[Molecular immunology in pediatrics]

Immunoglobulin and T-cell antigen receptor genes in their germline form are organized as discontinuous DNA elements that are joined by recombinations during lymphocyte development. The analysis of immunoglobulin and T-cell receptor gene structure as well as the analysis of chromosomal translocations has been of great value in defining the lineage of neoplasms, determining the clonality of abnormal lymphocyte proliferations, diagnosis and monitoring of lymphoid malignancies and determining the state of maturation of B- and T-cells. The basic principles of molecular genetics have established some common basis for understanding immune activation and regulation, and thereby have opened new possibilities in studying immunodeficiency and autoimmune diseases. Thus, the application of this molecular genetic approach has great potential for complementing conventional marker analysis, cytogenetics and histopathology in the evaluation of these diseases.