Investigation of occurrence of osteonecrosis of the femoral head after increasing corticosteroids in patients with recurring systemic lupus erythematosus

Osteonecrosis (ON) of the femoral head is known to occur commonly in cases with systemic lupus erythematosus (SLE) that received corticosteroid (CS) treatment. However, there have been no detailed reports about the onset of ON in cases with recurrence of SLE. Using MRI, we followed up 17 patients who experienced recurrence of SLE for at least 1 year at our hospital and in whom the CS dose was increased from a maintenance dose to middle to high dose to see if ON would occur. We then compared the group that developed ON and the group that did not with respect to patient characteristics, blood test results, changes in serum lipid levels, and CS dose. ON occurred in five subjects (29.4%), revealing that osteonecrosis occurs not only when CS are first administered but also in cases which the CS dose is increased for recurrence of SLE. Especially, serum cholesterol levels and its rate of increase soared rapidly soon after increasing the CS dose in the ON group as compared with the non-ON group (P < 0.05). This suggests that increased serum lipid levels might be a contributing factor to onset of ON. Moreover, SLE disease activity index 2000 (SLEDAI-2K) scores when the CS dose was increased were significantly (P < 0.05) higher in the ON group, suggesting that SLE disease activity itself is a risk factor for onset of ON.