En betydelig procentdel af disse patienter led imidlertid af leukæmi, en lidelse der associeres med Sweets syndrom, og en kausal sammenhæng med filgrastim er derfor ikke påvist.
However, since a significant percentage of these patients were suffering from leukaemia, a condition known to be associated with Sweet's syndrome, a causal relationship with filgrastim has not been established.