Increased numbers of circulating basophil progenitors in XXXX @entity1 .

@entity1 @entity6722 @entity66 @entity1097 @entity402 @entity56 @entity112
Recruitment of basophils to sites of homocytotropic antibody-mediated @entity56 has been well documented in both experimental and clinical situations. Mechanisms underlying tissue basophil accumulation, however, remain unclear and may involve @entity6722 , cell proliferation, or both. We have recently reported the presence in @entity1 blood of circulating basophil/mast cell progenitors on the basis of @entity112 content of granulocyte colonies grown in methylcellulose. In the current studies we have analyzed the peripheral blood of 30 @entity1 with @entity402 and 25 comparable control subjects for frequency of basophil/mast cell progenitors by analysis of the @entity112 content of individual granulocyte colonies. Forty percent of granulocyte colonies in cultures of @entity1097 @entity1 contained @entity112 in comparison to only 11% in cultures of control subjects (p less than 0.001). @entity112 content per colony as well as mean @entity112 per cell in each colony was higher in granulocyte colonies of @entity1097 subjects and could not be related to colony size or culture conditions. Granulocyte colony growth was enhanced by antigen-stimulated, peripheral blood lymphomononuclear cell--conditioned media of @entity1097 @entity1 . @entity112 -positive colonies were found more frequently in active versus quiescent @entity66 (p less than 0.05). These results are consistent with the hypothesis that basophils accumulate at sites of @entity56 at least in part by recruitment of progenitors from circulation and subsequent differentiation in situ in response to lymphokines. Further studies by use of hemopoietic assays could elucidate the contribution of basophil production to the development of @entity56 .
