Immune Response to Cytomegalovirus

This study will evaluate immune responses against cytomegalovirus (CMV). About 80 percent of adults have been exposed to this virus. CMV typically remains dormant (inactive) in the body, causing no problems. In people with immune suppression, however, the virus can become reactivated and cause life-threatening pneumonia. The knowledge gained from this study may be useful in developing ways to improve immune responses to CMV in stem cell transplant recipients. Healthy normal volunteers between 18 and 65 years of age who have been exposed to cytomegalovirus are eligible for this study. Candidates will be screened with a medical history and blood tests. Those enrolled will provide a 30-milliliter (6-tablespoon) blood sample once a week for 4 weeks and a final sample 2 months later. The blood will be used to design a test to detect immune responses against CMV and determine the differences in these responses among healthy individuals.