Background: Recently, tumor markers (CA 125 and SCC) have been suggested as possible activity markers of systemic lupus erythematosus (SLE), but study results have been contradictory.
Objective: The aim of this study was to evaluate the possible relationship between CA 125 and SCC serum levels and SLE activity.
Patients and methods: Serum levels of CA 125 from 59 patients and levels of SCC from 53 patients with SLE were analyzed. Both tumor markers were determined by ELISA, considering 35 U/ml (CA 125) and 2.5 ng/ml (SCC) respectively as the upper limit of normality. The serum levels of these tumor markers were correlated with the SLE disease activity index (SLEDAI).
Results: The CA 125 concentrations in active SLE (mean 13.8 + 15.3) were similar to those in inactive patients (mean 13.1 + 11.7 U/ml). Significantly high CA 125 serum levels were found only in SLE patients with nephrotic syndrome (p = 0.001). No significant differences were found in SCC serum levels in SLE patients with (mean 0.9 +/- 0.8 ng/ml) or without activity (mean 1.1 +/- 1.3 ng/ml). Likewise, no relationship between SCC serum levels and parameters related to SLE activity were found, excluding slight increases associated with renal failure.
Conclusions: The correlation that some authors have found between elevated serum levels of CA 125 and SLE activity is only associated with the presence of nephrotic syndrome. Likewise, SCC is not related with SLE activity and the increases found may be due to renal failure.