Background:

Over 80% of the hemophiliac population who became infected with HIV prior to 1985 are also co-infected with HCV. Thus, hemophiliacs represent an important population for studies of the natural history of these chronic viral infections.

Moreover, the high rate of co-infection makes it an ideal group for assessing the interaction between the viruses and the relationship between viral specific immune responses and clinical progression.

Although the hemophiliac poulation is unique, co-infection by these chronic viral pathogens is becoming increasingly common, particularly amongst intravenous drug users, who account for approximately 25% of the HIV-1 epidemic in the United States.

Objectives:

The aim of this study is to determine if polymorphism in the promoter region of TH1 and Th2 cytokines are associated with (1) intracellular cytokines levels in CD4 + Tcells, (2) Human Immunodeficiency Virus (HIV) and Hepatitis C virus (HCV) viral loads, and (3) clinical progression of HIV1 to AIDS in hemophiliacs.

Eligibility:

The current proposal will investigate host genetic factors related to HIV-1 and HCV immunopathogenesis by studying children and adolescents enrolled in the Hemophilia Growth and Development Study (HGDS).

Design:

This study is in collaboration with the principle investigators of the Hemophilia Growth and Development Study (HGDS) as part of a grant "Pathogenesis of HIV and HCV in Hemophilia: HGDS-3" with funding support by NIH/NICHD for the period 9/25/01 through 8/31/2005.

This multicenter, United States study represents a well-characterized, prospectively followed cohort of HCV-infected hemophiliacs, of whom 207 are HIV-1 co-infected.

Enrollment of the hemophiliac cohort was completed between 3/89 and 6/90. The final observation of the cohort (follow-up 16) was concluded during 7/98. No new samples or clinical data will be collected on this population.

The LGD plays two roles in this project: (1) an administrative role overseeing the withdrawal, handling, and transport of samples from the HGDS/LGD and central repositories at the NCI-Frederick, and (2) a scientific role continuing investigations to determine the role of host genetic factors in Th1 and Th2 immune response and regulation of HCV and HIV viral replication..