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Study on the Difference of Urine Sediment Preparation for Microscopic Examination

현미경검사를 위한 요침사 표본제작에 따른 차이 연구

  • Lee, Hyeok-Jae (Department of Biomedical Laboratory Science, Gwangju Health University) ;
  • Park, Chul (Department of Biomedical Laboratory Science, Gwangyang Health College) ;
  • Seo, Min-Young (Department of Biomedical Laboratory Science, Gwangju Health University)
  • 이혁재 (광주보건대학교 임상병리과) ;
  • 박철 (광양보건대학교 임상병리과) ;
  • 서민영 (광주보건대학교 임상병리과)
  • Received : 2017.10.18
  • Accepted : 2017.10.26
  • Published : 2017.12.31

Abstract

Urinalysis is considered to be easier and simpler than other tests. It has been known to cause no burden to patients, while offering important information on diagnosing, treating, and determining the prognoses of kidney and urinary tract diseases. Urinary sediments are usually performed by microscopic examination of centrifuged urine by technologist. The guidelines proposed by the Korean Association of External Quality Assessment Service are actually different from those actually practiced by medical institutions and taught to biomedical students in textbooks. Therefore, we verified whether different sediment preparation methods lead different test results. Specimens that tested positive from the occult blood and leukocyte esterase in the urine dipstick test were randomly selected for a microscopic examination. The differences in the urine sediment preparation affected the sediment concentrations, which influenced the cell grade and cell number per HPF. The first factor in determining the sediment concentration is the centrifugal force. Many medical institutions use 1,500 rpm as the centrifugal speed without considering the radius of the centrifuge; such a value may not be accurate for 400 G. Consequently, there were differences in urine concentrations, which influenced the results. The second factor is the amount of sediment in urine. Different amounts of the remaining supernatant led to different sediment concentration factors, again, causing different results. Furthermore, not only by using a pipette to obtain an accurate amount as stipulated, but also by roughly obtaining a drop, the microscopic examination using such a volume of sediment examined affected the results. Therefore, this study highlights the importance of standardization of urine sediment preparation procedures to promote consistency and accuracy across institutions.

Acknowledgement

Supported by : Gwangju Health University

References

  1. Kim KD. Urinalysis and body fluid analysis. Korean society for laboratory medicine, Laboratory Medicine. 5th ed. Seoul: E-public; 2014. Chap 497-508.
  2. Shin SY, Kwon MJ, Woo HY, Park HS, Kim YJ. Preliminary evaluation of the URISCAN SUPER and usefulness of a new urine reagent strip to detect ascorbic acid. J Lab Med Qual Assur. 2011;33(2):63-69.
  3. Tae-Hee Han. Urinalysis: The usefulness and limitations of urine dipstick testing. J Korean Soc Pediatr Nephrol. 2013; 17(2):42-48. https://doi.org/10.3339/jkspn.2013.17.2.42
  4. Fuller CE, Threatte GA, Henry JB. Basic examination of urine. In: Henry JB, ed. Clinical diagnosis and management by laboratory methods. 20th ed. Philadelphia: WB Saunders; 2001. Chap 367-402.
  5. Hemmelgarn BR, Manns BJ, LIoyd A, James MT, Klarenbach S, Quinn RR, et al. Relation between kidney function, proteinuria and adverse outcomes. JAMA. 2010;303(5):423-429. https://doi.org/10.1001/jama.2010.39
  6. Huussen J, Koene RA, Hilbrands LB. The urinary sediment a simple and useful diagnostic tool in patients with haematuria. Neth J Med. 2004;62(1):4-9.
  7. Simerville JA, Maxted WC, Pahira JJ. Urinalysis: a comprehensive review. Am Fam Physician. 2005;71(6):1153-1162.
  8. Ben-Ezra J, Bork L, McPherson RA. Evaluation of the sysmex UF-100 automated urinalysis analyzer. Clin Chem. 1998;44(1): 92-95.
  9. Winkel P, Statland BE, Jorgensen K. Urine microscopy an ill-defined method, examined by a multifactorial technique. Clin Chem. 1974;20(4):436-439.
  10. Elin RJ, Hosseini JM, Kestner J, Rawe M, Ruddel M, Nishi HH. Comparison of automated and manual methods for urinalysis. Am J Clin Pathol. 1986;86(6):731-737. https://doi.org/10.1093/ajcp/86.6.731
  11. Jeon CH, Lee AJ, Kim KY. Annual report on external quality assessment scheme for urinalysis and faecal occult blood testing in Korea (2014). J Lab Med Qual Assur. 2015;37(4):179-189. https://doi.org/10.15263/jlmqa.2015.37.4.179
  12. Lee AJ, Jeon CH, Kim SG, Suh HS, Bae YC. Comparison of analytical performance between the sysmex UF-100 flow cytometer and the Iris IQ200 urine microscopy system. J Lab Med Qual Assur. 2010;32(1):181-188.
  13. Kim KD, Koo SH, Kim EC, Kim JM, Kim CH, Kim JQ, et al. Annual report on external quality assessment in urinalysis in korea (1998). J Clin Pathol & Quality Control. 1999;21(1): 81-93.
  14. Kim JQ , Kim DC, Jo SS. The present situation of quality assurance of urinalysis including urinary sediment analysis based on korean external quality assurance survey and its prospective. J Clin Pathol & Quality Control. 2000;22(2):265-270.
  15. Kim DC, Yoo YM, Jo SS, Park JW, Yoo YM, Kim JQ. Laboratory evaluation of fully automated urine cell analyzer sysmex UF-100. J Clin Pathol & Quality Control. 2001;23(2):299-306.
  16. Koken T, Aktepe OC, Serteser M, Samli M, Kahraman A, Dogan N. Determination of cut-off values for leucocytes and bacteria for urine flow cytometer (UF-100) in urinary tract infections. Int Urol Nephrol. 2002;34(2):175-178. https://doi.org/10.1023/A:1023292113462