Project Details
Description
This epidemiologic study will examine the influence of the insulin-like growth factor (IGF)-axis on the
pathogenesis of HIV and human papillomavirus (HPV), two sexually transmitted viruses. Recent data suggest
that the IGF-axis plays a role in host immunity through its effects on cell proliferation and survival, prompting
speculation that it might also affect the rate of HIV disease progression. IGF-I, a hormone with mitogenic/antiapoptotic
activity can, in animal models, increase lymphocyte count, and even induce thymic regeneration in
FIV infected cats. In contrast, the major IGF binding protein (IGFBP), IGFBP-3, has both indirect (sequestering
IGF-I) and direct (IGF-I independent) anti-mitotic/pro-apoptotic activity, and is hypothesized to accelerate HIV
disease. However, there is little human data. We conducted a pilot investigation using only baseline specimens
from the Women[unreadable]s Interagency HIV Study (WIHS), an ongoing cohort of HIV-positive (N=2,793) and HIVnegative
(N=975) women, initiated in 1994. Incident clinical AIDS (N=101 cases) was associated with ? IGFBP-
3 (HR=2.7;1.3-5.4) in data/specimens obtained prior to the widespread use of HAART (pre-HAART) [reprint 1]
- consistent with IGFBP-3[unreadable]s proposed anti-mitotic/pro-apoptotic effects on the immune system. The association
of IGF-I with AIDS was also in the expected direction, albeit, non-significant (HR=0.64;0.35-1.18), and both
? IGFBP-3 (Ptrend=0.02) and ? IGF-I (Ptrend=0.02) were associated with rapid CD4+ T-cell decline. The role of
the IGF-axis in HPV natural history was studied in 137 HIV-negative women. Persistence of oncogenic HPV was
associated with ? IGF-I/IGFBP-3 ratio (HR=7.1;1.8-25), while ? IGFBP-3 was associated with very low risk of
oncogenic HPV-positive cervical neoplasia (HR= 0.07; 0.01-0.66); most other results were non-significant but in
the expected direction - consistent with the IGF-axis[unreadable]s effects on other tumors and recent cross-sectional
studies of cervical neoplasia. These prospective pilot data have clear clinical implications. For HIV, they imply
that the IGF-axis might be exploited as a target for therapies to slow HIV disease (lengthening the time until
HAART use becomes needed). If in the current study we find similar results in women using HAART, it could
suggest also targeting the IGF-axis during HAART. Similarly, for HPV, our data suggest that the IGF-axis may
have untapped potential to treat/prevent disease. The project is notable, therefore, for having potential to open
several new areas of epidemiologic and clinical investigation. Under this grant we will for the first time study
women using HAART; conduct repeated testing of IGF-I and IGFBP-3 at sequential study visits to carefully
characterize IGF-I and IGFBP-3 exposure; study additional IGF-axis related components, including IGF-II, free
(bioactive) IGF-I, and C-peptide. This grant will also greatly increase the number of cases for each endpoint.
The Specific Aims are to study the role of the IGF-axis in: (1) HIV disease progression in women not using
HAART (based on specimens/data obtained prior to the HAART era); (2) The risk of AIDS related death in
women using HAART; and (3) The natural history of oncogenic HPV in HIV-positive and -negative women.
Status | Finished |
---|---|
Effective start/end date | 8/1/08 → 7/31/10 |
ASJC
- Infectious Diseases
- Medicine(all)
- Immunology and Microbiology(all)
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