Search

Introduction Large granular lymphocytes ( LGLs) are medium- to large-sized lymphocytes with azurophilic cytoplasmic granules. Reactive vs. neoplastic LGLs are usually morphologically indistinguishable. Methods We investigated 25 consecutive cases of LGL lymphoproliferation using flow cytometric T cell receptor Vβ ( FC-Vβ) repertoire and T cell receptor gene rearrangement ( TCR- GR) in detecting clonality. Results Seventeen patients (68%) were T- LGL leukemia (T- LGLL) with a male predominance, a median age of 67, and a median absolute LGL count of 2.592 × 109/L. All cases were clonal using the FC-Vβ analysis, and all but one (94%) was clonal by TCR- GR. Eight patients (32%) had reactive LGL lymphoproliferation. Two had EBV-associated infectious mononucleosis; one was clonal by both FC-Vβ and TCR- GR; and the other was clonal only by TCR- GR. The remaining six cases were polyclonal by both assays. Patients with reactive LGL lymphoproliferation were more frequently associated with an underlying/concurrent malignancy than those with T- LGLL (4/8 cases vs. 1/17; P = 0.023, Fisher's exact test). We compared the demographic, hemogram, and clonality data between these two groups and found that the only significant difference was the lower median platelet count in the LGL lymphocytosis group (201 × 109/L vs. 223 × 109/L; P = 0.031; Student's t-test). A literature review including the current study showed a high sensitivity of FC-Vβ analysis for T- LGLL (97.2%; 107/110 cases). Conclusions FC-Vβ analysis was slightly more sensitive than TCR- GR for the detection of clonal T cell lymphoproliferation. However, we must interpret the laboratory findings with clinical context as clonal T cell lymphoproliferation may occur in patients with viral infection. [ABSTRACT FROM AUTHOR]

Aberrant antigen expression in acute myeloid leukemia (AML) has been extensively studied in the West with limited reports from Taiwan. We carried out this retrospective study to characterize the frequency and significance of aberrant antigen expression of AML in Taiwan. Among 111 cases, 58 (52%) showed aberrant antigen expression, most frequently CD7 (27%) and CD56 (23%). Aberrant CD7 expression was observed in all non-AML-M3 subtypes, most frequently in AML-M7 (4/6, 67%); while CD19 expression was only observed in AML-M2 (5/36, 14%). CD56 expression was most common in AML-M5 (4/8, 50%). The relative frequency of CD19 and CD56 expression in AML with t(8;21) was higher than those with other chromosomal abnormalities or normal karyotype ( P = 0.011 and 0.005, respectively). In non-M3 AML, aberrant antigen expression was identified in 56/96 (58%) cases, in contrast to 2/15 (13%) AML-M3 cases ( P = 0.001). CD7, CD19 and CD56 expression was not correlated with remission rate. We concluded that aberrant immunophenotype was more frequent in non-M3 leukemias in Taiwan. The relative frequency of CD19 and/or CD56 expression in AML with t(8;21) was significantly higher than those without this translocation and co-expression of these two antigens may serve as the surrogate markers for AML with t(8;21). [ABSTRACT FROM AUTHOR]