An immunological basis for the anaemia of acute Salmonella gallinarum infection of chicken. I. Haematological changes and their association with in vivo modification of the erythrocytes.

The haematological changes occurring during the course of acute Salmonella gallinarum infection of chicken have been investigated. A severe, acute anaemia, together with reticulocytosis and hepato-splenomegaly, were regularly observed. The findings indicated that these changes were due to increased extravascular destruction of erythrocytes rather than by inhibition of haemopoietic activity. Coincidentally with the development of the anaemia, erythrocytes became regularly modified serologically in vivo, suggesting a possible relationship between these two phenomena. In contrast, in chickens which died of the per-acute form, where normal haematologic values were found, in vivo erythrocyte modification was not detected. As the anaemia increased in severity, a change in the type and in vivo erythrocyte modification was also frequently noted. It is considered that in vivo erythrocyte modification initiates the severe haematological changes observed and it is postulated that the underlying mechanism of increased erythrocyte destruction is immunological.