There is no correlation between the serum level of interleukin-21 and bullous pemphigoid

Abstract

Objective To investigate the correlations of the serum level of interleukin-21 (IL-21) with anti-BP180 antibodies, peripheral eosinophil level, bullous pemphigoid disease area index (BPDAI) in patients with bullous pemphigoid (BP) . Methods A total of 31 patients with bullous pemphigoid and 31 healthy controls were enrolled into this study. Blood samples were collected from all the subjects, and enzyme-linked immunosorbent assay (ELISA) was performed to detect the serum level of IL-21 and serum titer of anti-BP180 antibodies. BPDAI was assessed among 13 patients, and the correlation of the IL-21 level with anti-BP180 antibody titers, eosinophil count and BPDAI were analyzed. Results No significant difference in the serum level of IL-21 was observed between the patients (M[P25 - P75]: 255.28 [156.19 - 361.59] ng/L) and healthy controls (150.47 [72.4 - 268.73] ng/L, P = 0.14) . There was no correlation between the serum level of IL-21 and serum titer of anti-BP180 antibodies (82.98 [26.82 - 132.92]U/ml, rs = 0.18, P = 0.332) . Among the 27 BP patients who underwent blood cell count, no correlation was found between the serum levels of IL-21 and whole-blood eosinophil counts (rs = 0.104, P = 0.606) . Among the 13 BP patients who underwent assessment of BPDAI, there was no correlation between the serum levels of IL-21 and BPDAI scores (rs = 0.233, P = 0.464) . Conclusion The IL-21 level is uncorrelated with anti-BP180 antibody level, peripheral eosinophil level or BPDAI in patients with BP. Key words: Pemphigoid, bullous; Eosinophils; Interleukin-21; Anti-BP180 antibody