|Budget Amount *help
¥3,100,000 (Direct Cost : ¥3,100,000)
Fiscal Year 1991 : ¥3,100,000 (Direct Cost : ¥3,100,000)
Infiltration pattern of mononuclear cell subpopulations in lung tissue and changes of cellular components in bronchoalveolar lavage (BAL) fluid were analyzed immunohistochemically in acute lung allograft rejection (BN/LEW) and mycoplasma pulmonis pneumonia in inbred rats. RESULTS : (1) All allotransplants developed acute rejection on day 2, and it advanced until day 6, demmonstrating severe perivascular and peribronchiolar infiltration of mononuclear cells. (2) In lung allograft rejection, marked infiltration of activated macrophages, moderate infiltration of helper and suppressor T lymphocytes, and slight or moderate infiltration of B lymphocytes were observed around bronchioles and vessels, as a thick layr of cells like concentric circles, forming a dense cuff. (3) In the mycoplasma pulmonis infection group, all rats developed acute or chronic bronchopneumonia. (4) In acute and chronic mycoplasma infection, focal inflammatory reactions were observed with various degrees of infiltration of mononuclear cell subpopulations around bronchioles and vessels, ranging from very mild to severe infiltration, even in the same section or even around the same bronchiole. (5) In BAL fluid, the number of total cells, macrophages, and neutrophils increased significantly both in the rejection group and infection group. CONCLUSIONS : The difference in the infiltration pattern between the focal, unequal and dappled infiltration in lung infection and the homogeneous and even cuff infiltration in acute rejection may be useful in differential diagnosis between acute rejection and infection after lung transplantation.