Residual Brain Infection in Relapsing-Fever Borreliosis - Lyme disease

georgia · medicine forum Guru Joined: 06 May 2005 Posts: 505

The Journal of Infectious Diseases 2006;193:1451-1458
C 2006 by the Infectious Diseases Society of America.

Residual Brain Infection in Relapsing-Fever Borreliosis

Diego Cadavid,1,2 Marie Sondey,1,2,
Edwin Garcia, and Catherine L. Lawson3

1Department of Neurology and Neuroscience and 2Center for the Study of
Emerging Pathogens, University of Medicine and Dentistry of New
Jersey-New
Jersey Medical School, Newark, and 3Department of Chemistry and
Chemical
Biology, Rutgers University, Piscataway, New Jersey

Background. Neurological involvement is common in the
spirochetal
infection relapsing fever (RF) in both humans and experimental animals.
RF
is best known for antigenic variation caused by the sequential
expression of
variable outer membrane lipoproteins of 2 sizes, variable small (Vsp)
and
variable large (Vlp) proteins. Less understood is the persistence of RF
borreliae in the brain after they are cleared from the blood, referred
to as
residual brain infection (RBI). Our goal was to investigate the
phenomenon
of RBI in RF.
Methods. We studied RBI in immunocompetent mice by culturing
blood
and perfused brain samples 1 month after intraperitoneal inoculation
with
Borrelia turicatae serotype 1 (Bt1). Mice deficient in Toll-like
receptor 2
(TLR2-/-) or in B and T cells (scid) were included for comparison.
Results. All scid mice had persistent infection in blood and
brain.
RBI was found in 3 (19%) of 16 immunocompetent and TLR2-/- mice. RBI
was
caused by either persistence of the original serotype (Bt1) or newly
emerged
Vsp (n = 1, renamed Bt3) or Vlp serotypes. The Vsp of Bt1 (Vsp1) and
Bt3
(Vsp3) were 75% identical.
Conclusions. RBI in RF is relatively frequent and can occur by
persistence of the original or newly emerged serotypes.

Received 24 August 2005; accepted 9 December 2005; electronically
published 4 April 2006.
Potential conflicts of interest: none reported.
Financial support: Foundation of the University of Medicine and
Dentistry of New Jersey (grant to D.C.); Heritage Affiliate of the
American
Heart Association (Scientist Development Grant 0235464T to D.C.).

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