Defective Helper T Cell Function in IgM Rheumatoid Factor Synthesis in Patients with Ankylosing Spondylitis

Abstract

Despite chronic inflammation and the presence of hypergammaglobulinemia, rheumatoid factor (RF) is rarely found in the blood of patients with ankylosing spondylitis (AS). We used ELISA to compare spontaneous and pokeweed mitogen (PWM)-induced IgG, IgM and IgM rheumatoid factor (IgM-RF) production in normals and in patients with rheumatoid arthritis (RA) and AS. The IgG and IgM synthesis in these three groups did not differ. However, the IgM-RF level in PWM-induced mononuclear cell cultured supernatants of AS was significantly decreased, compared with normal and RA patients. Furthermore, mixing experiments by co-culture of normal T or B cells with patient's B or T cells in the presence of PWM revealed a deficiency of the helper T cell function in patients with AS. These results illustrate the cellular mechanism of the seronegativity of the rheumatoid factor in patients with ankylosing spondylitis.

IgG Anti-Melanocyte Antibodies Purified from Patients with Active Vitiligo Induce HLA-DR and Intercellular Adhesion Molecule-1 Expression and an Increase in Interleukin-8 Release by Melanocytes

“…None of the participants had received medical treatment in the preceding 3 mo. The sera were collected from patients and normal controls for puri®cation as in a previous (Yu et al, 1989). The fraction II (IgG) obtained from Sephacryl S-300 gel ®ltration was further absorbed by the protein A-Sepharose 4B (Pharmacia LKB, Uppsala, Sweden).…”

Narrow‐band UVB irradiation stimulates the migration and functional development of vitiligo‐IgG antibodies‐treated pigment cells

“…None of the participants had received medical treatment in the preceding 3 months. The sera were collected from patients and normal controls for purification as in a previous study 29 . The protocols for purification of sera IgG and determination of purified IgG concentrations were described in our previous study 22 …”