Markers in cutaneous lupus erythematosus indicating systemic involvement. A multicenter study on 296 patients

Lupus erythematosus (LE) is an autoimmune disorder, involving the skin and/or other internal organs. As cutaneous variants, chronic discoid LE (CDLE) and subacute cutaneous LE (SCLE) usually have a better prognosis, however, involvement of internal organs with transition into systemic disease may occur. The aim of this study was to assess the significance of some clinical and laboratory criteria that could serve as markers for early recognition of systemic involvement in cutaneous LE. Three hundred and seventy-nine patients with LE, seen in five cooperating Departments of Dermatology during the years 1989-1994, were documented by electronic data processing according to a common protocol. Two hundred and forty-five of these patients had cutaneous LE (CDLE or SCLE), and 51 had systemic LE (SLE) and were included in this study. Forty-nine patients with either CDLE/SCLE or SLE were not evaluated because of incomplete documentation; also, 34 patients suffered from other LE subsets and were likewise excluded from the evaluation. Multivariate statistical analysis was used to assess the value of seven selected variables for distinguishing between the CDLE/SCLE and SLE groups: ESR, titers of antinuclear antibodies, anti-dsDNA-antibodies, photosensitivity, presence of arthralgias, recurrent headaches and signs of nephropathy. Univariate and multivariate analysis of the obtained data showed that signs of nephropathy (proteinuria, hematuria) was the variable with the highest statistical relevance for distinguishing between patients with cutaneous (CDLE/SCLE) and with systemic LE (SLE) in all statistical models tested, followed by the presence of arthralgias and of high ANA titers (> or =1:320). In contrast, low ANA titers as well as anti-dsDNA antibodies showed little or no statistical relevance as a criterion for distinction. It seems, therefore, that cutaneous LE patients showing signs of nephropathy, presence of arthralgias and elevated ANA titers (> or =1:320) should be carefully monitored, because they may be at risk of developing systemic LE involvement.