TNF and systemic sclerosis: Serum TNF-α concentrations did not differ between AAV and controls (7.7 ± 5.7 vs. 3.3 ± 1.9 pg/ml; p = 0.34) but they were significantly lower in AAV than in SSc (7.7 ± 5.7 vs. 28.6 ± 35.9 pg/ml; p < 0.0001).