Serological profile and clinical features of nucleolar antinuclear pattern in patients with systemic lupus erythematosus from southwestern Spain

Nucleolar staining of antinuclear antibodies (ANAs) is not exclusive to patients suffering systemic sclerosis (SSc) since it can occur in other autoimmune diseases, such as systemic lupus erythematosus (SLE). The nucleolar ANA pattern presents a low incidence in patients with SLE, with less than 9% reported in some studies. The significance of nucleolar staining and antinucleolar antibodies (ANoA) in SLE is still unknown, as is its association with clinical manifestations. To address these issues, a case-control study was carried out. Twenty-eight cases of SLE with nucleolar staining were enrolled, as well as 73 controls with no nucleolar staining and different ANA patterns (homogeneous, speckled, and combined homogeneous and speckled). The homogeneous nucleolar pattern was the most frequent (27 out of 28), and in 75% was combined with other ANA patterns. The anti-double stranded DNA antibodies showed no differences between the two groups of patients, nor the auto-antibodies detected by line immunoassay (LIA). However, we have found an increased frequency of anti-PM-Scl antibodies with respect to the controls (p=0.02), in addition to the association between Raynaud's phenomenon (RP) and anti-PM-Scl antibodies (OR=20.72, 95% CI 1.33-323.19, p=0.03). Moreover, the cases of SLE showed a 7.78-fold increase in the risk of developing cancer (95%, CI 1.85-32.75, p=0.005) with respect to the control group. Taken together these findings suggest that nucleolar staining represents a comorbidity factor in patients with SLE, although its significance must still be determined.