Longitudinal Analysis of Plasmodium Falciparum-Specific Immunity in Travelers and Immigrants From Malaria Endemic Areas to the United States
| Status: | Terminated |
|---|---|
| Conditions: | Infectious Disease |
| Therapuetic Areas: | Immunology / Infectious Diseases |
| Healthy: | No |
| Age Range: | 18 - 65 |
| Updated: | 3/27/2019 |
| Start Date: | May 15, 2014 |
| End Date: | March 15, 2016 |
Plasmodium falciparum malaria is a major cause of morbidity and mortality in tropical and
sub-tropical areas worldwide. Repeated P. falciparum infections in endemic areas induce
protective immunity, thus providing optimism that an effective malaria vaccine can be
developed. Key to the development of such a vaccine is an understanding of the immune
mechanisms underlying protection and the longevity of these responses in the absence of
continuous P. falciparum exposure. Anecdotal evidence suggests clinical immunity to malaria
wanes within months to years after an immune individual leaves an endemic area. A detailed,
systematic description of the quality and longevity of the P. falciparum-specific humoral and
cellular immune responses in such individuals over time in the absence of ongoing exposure is
lacking.
This protocol will attempt to fill this knowledge gap through comprehensive longitudinal
immunological analyses of two populations of healthy adult volunteers: 1) naive travelers
returning from malaria endemic areas recently treated (within 2 weeks) for acute P.
falciparum malaria and referred from hospitals in the metropolitan Washington DC area; and 2)
immigrants from malaria endemic areas living in the metropolitan Washington DC area with
serologic evidence of past P. falciparum exposure. In both groups, venipuncture and possibly
apheresis will be performed for the isolation of plasma, RNA and peripheral blood mononuclear
cells (PBMCs) which will be analysed to understand the components of innate and adaptive
immunity to malaria. Na(SqrRoot) ve travelers returning from malaria endemic areas recently
treated for acute malaria will undergo venipuncture at enrollment, then once every 2 weeks
for 2 months, then every 3 months for 1 year, and then every 6 months for up to 5 years.
Immigrants will be seen every three months for one year and then every six months for up to 5
years. All subjects who return to the U.S. from a malaria endemic area will be evaluated
within two weeks of return for repeat venipuncture and will restart the same sequence of
blood draws as naive travelers. Optional apheresis will be performed on both na(SqrRoot) ve
travelers and immigrants at enrollment, at 1, 6, and 12 months, then yearly therafter.
The primary objective is to estimate the quality and longevity of P. falciparum-specific
humoral and cellular immune responses in the absence of ongoing P. falciparum exposure in
both returned na(SqrRoot) ve travelers and immigrants. The secondary objective is to compare
the P. falciparum-specific humoral and cellular immune response in na(SqrRoot) ve travelers
and immigrants to individuals in malaria-endemic areas enrolled in ongoing LIG protocols in
Mali.
sub-tropical areas worldwide. Repeated P. falciparum infections in endemic areas induce
protective immunity, thus providing optimism that an effective malaria vaccine can be
developed. Key to the development of such a vaccine is an understanding of the immune
mechanisms underlying protection and the longevity of these responses in the absence of
continuous P. falciparum exposure. Anecdotal evidence suggests clinical immunity to malaria
wanes within months to years after an immune individual leaves an endemic area. A detailed,
systematic description of the quality and longevity of the P. falciparum-specific humoral and
cellular immune responses in such individuals over time in the absence of ongoing exposure is
lacking.
This protocol will attempt to fill this knowledge gap through comprehensive longitudinal
immunological analyses of two populations of healthy adult volunteers: 1) naive travelers
returning from malaria endemic areas recently treated (within 2 weeks) for acute P.
falciparum malaria and referred from hospitals in the metropolitan Washington DC area; and 2)
immigrants from malaria endemic areas living in the metropolitan Washington DC area with
serologic evidence of past P. falciparum exposure. In both groups, venipuncture and possibly
apheresis will be performed for the isolation of plasma, RNA and peripheral blood mononuclear
cells (PBMCs) which will be analysed to understand the components of innate and adaptive
immunity to malaria. Na(SqrRoot) ve travelers returning from malaria endemic areas recently
treated for acute malaria will undergo venipuncture at enrollment, then once every 2 weeks
for 2 months, then every 3 months for 1 year, and then every 6 months for up to 5 years.
Immigrants will be seen every three months for one year and then every six months for up to 5
years. All subjects who return to the U.S. from a malaria endemic area will be evaluated
within two weeks of return for repeat venipuncture and will restart the same sequence of
blood draws as naive travelers. Optional apheresis will be performed on both na(SqrRoot) ve
travelers and immigrants at enrollment, at 1, 6, and 12 months, then yearly therafter.
The primary objective is to estimate the quality and longevity of P. falciparum-specific
humoral and cellular immune responses in the absence of ongoing P. falciparum exposure in
both returned na(SqrRoot) ve travelers and immigrants. The secondary objective is to compare
the P. falciparum-specific humoral and cellular immune response in na(SqrRoot) ve travelers
and immigrants to individuals in malaria-endemic areas enrolled in ongoing LIG protocols in
Mali.
Plasmodium falciparum malaria is a major cause of morbidity and mortality in tropical and
sub-tropical areas worldwide. Repeated P. falciparum infections in endemic areas induce
protective immunity, thus providing optimism that an effective malaria vaccine can be
developed. Key to the development of such a vaccine is an understanding of the immune
mechanisms underlying protection and the longevity of these responses in the absence of
continuous P. falciparum exposure. Anecdotal evidence suggests clinical immunity to malaria
wanes within months to years after an immune individual leaves an endemic area. A detailed,
systematic description of the quality and longevity of the P. falciparum-specific humoral and
cellular immune responses in such individuals over time in the absence of ongoing exposure is
lacking.
This protocol will attempt to fill this knowledge gap through comprehensive longitudinal
immunological analyses of two populations of healthy adult volunteers: 1) naive travelers
returning from malaria endemic areas recently treated (within 2 weeks) for acute P.
falciparum malaria and referred from hospitals in the metropolitan Washington DC area; and 2)
immigrants from malaria endemic areas living in the metropolitan Washington DC area with
serologic evidence of past P. falciparum exposure. In both groups, venipuncture and possibly
apheresis will be performed for the isolation of plasma, RNA and peripheral blood mononuclear
cells (PBMCs) which will be analysed to understand the components of innate and adaptive
immunity to malaria. Na(SqrRoot) ve travelers returning from malaria endemic areas recently
treated for acute malaria will undergo venipuncture at enrollment, then once every 2 weeks
for 2 months, then every 3 months for 1 year, and then every 6 months for up to 5 years.
Immigrants will be seen every three months for one year and then every six months for up to 5
years. All subjects who return to the U.S. from a malaria endemic area will be evaluated
within two weeks of return for repeat venipuncture and will restart the same sequence of
blood draws as naive travelers. Optional apheresis will be performed on both na(SqrRoot) ve
travelers and immigrants at enrollment, at 1, 6, and 12 months, then yearly therafter.
The primary objective is to estimate the quality and longevity of P. falciparum-specific
humoral and cellular immune responses in the absence of ongoing P. falciparum exposure in
both returned na(SqrRoot) ve travelers and immigrants. The secondary objective is to compare
the P. falciparum-specific humoral and cellular immune response in na(SqrRoot) ve travelers
and immigrants to individuals in malaria-endemic areas enrolled in ongoing LIG protocols in
Mali.
sub-tropical areas worldwide. Repeated P. falciparum infections in endemic areas induce
protective immunity, thus providing optimism that an effective malaria vaccine can be
developed. Key to the development of such a vaccine is an understanding of the immune
mechanisms underlying protection and the longevity of these responses in the absence of
continuous P. falciparum exposure. Anecdotal evidence suggests clinical immunity to malaria
wanes within months to years after an immune individual leaves an endemic area. A detailed,
systematic description of the quality and longevity of the P. falciparum-specific humoral and
cellular immune responses in such individuals over time in the absence of ongoing exposure is
lacking.
This protocol will attempt to fill this knowledge gap through comprehensive longitudinal
immunological analyses of two populations of healthy adult volunteers: 1) naive travelers
returning from malaria endemic areas recently treated (within 2 weeks) for acute P.
falciparum malaria and referred from hospitals in the metropolitan Washington DC area; and 2)
immigrants from malaria endemic areas living in the metropolitan Washington DC area with
serologic evidence of past P. falciparum exposure. In both groups, venipuncture and possibly
apheresis will be performed for the isolation of plasma, RNA and peripheral blood mononuclear
cells (PBMCs) which will be analysed to understand the components of innate and adaptive
immunity to malaria. Na(SqrRoot) ve travelers returning from malaria endemic areas recently
treated for acute malaria will undergo venipuncture at enrollment, then once every 2 weeks
for 2 months, then every 3 months for 1 year, and then every 6 months for up to 5 years.
Immigrants will be seen every three months for one year and then every six months for up to 5
years. All subjects who return to the U.S. from a malaria endemic area will be evaluated
within two weeks of return for repeat venipuncture and will restart the same sequence of
blood draws as naive travelers. Optional apheresis will be performed on both na(SqrRoot) ve
travelers and immigrants at enrollment, at 1, 6, and 12 months, then yearly therafter.
The primary objective is to estimate the quality and longevity of P. falciparum-specific
humoral and cellular immune responses in the absence of ongoing P. falciparum exposure in
both returned na(SqrRoot) ve travelers and immigrants. The secondary objective is to compare
the P. falciparum-specific humoral and cellular immune response in na(SqrRoot) ve travelers
and immigrants to individuals in malaria-endemic areas enrolled in ongoing LIG protocols in
Mali.
- INCLUSION CRITERIA:
- All Subjects: Age 18-65
- Agree to have blood specimens stored for future research and genetic studies
Malaria endemicity will be defined according to CDC Yellow Book criteria available at:
http://wwwnc.cdc.gov/travel/yellowbook/2014/chapter-3-infectious-diseases-related-totravel/
malaria#3929
NaIve travelers returning from malaria endemic areas recently treated for malaria:
-Treated for acute P. falciparum malaria within 4 weeks of enrolling in this study as
determined by clinical and microbiologic evidence (including blood smear) of infection as
indicated by medical records
Immigrants from malaria endemic areas:
- Confirmation of having lived in a malaria endemic area through documentation or
verifiable detailed immigration history.
- Evidence of past P. falciparum exposure with positive AMA -1 ELISA.
SUBJECT EXCLUSION CRITERIA:
- History of HIV and/or hepatitis C.
- Inadequate peripheral venous access
- Current use of the steroid equivalent of prednisone 20mg/day or more or other systemic
immunosuppressants
- Underlying heart disease, lung disease, bleeding disorder, or other conditions that,
in the judgment of the investigator, contraindicates study participation
- Temperature greater than or equal to 37.5 (Infinite)C or other clinical evidence of an
acute infection
- Currently pregnant (positive urine beta-HCG) or breastfeeding
We found this trial at
1
site
9000 Rockville Pike
Bethesda, Maryland 20892
Bethesda, Maryland 20892
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