Performance Evaluation of the ichroma SMART Analyzer in Measuring C-reactive Protein and Procalcitonin Levels

BACKGROUND: For monitoring infection and inflammation episodes, biomarkers of host response, such as C-reactive protein (CRP) and procalcitonin (PCT), are now being recognized as useful tools in the diagnostic process. We aimed at evaluating the analytical performance of the recently developed semi-automated ichroma SMART system (Boditech Med Inc., Korea), which allows measurements of both CRP and PCT. METHODS: We evaluated the analytical performance of the ichroma SMART system and the agreement between its results and the laboratory standards for CRP and PCT measurements. The precision and linearity as well as the method of measurement were compared to the DxC 800 (Beckman Coulter, USA) for CRP and to the VIDAS (bioMerieux SA, France) for PCT, according to corresponding CLSI guidelines. Additionally, we evaluated the carryover rates between specimens. RESULTS: The total precision (% CV) of the ichroma SMART system in measuring low, middle, and high level controls (level 1, 2, 3) was 6.32%, 5.75%, and 3.56% for CRP, and 8.07%, 6.24%, and 6.53% for PCT. In the linearity test, R2 was 0.9997 and 0.9982 for CRP (0.1-336.8 mg/L) and PCT (0.05-60.91 ng/mL), respectively. Good correlation was observed between ichroma SMART and DxC 800 for CRP (r=0.997), and between ichroma SMART and VIDAS for PCT (r=0.992). Carry-over effect was 0.02% for CRP and 0.04% for PCT. CONCLUSIONS: The ichroma SMART system showed an adequate performance and appeared to be a suitable clinical analyzer with a simple operating procedure for the measurement of CRP and PCT.

The Frequency of Unexpected Antibodies and Clinical Characteristics of Transfusion Candidates in a General Hospital During the Past 12 Years / 임상검사와정도관리

BACKGROUND: Unexpected antibodies are an important cause of hemolytic transfusion reaction. Thus, unexpected antibody screening and identification tests should be performed before every transfusion. We evaluated the frequency and distribution of unexpected antibodies and the clinical characteristics of patients in a Korean secondary general hospital with 745 beds in the past 12 years. METHODS: Between March 2000 and October 2011, unexpected antibody screening and an identification test using the Bio-Rad ID-System (Bio-Rad, USA) were performed in 72,600 patients. RESULTS: Of the 72,600 patients, 467 (0.64%) showed positive results for antibody screening tests. Among them, alloantibodies were identified in 324 (69.4%) patients and the types of alloantibodies were not identified in 64 (13.7%) patients. Autoantibodies were detected in 71 (15.2%) patients and panagglutination reactions were detected in 8 (1.7%). Of the 467 cases, 164 (35.1%) had a history of transfusion in our hospital. Among the 324 patients in whom alloantibodies were identified, anti-E (37.3%), anti-Lea (16.7%), anti-E and anti-c (14.8%), anti-C and anti-e (5.6%), anti-Leb (4.9%), anti-D (4.6%), anti-Jka (3.1%), anti-S (2.5%), and anti-M (1.9%) were detected. In 41 of the 324 (12.7%) of these patients, the types of antibodies were identified with the NaCl/Enzyme gel test but not with the LISS/Coombs gel test. CONCLUSIONS: Among the 467 patients, 130 (27.8%) in whom unexpected antibodies were detected, were scheduled for surgery. Because 101 of these 130 patients (77.7%) were unimmunized, unexpected antibody screening may be important in secondary hospitals with patients who do not have a detailed transfusion history. We identified Rh, P, and Lewis group antibodies more efficiently with a combination of the LISS/Coombs gel test and the NaCl/Enzyme gel test.