Relationship between In Vitro Chemosensitivity assessed with MTT Assay and Clinical Outcomes in 103 Patients with Acute Leukemia / 대한진단검사의학회지

BACKGROUND: Cellular drug resistance is supposed to play a major role in chemotherapy failure or relapse. The purpose of this study was to analyze the relationship between in vitro chemosensitivity test results using a 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and clinical response on chemotherapy, and to find the possibility of optimizing the treatment protocol for individual patients according to their actual drug resistance. METHODS: For MTT assay, we obtained bone marrow aspirates from 103 patients with acute leukemia at the time of initial diagnosis or relapse. The following drugs were tested: cytarabine, vincristine, methotrexate, daunorubicin, dexamethasone, L-asparaginase, and mitoxantrone. To evaluate clinical responses after induction chemotherapy, we followed up on their bone marrow study. RESULTS: In our study, in vitro chemosensitivity test with the MTT assay significantly predicted whether patients with AML remained continuous complete remission or went into relapse. It also predicted whether or not child patients with ALL would acquire complete remission after induction chemotherapy. CONCLUSIONS: Although it does not provide the insight into the mechanisms that cause drug resistance, the MTT assay may be a useful tool in individually optimizing the chemotherapy of patients with acute leukemia.

Discrepant results by High Protein Anti-D and Low Protein Anti-D in a D Negative Newborn / 대한임상병리학회지

High-protein anti-D reagents prepared from pools of human serum have been used for routine RhD typing but, low-protein, saline reactive anti-D reagents formulated predominantly with monoclonal antibodies are in current use. Because some of the high-protein reagents contain macromolecular additives that may cause red cells coated with immunoglobulin to aggregate spontaneously, antisera with these additives may produce a false-positive reaction. A four-day old male was admitted due to severe jaundice. Initially, the RhD type of the newborn using a high-protein reagent was D-positive and then, using two low-protein reagents, it was D-negative. The blood type of the mother was B, CDe, and that of the newborn was B, CcdEe. The direct antiglobulin test on the newborn's RBC was positive. Anti-E and anti-c were identified in the mother's serum and anti-E only was identified in the newborn's serum. The newborn was treated with phototherapy for 10 days and discharged as recovered. We present a case of hemolytic disease of the D negative newborn, which showed a discrepancy between high protein anti-D and low protein anti-D. With a review of literature, the newborn was possibly misinterpreted as D positive.