WG can be associated with serious consequences that can occur as a result of active disease or from the side effects of treatment. If the medications used to treat WG were safe, the risk of exposing even a significant proportion of individuals to unwarranted treatment might be a reasonable approach in light of the nature of the disease process. In the setting of toxic medications though, the use of preemptive treatment based on ANCA alone and the potential for unnecessary exposure to side effects cannot be justified in the absence of compelling evidence. Unfortunately, the medical literature does not support that the benefits of preemptive treatment determined by ANCA outweigh the risks. To treat solely on the basis of ANCA potentially exposes an unacceptably high number of patients to the toxicities of treatment that they would not have needed. It is for these reasons that treatment decisions in WG should not be based on ANCA alone in the absence of clinical evidence of disease activity.