To evaluate prolactin (PRL) serum levels in prepubertal girls affected with 2 different subtypes of pauciarticular onset juvenile chronic arthritis (JCA) and with previous acute postinfectious arthritis in remission (AA), and to correlate the relationship of PRL versus interleukin 6 (IL-6) serum levels.
Eleven girls with antinuclear antibody (ANA) positive early onset pauciarticular JCA, 8 with ANA negative late onset pauciarticular JCA of various forms (considered to have spondyloarthropathy, SpA), and 7 who had had AA were evaluated for serum concentrations of PRL, IL-6, and thyroid hormones and presence of uveitis. All were prepubertal and without clinical or biological signs of disease activity.
Mean serum concentrations of PRL were significantly increased in ANA positive (8.9 +/- 4.0 ng/ml) patients and in patients with SpA (7.8 +/- 2.4 ng/ml) compared to those of AA patients (4.4 +/- 0.3 ng/ml) (p = 0.01 and p = 0.025, respectively) and to controls. Both ANA positive and SpA patients showed increased mean serum concentrations of IL-6 in comparison with AA patients and controls. Significant correlation between PRL and IL-6 concentrations (r = 0.604, p = 0.002) was observed from the whole series.
We found a direct correlation between serum levels of PRL and IL-6 in both ANA positive JCA patients and in ANA negative SpA patients; thus, hyperprolactinemia correlates better with the chronic course of the disease than with ANA positivity.