Serum IgG antibody response to pneumocystis carinii among immunosuppressed, malnourished and healthy rats

In this work, humoral immune responses to Pneumocystis carinii were studied using IFAT during the period of infection and recovery of immunosuppressed and malnourished rats compared to healthy group. Serum IgG antibody titers to the organism were absents in rats administered corticosteroids, but arose after steroid tapering, with disappearance of the organism from their lungs due to reactivation of the immune system. While, in malnourished infected rats, clearance of the organism had occurred after regaining the protein diet with progressive increase in IgG level denoting their immunocompetent state. IgG antibody appeared in the serum of control healthy rats with the progress of age at low non diagnostic level, indicating the presence of dormant parasites in their lungs

Effect of graded infections with toxocara canis eggs on local pulmonary and systemic immune responses

Comparison between local pulmonary and splenic immune responses in Toxacara canis infection was done. It was found that, there is and increase by about 2.6 to 3.3 times in eosinophilic count in the lung than in peripheral blood. The response of the lymphocytes to T. canis excretory-secretory antigen in the lung is greater than splenic lymphocytes, which suggested that there is an accumulation of antigen reactive T. cells in the prephary [lung]. Also, the effect of graded infections on systemic immunity was studied. It was found that there is an increase in antibody levels. Eosinophilic counts and lymphocytes blastogenesis assay with increasing the dose of infection. This helps to explain the different clinical pictures of patients infected with this parasite

Pneumocystis carinii: recognition of the infection in albino rats using different stains

The present study aims to throw lights on the best staining method for cytodiagnosis of this organism with the sequential pathological changes in the infected lungs. An immunosuppression state was induced in albino rats for 6-8 weeks, then rats were sacrificed weekly and lungs were examined for infection using different stains. In stained smears, intracystic bodies have been identified using Giemsa, Papanicolaou and Toluidine blue stains. On the other hand, cysts were inspected in paraffin sections using Gomori methenamine silver nitrate [GMS] and weight Gram stains. Histopathologically, in sections stained with H and E, features of Pneumocystis carinii pneumonia were obvious, foamy exudation, inflammatory infiltration formed mainly of histiocytes, plasma cells, lymphocytes, thickening of aleolar septa and, lastly, formation of hyaline membrane in some aleoli