A method for assessing the level of diversity of an immunorepertoire comprising the steps of: (a) amplifying polynucleotides from a population of white blood cells from a human or animal subject in a reaction mix comprising target-specific nested primers to produce a set of first amplicons, at least a portion of the target-specific nested primers comprising additional nucleotides which, during amplification, serve as a template for incorporating into the first amplicons a binding site for at least one common primer; (b) transferring a portion of the first reaction mix containing the first amplicons to a second reaction mix comprising at least one common primer; (c) amplifying, using the at least one common primer, the first amplicons to produce a set of second amplicons; (d) sequencing the second amplicons to identify V J rearrangement sequences in the subpopulation of white blood cells; (e) using the identified V J rearrangement sequences to quantify both the total number of cells in a population of immune system cells and the total numbers of cells within each distinct CDR3 clonotype identified within the population; and (f) identifying the number of distinct CDR3 clonotypes that comprise a significant percentage of a total number of cells counted within that population, wherein a normal state is characterized by the presence of a greater variety of distinct CDR3 clonotypes represented within the significant percentage of the total number of cells and an abnormal state is characterized by the presence of a lesser number of distinct CDR3 clonotypes represented within significant percentage of the total number of cells, wherein the diversity of the distinct CDR3 clonotypes is measured by the diversity index (D N), wherein D N is determined by C/S x 100, where C is a minimum number of distinct CDR3 clonotypes amounting to greater than or equal to N percent of a total of sequencing reads obtained following amplification and sequencing of polynucleotides isolated from the population of cells, wherein S is the number of distinct CDR3 clonotypes in ranked dominance configuration. (a) amplifying polynucleotides from a population of white blood cells from a human or animal subject in a reaction mix comprising target-specific nested primers to produce a set of first amplicons, at least a portion of the target-specific nested primers comprising additional nucleotides which, during amplification, serve as a template for incorporating into the first amplicons a binding site for at least one common primer; (b) transferring a portion of the first reaction mix containing the first amplicons to a second reaction mix comprising at least one common primer; (c) amplifying, using the at least one common primer, the first amplicons to produce a set of second amplicons; (d) sequencing the second amplicons to identify V J rearrangement sequences in the subpopulation of white blood cells; (e) using the identified V J rearrangement sequences to quantify both the total number of cells in a population of immune system cells and the total numbers of cells within each distinct CDR3 clonotype identified within the population; and (f) identifying the number of distinct CDR3 clonotypes that comprise a significant percentage of a total number of cells counted within that population, wherein a normal state is characterized by the presence of a greater variety of distinct CDR3 clonotypes represented within the significant percentage of the total number of cells and an abnormal state is characterized by the presence of a lesser number of distinct CDR3 clonotypes represented within significant percentage of the total number of cells,