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Toxicological information

Immunotoxicity

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Description of key information

Studies in rodents have shown significant suppression of immune function following exposure to CTC, but only at doses well above those causing liver effects.

Key value for chemical safety assessment

Additional information

From ATSDR toxicological profile (2005):

Studies in rodents have shown significant suppression of immune function following exposure to CTC, but only at doses well above those causing liver effects: “suppression of immune function (reductions in IgM antibody-forming cell activity, T-cell activity, lymphocyte counts, or host resistance to bacteria) has been observed in animals exposed short-term to oral doses of CTC higher than those causing liver effects. Studies in rodents have shown significant suppression of immune function following exposure to CTC. Exposure of female mice to CTC orally at 500 mg/kg/day for 7 consecutive days caused suppression of T-cell-dependent humoral responses to sheep red blood cells. Exposure of rats up to 160 mg/kg/day for 10 days by oral gavage did not alter the primary antibody response to SRBC, natural killer cell activity, or cytotoxic T-lymphocyte responses; also, spleen and thymus weights were comparable to controls. In female mice exposed to daily gavage doses between 50 and 500 mg/kg/day for 14 days (sufficient for hepatotoxicity) the T-cell-dependent humoral response to SRBC was suppressed at ≥ 50 mg/kg/day, serum anti-SRBC IgM titers were reduced at 100 mg/kg/day, and the absolute number and percentage of CD4+CD8- T-cells per spleen was reduced at 500 mg/kg/day.

Justification for classification or non-classification

No classification is proposed.