Chronic Lyme patients frequenly have a poor antibody response as seen on a Western Blot. Frequently there is a predominance of IgM bands. IgG responses may be sparse or absent. Patients who test positive according to the national CDC surveillance criteria usually do so by meeting the IgM criteria. This is still seen in patients who have had Lyme disease for many years. IgM antibodies are the "quick and dirty" response of B lyphocyte antibody production. These are churned out early after antigen (Lyme protein) presenation to helper T cells. IgM antibodies are not particularly effective. They are larger and do not bind all that well to target antigen proteins. These antibodies may show less specificity and be more like to induce autoimmune reactions due to molecular mimicry. The same B cells or plasma cells that produce IgM antibodies (immunoglobulins) also produce IgG antibodies. A molecular switch is pulled after the initial period of infection. IgM production is shut down. The B cells or plasma cells now kick into gear manufacturing IgG antibodies. These smaller, more precise antibodies bind better to the target proteins. It takes time for the "antibody factory" to gear up and make these preferred antibodies. This is why the Immune system provides this two punch approach to dealing with germs. These (IgG) antibodies are typically associated with immunity to a particular disease. This is for example the response one would expect to see after an effective vaccine.
With this in mind, I have started paying attention to the balance sheet, as it were. I compare the IgM and IgG responses seen in various patients. Patients with a predominat IgG response fare much better in general. For example, I saw a patient yesterday who had presented with severe symptoms of longstanding disseminated Lyme disease about 18 months ago. He responded remarkably well to treatment, despite an advanced age of 76. Therapy was stopped after one year. He experienced a prompt therapeutic response followed by full remission. Six months later he reports
robust health. I glanced at his Western Blot. He had 7 IgG bands and zero IgM bands. His immune responses to Lyme were appropriate. Unfortunately this is the exception not the rule.
Patients with predominant IgM responses generally do not respond nearly as well to therapy. Therapy is required for a much longer period of time. These patients require more creative combination therapies and attention to co-infection.
It is not essentially a host response issue. Patients make normal IgG antibodies when exposed to other infectious diseases. There is something unique about Lyme disease. Somehow it short circuits the switching of IgM and IgG antibodies.
There is a subset of patients whose immune systems apparently go beserk when exposed to Lyme. Dr. Kilani reports Western Blot strips in which the entire strip, IgG and IgM turn black. He suspects these patients may have autoimmune hyper-reactivity. I have no experience to support or confirm this observation. I will keep a look out.