Toxoplasma gondii: effect of maternal infection in the development of lymphoid organs of BALB/c neonates.

Toxoplasmosis is one of the worldwide parasitic zoonoses. Alterations in the lymphopoietic system are still poorly studied. We analyzed lymphoid organs of BALB/c mice neonates from Toxoplasma gondii-intraperitoneally-infected mothers on 19th day of gestation, with 30 tachyzoites of strain RH. Normal non-infected pregnant females were used as controls. At 7 days after birth, animals were classified as neonates from infected (NIM) and neonates from non-infected mothers (NNIM). Weight of the thymus and number of thymic cells in NIM were decreased, percentage of apoptosis was significantly increased. Decrease in lymphocytes and monocytes and an increase of plasma cells were observed in bone marrow of NIM. Peripheral blood of NIM showed an increase of monocytes and neutrophils and a decrease in lymphocytes. Infection of the mother during the last day of gestation provokes in the neonates changes in the lymphoid organs that could explain survival of 75% of them.

Reconstitution of T-cell function in severe combined immunodeficiency disease following transplantation of early embryonic liver cells.

In a 51/2-month-old male infant with adenosine deaminase-positive severe combined immunodeficiency disease, who had no suitable bone marrow donor, immunologic reconstitution was attempted with lymphoid cells obtained from the liver of a 4- to 5-week-old-male human embryo. A mild graft-versus-host reaction began three weeks later. T-cells, which were absent prior to infusion of hepatic lymphoid cells, rose to a maximum of 554/mm3 at 16 weeks post transplantation. A normal lymphocyte response to pokeweek mitogen was not present until 25 to 30 weeks and to allogeneic cells until 39 weeks. Postive in vitro lymphocyte responses to Candida albicans were found repeatedly after 52 weeks. Twenty months following transplantation the patient is free of clinical infection, although he requires regular injections of gamma globulin.