Topics, as I noted a fortnight ago in my uniquely misspelled and ungrammatical way, never die**. Or even fade away. There are popular ideas that persist in the world that have little to do with reality. In the reality based world of medicine there are concepts that refuse to die. Atelectasis causing fever or the need to ‘double cover’ Pseudomonas. Neither are true, yet every year medical students tell me that is what they have been taught. It is said the only way new ideas take hold is for those that hold the old ideas to die off. So maybe 50 years from now those medical myths will be gone.
Popular culture also its myths. Take the immune system. Please. It is not a bicep that can be made stronger with a little exercise. It is a complex network of cells and proteins. There are antibodies (IgG (with five subtypes, IgM, IgA, IgE),the complement pathway, polymorphonuclear cells, monocytes, lymphocytes in a profusion that rivals beetles. God, I think, has an inordinate fondness for lymphocytes. There is the Toll system, the cytokines and lymphokines, the non-specific defenses like cilia and mannose binding lectin and on and on and on.
I have a journeyman’s understanding of the immune system, what is needed to understand why a given patient has an infection, although there is little I can do to reverse the immunologic defects: abnormal antibodies from Waldenström’s or low mannose binding lectin levels from liver disease are not amenable to clinical intervention. (more…)