Local immunoglobulin production in synovial tissue in patients with Lyme borreliosis

A study was made to find out whether immunoglobulins are produced locally in synovial tissue in patients with Lyme borreliosis. Synovial fluid specimens from six patients with Lyme borreliosis were compared with those from 25 patients with rheumatoid arthritis, psoriatic arthritis, unspecified oligoarthritis or arthrosis (control group). Agarose electrophoresis revealed local oligoclonal IgG and IgM bands in the synovial fluid of two patients with Lyme borreliosis, but no local bands were observed in the control group. An index for local synthesis of immunoglobulins in synovial fluid was calculated in analogy with the IgG index for cerebrospinal fluid. The two patients with Lyme borreliosis in whom oligoclonal bands were seen in the synovial fluid showed the highest synovial fluid IgG indices and the highest concentrations of specific IgG antibodies against Borrelia spirochetes in synovial fluid. The presence of local oligoclonal immunoglobulin bands and a high synovial fluid IgG index suggest that immunoglobulins are produced locally within the synovial tissue in some patients with Lyme borreliosis. The increase in immunoglobulins may be a response to a local invasion of Borrelia spirochetes or may represent an immune reaction which continues after the spirochetes no longer are viable.