Objective: Patients characterized with antinuclear antibodies (ANA) and disease symptoms related to one organ system can be described as having incomplete systemic lupus erythematosus (SLE). The aim of this multicentre study was to describe the outcome of these so-called incomplete SLE patients. Two aspects of the outcome were studied: (i) the disease course, defined by the presence or absence of clinical symptoms; and (ii) the number of patients that eventually developed full SLE.
Methods: Outcome parameters were the ACR criteria, the SLE disease Activity Index (SLEDAI), the European Consensus Lupus Activity Measure (ECLAM) and the requirement for treatment. In 10 European rheumatology centres, patients who had been evaluated in the last 3 months of 1994 and had been diagnosed as having incomplete SLE on clinical grounds for at least 1 yr were included in the study. All 122 patients who were included in the study were evaluated annually during 3 yr of follow-up.
Results: Our results are confined to a patient cohort defined by disease duration of at least 1 yr, being under clinical care at the different centres in Europe. These patients showed disease activity that was related mostly to symptoms of the skin and the musculoskeletal system, and leucocytopenia. During the follow-up, low doses of prednisolone were still being prescribed in 43% of the patients. On recruitment to the study, 22 of the 122 incomplete SLE patients already fulfilled the ACR criteria for the diagnosis of SLE. In the 3 yr of follow-up only three patients developed SLE.
Conclusions: A high proportion of patients in our cohort defined on clinical grounds as having incomplete SLE eventually showed disease activity defined by the SLEDAI as well as ECLAM. However, only three cases developed to SLE during the follow-up. This suggests that incomplete SLE forms a subgroup of SLE that has a good prognosis.