Prevalence of soft tissue calcifications in patients with SLE and effects of alfacarcidol

To clarify the prevalence and etiology of ectopic calcification in patients with systemic lupus erythematosus (SLE), especially under the active vitamin D3 administrations and to reveal the risk factors of ectopic calcification.

Sixty patients with SLE, excluding the patients on dialysis were studied. We examined radiographs of hands, forearms, upper and lower extremities, and pelvises of all patients to evaluate ectopic calcification.

The prevalence of ectopic calcification in SLE was 40% (24 out of 60 patients), found in 6.7% (4 patients) in peripheral arteries, 33.3% (20 patients) in periarticular area and 16.7% (10 patients) in other soft tissues. The incidence of lupus nephritis and nephrotic syndrome were significantly higher (respectively: P=0. 0144 and P=0.0348) in the calcification-positive than negative group. Total protein levels (7.04+/-0.6 g/dl) of patients in the calcification-positive group were decreased significantly (P=0.0056) compared with 7.48+/-0.55 g/dl in the negative group. However, other biochemical parameters were not significantly different between the two groups. Sixty-three percent of the SLE patients with ectopic calcification received alfacarcidol, which is significantly (P=0. 0007) higher than the 19% in patients without calcification.

It is suggested that the alfacarcidol therapy and lupus nephritis could increase the risk of ectopic calcification in SLE patients.