most controversial topic in the field of transfusion medicine, most of the transfusions worldwide are associated with the deleterious effects of immunomodulation, simplified for PG students with latest article support

1. TRANSFUSION RELATED
IMMUNOMODULATION
DR AKSHAYA TOMAR
DEPT OF IMMUNOHEMATOLOGY AND
BLOOD TRANSFUSION
AFMC PUNE

2. FOREWORD
• In most clinical situations in which we are
administering blood, the risk of transfusion far
exceeds the benefit of transfusion

3. INTRODUCTION
• The constellation of all Allogenic blood transfusion(ABT)
related laboratory and clinical findings is known as
Transfusion Related Immunomodulation
• It encompasses effects attributable to ABT by means of
- Immunomodulatory
- Pro inflammatory mechanisms
 ABT may either cause alloimmunization or induce tolerance
• The presence or absence of autologous HLA-DR Ag on donor’s WBC plays
a decisive role

4. INTRODUCTION
• Donor sharing at least 1 HLA-DR with recipient will induce
tolerance, whereas fully mismatched transfusion leads to
alloimmunization
• Evidences from variety of sources indicates that ABT enhances
the survival of renal allografts
• Published literature has suggested that TRIM effects may be mediated by :
- Soluble HLA class I peptides that circulate in allogeneic plasma
- Soluble biologic response modifiers released in time dependent manner
from WBC granules/RBC membrane/Platelet concentrates during storage
- Allogeneic mononuclear cells

5. INTRODUCTION
• ABT has been shown to cause:
1. Decreased helper T-cell count
2. Decreased helper/suppressor t-lymphocyte ratio
3. Decreased lymphocyte response to mitogens
4. Decreased natural killer (NK) cell function
5. Reduction in delayed-type hypersensitivity
6. Defective antigen presentation
7. Suppression of lymphocyte blastogenesis
8. Decreased cytokine (IL-2, interferon production)
9. Decreased monocyte/macrophage phagocytic function

6. HISTORY
• 1945 : Medawar demonstrated that blood shared Ag with
other tissues (Noted that animals rejected skin grafts from the
blood donors as animals immunized to the donor by prior
transfusion)
• 1964 : Halasz et al report that dogs given donor blood with a
renal graft had prolonged survival
• 1972 : Opelz et al, Multicentric Prospective RCT of potential
candidates of cadaveric renal transplant received either ABT
or no transfusions
At 1 year, survival rate of transplanted kidneys : 90% in ABT
arm and 82% in no transfusion arm

7. HISTORY
• This study led to widespread practice of deliberately
transfusing patients on transplant lists ,it came to halt with
HIV and HCV epidemics
• 1980 : Brunson & others begin using the term Transfusion
associated Immunosuppression to explain these effects
• 1981 : Gantt suggested possibility of an association between
ABT and increased cancer recurrence
• 1990s : Universal leukoreduction implemented which actually
removed the opportunity to conduct RCTs (prospective
studies) to establish adverse TRIM effects

8. CLINICAL RELEVANCE
BENEFITS RISKS
Improved renal allograft
survival
Possible increased cancer
recurrence
Treatment of recurrent
spontaneous abortion(where
they share HLA Ag with father)
Possible increase perioperative
infection
Reduction of risk of crohn’s
disease
Increased short term mortality
in cardiac surgery setting
Increase in the risk of
reactivation of CMV & HIV

9. WHY BENEFIT FROM ABT?
• If blood being transfused is already leukoreduced benefit
obtained from ABT is minimal in Renal transplant
• During refrigeration APCs lose their ability to deliver co-
stimulation.
• Following ABT, the recipient’s T cells are stimulated by
allogenic donor APCs in the absence of co-stimulation

10. MECHANISM OF TRIM
TRIM EFFECT OF ABT
Allogenic
WBCs
Soluble
Biologic
response
modifiers
Soluble HLA
peptides
ABT itself
predisposing
to infection
Down regulation
of recipient
immune system
Pro inflammatory
response
ROS,
Proteolytic
enzymes
Elastase
,myeloperoxidase,TGF β

11. MECHANISM OF TRIM
Source : Transplantation
journal,2009
Article : Transfusion
related
IMMUNOSUPPRESSION
Simon Hellings
Morris A Blajchman

12. BIOLOGICAL RESPONSE MODIFIERS
• These mediators are contained in intracellular WBC granules,
and are released in a time-dependent manner as the WBCs
deteriorate.
• BRM includes
– Histamine
– Myeloperoxidase
– Eosinophilic cationic protein
– Plasminogen activator inhibitor
– They have been shown to decrease neutrophil function thereby
contributing to development of immunosuppression
Increases 3-25 X over 0 to
35 days of storage

13. MICROCHIMERISM
• When donor & recipient HLA compatibility is such that there
is a persistence of small numbers of donor lymphocytes and
APCs in circulation or organs of the ABT recipient
• Microchimerism results in release of IL-4,IL-10 and TGF β from
Th-2 lymphocytes, these cytokines have been shown to inhibit
the production of Th-1 cells and to deactivate cytotoxic T cells
,thereby suppressing allograft rejection.
• It has been demonstrated in trauma patients only till now

14. SOLUBLE HLA MOLECULES
• Liver is the main source of HLA molecules in the circulation
and they are found in the supernatant fluid of RBCs & Plasma
• Nonpolymorphic peptides derived from HLA class I molecules
might induce antigen-nonspecific immunosuppression,
whereas polymorphic HLA class I peptides have antigen-
specific immunomodulatory effects.
• It also seems possible that allogeneic plasma containing
soluble HLA antigens may enter the recipient’s thymic
circulation, producing clonal deletion of the recipient’s T cells
that are directed against the allogeneic donor antigens

15. SOLUBLE HLA MOLECULE
• Ghio et al. and Puppo et al found soluble Fas-ligand (sFasL)
and soluble HLA class I molecules in the supernatant plasma
of RBC and random-donor platelet units.
• Infusion of sFasL in transfused blood components may bind
the Fas molecule expressed on the NK and cytotoxic T-cells of
the recipient
• This impair there function and impedes the apoptosis of viral
infected cells

16. EFFECT ON WBC OF STORAGE
• WBC apoptosis begins immediately after blood withdrawal
with granulocytes , then monocytes ; while lymphocytes
remain viable for 25 days
Apoptotic cells
engages
Annexin V receptor/Phosphatidylserine
receptor on macrophage
Releases PGE2 & TGF-β
Suppresses
macrophages/NK
cells
Impair APC capacity

17. EFFECT ON WBCs ON STORAGE
• Viable WBCs can act as a responder or as stimulator cells
inducing cellular immunity or antibody production in the
recipient
T
CELL
3-5d of storage Functional
phosphorylation
defect
Protein synthesis
Responder capacity
Donor
APCs
10-14 d
Reduction in co
stimulatory
molecules
Capacity to stimulate
recipient T helper cells

18. CLINICAL TRIM EFFECTS

19. POTENTIALLY VULNERABLE POPULATIONS
• Postoperative
• Trauma
• Sepsis
• Cardiopulmonary Bypass
• Transplantation
• Pediatrics

20. BENEFICIAL EFFECTS

21. Beneficial Clinical Effects
• Agency for Healthcare Research and Quality (AHRQ) reviewed
all available clinical evidence and suggested,
- Pretransplant ABT has a neutral to beneficial effect on
graft rejection, graft survival and patient survival
• Most current evidence appears to indicate that improvements
in graft survival are now attainable without pretransplant
ABTs.
• Graft outcome risk-benefit ratio justified avoidance of ABTs as
far as possible with the improvement in peri-transplant
immunosuppression therapy.

22. Beneficial Clinical Effects
• Enhanced survival of Renal Allografts :
- The beneficial effect of Pretransplant Allogenic Blood
transfusion was thought to be less important with the advent
of Cyclosporine
- A multicenter observational study (58,036 renal allografts
from cadaveric donors) indicated that patients who had
received ABT were still more likely to have a successful renal
allograft.
- This benefit was not observed with pancreas , skin or heart
allograft

23. Beneficial Clinical Effects
• Enhanced survival of Renal Allografts :
- The graft outcome risk–benefit ratio has now become too
high to justify consideration of pretransplant ABTs when these
can be avoided.

24. Beneficial Clinical Effects
• Recurrent Spontaneous Abortions (RSA):
- Fetus represents a semi-allogeneic graft to its mother, and
maintenance of a pregnancy depends on immunologic
equilibrium between the implanted fetus and the maternal
immune response to the fetus.
- Sharing HLA Ag (consanguinous marriage) causes alteration
of this balance
- American Society of Reproductive Immunology(ASRI) –
found ABT effective , 8-10% benefit
- Recent RCT 2011 enrolled 183 women with 3 or more SA –
found ABT non significant

25. Beneficial Clinical Effects
• Reduced risk of Crohn’s disease :
- Pooled data from existing studies suggest that the
recurrence rate in transfused vs non-transfused patients is
similar (37.5% vs 40.5%)
- Heterogenous studies(different follow-up periods & surgical
interventions)
- Large RCT needed to establish beneficial effect

26. DELETERIOUS EFFECTS

27. CANCER RECURRENCE
• The possible recurrence of cancer by ABT has been examined
in over 100 observational clinical studies and 3 RCTs
• To date, no RCT has enrolled patients with sarcomas tumors
whose growth is stimulated by TGF-β—or patients with
tumors for which the immune response plays a major role.
• No adverse TRIM effect of ABT on cancer recurrence was
detected across the 3 studies. (Colorectal Ca Surgery)

28. POSTOPERATIVE INFECTIONS
• Over 20 RCTs and 40 observational studies investigated
association between perioperative ABT and postop infection
• No effect to 7.3 fold increase in infections in ABT patients
• Meta analysis by Vamvakas et al found no significant
association between the outcomes of patients that received
ABTs vs those that did not
• Several preclinical and clinical observations, however, support
the hypothesis that ABT in general, and WBC-containing ABT
in particular, may be associated with Multi organ failure

29. POSTOPERATIVE INFECTIONS
Multivariate Analysis transfusion
independently increased risk for VAP
OR 1.89
1
1.2
1.4
1.6
1.8
1 2 3 4 5+
Adjustedhazardratio
serious bacterial
infection
pneumonia
Carson et al, Transfusion 1999;39

30. PROPOSED MECHANISM OF NON WBC
REDUCED ABT AND MULTI ORGAN FAILURE
IT’S A PROINFLAMMATORY
RATHER THAN
IMMUNOMODULATORY EFFECT

31. INCREASED RISK OF SHORT TERM MORTALITY
(3 MONTHS POST TRANSFUSION)
• This RCT had been designed to investigate an association
between non-WBC-reduced ABT and postoperative infection
but instead observed an association between non-WBC-
reduced ABT and mortality.
• Non WBC reduced ABT predispose to MOF and hence
increased mortality
• Most evidence suggests that tissue injury is mediated by
reactive oxygen species and proteolytic enzymes released
from activated neutrophils

32. TRIM IN THE ICU
• Given the mixed results of both preclinical and clinical studies,
it is tempting to conclude that TRIM does not exist or if it does
occur the effects must be small compared to other insults
patients face in the ICU setting

33. WHAT ABOUT LEUKOREDUCED BLOOD
• Leukoreduction reduces CMV,EBV, HLA
alloimunization,Bacterial/parasite contamination
• Sparrow et al has demonstrated that prestorage
leukoreduction may help in abolishing TRIM
• In clinical studies, only postop cardiac patients have
demonstrated a benefit in reduction in postop infection
• Even in this setting, however, the reasons for the excess
deaths attributed to WBC containing ABT remain elusive

34. ASSOCIATION OF WBC CONTAINING ABT WITH POSTOP
INFECTION
SOURCE
:BLOOD VOL
21,2007

35. ASSOCIATION OF WBC CONTAINING ABT WITH SHORT
TERM MORTALITY
SOURCE :BLOOD
VOL 21,2007

36. ASSOCIATION OF WBC CONTAINING ABT WITH
MORTALITY FROM ALL CAUSES
SOURCE :BLOOD
VOL 21,2007

37. ASSOCIATION OF WBC CONTAINING ABT WITH CANCER
RECURRENCE
SOURCE:T
(TRIM): An update
E.C. Vamvakas
, M.A. Blajchman
Depicts Postop infection
/no recurrence

38. METHODOLOGICAL PROBLEMS IN THE STUDY
OF TRIM
• Numerous observational study, insufficient prospective
double blinded RCTs
• Likelihood of confounding factors (patients receiving
transfusion are different from those not receiving transfusion)
• Widespread introduction of universal leukoreduction
decreases the opportunity to perform RCTs

39. CONCLUSION
• TRIM is a real biological phenomenon, one established
beneficial effect in humans(augmentation of renal allograft
survival) however various deleterious effect has not been
confirmed yet
• RCT which is consistent with establishing adverse effect is in
cardiac surgery patients(Leukoreduced blood reduce the short
term mortality from all causes)
• Clinical studies needed to elucidate the mechanism and
clinical significance of proinflammatory effect of non WBC
reduced blood

40. CONCLUSION
• It is difficult to reach firm conclusions about the existence
of adverse TRIM effects, or to make definitive recommendations
• The available RCTs have not demonstrated a benefit from
autologous transfusion in preventing adverse TRIM effects

41. BIBLIOGRAPHY
• Rossi’s principle of transfusion medicine
• Transfusion immunomodulation or TRIM: What does it mean
clinically? M. A. BLAJCHMAN <Hematology 2005>
• Transfusion-related immunomodulation: review of the
literature and implications for pediatric critical illness
<Transfusion 2017>
• Transfusion-related immunomodulation (TRIM): An update
Eleftherios C. Vamvakas a, Morris A. Blajchman<Blood 2007>
• TRIM: Review <National Institute of Health 2011>

42. THANK YOU