[Changes in the granulocyte membrane in mucoviscidosis]

Important polymorphonuclear leukocyte (PMN) functions are dependent on an intact cytoskeleton, consistent of the microtubulus and microfilament system. This can be assayed from the mobility of fluorescence labelled Concanavalin A (Con A) receptor complexes on the cell surface. Con A shows an uniform surface distribution on cells with an intact microtubulus system, whereas it's disruption causes a Con A cap formation. The alteration of the microtubulus and microfilament systems induces a patchy Con A distribution. Only 44% PMNs of 20 children with cystic fibrosis exhibited with a random Con A fluorescence distribution an intact cytoskeleton compared to 69% control PMNs. But 32% cystic fibrosis PMNs and 23% control PMNs showed a Con A capping phenomena, which is associated with a microtubulus alteration. In addition, 24% cystic fibrosis PMNs demonstrated a patchy fluorescence, representing a microtubulus and microfilament disruption, compared to 8% patched control PMNs. This study supports the idea, that the chronic bacterial infections cause in cystic fibrosis PMNs a cytoskeleton defect, which represents as a leukocyte-function defect an additional infection promoting factor.