Certain Antibodies More Critical Than Others In Defining Spirochete Loads.(Brief Article)

2001 MAY 16 - (NewsRx.com & NewsRx.net) --

by N.R. Saltmarsh, staff medical writer - Immunoglobulin G (IgG) antibodies are much more effective than IgM antibodies in reducing the spirochetal load in primates infected with Borrelia burgdorferi, according to a new study.

Rhesus monkeys with artificially suppressed immunity were able to produce IgM in response to B. burgdorferi infection, but not IgG, and carried a high burden of spirochetes compared with immunocompetent monkeys, reported A.R. Pachner and colleagues. Their results were published in Clinical and Diagnostic Laboratory Immunology.

"We hypothesized that rapid development of anti-B. burgdorferi antibody in immunocompetent non-human primates (NHPs) is the major determinant of the reduction of the spirochetal load in Lyme borreliosis," said Pachner and team.

Using B. burgdorferi, the researchers experimentally infected both immunocompetent monkeys and those with dexamethasone-suppressed immunity. They then measured spirochete load by polymerase chain reaction (PCR) and characterized immune responses for both types of monkeys.

After one month, the dexamethasone-treated monkeys showed inhibited IgG but not IgM response to B. burgdorferi and greater IgM levels than immunocompetent monkeys. Nevertheless, spirochete loads were much higher in the immune-suppressed monkeys than in the immunocompetent ones ("Lyme borreliosis ...