|
Dennis N. Bourdette, Michael Riscoe, Ray Houghton1,
Darin Dillon1, Steven Reed1, Linda A. McCauley,
S. Wendy Johnston, Michael L. Wynn, Andre Barkhuizen, Thomas Ward, Peter
S. Spencer and other members of PEHRC
Portland Environmental Hazards Research Center (PEHRC)
1Corixa Corporation, Seattle, WA
L. tropica, a parasite endemic to the Persian Gulf,
typically causes cutaneous leishmaniasis. At least eight PGW veterans
developed viscerotropic leishmaniasis from L. tropica (N Engl J
Med 328:1383-7, 1993). Viscerotropic leishmaniasis can be difficult to
detect and can cause symptoms such as chronic fatigue and abdominal pain
similar to those of veterans with PGW Unexplained Illness. To determine
whether viscerotropic leishmaniasis might explain the health problems
of some veterans with PGWUI, we assessed the frequency of immune reactivity
to a L. tropica antigen among PGW veterans from Oregon and Washington.
Sera from the first 200 subjects participating in a population-based,
case-control study of PGW veterans from a randomly selected population
survey were tested for reactivity to a L. tropica recombinant protein
using an ELISA. This assay was previously shown to be capable of detecting
immune reactivity to L. tropica among veterans with documented
viscerotropic leishmaniasis (Proc Natl Acad Sci, USA, 92:7981-85,1995).
Samples with OD >3SD above the mean OD of sera from healthy, non-veteran
controls were considered positive.
Positive serology by ELISA to the L. tropica recombinant
protein was found in 18 of the 200 veterans (9%). Among cases of PGWUI,
10% had positive serologies while 6% of PGW veteran controls had positive
serologies. None of the subjects with positive serology had abnormalities
on physical examination or routine blood tests, including liver function
and complete blood count. Subsequent follow-up on subjects with positive
serologies by an infectious disease specialist failed to disclose evidence
of clinically active leishmaniasis.
In conclusion, 5-10% of PGW veterans may have serologic
evidence of exposure to L. tropica. None of the subjects with positive
serologies in this study had evidence of active infection with L. tropica,
suggesting that L. tropica infection is rarely a cause of significant
health problems among PGW veterans.
"Keywords:" Leishmania Gulf War veteran Serotest
This work was supported by a grant from the Department of
Veterans Affairs to the PEHRC, a joint project of the Portland Veterans
Affairs Medical Center and the Center for Research on Occupational and
Environmental Toxicology, Oregon Health Sciences University. |
