B cell-activating factor is a novel diagnosis parameter for asthma

Asthma is a life-threatening immediate-type allergic disease. B cell-activating factor (BAFF) is a key regulator of B lymphocyte development and is required to generate and maintain the mature B cell pool.

To investigate the level of BAFF in the serum of asthma patients and the role of BAFF on T cells.

The BAFF level was measured by enzyme-linked immunosorbent assay. Peripheral blood mononuclear cells (PBMC) from asthma patients were analyzed by flow cytometry. T8.1 cells were used to test the role of BAFF on T cell-antigen-presenting cell (APC) conjugate formation.

The BAFF level in patient serum was elevated relative to normal serum. Immunoglobulin E (IgE) concentration and the percentage of CD3+ T and CD19+ B cells vary according to the serum BAFF level. Patients with high BAFF and high IgE (group II) and those with high BAFF and low IgE (group III) show a high ratio of CD3+ T to CD19+ B cells, and the opposite is seen for patients with low BAFF and high IgE (group I) and those with low BAFF and low IgE (group IV). The addition of BAFF increased PBMC proliferation and T cell-APC conjugate formation. BAFF concentration in serum decreased after treatment with antiasthmatic drugs including glucocorticoids and immunosuppressants.

These findings suggest that the serum BAFF level is high in both IgE-mediated asthma and non-IgE-mediated asthma and extend our knowledge about the fact that BAFF may play a stimulatory role on the proliferation of T cells. Thus, BAFF could be a parameter to monitor the severity of asthma symptoms.