Effects of dengue virus infection on peripheral blood cells of mice exposed to hexavalent chromium with drinking water.

BACKGROUND & OBJECTIVE: The occupational and non-occupational exposure to hexavalent chromium Cr (VI) is common. The effect of chromium compromises the immune response of the host. Dengue virus (DV) infection causes various changes in the peripheral blood cells. It is, therefore, possible that the chromium toxicity may affect the disease process during DV infection. The present study aims to study the effects of dengue virus infection on peripheral blood cells of mice fed Cr (VI) with drinking water.

METHODS

One group of mice was given ad libitum drinking water containing Cr (VI) and the other group used as the normal control mice was given plain water to drink. At the 3, 6 and 9 wk of Cr (VI) drinking, a set of mice from each group was inoculated intracerebrally (ic) with DV and studied at the 4th and 8th day post inoculation.

RESULTS

It was observed that Cr (VI) drinking led to reduction in lymphocytes, haemoglobin and the haematocrit values while the granulocyte, monocyte and platelet counts were increased. On the other hand, most of the parameters were decreased following inoculation of normal mice with DV. In Cr (VI)-fed mice the effects of DV infection were minimal. The most significant finding of these experiments was that the reduction in platelet counts following inoculation with DV was markedly less in Cr (VI)-fed mice than that in DV-inoculated normal control mice.

INTERPRETATION & CONCLUSION: Cr(VI) compounds have been declared as a potent occupational carcinogen. On the contrary, Cr(III) salts such as chromium polynicotinate, chromium chloride and chromium picolinate, are used as micronutrients and nutritional supplements, and have been shown to exhibit health benefits in animals and humans. Whether therapeutic doses of chromium (III) compounds may be able to prevent the DV-induced fall in platelet counts, needs to be investigated.