CCA-13527; No of Pages 1 Clinica Chimica Acta xxx (2014) xxx
Contents lists available at ScienceDirect
Clinica Chimica Acta journal homepage: www.elsevier.com/locate/clinchim
7 5
Letter to the editor Point of care testing for measurement of white blood cell count and C-reactive protein levels in blood
which is in contradiction with other studies [3–5]. Validation of this study should be done at large sample size. Kotani et al. have made an interesting observation and on the same line of thought more POCT assays should be developed for making the diagnosis more accurate. In current scenario, POCT assays hold promise of rapid diagnosis and precise treatment of patients. I hope that the above mentioned points might add to the article written by Kotani et al.
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[1] Kotani K, Minami T, Abe T, Sato J, Taniguchi N, Yamada T. Development of a new point-of-care testing system for measuring white blood cell and C-reactive protein levels in whole blood samples. Clin Chim Acta 2014;433:145–9. [2] Mundt LA, Shanahan K. Graff's textbook of routine urinalysis and body fluids. Wolters Kluwer/Lippincott Williams & Wilkins Health; 2010. [3] Caldas JP, Marba ST, Blotta MH, Calil R, Morais SS, Oliveira RT. Accuracy of white blood cell count, C-reactive protein, interleukin-6 and tumor necrosis factor alpha for diagnosing late neonatal sepsis. J Pediatr (Rio J) Nov–Dec 2008;84(6):536–42. [4] Takemura Y, Ishida H, Saitoh H, Kure H, Kakoi H, Ebisawa K, et al. Economic consequence of immediate testing for C-reactive protein and leukocyte count in new outpatients with acute infection. Clin Chim Acta 2005 Oct;360(1–2):114–21. [5] Peltola H, Ahlqvist J, Rapola J, Rasanen J, Louhimo I, Saarinen M, et al. C-reactive protein compared with white blood cell count and erythrocyte sedimentation rate in the diagnosis of acute appendicitis in children. Acta Chir Scand 1986 Jan;152:55–8.
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Kirtimaan Syal 59 Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India. 60 E-mail address: [email protected]. 61 4 May 2014 62 Available online xxxx 63
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References
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White blood cell (WBC) count and C-reactive protein (CRP) levels are key markers of infection and inflammation. Their high levels are indicative of immune response. Recently, new point of care testing (POCT) assays for measurement of WBC count and CRP levels have been suggested and evaluated by Kotani et al. [1]. These assays are based on the qualitative analysis of granulocyte esterase activity for the estimation of WBC count and exploit the principles of immunochromatographic assay for the determination of CRP levels, respectively. Authors have advocated the concurrent determination of both of the markers which could be useful in decision making of antibiotic administration. I would like to add that many drug molecules such as imipenem, meropenem and clavuanic acid may give false positive for granulocyte esterase assay. Furthermore, drugs such as cephalexin, cephalothin, gentamycin and tetracycline, high concentrations of oxalic acid and ascorbic acid are known to negatively interfere with esterase test [2]. Therefore, patient history should be properly investigated before performing these assays. Authors of the paper have rightly pointed out that this test cannot work for patients with neutropenia. It is worth mentioning that the test results would be inaccurate in cases of neutrophilia as well. Also, these assays are qualitative and conclusion drawn from them should be verified by other assays/diagnosis in critical cases. Authors have mentioned that the correlation between the values obtained using the POCT-WBC and POCT-CRP was weak in their study
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Dear Editor:
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http://dx.doi.org/10.1016/j.cca.2014.05.023 0009-8981/© 2014 Published by Elsevier B.V.
Please cite this article as: Syal K, Point of care testing for measurement of white blood cell count and C-reactive protein levels in blood, Clin Chim Acta (2014), http://dx.doi.org/10.1016/j.cca.2014.05.023
Contents lists available at ScienceDirect
Clinica Chimica Acta journal homepage: www.elsevier.com/locate/clinchim
7 5
Letter to the editor Point of care testing for measurement of white blood cell count and C-reactive protein levels in blood
which is in contradiction with other studies [3–5]. Validation of this study should be done at large sample size. Kotani et al. have made an interesting observation and on the same line of thought more POCT assays should be developed for making the diagnosis more accurate. In current scenario, POCT assays hold promise of rapid diagnosis and precise treatment of patients. I hope that the above mentioned points might add to the article written by Kotani et al.
F
2 3 6 4
24 25 26 27 28 29 30 31 32 64
C
22 23
E
20 21 Q1
R
18 19
[1] Kotani K, Minami T, Abe T, Sato J, Taniguchi N, Yamada T. Development of a new point-of-care testing system for measuring white blood cell and C-reactive protein levels in whole blood samples. Clin Chim Acta 2014;433:145–9. [2] Mundt LA, Shanahan K. Graff's textbook of routine urinalysis and body fluids. Wolters Kluwer/Lippincott Williams & Wilkins Health; 2010. [3] Caldas JP, Marba ST, Blotta MH, Calil R, Morais SS, Oliveira RT. Accuracy of white blood cell count, C-reactive protein, interleukin-6 and tumor necrosis factor alpha for diagnosing late neonatal sepsis. J Pediatr (Rio J) Nov–Dec 2008;84(6):536–42. [4] Takemura Y, Ishida H, Saitoh H, Kure H, Kakoi H, Ebisawa K, et al. Economic consequence of immediate testing for C-reactive protein and leukocyte count in new outpatients with acute infection. Clin Chim Acta 2005 Oct;360(1–2):114–21. [5] Peltola H, Ahlqvist J, Rapola J, Rasanen J, Louhimo I, Saarinen M, et al. C-reactive protein compared with white blood cell count and erythrocyte sedimentation rate in the diagnosis of acute appendicitis in children. Acta Chir Scand 1986 Jan;152:55–8.
34 35 36 37 38 39
41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58
Kirtimaan Syal 59 Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India. 60 E-mail address: [email protected]. 61 4 May 2014 62 Available online xxxx 63
R
16 17
33
40
N C O
14 15
References
U
12 13
P
White blood cell (WBC) count and C-reactive protein (CRP) levels are key markers of infection and inflammation. Their high levels are indicative of immune response. Recently, new point of care testing (POCT) assays for measurement of WBC count and CRP levels have been suggested and evaluated by Kotani et al. [1]. These assays are based on the qualitative analysis of granulocyte esterase activity for the estimation of WBC count and exploit the principles of immunochromatographic assay for the determination of CRP levels, respectively. Authors have advocated the concurrent determination of both of the markers which could be useful in decision making of antibiotic administration. I would like to add that many drug molecules such as imipenem, meropenem and clavuanic acid may give false positive for granulocyte esterase assay. Furthermore, drugs such as cephalexin, cephalothin, gentamycin and tetracycline, high concentrations of oxalic acid and ascorbic acid are known to negatively interfere with esterase test [2]. Therefore, patient history should be properly investigated before performing these assays. Authors of the paper have rightly pointed out that this test cannot work for patients with neutropenia. It is worth mentioning that the test results would be inaccurate in cases of neutrophilia as well. Also, these assays are qualitative and conclusion drawn from them should be verified by other assays/diagnosis in critical cases. Authors have mentioned that the correlation between the values obtained using the POCT-WBC and POCT-CRP was weak in their study
D
10 11
E
Dear Editor:
T
9
O
8
R O
1
http://dx.doi.org/10.1016/j.cca.2014.05.023 0009-8981/© 2014 Published by Elsevier B.V.
Please cite this article as: Syal K, Point of care testing for measurement of white blood cell count and C-reactive protein levels in blood, Clin Chim Acta (2014), http://dx.doi.org/10.1016/j.cca.2014.05.023
