Predictive value of immunological markers in systemic sclerosis

Systemic sclerosis (SSc) is a collagenosis characterized by excessive deposition of collagen in the skin and viscera, in a background of immune disorder. The immunological profile of SSc often shows elevated levels of antinuclear antibodies (ANAs). However, many authors have identified cases of SSc having normal ANA levels, framed as paraneoplastic SSc. Among patients with negative ANAs in our group, we did not identify any neoplastic process that could support this hypothesis. The extended detection of autoantibodies is extremely useful in establishing the subset of SSc. Thus, anti-Scl70 antibodies are specific for the diffuse subset of SSc, while anticentromere antibodies (ACAs) have specificity for a limited subset. However, studies have shown the existence of cases of diffuse SSc having high titers of ACAs and cases of limited SSc with high titers of anti-Scl70 antibodies. This indicates an inconsistent association between the disease subset and the autoantibodies specific to each subset. Our study found a more balanced consistency between disease subsets and autoantibodies specific for each subset. Therefore, the percentages of patients having an immunological profile inconsistent with the subset of SSc, are lower than those found by other authors. This observation opens the perspective of larger studies on the immunological profile in SSc.