Systemic lupus erythematosus activity. An operational definition

Improved diagnosis and treatment have reduced mortality from SLE and present us with an opportunity to consider SLE in finer distinctions than alive or dead. Although much has been learned about SLE without a gold standard of disease activity or a universally agreed-upon definition of SLE activity, standardization of one or more measures would greatly enhance our ability to compare results from different centers and to communicate more precisely. It is unlikely that any of the existing measures or any ones to be developed will completely satisfy everyone's needs but it is pointless to proliferate new ones without testing their metric properties. Some differences in concept are desirable, particularly for investigators who have specialized interests or insights, but each should meet criteria of reliability and validity and have explicit definitions of terms, rules for their ascertainment, and the time period covered. Moreover, agreement on minimum essential elements of any SLE activity measure and their operational definitions would be a boon. SLE activity is one dimension in the disease pathway of lupus and implies a continuous phenomena that is potentially reversible. Organ damage, another point in the path of causation, connotes irreversible disease. We recommend that minimum essential elements be based on their frequency of occurrence, biological sensibleness, and the likelihood that degrees of activity can be rated reliably to show a change in a clinical state. The rating should be independent of whether a therapy is employed. Since activity is always considered with severity, the two dimensions could be recognized in the scale. Severity can be used to expand a scale's gradations if a symptom or sign is present. Severity could be rated by the need to treat with immunosuppressive agents, the need to follow the patient more closely, or the functional or prognostic consequences of the manifestation. For every organ system clinical judgment should be used to decide whether and how the scale should be constructed. For instance, in skin manifestations one could construct a scale by describing the extent of the lesion over the body and whether the lesion has potential for scarring, i.e., involving the dermis. However, the presence of, rather than the number of, cytoid bodies might be the only thing that is clinically important in rating the eye.(ABSTRACT TRUNCATED AT 400 WORDS)