Antiprolactin autoantibodies in systemic lupus erythematosus: frequency and correlation with prolactinemia and disease activity

• Published in: Journal of rheumatology 2001-07, Vol.28 (7), p.1546-1553
• Main Authors: A Leaños-Miranda, D Pascoe-Lira, K A Chávez-Rueda, F Blanco-Favela
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Autoantibodies - blood; Biological and medical sciences; Female; Humans; Hyperprolactinemia - immunology; Lupus Erythematosus, Systemic - immunology; Male; Medical sciences; Middle Aged; Prolactin - blood; Prolactin - immunology; Radioimmunoassay; Sarcoidosis. Granulomatous diseases of unproved etiology. Connective tissue diseases. Elastic tissue diseases. Vasculitis; Severity of Illness Index
• ISSN: 0315-162X; 1499-2752

OBJECTIVE: To determine in patients with systemic lupus erythematosus (SLE) (1) the frequency of antiprolactin (anti-PRL) autoantibodies, and (2) the relationships among anti-PRL autoantibodies, serum prolactin (PRL) levels, and lupus activity. METHODS: In a cross sectional study 259 consecutive patients with SLE were tested for serum PRL levels and anti-PRL autoantibodies based on disease activity. RESULTS: The frequency of anti-PRL was 5% (13/259), and all SLE patients with anti-PRL had hyperprolactinemia. There was lupus activity in 110 patients (42.5%) and there was no significant difference in frequency of anti-PRL autoantibodies between patients with or without lupus activity (5.5 vs 4.7%; p = 0.99). Only a high level of serum PRL was associated with lupus activity independent from other studied variables (p = 0.024). There was a negative but nonsignificant correlation between the titers of anti-PRL autoantibody and SLEDAI (r(s) = -0.16, p = 0.59). Anti-PRL positive patients had higher levels of serum PRL than anti-PRL negative patients (33.2+/-13.8 vs 11.6+/-13.2 ng/ml; p = 0.0001) and a significantly different frequency of hyperprolactinemia (100 vs 11.4%; p = 0.00001). CONCLUSION: The presence of anti-PRL autoantibodies was associated with hyperprolactinemic status and high serum PRL levels; these data suggest that anti-PRL autoantibodies could be the cause of hyperprolactinemia in a subset of patients with SLE. An increase in serum PRL levels proved to be an important independent factor related to lupus activity, but there was no relationship between anti-PRL autoantibodies and lupus activity.