Blood samples are collected periodically for immunological marker studies. Samples are analyzed for T-regulatory cell, T-and B-lymphocyte, and NK cell activity in peripheral blood mononuclear cells (PBMC), phagocytic index in monocytes and granulocytes, and cytokine secretion and upregulation by flow cytometry, cytotoxicity assays, cytolysis assays, T-regulatory cell assay, or T/B/NK cell population subset assays. Changes in the production of tumor necrosis factor-alpha and interferon-gamma in serum and in supernatants of PBMCs are analyzed via standard enzyme-linked immunosorbent assay.