Immune function in newly diagnosed children with malignancy.

BACKGROUND In Germany, 1800 new patients younger than 15 years contract with a malignancy each year. Leukemia is the most common disease (34%) followed by central nervous system tumors (23%) and lymphoma (12%). Prognosis and tumor entities differ significantly from adult tumors. However, even if prognosis and therapy efforts have dramatically improved over the last decades, malignancies are still the major cause for death in this age group. Tumor genesis of many pediatric tumors remains unclear. A favorable factor for tumor development is known to be immunodeficiency. For tumor surveillance adequate T-cell numbers and repertoire diversity are key elements that have been extensively studied.1,2 In addition, cytokines are critical for the effectiveness of that response.3 Even if many reports exist about immune reconstitution and function during and after intensive chemotherapy,1,2 immune function at diagnosis has not been studied yet. As well known for certain congenital immunodeficiencies,4 we suppose that an underlying immune deficit and immune compromise because of the malignancy may promote tumor growth and may be important for novel approaches and future therapeutic strategies. To advance the understanding of tumor dynamic and immune escape mechanism, lymphocyte subpopulations and immune functioning in newly diagnosed children with malignancy before the beginning of therapy were investigated.