Cholestatic jaundice associated with danazol therapy

Using Chemical-Induced Gene Expression in Cultured Human Cells to Predict Chemical Toxicity

Chemical toxicity is conventionally evaluated in animal models. However, animal models are resource intensive; moreover, they face ethical and scientific challenges because the outcomes obtained by animal testing may not correlate with human responses. To develop an alternative method for assessing chemical toxicity, we investigated the feasibility of using chemical-induced genome-wide expression changes in cultured human cells to predict the potential of a chemical to cause specific organ injuries in humans. We first created signatures of chemical-induced gene expression in a vertebral-cancer of the prostate cell line for ∼15,000 chemicals tested in the US National Institutes of Health Library of Integrated Network-Based Cellular Signatures program. We then used the signatures to create naı̈ve Bayesian prediction models for chemical-induced human liver cholestasis, interstitial nephritis, and long QT syndrome. Detailed cross-validation analyses indicated that the models were robust with respect to false positives and false negatives in the samples we used to train the models and could predict the likelihood that chemicals would cause specific organ injuries. In addition, we performed a literature search for drugs and dietary supplements, not formally categorized as causing organ injuries in humans but predicted by our models to be most likely to do so. We found a high percentage of these compounds associated with case reports of relevant organ injuries, lending support to the idea that in vitro cell-based experiments can be used to predict the toxic potential of chemicals. We believe that this approach, combined with a robust technique to model human exposure to chemicals, may serve as a promising alternative to animal-based chemical toxicity assessment.

The use of danazol in the therapy of immune-mediated disease of dogs

Currently available therapeutic protocols for immune-mediated diseases in dogs and cats can be associated with poor response rates and a high incidence of side effects. The development of multidrug protocols often results in a synergistic effect that more efficiently suppresses the immune response. One drug that may be added to other therapies is danazol, an androgen with immunomodulating properties. Androgens are known to suppress aberrant immune responses, and the fact that immune-mediated diseases are more common in females supports this. Danazol has been used in humans with immune-mediated hemolytic anemia and thrombocytopenia with some success. Danazol appears to reduce the binding of immuno-globulin and complement to the red blood cell or platelet surface and also may alter cytokine concentrations. The use of danazol in dogs with immunemediated hemolytic anemia and thrombocytopenia has been reported; however, the small number of animals evaluated make it difficult to assess its usefulness in veterinary medicine.

Ultrastructural features of danazol-induced cholestasis: a case study

A case study of a severe cholestatic syndrome induced by danazol, with ultrastructural description of liver morphology, is reported. Cholestasis appeared after 3 months treatment with danazol (300 mg/daily) and completely resolved 2 months after withdrawal. In spite of the severe increase in serum bilirubin and total serum bile salts, transaminases were only slightly elevated and GGT and alkaline phosphatases were almost normal. Light microscopy shows a pattern of predominantly centrolobular cholestasis without necrosis, with minimal inflammatory infiltrate and with no sign of bile ductule involvement. At the ultrastructural level very dilated bile canaliculus predominate with stunted or loss of microvilli and dense bile material in the lumen. Nonspecific alterations were seen in hepatocyte intracellular organelles. It is suggested that danazol may cause a rare but severe hepatocanalicular cholestasis, differing from the "bland" cholestasis frequently described during therapy with other anabolic steroids.