Tuesday, October 4, 2011

More bands

A 42 year old male came into my office, reluctantly. He thought he was fine. He only came in to mollify an insistent spouse, a spouse familiar with a disease she herself has suffered with.

Ok - He had a tick bite a year ago - attached for a short time; he never became ill.

When I took a history symptoms began to emerge. He had been a little tired recently but thought this normal. He had had some depression and irritability and fragmented sleep. He had had some generalized body stiffness, especially involving his hands and knees. Maybe his memory was not as good as it was a year ago, chalked up to "old age."

His physical exam was unremarkable.

A Lyme Western Blot was sent to Stony Brook University Medical Center. Here are the (IgM) Lyme Western Blot results: The report says indeterminate. An IgM 41 band is reported.

Other "nonspecific IgM" were also found: 18, 37, 72, and 93.

Before you get too excited, let's discus why the IgM report is called indeterminate. In this case, the WB bands are interpreted based on the assumption the patient has already had a positive ELISA test for Lyme. This designation indeterminate assumes the blot is the second -confirmational part of the two tier test endorsed by the CDC surveillance case definition test. Of course the ELISA was never done - so the designation, indeterminate has no significance.(I think).

Based on the same CDC test, the 18 and 93 bands are considered specific only if IgG bands, those included in the second leg of the (IgG) CDC surveillance test. IgM bands are reported specific, by the same logic, only if they are bands 23, 39 and 41.

Of interest to me is the report of a 37 and 72 band.

Stony Brook reports these bands because they manufacture their own Western Blot kits which show many more bands than the other labs. The 37 band is considered specific for Lyme (based on my reading). The 72 band is a cross-reacting spirochete band. When the 37 band is combined with the 41 and 93 bands the evidence for exposure to Bb seems compelling.

The treatment for this disease is discussed elsewhere (somewhere) in this blog.