Murine mercury-induced immune-complex disease: effect of cyclophosphamide treatment and importance of T-cells.

The renal immune-complex (IC) disease induced in BALB/c mice by subcutaneous injection of mercuric chloride (1.6 mg/kg b.w.) every third day for 8 weeks was prevented by the intraperitoneal injection of cyclophosphamide (20 mg/kg b.w.) 24 h prior to mercury injection. The importance of T-cells in the induction of immune-complex disease was studied. BALB/c mice given drinking water containing 20 mg/l of HgCl2 for 10 weeks showed an increased titre of granular, mesangial IgG deposits and vessel wall IgG deposits. Identically treated, congenic nude BALB/c mice with a similar body burden of mercury developed no IC-disease. Cytophotometric analysis of the T-cell subsets in subcutaneously mercury-treated mice revealed a decrease in the fraction of T-helper (L3T4+) splenic cells in the SJL and C57BL/6J strains; no significant change in the T-cell subsets was found in BALB/c mice. C57BL/6J mice, resistant to induction of IC-disease by mercury, showed no increase in the fraction of T-suppressor/cytotoxic (Lyt-2+) cells and no change in the T-helper/T-suppressor cell ratio. C57BL/6J mice could not be rendered susceptible to mercury-induced IC-disease by treatment with different doses of cyclophosphamide.