Tuberculin Skin Test (TST) / Mantoux Test - The Equivalence of PPD RT 23 vs PPD-S

 Availability in HKGU: 2 TU / 0.1 ml of PPD RT 23 [AJ Vaccine, Denmark - Follow Box ]

Type	Reference	Dosage Recommended
PPD RT 23 SSI	Tuberculin PPD RT 23 SSI for Mantoux Test [AJ Vaccines Leaflet, Updated 01-2019]	2 TU (0.1 ml) initially, 10 TU (using formulation of 10 TU / 0.1 ml) may be used if the initial reading is < 6 mm For all strengths the dose is 0.1 ml of the PPD RT 23 Solution.
	Tuberculin PPD RT 23 SSI for Mantoux Test [Stamens Serum Institut, Updated 05-2012]	When used for a medical diagnostic purpose, recommended to apply 0.1 ml of 2 TU of Tuberculin PPD RT 23 SSI.
PPD-S	PPD Tuberculin Mammalian [BB-NCIPD Ltd, Bulgaria, Updated Jan 2011]	Tuberculin PPD 5 TU / 0.1 ml is bio-equivalent to 5 IU of PPD-S (International Standard) per test dose (0.1 ml)  The standard strength for diagnostic purpose is 5 TU (0.1 ml) Tuberculin PPD.
	UptoDate: Tuberculin Skin Test & https://www.rxlist.com/tubersol-drug.htm	Tubersol ® : 5 units/0.1 mL US Standard Tuberculin PPD-S Dosage: Intradermal: 5 units (0.1 mL)

 

Reference	Description	Equivalence
https://www.ncbi.nlm.nih.gov/books/NBK556037/   PPD Skin Test (Pahal & Sharma, Feb 2021)	Outside the United States, some other tuberculin antigens such as RT 23 formulation may be used. The dosage of PPD-S and RT 23 formulation differs. The dosage for PPD-S formulation is 5 units in 0.1 ml.	No equivalence provided
Standardization of Mantoux Test (Indian Pediatrics 2002; 39:404-406)	Presently only two tubeculins have been accepted as standard tuberculins by WHO, i.e., PPD-S and PPD RT 23.  A standard 5 tuberculin unit (5TU) dose of PPD-S is defined as delayed skin activitiy contained in a 0.1 µg/0.1 ml dose of PPD-S. 1 TU of PPD-RT 23 is equivalent to 5 TU of PPD-S(3).  For last 10 years, use of 2TU for surveys has been suggested by WHO but some countries continue to use 1TU for population surveys	1 TU RT 23 = 5 TU PPD-S
https://www.who.int/tb/areas-of-work/preventive-care/ltbi/cg.pdf   (Dr Christopher Gilpin, Global TB Programme, World Health Organisation)	WHO’s recommended techniques for diagnosing LTBI TST 5 tuberculin units (TU) of tuberculin PPD-S or 2TU of tuberculin PPD RT 23	2 TU RT 23 = 5 TU PPD-S
http://www.lancet.co.ug/index.php/media-centre/newsletters/tu/	The Mantoux TST is the most reliable test available. The test requires: ·       2 units of tuberculin purified protein derivative PPD-RT23 2TU OR ·       5 units of PPD-S 5TU The dose is the same for adults and children. The TST is performed by injecting 0.1 ml of tuberculin purified protein derivative (PPD) of the correct strength into the inner surface of the forearm.	2 TU RT 23 = 5 TU PPD-S
https://academic.oup.com/femspd/article/66/3/273/576710  Purified protein derivatives of tuberculin — past, present, and future  Yang et al. FEMS Immunology & Medical Microbiology, Volume 66, Issue 3, December 2012, Pages 273–280	PPD-S was comprised of approximately 92.9% protein, 5.9% polysaccharide, and 1.2% nucleic acid. Because of its enhanced purity and potency, PPD-S was adopted as the international standard of tuberculin by the World Health Organization (WHO) in 1952. As of 1978, the Food and Drug Administration (FDA) required that all lots of PPD be qualified by biological assay and must show a potency equivalent to that of PPD-S.  In the United States and Canada, the potency of PPD is expressed as a tuberculin unit (TU) rather than IU. One TU is defined as 0.02 µg of PPD-S. Five TU is the standard dose for intradermal diagnostic use, as determined from epidemiological studies.  Currently, 2 TU of PPD-RT23 with Tween 80 is recommended by the WHO and the International Union Against Tuberculosis and Lung Disease (IUATLD). RT23 is the most widely used PPD product globally.	2 TU RT 23 = 5 TU PPD-S

 Potential further reading:  Indian Dermatol Online J. 2012 Jan-Apr; 3(1): 2–6. Mantoux test and its interpretation. Accessed at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3481914/

 Accessed on 19 July 2021 by J. Ho