July/August Eurolabnews

Foreword

Reported by Harjit Pal Bhattoa, Editor EFLM EuroLabNews

Striving to keep its readers uptodate, the present EFLM EuroLabNews is released with a full-fledged commitment to include news items in all its regular columns. The Hot Topic is on Particle profiles during Urinalysis by José Antonio Tesser Poloni. Giuseppe Lippi, the Chair of the IFCC Task Force on COVID-19 presents a perspective on the role of Laboratory Medicine during the pandemia and stresses the grave need and urgency for testing. Illustrating the professional dedication of the EFLM, Evgenija Homsak, Chair of the EFLM Professional Committee, announces extension of eligibility for membership of the EFLM Academy to non-European individuals. The EFLM held its 13th General Meeting in an extraordinary setting in the form of a web-meeting with an exemplary number of participants representing 24 National Societies. The EFLM President Ana-Maria Simundic presented her report touching upon all activities of the EFLM. A total of 4 news National Societies were approved as new EFLM member societies. With a delighting look, Adina Hutanu, Burna Lo Sasso and Lejla Alic, all members of the EFLM Working Group Promotions and Publications, present the latest EFLM publications illustrated by brilliant infographics. The IFCC corner is highlighted by the IFCC President Koshrow Adeli’s message. The Calendar of Events lists all upcoming events, as expected, change in dates or cancellations should be closely followed. And above all, the EFLM EuroLabNews team wishes all our readers good health, keep safe!

1. Hot Topic in Laboratory Medicine

Particle profiles – a useful classification of urinary findings

Reported by José Antonio Tesser Poloni, Universidade do Vale do Rio dos Sinos, São Leopoldo, Brasil

Urinalysis, including both chemical strip test and urine microscopy, is a common screening and diagnostic test in clinical laboratories, since the discovery of clinical microscopy in the 19th century [1-3]. It has survived because of some features we expect from modern tests as well: it is fast, its price is low and the method appears simple. Microscopy of concentrated urine sediment with proper optics and standardized procedures, and performed by an experienced professional provides useful diagnostic information on the state of the kidneys and the urinary tract [4-8].

The types of components, such as cells, casts and crystals, present in the urine sediment depend on the underlying disease and the pathophysiological conditions. The classification of the identified urine sediment components helps in differentiation of underlying states, i.e., inflammation, tumor or functional abnormality of kidneys and the urinary tract [9, 10].

Urinalysis is most useful, when the found particles and results of chemical strip test or quantitative protein measurement are combined into patterns of urinary findings when associated with different diseases [11, 12]. Those profiles are not commonly used despite the long tradition of urine microscopy. Some of the most common profiles are summarized below, including their typical particles.

Tubular injury profile: free renal tubular epithelial cells (RTECs), casts containing RTECs and granular casts

The patient with acute kidney injury (AKI) with this combination of urinary findings is likely to suffer from acute tubular necrosis (ATN), induced by either an ischemic event or administration of a nephrotoxin, or both. The injured tubular cells are sloughed into the tubular lumen and form a cast in combination with Tamm-Horsfall matrix protein [11].

Nephrotic profile: lipiduria and marked cylindruria, especially fatty casts and casts containing RTECs

The nephrotic sediment is observed in patients with nephrotic syndrome. This is a condition characterized by proteinuria of >3.5 g/24 hours associated with hypoalbuminemia, hypercholesterolemia, and variable oedema. In most instances, nephrotic syndrome is caused by non-proliferative glomerulopathies that at renal biopsy have little or no evidence of glomerular inflammation. Any glomerular disease may cause a nephrotic syndrome, between the most common are minimal change disease, focal segmental glomerulosclerosis, and diabetic nephropathy [11].

Nephritic profile: haematuria with dysmorphic red blood cells (RBCs), RTECs, casts containing RBCs, and proteinuria

Patients with this constellation of findings are likely to have glomerular disease or renal vasculitis. On glomerular disease, this presentation is termed nephritic syndrome (this is defined as a sudden increase in serum creatinine associated with the appearance of hematuria, variable proteinuria, oliguria and hypertension) and strongly suggests glomerulonephritis [9,10].

Nephrotic and nephritic profile: hematuria with dysmorphic RBCs, RTECs, casts containing RBCs, intense proteinuria and lipiduria

A urine profile with both nephrotic and nephritic features may be found in all proliferative glomerulonephritis [11]. Urinary findings will be composed by a mix of what was explained above.

Urinary tract infection (UTI) profile, caused by bacteria: bacteriuria and leukocyturia

Bacteriuria and leukocyturia are typical in UTI [10]. However, if cast- containing leukocytes are observed coupled with bacteriuria and leukocyturia, pyelonephritis can be suspected. This kind of observation is not sensitive, but when present it helps in the differentiation between an UTI in the lower urinary tract (bacteria + leukocyturia) from an UTI in the upper urinary tract (bacteria + leukocyturia + casts containing leukocytes), in addition to fever, low-back pain or laboratory tests related to systemic inflammation (such as C-reactive protein).

The 5 urinary profiles listed here exemplify the information we can find in urine samples with a microscope. More urinary profiles or more detailed variations of a single profile can be detected in more specific clinical conditions.

More information, examples and a didactic quiz can be found in EFLM eLearning platform (accessible for EFLM Academy members only).

Urinalysis webinar

References

  1. Delanghe JR, Speeckaert MM. Preanalytics in urinalysis. Clin Biochem. 2016;49(18):1346-1350. doi:10.1016/j.clinbiochem.2016.10.016.
  2. Fogazzi GB, Verdesca S, Garigali G. Urinalysis: core curriculum 2008. Am J Kidney Dis. 2008;51(6):1052-1067. doi:10.1053/j.ajkd.2007.11.039.
  3. Fogazzi GB. Urinary sediment: still an important diagnostic tool. Clin Chem Lab Med. 2015;53(Suppl 2):s1451. doi:10.1515/cclm-2015-0898.
  4. European Confederation of Laboratory Medicine. European urinalysis guidelines. Scand J Clin Lab Invest. 2000;60(Suppl 231):1-96.
  5. Kanbay M, Kasapoglu B, Perazella MA. Acute tubular necrosis and pre-renal acute kidney injury: utility of urine microscopy in their evaluation- a systematic review. Int Urol Nephrol. 2010;42(2):425-433. doi:10.1007/s11255-009-9673-3.
  6. Fogazzi GB, Cameron JS, Ritz E, Ponticelli C (1994) The history of urinary microscopy to the end of the 19th century. Am J Nephrol 14:452–457.
  7. Becker GJ, Fairley KF (2001) urinalysis. In: Massry SG, Glassock RJ (eds) Textbook of nephrology. 4th edn, Philadelphia: Lippincott Williams and Wilkins, pp 1765– 1783.
  8. Fogazzi GB, Garigali G, Pirovano B, Muratore MT, Raimondi S, Berti S (2007) How to improve the teaching of urine microscopy. Clin Chem Lab Med 45:407–412.
  9. Cavanaugh C, Perazella MA. Urine Sediment Examination in the Diagnosis and Management of Kidney Disease: Core Curriculum 2019. American Journal of Kidney Diseases. 2019;73(2):258-272.
  10. Miyachi HM. In the Preface of “Sysmex Atlas of Urinary Sediment”, June 2012.
  11. Fogazzi GB, Verdesca S. Interpretation of the urinary sediment findings in Fogazzi GB. The urinary sediment an integrated view. 3rd edition, Elsevier Masson 2010. (Fogazzi is the first pioneer on the topic)
  12. Perazella MA. Urinalysis and urine microscopy in Reilly Jr. RF and Perazella MA. Nephrology in 30 days. 2nd edition, Lange 2014.