Immunopathology of New Zealand Black mice treated with antilymphocyte globulin.

Antilymphocytic globulin (ALG) suppressed the development of haemolytic anaemia with positive antiglobulin (Coombs) reactions in intact and adult thymectomized New Zealand Black (NZB) mice, although some recipients eventually became positive after treatment was stopped. Macroglobulinaemia and lymphoid cell infiltrates were resistant and complex nephritis was unaffected by, and in thymectomized recipients accelerated by, ALG, whilst many such recipients developed severe Coombs negative haemolytic anaemia. Splenomegaly was less pronounced in ALG treated than in control NZB mice. However, lymphoproliferative changes in general, and reticulum cell hyperplasia in particular, progressed despite ALG treatment in early life. On the other hand, this agent did not provoke overt neoplasia in the lymphatic or other tissues. Syngeneic lymphoid cells from young donors did not influence the disease of ALG treated mice but rat lymphoid cells in thymectomized recipients induced a temporary suppression of macroglobulinaemia and reticulum cell proliferation was reduced.