; and five patients (30 percent) had encephalopathy and/or Reye's syndrome. In several reports liver damage has also been associated with the use of acetaminophen in therapeutic or near-therapeutic dosages. Of 18 patients, nine appeared to have ingested acetaminophen in amounts approaching overdose. Of the remaining nine patients, six were alcoholics. In the entire group, only five patients did not have a history of alcohol abuse; in three, glutathione depletion was suggested as a possible explanation for hepatotoxicity. The association with alcoholism or glutathione depletion suggests that host susceptibility may play a critical role. In two patients, long-term use of acetaminophen resulted in liver injury suggestive of chronic active hepatitis, possibly on the basis of an idiosyncratic reaction. In a study of chronic liver disease, acetaminophen half-life was prolonged (168 percent) without accumulation at 4 g a day over five days. In a double-blind, two-week, cross-over study, no clinical or laboratory evidence of adverse effects was found. There is, therefore, no evidence that chronic liver disease increases the risk of hepatotoxicity following the administration of acetaminophen in therapeutic doses. Thus, acetaminophen is the preferred antipyretic analgesic in patients with liver disease. Salicylates should be avoided since many of the adverse effects associated with these drugs are similar to the complications of chronic liver disease.