Medicine:Sucrose lysis test

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Sucrose lysis test
Medical diagnostics
Sucrose lysis test.jpg
SynonymsSucrose hemolysis test
Purposescreening and diagnosis of paroxysmal nocturnal hemoglobinuria

The sucrose lysis test is a diagnostic laboratory test used for diagnosing paroxysmal nocturnal hemoglobinuria (PNH), as well as for hypoplastic anemias and any hemolytic anemia with an unclear cause.[1] The test works by using sucrose, which creates a low ionic strength environment that allows complement to bind to red blood cells.[1] In individuals with PNH, some red blood cells are especially vulnerable to lysis caused by complement.[1] The test may also produce suspicious results in other hematologic conditions, including megaloblastic anemia and autoimmune hemolytic anemia.[1] False-negative results can occur when complement activity is absent in the serum.[1] A simpler alternative called the sugar water test also involves mixing blood with sugar and observing for hemolysis, using the same principle as the sucrose lysis test.[1]

History

The sucrose hemolysis test was developed in the 1960s.[2] Hartmann and Jenkins first described the test in 1966.[3][4] The test was devised as a superior screen for PNH compared to the Ham's acid hemolysis test (HT) that was developed in the 1930s.[2] For decades, these two tests were the primary methods of diagnosing PNH.[2] The test is now obsolete being replaced by more advanced methods such as flow cytometry with monoclonal antibodies CD55/CD59 that target glycosylphosphatidylinositol-anchored proteins (GPI-AP) with the addition of inactivated fluorescently labeled bacterial toxins, such as fluorescently labeled aerolysin (FLAER).[2][5] Flow cytometry is the most sensitive and useful assay currently available to screen and diagnosis PNH.[5]

Description

The sucrose lysis test uses an isotonic sucrose solution to lower the ionic strength of serum, which triggers the activation of the classic complement pathway, leading to the lysis of cells that are sensitive to complement.[6]

In the sucrose lysis test, patient RBCs are washed and resuspended in a buffered sucrose solution.[7] The solution is then incubated at a set temperature for a specified period, during which complement-mediated lysis occurs.[7] After incubation, the solution is centrifuged, and the amount of hemoglobin released is measured spectrophotometrically.[7] The degree of lysis is compared to that of control samples.[7]

Although more sensitive than the Ham test, it is not as specific since some RBCs hemolyze to a minor degree in autoimmune hemolytic anemias, leukemia, and aplastic anemia.[6] Although affordable and straightforward to perform, the test is more labor-intensive because PNH RBCs have a short half-life in circulation.[6]

Diagnosis

After one hour of incubation at 25 °C, greater than 5% of red blood cells demonstrating lysis is positive for PNH.[8]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 McPherson, Richard A.; Pincus, Matthew R.; Henry, John Bernard (2007). Henry's clinical diagnosis and management by laboratory methods.. Philadelphia: Saunders Elsevier. ISBN 978-1-4160-0287-1. OCLC 70327781. 
  2. 2.0 2.1 2.2 2.3 Krauss, Jonathan S. (2012). "The Laboratory Diagnosis of Paroxysmal Nocturnal Hemoglobinuria (PNH): Update 2010". Laboratory Medicine (Oxford University Press (OUP)) 43 (1): 20–24. doi:10.1309/lmr59zn0mfzmgqrb. ISSN 0007-5027. 
  3. Hartmann, Robert C.; Jenkins, David E. (1966-07-21). "The Sugar-Water Test for Paroxysmal Nocturnal Hemoglobinuria". New England Journal of Medicine (Massachusetts Medical Society) 275 (3): 155–157. doi:10.1056/nejm196607212750308. ISSN 0028-4793. PMID 5938862. 
  4. Hsu, T. C. S.; Steinberg, J.; Doux, R.; Sawitsky, A. (1979). "The Low Ionic Strength Reaction of Human Blood: Relationship between the Binding of Serum Immunoglobulin and Complement to Red Blood Cells and Surface Charge of the Cells". British Journal of Haematology (Wiley) 42 (3): 403–415. doi:10.1111/j.1365-2141.1979.tb01149.x. ISSN 0007-1048. PMID 38828. 
  5. 5.0 5.1 Young, Neal S.; Meyers, Gabrielle; Schrezenmeier, Hubert; Hillmen, Peter; Hill, Anita (2009). "The Management of Paroxysmal Nocturnal Hemoglobinuria: Recent Advances in Diagnosis and Treatment and New Hope for Patients". Seminars in Hematology (Elsevier BV) 46 (1 Suppl 1): S1–S16. doi:10.1053/j.seminhematol.2008.11.004. ISSN 0037-1963. PMID 19171207. 
  6. 6.0 6.1 6.2 Besa, Emmanuel C (2022-05-12). "Paroxysmal Nocturnal Hemoglobinuria Workup: Approach Considerations, Laboratory Studies, Imaging Studies". https://emedicine.medscape.com/article/207468-workup#c5. 
  7. 7.0 7.1 7.2 7.3 KANN, HERBERT E.; MENGEL, CHARLES E.; MERIWETHER, WILHELM D.; EBBERT, LARRY (1968-07-01). "Production of In Vitro Lytic Characteristics of Paroxysmal Nocturnal Hemoglobinuria Erythrocytes in Normal Erythrocytes". Blood (American Society of Hematology) 32 (1): 49–58. doi:10.1182/blood.v32.1.49.49. ISSN 0006-4971. PMID 5658390. 
  8. Krauss, Jonathan S (2003-10-01). "Laboratory Diagnosis of Paroxysmal Nocturnal Hemoglobinuria". Annals of Clinical & Laboratory Science 33 (4): 401–406. ISSN 0091-7370. PMID 14584753. http://www.annclinlabsci.org/content/33/4/401.full. Retrieved 2023-03-16.