Analytical Performance of Bio-Rad D-100 on a Hemoglobin A1c Assay

BACKGROUND: Hemoglobin A1c (HbA1c) is considered a marker useful for the follow-up and diagnosis of diabetes and implies the importance of reliable assay methods that are traceable to a reference method. We evaluated analytical performance of a new high-performance liquid chromatography system for the HbA1c assay: D-100 from Bio-Rad Laboratories (USA). METHODS: We evaluated precision, linearity, and carry-over of D-100, according to the Clinical and Laboratory Standards Institute's guidelines. Comparative analysis of D-100 with Integra 800 (Roche Diagnostics, Germany) and Capillarys 3 (Sebia, France) was conducted. Additionally, we evaluated the throughput of the three instruments. RESULTS: Precision of low- and high-concentration controls in D-100 showed a CV of less than 1%. The linearity was excellent (R²=0.999) in the range of 3.51-18.7%, and carry-over was not observed. HbA1c results of D-100 (n=144) showed good correlation with those of Integra 800 (r=0.993) and Capillarys 3 (r=0.996). The % bias between D-100 and Integra 800 or Capillarys 3 was within the allowable range at all 3 medical decision levels (5.7%, 6.5%, and 10.0%). Elapsed time in the analysis of the first sample by D-100 was shorter than that of Integra 800 (2.4 vs. 11.1 minutes), but subsequent samples took more time (0.8 vs. 0.3 minutes per sample). CONCLUSIONS: D-100 showed reliable analytical performance with good precision and linearity, minimal carry-over, and acceptable comparative characteristics relative to other instruments. D-100 is expected to be useful for clinical measurements of HbA1c for diabetes diagnosis and theranostics.

Reduction of the Platelet Transfusion Dose and Its Effects / 대한진단검사의학회지

BACKGROUND: In Korea, a platelet transfusion dose (TD) of 8 units of platelet concentrates (PC) is usually used. To minimize the shortage of blood products and transfusion-related adverse reactions, the TD has been changed from 8 to 6 units in 2006 in our hospital. Here, we analyzed the dose reduction effect on patients' platelet counts and transfusion frequency. METHODS: We compared the amount of issued PC, platelet counts before and after transfusion, post-transfusion platelet increments, and transfusion frequencies in patients who were transfused with 8 PC in 2006 and 6 PC in 2008. RESULTS: Despite an increase in the number of admitted patients by 20% in 2008 with a disease distribution similar to that in 2006, the number of issued PC in 2008 was decreased by 26.6% compared to that in 2006. In 2008, post-transfusion platelet counts, pre-transfusion platelet counts in patients transfused with 320 mL whole blood-derived PC, and platelet increments in patients transfused with 400 mL whole blood-derived PC were significantly decreased. However, the mean transfusion frequency per one month was not significantly different, 4.3 times in 2006 and 4.7 in 2008. CONCLUSIONS: By implementing a policy of platelet TD restriction, the amount of total issued PC was markedly decreased. Although post-transfusion platelet counts were decreased, the transfusion frequency in a month was not significantly increased. The restriction of platelet TD was helpful for increasing physicians' recognition of blood shortage while achieving similar transfusion effects. We conclude that 6 units of PC would be a better guideline for the platelet TD.

A Case of Hemolytic Transfusion Reaction in a Patient with Anti-E, Anti-M, Anti-Jkb, and Anti-Lea / 대한수혈학회지

We reported a case of hemolytic transfusion reaction that was related to multiple RBC antibodies such as anti-E, anti-M, anti-Jkb and anti-Lea after serial RBC transfusions. A forty-nine year old female visited the emergency room (ER) with hematochezia. She had previously received 16 units of packed RBCs from 2003 to Jan 2007 for her intermittent esophageal varix bleeding. No specific antibodies were identified before this visiting. At the ER, under the request for packed RBCs, we identified anti-E antibody within her serum. Her blood type was AB, RhD+ with the phenotype of CcDe. She received 5 units of E antigen negative RBCs. However, she showed hemolytic transfusion reactions such as mild fever with a decrease of hemoglobin from 11.4 g/dL to 6.8 g/dL after the transfusion. From the 8th to the 10th hospital day, another 3 units of E-antigen negative with the least incompatible RBCs were transfused to the patient, but the level of hemoglobin was not definitely increased. At the 14th hospital day, she received a final 2 units of leuko-reduced RBCs without E, M and Jkb antigens. Her hemoglobin was increased right after the final transfusion. We found that the patient's serum reacted with multiple RBC antibodies such as anti-E, anti-M, anti-Jkb and anti-Lea antibodies. She finally recovered from acute varix bleeding and was discharged on the 26th hospital day with the level of hemoglobin being 8.3 g/dL.

The Usage of Uncrossmatched Group O, Rh-Negative RBCs for Emergency Transfusion / 대한수혈학회지

BACKGROUND: The use of uncrossmatched group O, Rh-negative RBCs has enabled immediate transfusion of patients who need critical care in life-threatening situations. We examined our 1-year experience with uncrossmatched group O, Rh-negative RBC transfusion in a tertiary care university hospital. METHODS: Uncrossmatched group O, Rh-negative RBCs were available for immediate transfusion upon request without performing any of the following pretransfusion tests: ABO and RhD typing, irregular antibody screening, crossmatching test. The characteristics of the transfused patients were studied retrospectively. RESULTS: Twenty-five patients received 56 units of uncrossmatched group O, Rh-negative RBCs from November 2005 to October 2006. An average of 2.24 units was issued to each patient, with no more than 4 units per patient being given; subsequent transfusion was done with type-specific, crossmatched blood. The average turnaround time for the release of uncrossmatched group O, Rh-negative RBCs was 1.8 minutes (mean+/-standard deviation: 1.8+/-1.96, range: 0~7 minutes). Seventeen patients died (68%), which included 16 patients who had received cardiopulmonary resuscitation. CONCLUSION: Patients admitted for traffic accident, falling down injury, gastrointestinal bleeding and aortic dissection received 72% of the emergency group O, Rh-negative RBCs, with a 72.2% mortality rate, which indicates the dire condition of these patients. The majority of RBCs for transfusion were available within 5 minutes upon request. Though group O, Rh-negative RBCs are recommended in emergency situations in which the blood group of the patient is unknown, the use of group O, Rh-positive RBCs may be an alternative blood supply, when considering the short supply of Rh-negative RBCs.