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According to WHO, several T-cell immunophenotypic markers may be aberrantly expressed in acute myeloid leukemia (AML) while others are typically absent. TdT may be positively expressed in greater than one third of cases, and CD2 and CD7 may be expressed frequently at a low intensity, however, the T-cell lineage specific antigen CD3 is usually absent. In the present investigation, 30 cases of AML were evaluated for CD2, CD3, CD4, CD5, CD7, CD8 and TdT expression, and mean fluorescence intensities (MFI) were quantified. Of the 3 (10%) cases positive for CD3 and CD8 expression, 1 was bright with a MFI greater than 501, and 2 cases were moderate. Of the 14 (46.7%) cases positive for CD4 expression, 1 was bright, 10 were moderate, and 3 were dim with MFI values between 201 and 300. TdT was positively expressed in 4 (13.3%) cases with MFI values between 301 and 500. CD2 and CD5 were positively expressed in 5 (16.7%) cases. While CD2 was moderate in all 5 cases, CD5 was bright in 3, moderate in 1, and dim in 1 case. Of the 15 (50%) cases positive for CD7 expression, 9 were bright, 5 were moderate, and 1 was dim. These data indicate that CD2 and CD7 may be frequently expressed at greater intensities than WHO specified, and CD4 may be aberrantly expressed more often than previous studies indicate. These results point to the need for a more extensive study to evaluate the potential prognostic significance of aberrant T-cell marker expression in AML. [ABSTRACT FROM AUTHOR]

Abstract: The WHO immunophenotype for plasma cell myeloma is deletion of CD19 and CD20, usual expression of CD38, CD138, and CD56, and occasional expression of CD10. Of the 39 cases of plasma cell dyscrasia in our study, the mean fluorescence intensities (MFI) of CD38, CD138, CD56, and CD19 were quantified in 30 cases. CD19 was absent in 38 of the cases (97.4%), whereas CD138 and CD38 were expressed in all 39 cases (100%). Most cases expressed CD38 and CD138 brightly with MFI values greater than 501, whereas all other marker expression was moderate with MFI greater than 301. Whereas CD38/CD56 dual expression was observed in 25 cases (64.1%), 14 failed to express CD56 (35.9%). CD56 expression was bright in 16 cases (53.3%), moderate in 2 cases (6.7%), and negative in the remaining 12 cases (40%) with MFI values of 200 or less. CD117 expression was positive in 9 of 24 cases (37.5%). In 32 of 39 cases, 27 were negative for CD20 (84.4%) and 28 were negative for CD10 (87.5%). Our results point to the value of quantitative fluorescence intensity in the flow cytometric evaluation of CD molecular expression or deletion in the diagnosis of hematopathologic disorders, such as plasma cell dyscrasia. [Copyright &y& Elsevier]