GENETIC CHANGES IN ATYPICAL HYPERPLASIA AND LYMPHOMA WITH ANGIOIMMUNOBLASTIC LYMPHADENOPATHY AND DYSPROTEINEMIA IN THE SAME PATIENTS

The transition between atypical hyperplasia and lymphoma with angioimm unoblastic lymphadenopathy and dysproteinaemia (AILD) was studied in s erial lymp node biopsy specimens from five patients using DNA analysis with Southern blot analysis, polymerase chain reaction, chromosomal a nalysis, and immunophenotyping. The chromosomal analysis showed additi onal abnormalities as the disease progressed to those present initiall y, and immunological staining showed a corresponding increase in the n umbers of CD4- and Ki67-positive cells. In the first biopsy from each patient a diagnosis of atypical hyperplasia with AILD was made and lym phoma excluding by the finding of only a few atypical lymphoid cells a nd the preservation of follicles with germinal centres. DNA analysis o f lymph nodes at this stage showed either germ lines or oligoclonal re arrangements of the T-cell receptor (TCR) and immunoglobulin heavy cha in genes. In the final biopsy, when a diagnosis of lymphoma with AILD was made, either a monoclonal rearrangement of the TCR was observed or one of the rearranged bands had increased in density. These results s uggest selective proliferation of a clone of abnormal cells may accoun t for the progression of atypical hyperplasia to lymphoma with AILD.