BLyS and April serum levels in patients with autoimmune thyroid diseases

Elevated B-Lymphocyte Stimulator (BLyS) and April (a proliferation-inducing ligand) expressions characterize several autoimmune diseases. We here analysed the possible role of BLyS and April in autoimmune thyroid diseases (AITD), comprising Hashimoto's thyroiditis (HT) and Graves' disease (GD). Seventy-seven patients with AITD and 77 blood donors (HBD) were enrolled in the study. Serum BLyS and April levels were assessed by ELISA. Results indicated a significant upregulation of BLyS in AITD patients (1.12 ± 0.39 ng/ml versus 0.666 ± 0.240 ng/ml in HBD; p < 0.0001), with GD patients presenting higher BLyS levels than HT patients (1.22 ± 0.42 ng/ml versus 1.07 ± 0.38 ng/ml; p = 0.0393). In contrast, April levels were downregulated, but only in HT patients [9.9 ± 36.6 (median 0) ng/ml versus 7.4 ± 22.1 (median 1.16) ng/ml in HBD; p = 0.003; and versus 4.2 ± 5.9 ng/ml (median 0.9) ng/ml in GD; p = 0.0353]. In HT patients, Levo-thyroxine supplementation further increased BLyS and tended to normalize April levels. Neither BLyS nor April did correlate with the levels of the pathognomonic autoantibodies (TPOAb, TgAb, TRAb). Data are preliminary, but, for the first time, we provide the analyses of BLyS and April levels in AITD patients, suggesting new tools for the diagnosis, prognosis and possible therapeutic management of AITD.