Acroosteolysis and bone metabolism parameters distinguish female patients with limited systemic sclerosis with and without calcinosis: a case control study.

Calcinosis usually represents a late manifestation of systemic sclerosis (SSc), inducing tissue damage and chronic calcifications. To analyze clinical and bone metabolism parameters associated with calcinosis in limited systemic sclerosis (lSSc), thirty-six female lSSc patients with calcinosis were compared with 36 female lSSc patients without calcinosis, matched by age, disease duration, and body mass index. Organ involvement, autoantibodies, bone density, and laboratory parameters were analyzed. Statistical significance was considered if p < 0.05. Calcinosis was significantly associated with acroosteolysis (69% vs. 22%, p < 0.001), higher modified Rodnan skin score (mRSS 4.28 ± 4.66 vs. 1.17 ± 2.50, p < 0.001), and higher 25-hydroxyvitamin D (25OHD) (24.46 ± 8.15 vs. 20.80 ± 6.60 ng/ml, p = 0.040) and phosphorus serum levels (3.81 ± 0.41 vs. 3.43 ± 0.45 mg/dl, p < 0.001). 25OHD levels > 30 ng/ml were also significantly more frequent in patients with calcinosis (p = 0.041). Regarding treatment, current use of corticosteroids was lower in patients with calcinosis compared with patients without calcinosis (8% vs. 28%, p = 0.032). On logistic regression analysis, acroosteolysis (OR = 12.04; 95% CI, 2.73-53.04; p = 0.001), mRSS (OR = 1.37; 95% CI, 1.11-1.69; p = 0.003), phosphorus serum levels (OR = 5.07; 95% CI, 1.06-24.23; p = 0.042), and lower glucocorticoid use (OR = 0.07; 95% CI, 0.007-0.66; p = 0.021) are independent risk factors for calcinosis. This study showed that limited SSc patients with calcinosis present a distinct clinic and biochemical profile when compared with a matched group without calcinosis, paired by disease duration, age and BMI. KEY POINTS: • Calcinosis in patients with limited SSc was associated with acroosteolysis, higher mRSS and higher serum levels of phosphorus.