Comparison of phenotyping and genotyping of lymphoid neoplasms

Abstract

Comparison of phenotyping (PT) and genotyping (GT) of lymphoid neoplasms was performed on 51 specimens including lymph nodes, bone marrows, and body fluids. PT was performed with a flow cytometer using a large monoclonal antibody panel. GT included the testing for gene rearrangements of heavy chain, kappa and lambda light chains, and T-cell receptor beta-chain genes with DNA probes. The results obtained from these two techniques were generally compatible in terms of clonality and cell lineage. Only one case of B-cell lymphoma was not diagnosed by PT but showed gene rearrangement. For T-cell lymphoma, GT offers a more definitive diagnosis than does PT. Biclonality was demonstrated in one case of hairy cell leukemia by GT only. The rearranged band also offers a definitive clonal identification based on electrophoretic mobility. GT can detect a monoclonal population as small as 5% and can be performed on old or fresh specimens. PT requires 20% abnormal cells and a fresh specimen. It is concluded that GT is superior to PT for lymphoid tumor diagnosis, but it should be reserved as a supplementary test at this stage because of its technical complexity.

Little evidence for clonal evolution of malignant haematopoietic cells following relapse after autologous bone marrow transplantation

“…Recently introduced molecular biological methods have raised hopes for an improved detection level in residual cancer. Among such methods, the Southern Blot gene rearrangement analysis has been found to allow for the identification of a clonal cell infiltration constituting between 1% and 5% of the bone marrow (28), whereas the routinely used single-colour IP has a sensitivity of about 5% due to lack of leukaemia-specific monoclonal antibodies (29). The PCR technique has an even higher degree of sensitivity (about 1 : lo5), but has some inherent pitfalls and cannot be utilized in the absence of specific primers (30).…”

Three-color flow cytometry in the diagnosis of malignant lymphoma based on the comparative cell morphology of lymphoma cells and reactive lymphocytes

“…9,[29][30][31][32][33] In the immunohistochemistry study by Picker et al, the inciThis study was supported in part by a research grant from the Gonryo Medical Foundation, and presented at the Symposium dence of loss of pan-T cell antigen in T-LBL was only 26%, while our study detected UCP-L in 20 of 21 cases (95%) in 35th Congress of Japanese Society of Reticuloendothelial System, Niigata, Japan, 11-12 June 1995. We are grateful to because dim positivity of CD45 and CD5 and/or bright positivity of CD7 on the lymphoma cells was easily detected by Dr Masahide Abe, Dr Takanori Aonuma, Dr Toshikazu Awataguchi, Dr Raul C Braylan, Dr Fumio Endo, Dr Kazuyasu Endo, 3-FCM.…”