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An analytical and clinical assessment of a glycogen phosphorylase BB assay
Abstracts of Poster Presentat/ons
CLINICAL INVESTIGATION 1.
A N A N A L Y T I C A L A N D CLINICAL A S S E S S M E N T
OF A GLYCOGEN PHOSPHORYLASE BB A S S A Y Moore, R.W., Aggarwal, M. and Jolly J., Sunnybrook H e a l t h Science Centre, University of Toronte, Ontario M4N 3M5 and Ryerson Polytechnic University, Toronto,Canada
Objective was to assess the plasma glycogen phosphorylase BB (GPBB) assay. This is designed for use at the bedside or in a Stat Laboratory as a m a r k e r for the detection of myocardial infarction in the first few hours after the event. Method The system used was "Target" from Pace Diagnostics Inc. read on a reading device, V-T 1000, V-Tech. Results The anticoagulant of choice was found and stability, linearity, precision, accuracy, interference characteristics of the method explored. A h e a l t h y reference range study was made. GPBB levels in 40 patients believed to have endured a myocardial infarction (MI) and 49 p a t i e n t s believed not to have h a d a n MI were compared. There was evidence t h a t GPBB increased before CKMB but t h e r e were also increases in GPBB in cases t h o u g h t not to be suffering from myocardial infarcts. Conclusion P l a s m a GPBB m a y be a m a r k e r for the early stages of MI.
2.
ANALYSIS OF FREE TO TOTAL P S A IN SERUM FOLLOWING RADIOTHERAPY FOR PROSTATE CANCER Crook, J., Bunting, P., Ottawa Regional Cancer Centre, Ottawa, ON, Canada; Sunnybrook H e a l t h Science Centre, Toronto, ON
Introduction and Objectives The range of "normal" PSA values compatible with cure following radiotherapy (RT) for prostate cancer (PCa) h a s yet to be established. Various thresholds, r a n g i n g from 0.5 to 4.0 ug/L are used to define biochemical disease-free status. Since the proportion of free PSA is lower in m e n with PCa, the ratio of free to total PSA (PSA-f/PSA-t) could theoretically be useful in d e t e r m i n i n g cancer-free s t a t u s after RT. Methods 91 m e n t r e a t e d with external b e a m RT from 10/88 to 10/94 were chosen for m e a s u r e m e n t of PSA-f/PSA-t by virtue of the fact t h a t they h a d a routine followup visit in 11/96 or 12/96. Free and total PSA were m e a s u r e d using the Boehringer-Mannhelm assay. 91 p a t i e n t s were biopsied 1 - 4 times. S t a n d a r d RT delivered a median prescribed dose of 66 Gy. Stage distribution was Tlb:7, Tlc:8, T2a:21, T2b/c:35, T3:20. Median follow-up was 40 m o n t h s (range: 16-98). Results Total serum PSA ranged form 0.1-10.0 ug/L. Since the m e a n PSA-f/PSA-t for p a t i e n t s with negative (n = 67) and i n d e t e r m i n a t e (n = 9) biopsies were 0.29 (SD:0.18) and 0.25 368
(SD:0.07) respectively (p = 0.13), these were combined. The m e a n PSA-f/PSA-t for those with positive biopsies (n=15) was 0.18 (SD:0.08) and was significantly different from those with negative or i n d e t e r m i n a t e biopsies (p < 0.001). Only one patient in the negative biopsy group with a PSA2.0 ug/L h a d a free/total ratio 0.15, suggesting t h a t a PSA2.0 ug/L is usually indicative of recurrence. Conclusion PSA-f/PSA-t may be a useful adjunct in diagnosing recurrent PCa after RT, especially for PSA from 1.1-2.0 ug/L, where failure is common, b u t not universal.
3.
CHIRON A C S - 1 8 0 C K M B - I I C U T - O F F V A L U E S Planet, G., CHAL, 200 Brisebois, Ch~teauguay, Quebec, J 6 K 4W8, C a n a d a
Objectives Verification of Chiron CKMB-II (C) and relative Index (RI) cutoffs. Methods 1) Reference intervals were evaluated with 25 men and 30 women (30-90 years old), with Hitachi 717 for CK (<195 and <115 UUL for men and women) and ACS-180 for CKMB-II. 2) correlations were done with CKMB from Roche Isomune (R), (n=40, CK 93-1936, C 1-119), and IMX (I), (n = 23, CK 119-2151, C 3,8-122). Results Respectively for men and women and m e n plus women CK UI/L is 97:15-179, 57:0-118, 75:0-157, CKMB ug/L is 1.22: 0-2.58, 0.64:0-1.38, 0.90:0-2.11, RI is 0.014:0-0.029, 0.013:00.030, 0.013:0-0.029. Correlations are C = 0.685"R-0.33 (7.9C = 12R), r2 = 0.93, and for RI C = 1.016"R-0.025, (0.015C = 0.040R) and C = 0.6"I + 3.6 (7.23C = 6I), r2 = 0.97, and for RI C = 0.676"I, r2 = 0.94 (0.021C = 0.030I) Conclusion The Chiron proposed cutoffs of 5 ug/L for CKMB-II and 0.025 for RI seems adequate, considering the calculated upper limit of 2.6 for C a n d a m e a n value of 7.6 from correlations, and the calculated upper limit of 0.029 for RI and the m e a n value of 0.018 from correlations.
4.
EFFECT OF GARLIC ON BLOOD A N T I O X I D A N T ENZYMES IN HYPERCHOLESTEROLEMIC ATHEROSCLEROSIS M a n t h a , S.V., Kalra, J, P r a s a d K., D e p a r t m e n t s of Pathology and Physiology, University of S a s k a t c h e w a n and Royal University Hospital, Saskatoon, Saskatchewan, S7N 0W8
Hypercholesterolemia is a major contributory factor in coronary atherosclerosis. Reactive oxygen metabolites (ROM) have been implicated in the development of hypercholesterolemic atheroCLINICAL BIOCHEMISTRY, VOLUME 30, J U N E 1997
CLINICAL INVESTIGATION 1.
A N A N A L Y T I C A L A N D CLINICAL A S S E S S M E N T
OF A GLYCOGEN PHOSPHORYLASE BB A S S A Y Moore, R.W., Aggarwal, M. and Jolly J., Sunnybrook H e a l t h Science Centre, University of Toronte, Ontario M4N 3M5 and Ryerson Polytechnic University, Toronto,Canada
Objective was to assess the plasma glycogen phosphorylase BB (GPBB) assay. This is designed for use at the bedside or in a Stat Laboratory as a m a r k e r for the detection of myocardial infarction in the first few hours after the event. Method The system used was "Target" from Pace Diagnostics Inc. read on a reading device, V-T 1000, V-Tech. Results The anticoagulant of choice was found and stability, linearity, precision, accuracy, interference characteristics of the method explored. A h e a l t h y reference range study was made. GPBB levels in 40 patients believed to have endured a myocardial infarction (MI) and 49 p a t i e n t s believed not to have h a d a n MI were compared. There was evidence t h a t GPBB increased before CKMB but t h e r e were also increases in GPBB in cases t h o u g h t not to be suffering from myocardial infarcts. Conclusion P l a s m a GPBB m a y be a m a r k e r for the early stages of MI.
2.
ANALYSIS OF FREE TO TOTAL P S A IN SERUM FOLLOWING RADIOTHERAPY FOR PROSTATE CANCER Crook, J., Bunting, P., Ottawa Regional Cancer Centre, Ottawa, ON, Canada; Sunnybrook H e a l t h Science Centre, Toronto, ON
Introduction and Objectives The range of "normal" PSA values compatible with cure following radiotherapy (RT) for prostate cancer (PCa) h a s yet to be established. Various thresholds, r a n g i n g from 0.5 to 4.0 ug/L are used to define biochemical disease-free status. Since the proportion of free PSA is lower in m e n with PCa, the ratio of free to total PSA (PSA-f/PSA-t) could theoretically be useful in d e t e r m i n i n g cancer-free s t a t u s after RT. Methods 91 m e n t r e a t e d with external b e a m RT from 10/88 to 10/94 were chosen for m e a s u r e m e n t of PSA-f/PSA-t by virtue of the fact t h a t they h a d a routine followup visit in 11/96 or 12/96. Free and total PSA were m e a s u r e d using the Boehringer-Mannhelm assay. 91 p a t i e n t s were biopsied 1 - 4 times. S t a n d a r d RT delivered a median prescribed dose of 66 Gy. Stage distribution was Tlb:7, Tlc:8, T2a:21, T2b/c:35, T3:20. Median follow-up was 40 m o n t h s (range: 16-98). Results Total serum PSA ranged form 0.1-10.0 ug/L. Since the m e a n PSA-f/PSA-t for p a t i e n t s with negative (n = 67) and i n d e t e r m i n a t e (n = 9) biopsies were 0.29 (SD:0.18) and 0.25 368
(SD:0.07) respectively (p = 0.13), these were combined. The m e a n PSA-f/PSA-t for those with positive biopsies (n=15) was 0.18 (SD:0.08) and was significantly different from those with negative or i n d e t e r m i n a t e biopsies (p < 0.001). Only one patient in the negative biopsy group with a PSA2.0 ug/L h a d a free/total ratio 0.15, suggesting t h a t a PSA2.0 ug/L is usually indicative of recurrence. Conclusion PSA-f/PSA-t may be a useful adjunct in diagnosing recurrent PCa after RT, especially for PSA from 1.1-2.0 ug/L, where failure is common, b u t not universal.
3.
CHIRON A C S - 1 8 0 C K M B - I I C U T - O F F V A L U E S Planet, G., CHAL, 200 Brisebois, Ch~teauguay, Quebec, J 6 K 4W8, C a n a d a
Objectives Verification of Chiron CKMB-II (C) and relative Index (RI) cutoffs. Methods 1) Reference intervals were evaluated with 25 men and 30 women (30-90 years old), with Hitachi 717 for CK (<195 and <115 UUL for men and women) and ACS-180 for CKMB-II. 2) correlations were done with CKMB from Roche Isomune (R), (n=40, CK 93-1936, C 1-119), and IMX (I), (n = 23, CK 119-2151, C 3,8-122). Results Respectively for men and women and m e n plus women CK UI/L is 97:15-179, 57:0-118, 75:0-157, CKMB ug/L is 1.22: 0-2.58, 0.64:0-1.38, 0.90:0-2.11, RI is 0.014:0-0.029, 0.013:00.030, 0.013:0-0.029. Correlations are C = 0.685"R-0.33 (7.9C = 12R), r2 = 0.93, and for RI C = 1.016"R-0.025, (0.015C = 0.040R) and C = 0.6"I + 3.6 (7.23C = 6I), r2 = 0.97, and for RI C = 0.676"I, r2 = 0.94 (0.021C = 0.030I) Conclusion The Chiron proposed cutoffs of 5 ug/L for CKMB-II and 0.025 for RI seems adequate, considering the calculated upper limit of 2.6 for C a n d a m e a n value of 7.6 from correlations, and the calculated upper limit of 0.029 for RI and the m e a n value of 0.018 from correlations.
4.
EFFECT OF GARLIC ON BLOOD A N T I O X I D A N T ENZYMES IN HYPERCHOLESTEROLEMIC ATHEROSCLEROSIS M a n t h a , S.V., Kalra, J, P r a s a d K., D e p a r t m e n t s of Pathology and Physiology, University of S a s k a t c h e w a n and Royal University Hospital, Saskatoon, Saskatchewan, S7N 0W8
Hypercholesterolemia is a major contributory factor in coronary atherosclerosis. Reactive oxygen metabolites (ROM) have been implicated in the development of hypercholesterolemic atheroCLINICAL BIOCHEMISTRY, VOLUME 30, J U N E 1997