CD4 and systemic lupus erythematosus: By the aid of the New Zealand Black/New Zealand White F1 hybrid (B/W) mouse model of SLE, one study showed that TCDD chronic exposure significantly lowered thymic and splenic weights, decreased the percentage of CD4 T cells, and also demonstrated an immunosuppressive effect on the prognosis of SLE, while DDT exposure markedly increased the incidence of albuminuria, reduced uterine weight and appeared to accelerate the development of albuminuria in lupus-prone mice, but had no measurable effects on immunity or mortality in that study [32].