Microtubules in PMNs from patients with familial Mediterranean fever.

Polymorphonuclear (PMN) cells derived from patients with Familial Mediterranean Fever (FMF) were evaluated in vitro for the function and concentration of their microtubules. Using the time-decay colchicine binding assay to determine the tubulin concentration in PMN cells, no difference was found in PMN cells derived from FMF patients in comparison with those from normal healthy subjects. Colchicine treatment had no effect on the detectable tubulin concentration in the cells. The mobility of fluorescent con A(F-con A)-receptor complexes on PMN membranes was used to test the function of the microtubules. PMNs from untreated FMF patients showed the same pattern of con A cap formation as seen in normal cells. PMNs derived from colchicine treated patients, however, showed 22-32% spontaneous cap formation. These cells also showed 10-30% more capping in comparison with normal or untreated FMF cells, for any given in vitro colchicine concentration, suggesting that at therapeutic doses, the colchicine does accumulate in the PMNs in vivo. We were unable to demonstrate a microtubule defect in the neutrophils from FMF patients in these studies.