Following publication of our article  we noticed an error in the stated dose of methotrexate within the section 'Results', in the paragraph 'Demographics and patient characteristics at study entry'.
In this paragraph, it is stated that two patients were receiving 20 mg/day methotrexate. This should read 20 mg/week methotrexate.
The paragraph should therefore read as follows:
A total of 14 Caucasian patients (13 females and 1 male; 23 to 53 years old, median age 40 years) were enrolled. At study entry, the patients had been initially diagnosed with SLE 1 to 19 years (median 10 years) earlier and were receiving corticosteroids (n = 13, 1 to 12 mg/day prednisolone) plus immunosuppressives (n = 11, including 50 to 200 mg/day azathioprine, n = 9; 20 mg/week methotrexate, n = 2; 2 g/day mycophenalate mofetil, n = 1), and antimalarials (n = 6, 200 to 600 mg/day hydroxychloroquine). All patients had positive ANA at study entry (titers of 80:1 to 5,120:1), and 5 patients (36%) had positive anti-dsDNA antibody levels (> 10 U/ml). Ten patients (71%) had ESR values that were elevated (> 15 mm/h) and 4 patients (29%) had raised CRP levels (> 0.5 mg/dl), while only 3 patients (21%) had C3 levels that were borderline low or decreased (< 90 mg/dl), and no patient had positive direct Coombs' or serum haptoglobulin levels elevated above borderline.