Search

Problem: Murine pregnancy is characterized by transient thymic atrophy and splenomegaly. Although some reports on the thymus are available, little is known about the role of the spleen. In the present study, sequential changes in the spleen have been evaluated during murine syngeneic pregnancy., Method of Study: Formation of germinal centers (GCs), immunoglobulin positive (Ig+) cells and interleukin (IL)-2, IL-4, and IL-6 were immunolocalized in the spleen during pregnancy and compared with a control group of virgin mice., Results: Initiation of T-cell dependent B-cell response with the induction of peanut agglutinin (PNA+) GCs correlated with decrease in IL-2 and maintenance of IL-4 and IL-6 on day-1 pregnancy followed by an increase in Ig+ cells., Conclusion: The immune response observed in the syngeneically pregnant mother is not directed to paternal major histocompatibility complex antigens. Present studies demonstrate for the first time the role of the spleen in initiating a T-cell dependent B-cell response with a shift of systemic immune response from T helper 1 to T helper 2 type.

Problem: The present study was carried out to see if the anti-idiotypic (anti-Id) antibody (Ab2) to progesterone could mimic the immunogenicity of the steroid hormone by giving rise to antiprogesterone antibodies (Ab3) and whether these antiprogesterone antibodies (Ab3) were biologically active., Method: Twenty virgin female Balb/C mice were actively immunized with the anti-Id antibody (Ab2). The antiprogesterone antibody (Ab3) titres in the serum were determined and the animals were used for fertility studies. In the passive immunization studies Balb/C female mice were injected i.p. with 100 micrograms of anti-Id antibody to see its effect on pregnancy., Results: The actively immunized animals when mated showed 80% reduction in their fertility rate. The duration of infertility (20-121 days) in these animals could be directly correlated with the concentration of antiprogesterone antibody (Ab3). The anti-Id antibody (Ab2) blocked pregnancy in 80% of the passively immunized mice., Conclusion: The studies show that anti-Id antibody to progesterone could mimic the immunogenicity of progesterone and give rise to antiprogesterone antibodies (Ab3). The anti-Id antibody successfully blocked pregnancy in mice both after active and passive immunization.

Platelet associated C3c and C3d (PAC3c and PAC3d) were quantitated by enzyme linked assay in 105 patients with idiopathic autoimmune thrombocytopenia (AITP) in whom elevated platelet associated immunoglobulins (IgG and IgM) had previously been documented. Increased levels of complement components were demonstrated in 46 of 105 patients (43.8%). In 11 of these patients, PAC3d alone was abnormal implying that C3b had been inactivated after cleavage by C3 inactivator in vivo. Complement binding was seen in two of 16 patients (12.5%) with raised PAIgG alone, four of 19 patients (21.0%) with raised PAIgM alone and in 40 of 70 patients (57.1%) in whom PAIgG and PAIgM were raised together. This difference was highly significant (P = 0.01). The clinical implication of these findings are discussed.