PI-Rb

1. Pathogen Inactivation by
Riboflavin
Dr. Rafiq Ahmad
Dammam Regional Laboratory & Blood Bank

2. Introduction
 Blood safety measures implemented to prevent transfusion transmitted
disease and TA-GVHD have been successful; however, risks remain
 Newly emerging pathogens, or pathogens of new concern, may defeat
the donor questionnaires and blood tests
 Leukocytes remaining after leukoreduction have the potential to cause
GVHD if blood products are not gamma-irradiated
 Efforts to mitigate these risks have focused on the use of riboflavin
(vitamin B2) and UV light to inactivate leukocytes and reduce
pathogens
 Device development focused on components first, and has expanded
to include a system for treating whole blood

3. Pathogen inactivation using Riboflavin
and UV light
Pathogen inactivation using Riboflavin and UV light
is a method by which infectious pathogens in blood
for transfusion are inactivated by adding riboflavin
and irradiating with UV light
This method reduces the infectious levels of
disease-causing agents that may be found in
donated blood components, while still maintaining
good quality blood components for transfusion
This type of approach to increase blood safety is
also known as “pathogen inactivation” in the
industry

4. Pathogen inactivation using Riboflavin
and UV light
 Despite measures that are in place in the developed
world to ensure the safety of blood products for
transfusion, a risk of disease transmission still exists.
Consequently, the development of pathogen
inactivation/reduction technologies for blood products
has been an ongoing effort in the field of transfusion
medicine.
 A procedure for the treatment of individual units of
single-donor (apheresis) or whole blood–derived, pooled,
platelets was introduced few years back.
 This technology uses riboflavin and light for the
treatment of platelets and plasma

5. Pathogen inactivation using Riboflavin
and UV light
1. Method
2. Examples of Pathogens inactivated by this
method
3. Application

6. Method
This pathogen reduction process involves adding
riboflavin (vitamin B2) to the blood component,
which is then placed into an illuminator where it is
exposed to UV light for about five to ten minutes
Exposure to UV light activates riboflavin and when
it is associated with nucleic acids (DNA and RNA),
riboflavin causes a chemical alteration to functional
groups of the nucleic acids thereby making
pathogens unable to replicate. In this way the
process prevents viruses, bacteria, parasites and
white blood cells, from replicating and causing
disease.

7. Method

8. Examples of Pathogens inactivated by this method
UV Light + Riboflavin → Irreversible Inactivation
This method using riboflavin and UV light
renders pathogens harmless by using a non-
mutagenic, non-toxic method
Riboflavin and its photoproducts are already
present in the human body and do not need to
be removed from blood products prior to
transfusion

9. Organisms to get inactivated
 Viruses – both enveloped and non-enveloped including: Avian
Flu, Chikungunya, CMV, Hepatitis A, Hepatitis B, Hepatitis C, HIV, Human
B-19, Influenza, Rabies, and West Nile. This adds a level of protection for
those receiving the transfusion product against viruses that donors are
screened for (and may be at a level too low to be detected- window period) as
well as those that they are not screened for at the time of their donation
 Bacteria – such as: B. cereus, E. cloacae, E. coli, K. pneumonia, P. acnes, S.
marcescens, S. aureus, S. epidermidis, S. agalactiae, S. mitis, S. pyogenes, and Y.
enterocolitica
 Parasites – including: Babesiosis, Chagas disease, Leishmaniasis, Malaria,
and Scrub typhus
 White blood cells – due to the effective inactivation of white blood cells in
donated blood products, riboflavin and UV light treatment may be used as an
alternative to gamma-irradiation for the prevention of transfusion-
associated graft-versus-host disease (TA-GVHD), a serious blood transfusion
related complication

10. Application
The riboflavin and UV light method for
pathogen reduction of platelets and plasma is in
routine use in multiple countries throughout
Europe
This same process is currently in development
for the treatment of whole blood, resulting in
pathogen reduction of the three components
(RBCs, platelets and plasma

11. Application

12. Clinical Trial and Surveillance Data To Date (March 2012)
Mirasol System Surveillance Data on > 58,000 Transfusions
(>24,000 Platelet and >34,000 FFP transfusions)
 No reports of serious adverse events related to use of Mirasol-treated platelet and
plasma products
 No cases of TRALI (transfusion-related acute lung injury) reported
 No reports of increased bleeding or increased platelet product utilization after
introduction
 Additionally, adequate therapeutic performance of Mirasol-treated platelets and
plasma has been demonstrated in several post-market clinical evaluations
Mirasol Clinical Evaluation Study Group, 2010; Antelo Caamaño et al. 2011; Antic et
al., 2011; Stanojkovic et al., 2010; Yañez et al., 2011; Yañez Izquierdo et al., 2009;
Antic et al. 2010; Antic & Stanojkovic 2011

13. Conclusion
 Riboflavin is an essential nutrient, also known as vitamin B2.
It is used for pathogen inactivation in platelets and plasma.
 Riboflavin is added and diluted inside the platelet or plasma
unit, which is then exposed to lighting with ultraviolet (UV)
light
 The riboflavin which is photoactivated in this way joins the
nucleic acids of the DNA and RNA and creates covalent
bonds. This process causes stable crossings of the genetic
material, breaking of the chain and modification of the bases,
which block the replication and transcription mechanisms and
cause cellular death
 Because Riboflavin is a product that occurs naturally in food,
there is no much distrust regarding their toxicity in small
quantities

14. Conclusion
 Riboflavin has been effective in the inactivation of Viruses,
bacteria and protozoans
 The Mirasol system, which was patented by Terumo BCT, is very
similar to that by Intercep (amotosalen)
 Because riboflavin is a natural substance, it is not necessary to
eliminate it from the final product, which simplifies the plasma
inactivation process and a priori confers it a more acceptable
toxicological profile

15. Mirasol Claims
 Mirasol System can be used to reduce pathogens and inactivate
leukocytes in platelet and plasma components, and in donated whole
blood
 Treatment with the Mirasol System is as effective as gamma irradiation
for the elimination of leukocyte viability and the prevention of TA-
GVHD
 The safety and effectiveness of the Mirasol System for Platelets and
Plasma has been established through extensive pre-clinical work and
through post-market surveillance and clinical studies
 Whole blood treated with the Mirasol System yields platelet and
plasma products with characteristics similar to components treated
with the Mirasol System. Treated pRBC are expected to meet FDA
criteria for stored pRBC.

16. The end!!!
Thank you