Cytotoxic and genotoxic monitoring of sickle cell anaemia patients treated with hydroxyurea.

Very satisfactory results have been obtained with the treatment of sickle cell anaemia with hydroxyurea (HU), an antineoplastic drug. This is because it significantly increases the levels of foetal haemoglobin. Nevertheless, inadequate dosages or prolonged treatment with this pharmaceutical can provoke cytotoxicity or genotoxicity, increasing the risk of neoplasia. We monitored patients under treatment with HU for possible mutagenic effects, through cytogenetic tests (mitotic index and chromosome aberrations) for one year. Checking at two-month intervals, the cytotoxic effect was not evident. There was no evidence of genotoxicity under the conditions of our experiment. However individuals treated with HU should be constantly monitored, as an absence of genotoxicity could be transitory; the mitotic index should also be observed, as an indicator of cytotoxicity.