Comparative Quantitative Analysis of Cluster of Differentiation 45 Antigen Expression on Lymphocyte Subsets / 대한진단검사의학회지

BACKGROUND: Since the recent introduction of radioimmunotherapy (RIT) using antibodies against cluster of differentiation (CD) 45 for the treatment of lymphoma, the clinical significance of the CD45 antigen has been increasing steadily. Here, we analyzed CD45 expression on lymphocyte subsets using flow cytometry in order to predict the susceptibility of normal lymphocytes to RIT. METHODS: Peripheral blood specimens were collected from 14 healthy individuals aged 25-54 yr. The mean fluorescence intensity (MFI) of the cell surface antigens was measured using a FACSCanto II system (Becton Dickinson Bioscience, USA). MFI values were converted into antibody binding capacity values using a Quantum Simply Cellular microbead kit (Bangs Laboratories, Inc., USA). RESULTS: Among the lymphocyte subsets, the expression of CD45 was the highest (725,368+/-42,763) on natural killer T (NKT) cells, 674,030+/-48,187 on cytotoxic/suppressor T cells, 588,750+/-48,090 on natural killer (NK) cells, 580,211+/-29,168 on helper T (Th) cells, and 499,436+/-21,737 on B cells. The Th cells and NK cells expressed a similar level of CD45 (P=0.502). Forward scatter was the highest in NKT cells (P<0.05), whereas side scatter differed significantly between each of the lymphocyte subsets (P<0.05). CD3 expression was highest in the Th and NKT cells. CONCLUSIONS: NKT cells express the highest levels of CD45 antigen. Therefore, this lymphocyte subset would be most profoundly affected by RIT or pretargeted RIT. The monitoring of this lymphocyte subset during and after RIT should prove helpful.

Comparative Quantitative Analysis of Cluster of Differentiation 45 Antigen Expression on Lymphocyte Subsets / 대한진단검사의학회지

BACKGROUND: Since the recent introduction of radioimmunotherapy (RIT) using antibodies against cluster of differentiation (CD) 45 for the treatment of lymphoma, the clinical significance of the CD45 antigen has been increasing steadily. Here, we analyzed CD45 expression on lymphocyte subsets using flow cytometry in order to predict the susceptibility of normal lymphocytes to RIT. METHODS: Peripheral blood specimens were collected from 14 healthy individuals aged 25-54 yr. The mean fluorescence intensity (MFI) of the cell surface antigens was measured using a FACSCanto II system (Becton Dickinson Bioscience, USA). MFI values were converted into antibody binding capacity values using a Quantum Simply Cellular microbead kit (Bangs Laboratories, Inc., USA). RESULTS: Among the lymphocyte subsets, the expression of CD45 was the highest (725,368+/-42,763) on natural killer T (NKT) cells, 674,030+/-48,187 on cytotoxic/suppressor T cells, 588,750+/-48,090 on natural killer (NK) cells, 580,211+/-29,168 on helper T (Th) cells, and 499,436+/-21,737 on B cells. The Th cells and NK cells expressed a similar level of CD45 (P=0.502). Forward scatter was the highest in NKT cells (P<0.05), whereas side scatter differed significantly between each of the lymphocyte subsets (P<0.05). CD3 expression was highest in the Th and NKT cells. CONCLUSIONS: NKT cells express the highest levels of CD45 antigen. Therefore, this lymphocyte subset would be most profoundly affected by RIT or pretargeted RIT. The monitoring of this lymphocyte subset during and after RIT should prove helpful.

HDL Cholesterol Reduction during Rosiglitazone and Fenofibrate Treatment in a Type 2 Diabetes Mellitus Patient with Dyslipidemia / 대한진단검사의학회지

Thiazolidinediones (TZD), which are widely used as insulin sensitizers, and fibrates, which are lipid-lowering drugs, are used in the treatment of dyslipidemia that commonly accompanies diabetes. Several reports suggest elevated levels of high-density lipoprotein (HDL) cholesterol, but the paradoxical reduction of HDL cholesterol level during single or combined TZD and fibrate therapies has been occasionally reported. Herein, we report a case of paradoxical decrease in HDL cholesterol and apolipoprotein A-1 levels during rosiglitazone and fenofibrate treatment for the first time in Korea. The patient was a 56-yr-old man presenting with type 2 diabetes mellitus and dyslipidemia. His HDL cholesterol and apolipoprotein A-1 levels returned to normal after the cessation of fenofibrate therapy. Since diabetes is an established risk factor of cardiovascular diseases, low HDL cholesterol can be a key cause of concern for patients with diabetes. Therefore, HDL cholesterol level should be determined before and after starting TZD and/or fibrate therapy in diabetic patients.

Near-tetraploidy Acute Myeloid Leukemia with RUNX1-RUNX1T1 Rearrangement Due to Cryptic t(8;21) / 대한진단검사의학회지

Tetraploidy or near-tetraploidy is a rare cytogenetic abnormality found in AML, and is divided into primary and secondary forms. The secondary tetraploidy or near-tetraploidy found in AML is known to be specifically associated with t(8;21). In this case report, FISH analysis detected RUNX1-RUNX1T1 gene rearrangement in the absence of cytogenetic abnormality of t(8;21), which suggests the presence of unvailed t(8;21). This is the first case report of tetraploidy or near-tetraploidy AML with cryptic RUNX1/RUNX1T1 in Korea. Although the prognosis of tetraploidy or near- tetraploidy with t(8;21) is known to be poor, this patient shows a relatively good clinical course compared to other reported cases.

Four Cases of Hematologic Malignancy Following Radioactive Iodine Therapy for Thyroid Cancer / 대한진단검사의학회지

Ionizing radiation including I131 might produce chromosomal translocation, causing hematologic malignancy. The incidence of leukemia following radioactive iodine treatment for thyroid cancer has been reported to be approximately 0.1 to 2.0% in Western countries, whereas fewer cases have been reported in Korea. We hereby report four cases of secondary hematologic malignancy, who received iodine therapy for thyroid cancer after thyroidectomy: two cases of acute lymphoblastic leukemia with t(9;22)(q34;q11.2), a case of MDS with 5q deletion, and a case of MDS with normal karyotype. Three cases of hematologic malignancy have developed after cumulative dosage of less than 800 mCi. The treatment intervals in two cases were less than 12 months, and the other two cases had I131 therapy only once. Assessment of causality using the Naranjo probability scale for adverse drug reactions showed that a 'possible' relationship existed between the use of I131 and secondary hematologic malignancy in all of the four cases in this report.