Role of ADAMTS13 in TTP and TMA

Ravi Sarode, MD

John H Childers Professorship in Pathology

Professor of Pathology and Internal Medicine (Hematology/Oncology),

Chief of Pathology and Medical Director

of Clinical Laboratory Services, UT Southwestern Medical Center

Director, Transfusion Medicine and Hemostasis

UT Southwestern Medical Center, Dallas, TX

AABB October 14th, 2018 Boston

Disclosures

Consultant Octapharma

Advisor Alexion

Chair DSMB, Ablynx

Please don’t confuse me early

in the morning!@#$%

Case-1

A 45-AAF (110 Kg) with uncontrolled diabetes, CKD stage IV and

hypertension (210/120) presents to the ED with altered mental status.

Hb 7 g/dl, Plt 45 x 109/L, LDH 400 (150-230 IU/L), S Cr 3 mg/dL.

Numerous schistocytes on PBS

Although a diagnosis of TTP is suspected further discussion and evaluation

of the patient suggest it could be malignant hypertension associated TMA.

Case-1 ARS

An ideal approach would be:

To obtain a stat ADAMTS13 level because you think this is not TTP

To perform emergent PLEX and send out ADAMTS13 (TAT 3-5 days)

To start and continue PLEX – since ADAMTS13 has no diagnostic value

To call Dr. Kiss for help!

Diagnostic value of ADAMTS13 in TTP vs TMA

Statements from ASFA consensus conference and “International working group for TTP and TMA” :

A severe ADAMTS13 deficiency (<10%) is diagnostic of TTP

Many TMAs present with similar clinical and hematological features

ADAMTS13 generally >20%

TTP must be differentiated from other TMAs because

• Exacerbation and relapses are common

• Requires aggressive immune therapy in ~50%

• Specific therapies: caplacizumab and recombinant ADAMTS13

• Other TMAs do not need PLEX and/or don’t respond

Neil’s study

TTP (n=38) TMA (n=30) P value

Median ADAMTS13 Undetectable (<5%) 51 (33-122%)

ADAMTS13 inhibitor 28 (74%) NA NA

Neurological features 23 (61%) 9(30%) 0.0155

Creatinine 1.2 0.85 2.7 2.2 0.0003

Platelet count (109/L) 23 ± 26 65 41 0.0001

LDH 1062 787 1359 ± 1371 0.27

Hematocrit 26.3 7.3 26.4 4.5

Schistocytes (mod to severe) 47% 30%

Haptoglobin undetectable 94% 61% 0.004

PLEX performed 35/38 (92%) 16/30 (53%)

Median # of PLEX 15 (3-107) 5 (2-10)

Mortality 2(5.7%) 1 (3.3)

In ADAMTS13

Utility of fast TAT - BJH

Patient ADAMTS13 Plt Diagnosis, clinical Management

1 <5% 9 New aTTP PLEX before ADAMTS13

2 <5% 24 New aTTP PLEX before ADAMTS13

3 <5% 9 New aTTP PLEX before ADAMTS13

4 36% 343 Known aTTP – HA during pregnancy 19 wks Re-assured

5 <5% 220 Known aTTP – subclinical relapse Rituximab out-pt

6 <5% 10 Known cTTP, viral illness and TMA Plasma infusion

7 47% 250 Known cTTP – monitoring during pregnancy Plasma infusion and PLEX

Thomas et al

Case ADAMTS13 Plt Final Diagnosis PLEX Clinical Outcome

1 42 5 Malignant HTN 1 then D/C Alive

2 104 9 DIC No Died

3 65 12 DIC No Died

4 38 24 Cancer-TMA No Died

5 36 142 D+ HUS No Alive

6 84 37 DIC No Died

7 92 21 D+ HUS No Alive

8 73 13 Drug – TMA (carfilzomib) 1 then D/C Alive

9 69 54 Pneumo-HUS 2 then D/C Alive

10 36 43 Sepsis/DIC No Alive

11 57 45 Malignant HTN No Alive

12 59 34 Vasculitis and CMV No Alive

13 63 95 Vasculitis No Alive

14 36 53 Post-cardiac Sx-TMA PI Alive

ADAMTS13 – Conflicting Test Results

52 AAF presented with acute cholecystitis and thrombocytopenia

Past history of ITP treated at OSH with steroids

Hb 7.7 g/dL, plt 14K, LDH 647 (IU/L), Hapto 5 mg/dL, 2/HPF schistocytes,

Negative DAT, DIC r/o, no plasma free hemoglobin

Hematologist and TM physician – “clinical judgement did not suggest TTP”

FRET assay (ATS-13, Immucor) under validation = 33%

Supported clinical impression that this is not TTP

Split sample sent to a ref lab = <1% activity (Technozym) + Ab 64 IU (<18)

Supported a diagnosis of TTP

ADAMTS13 Conflicting Test Results- ARS

Based on this conflicting information from in-house FRET assay undergoing validation (33% activity) compared to a reference lab value (<1%), with a clinical history of past ITP, current plt count of 14K, elevated LDH and very low haptoglobin in the absence of DIC or other TMA would you support a diagnosis of TTP?

YES

NO

ADAMTS13 Conflicting Test Results

No intervention based on low clinical suspicion and in-house assay

Next day 2nd specimen was sent to another ref lab as part of their validation process – the same Immucor ATS-13 FRET assay

However, in the mean time started PLEX with CPP

Clinical improvement and Plt normalized with 7 PLEXs (174 x 109/L)

ADAMTS13 23% from 2nd ref lab with a negative inhibitor

ADAMTS13 from the same ref lab was 65% - 3 days post D/C PLEX

“Although clinical suspicion was low and not corroborated by FRET assay, we elected to continue PLEX since plt count rose in apparent response to the treatment!”

Conclusions?

Case - 2

27 y/o HF presents with pelvic pain x 2 d

Altered color perception L- eye x 1d

URI – 1 week prior

Neuro exam – no focal deficits, vision 20/20, CT head unremarkable

CBC: Hb = 12.1 g/dL, Plt = 5 x109/L

Recommends hemolysis and DIC work-up, Ophthalmology consult = B/L chorioretinopathy with serous retinal detachment, no optic neuritis

No schistocytes on PBS

H/O fellow = Dx ITP, IV solumedrol and IVIG

Case-2 ARS

Based on normal Hb, no schistocytes, and severe thrombocytopenia, what is your first diagnosis?

ITP

TTP

Labs Next Day

• Haptoglobin <10, LDH = 709 (<220), Retic 2.5% , PBS – no schistocytes or spherocytes

IVIG + steroids Platelets IVIG

4 Days Later

Despite aggressive ITP treatment no improvement

Headaches developed

Another Hematology attending suspected TTP

PBS = 10-12 schistocytes/HPF

LDH = 709 – 943 – 1255

Emergent PLEX started

ADAMTS-13 <5%; inhibitor 0.9 U/mL

Retrospective study of national database of 423 TTP patients

84 patients (20%) were initially misdiagnosed

Goal was to determine causes for diagnostic errors and consequences to delay in treatment

Causes of Errors in TTP Diagnosis

Evans syndrome = 51%

ITP = 37%

Absence of schistocytes or anemia

Positive DAT

At UTSW:

Stroke as a presenting feature without hematological involvement

Acute renal failure – aHUS first diagnosis

No anemia or schistocytes

ITPvs

TTP

Hematologist

Accuracy and Speed of ADAMTS13 assays

Because of diagnostic cut off of <10%, it is essential that the ADAMTS13 measurement be accurate for clinical decision making to either initiate or continue PLEX

Rapid TAT is also essential for better patient care, to reduce patient harm from unnecessary treatments, and reduce healthcare cost

Current ADAMTS13 Assays

Use rVWF-73 fragment with a cleavage site for ADAMTS13.

The cleaved fragment measured by

FRET (Fluorescence resonance energy transfer) assay

ELISA

FRET-Assay Principle

TECHNOZYM – ADAMTS13 Chromogenic ELISA

ARS

Which of the following ADAMTS13 assays may be affected by high bilirubin and high free plasma hemoglobin?

VFW-73 FRET assay

VWF-73 ELISA assay

Detection of autoantibody to ADAMTS13

Almost essential to rule out congenital TTP and probably to give rituximab

Inhibitor assay - Bethesda type assay – neutralizing antibody

• Usually detected in ~80% at presentation and later in some others

• No good correlation with response and relapse

Anti-ADAMTS13 antibody – ELISA assay – detects both neutralizing and clearing antibodies

• Very high titer may predict poor response or exacerbation/relapse

Role of ADAMTS13 during Acute Episode

Wu et al measured daily ADAMTS13 in 19 pts

12/19 still had activity <10% by day 7

They required longer treatment to achieve a clinical response when compared to those who had >10% activity (p <0.001)

There was also a trend for more exacerbation

Good candidate for rituximab

Wu et al Transfusion 2015

Case -3

Early July 2015 a 62 AAF was diagnosed with TTP at OSH

7/23/2015 Presented to us with exacerbation

ADAMTS13 was <5%

Daily PLEX x 5 with plt >150K

Tapered

Given two standard doses of rituximab (375 mg/m2)

Case-3 ARS

9/10/2015 ADAMTs 13 = 59% and plt 275K

10/2/2015 ADAMTS <5% and plt 293 K

What would you do:

Admit for PLEX because ADAMTS13<5%

Wait and watch – weekly CBC to monitor plt

Give rituximab

Give steroids

During follow-up her ADAMTS13 and management

Dates ADAMTS13 Platelet counts Rituximab ADAMTS13 post-RTX

9/10/2015 59% 275 Not given ND

10/2/2015 <5% 293 4 Std doses 84%

12/7/2015 55% 336 2 std doses 86%

7/19/2016 31% 293 4 low doses 97%

2/3/2017 46% 383 4 low doses 102%

12/13/2017 34% 337 4 low doses 83%

8/10/2018 27% 347 4 low doses 61%

Std = 375 mg/m2 weekly, low dose = 100 mg fixed dose weekly

Role of ADAMTS13 during Remission

Jin et al – Higher relapse rate in patients with lower ADAMTS13 during remission (24 pts in the study)

Hie et al – 46/109 patients had relapses and severe deficiency was found in 46% as compared to 22% who did not have severe deficiency at relapse.

However, not all patients with severe or low ADAMTS13 levels are uniformly associated with relapses

Some remain low without relapses

Others normalize these levels

Therefore, a clinical decision to use preemptive rituximab should be based on risk-benefit discussion or previous history

Jin et al BJH 2008, Hie et al Blood 2014

92 patients with long term f/u had ADAMTS13 measured regularly

All had activity <10% during clinical remission

Given preemptive rituximab (1-4 doses)

“0” clinical or hematological relapse over 31.5 months f/u

Before preemptive regimen

40% (37/92) had a median of 3 (IQR 2-3) relapses

Historically 23 patients with persistent ADAMTS13 <10%

74% (16/23) had relapse over 7 year f/u

Prediction of relapse ADAMTS13 related bio-markers

Biomarker At the time of diagnosis

Measured at Clinical response

Measured in Remission

ADAMTS13 <5% Diagnostic of TTP Predictor of relapse Predictor of relapse

ADAMTS13 Antigen No association Higher levels = sustained remission

Associated with relapse vs no association

ADAMTS13 inhibitor No association No association Associated with relapse

Anti-ADAMTS13 antibody

IgG associated with relapse

- IgG associated with relapse

VWF Ag No association No association No association

Masias and Cataland, Blood 2018

ADAMTS13 in other TMAs

Mild to Moderately decreased in some TMA

Severe sepsis = mean 43% (IQR 32.7-67%)

Organ failure = mean 67% (IQR 57.4-87.9)

Malignancy, vasculitis = median 33.5% (range 16-47%)

Malignant HTN = median 64%

HSCT transplantation – usually TMA is aHUS with ADAMTS13 being not severely deficienct

Masias and Cataland, Blood 2018

Severe ADAMTS13 (<10%) is diagnostic of TTPTMAs do not have severe ADAMTS13 deficiency and do not benefit from PLEXRapid TAT for ADAMTS13 assay is desirableADAMTS13 assay selection should be done judiciously ADAMST13 levels are useful biomarker During acute episode At clinical response including for taperDuring remission to predict exacerbation and relapses.

Summary

Joseph E. Kiss, M. D.

Medical Director

Northeast Division Blood Services

Vitalant

Professor of Medicine

Division of Hematology-Oncology

Department of MedicineUniversity of Pittsburgh

Pittsburgh, PA

Blood Systems and The Institute for Transfusion Medicine are now Vitalant

ADAMTS13 in the Pathogenesis of Sepsis

with Multiple Organ Failure (MOF)

Joseph E. Kiss, MDDisclosures

• Ablynx nv : Medical Advisory Board

Objectives

1. Recognize clinical phenotypes of sepsis and the risk

of developing multiorgan failure (MOF)

2. Consider the relationship between new onset

thrombocytopenia, von willebrand factor excess,

and ADAMTS13 deficiency in critically-ill patients

3. Understand the rationale for considering ADAMTS13

replacement or VWF-directed therapy in

Thrombocytopenia-associated MOF (“TAMOF”)

www.aabb.org

ARS Question 1: In patients admitted to the intensive care unit,

thrombocytopenia (platelet count < 100, 000/ul) either on admission or developing

while in the ICU is an independent risk factor for mortality.

TRUE

FALSE

Microbial

Invasion

SIRSSepsis Severe

Sepsis Septic

Shock

MSOF

[Inflammation]

[Documented

Infection] [Hypotension

Hypoperfusion][Pressors]

ACCP/SCCM 1992

Mortality in Sepsis is Related to Organ Failure

SEPSISMortality 15-30%,Decreasing in recentsurveys

11% for kids <1 year – teens

40% for ages >85 years

Women have lower age-specific incidence and mortality

Up to 70% in patients with >3 failing organs

Vincent CCM 1998

Thrombocytopenia-associated MOF

ICU Patient

and J. Carcillo MD

Both the presence and severity of thrombocytopenia independently

predict mortality in the ICUHui P. CHEST 2011

Thrombocytopenia in the ICU

• 8.3% to 67.6% of patients on admission

• 13.0% to 44.1% of patients during the ICU stay Hui P. CHEST 2011

**

SEPSIS Subtypes

Podd & Carcillo 2017

ARS Question 2: What Causes Platelet Consumption

and Microthrombi in TTP?

A. Severe ADAMTS13 deficiency (< 10%

Activity)

B. Platelet Activating Factor (PAF)

C. Ultralarge VWF multimers (ULWWF)

D. Unknown

Platelet Aggregation is Increased in Proportion to VWF Multimer Size

Moake J. JCI 1986

3

1 2 3

1

2

Severe Sepsis is associated with an Intense Endotheliopathy +/- Coagulopathy

• Increased cytokines & inflammatory mediators

• Endothelial activation & apoptosis, loss of vascular integrity

• Enhanced pro-thrombotic milieu

– Tissue factor expression– Decreased natural

anticoagulants– Decreased thrombomodulin– Release of PAI-1 (decreased

fibrinolysis)– Decreased ADAMTS13;

increased vWF (ULvWF)

• Microvascular thrombosis, impaired tissue perfusion, organ failure

PAI-1

I-CAM

IL-1IL-6

TMIIa

PC APC

TMIIa

IIa Tissue

Factor

ATIII

PS

PSATIII

ADAMTS13

ADAMTS13

VWF

VWF

Day in MOF 1 3 5 Control

%ADAMTS13

Activity 23 12 21 100

%vWf

Antigen 238 338 320 100

Platelet Ct 52 29 37

INR 1.4 3.5 2

PAI-1

activity 12.7 105 105 <23

ADAMTS13 activity remained lowPresence of Ultra large vWf multimersElevated vWf Antigen, INR, and PAI-1 activity

Day 1 Control 3 5

3 year old boy, Gram negative sepsisPersistent Multi-organ Failure and Death

Nguyen TC. Crit Care Med 2008 Vol. 36, No. 10

Anti-vwf ab stain of brain and

kidney at autopsy

“ULVWF”

Decreased ADAMTS13 Activity in Inflammation - Mechanisms

• Consumption - Significant inverse relationship between ADAMTS13 & VWF

Dong J Biol Chem 2003;278:29633

Majerus J Biol Chem 2005;280:21773

Nguyen Haematologica 2007;92:121

• Proteolysis – Thrombin, plasmin, neutrophil elastaseCrawley Blood 2005;105:1085

Ono Blood 2006;107:528

• Inhibition – IL6, hemoglobin, thrombospondinBernardo Blood 2004;104:100

Studt Blood 2005;105:542

Novelli haematologica 2013; 98;e132

Alternative Mechanisms can also make VWF Resistant to ADAMTS13

• Oxidation of VWF met1606 (cleavage site in A2 domain)

De Filippis Biochem J 2012; 442:423

Lancellotti Free Rad Bio Med 2009; 48: 446

Ono T. Blood 2006;107:528

Secondary Deficiency of ADAMTS13

May Play a Role in Renal Injury in Sepsis

Ono T. Blood 2006;107:528

Ono T. Blood 2006;107:528

Decreased ADAMTS13 and Appearance of ULVWF in Critically Ill Patients

Relationship between ADAMTS13 activity and Cleavage of Endothelial Cell-ULVWF

Dong J-F. 2004

www.aabb.org

ARS Question 3: In your institution, have you been requested to

perform plasma exchange in a patient with sepsis multiorgan-failure?

Yes

No

I. PLEX is first line therapy

II. PLEX is second line therapy

III. PLEX is is not established. Decision

making should be individualized.

IV.PLEX is ineffective or harmful. Go to the

IRB!

ARS Question 4: According to Current ASFA (American

Association for Apheresis) Guidelines, the role of plasma exchange (PLEX) in sepsis

multiorgan failure is classified as category:

There have been numerous failures of monotherapy

directed at signaling molecules, inflammatory and coagulation

mediators in sepsis…“…the exact targets for blood

purification in sepsis are unknown.”

F. Zhou & J. KellumCrit Care Med 2013; 41:2209–2220

Targeted Therapies in Sepsis have Failed to Improve Outcome

• IL-1ra (1994)

• Endotoxin (1995)

• TNF-alpha (1996)

• Activated Protein C (2001)

• TFPI (2003)

• ATIII (1985-2013)

• Others

Early Rationale for TPE

EH-1

EH-3

EH-2

Metchnikoff: “Blood poisoning”EH: Early (EVIL) Humour

PLASMAEXCHANGE

MAN

Courtesy of J. Carcillo MD

Hypothesis: How Might Plasma Exchange Therapy Work in

Sepsis-Multiple Organ Failure (MOF)?

• Plasma exchange removes – Inflammatory mediators (endotoxin, cytokines)

– Other toxic mediators (hemoglobin)

– Fibrinolytic pathway inhibitors (PAI-1)

– Thrombogenic high molecular weight vWF

• Plasma exchange replenishes – ADAMTS 13

– Physiologic anticoagulants (Protein C, ATIII, TFPI, etc.), inhibitors (haptoglobin)

These changes may restore vascular homeostasis (anticoagulant/profibrinolytic), diminish microvascular thrombosis, improve tissue perfusion and reverse organ failure in “ischemic microangiopathy”

TPE in Sepsis/Septic Shock: Results of Meta-analyses

RR, 0.63 [95%CI, 0.42-0.96]; p=0.03, 2 trials, n=128

RR, 0.83 [95%CI, 0.45-1.52]; p=0.53, 3 trials, n=194

(Plasma-JK)

1

2

3

Therapeutic Rationale: Early intensive removal of sepsis mediators

Plasmapheresis in Severe Sepsis & Septic Shock: A Prospective, Randomized, Controlled Trial

Busund R, et al 2002

• RCT 106 consecutive ICU patients

• 28-day mortality

PEX(n=54) Control(n=52) p

18 (33.3%) 28 (53.8%) 0.05*ARDS 2 4

CV 7 10

MOF 6 13

Cerebral 0 1

edema

DIC 1 0

Bleeding 2 0

*p= 0.07(NS) after adjusting for correcting for baseline imbalance

Cau

se o

f D

eat

h

• Design: single center RCT in a pediatric ICU

• Inclusion criteria: children with platelet count < 100K and 3 failed organs for 24 h (a condition associated with 80% mortality in CHP PICU regardless of diagnostic category)

• Protocol: treatment within 30h of meeting criteria with plasma exchange for two 7-day cycles of 1.5 volume x 1 d followed by 1 volume x 6d, or until the resolution to < 3 organ failure for 48h

RCT of Plasma Exchange in Pediatric Patients with Thrombocytopenia Associated MOF

Nguyen TC. Crit Care Med 2008 Vol. 36, No. 10

Therapeutic Rationale: Restore vascular homeostasis

(antithrombotic/profibrinolytic)in “ischemic microangiopathy”

Pediatric Logistic Organ Dysfunction Score

DAY

0 5 10 15 20 25 30

PE

LO

D

0

20

40

60

80

100

Plasma Exchange

No Plasma Exchange

Figure 3. Pediatric Logistic Organ Dysfunction Score, Mean with standarderror for patients who received plasma exchange therapy (N = 5) and who did not receive plasma exchange therapy (N = 5) for each day x 28 days.

17

PELOD decreased from 25.0 2.0 to 0.8 0.6 with plasma exchangeat 28 d

PELOD increased from 25.4 2.3 to 73.6 18.4 without plasma exchange at 28 dp < 0.05

Plasma exchange: 5/5 patients survived

No plasma exchange: 1/5 patients survived

Pediatric Logistic Organ Dysfunction Score

Nguyen TC. Crit Care Med 2008 Vol. 36, No. 10

Plasma Exchange Replenishes ADAMTS13

Activity in TAMOF

ADAMTS13 Activity and PEx vs No PEx

Day

0 1 2 3 4 5 6 7 8

AD

AM

TS

13

Activity (

% r

ela

tive

to

co

ntr

ols

)

-20

0

20

40

60

80

100

day vs pe cp

day vs nope cp

Plasma Exchangen = 4

No Plasma Exchangen = 4

2F ANOVA p<0.05

Nguyen TC. Crit Care Med 2008 Vol. 36, No. 10

Qu et al.

Effect of sustained treatment on organ function

Conclusions• The pathophysiologic features of sepsis induced-

MSOF provide a rational basis for consideration of ADAMTS13 replacement and/or VWF-directed therapy

• Some studies and clinical trials suggest that plasma exchange improves organ failure & outcome, however, they also have important design and/or methodologic issues that limit interpretation of efficacy (and safety).

• Protocols that adopt (and registries that study) daily, sustained TPE with plasma replacement are needed!

• Children’s Hospital of Pittsburgh

• Drs. Trung C. Nguyen, Joseph A. Carcillo, & the dedicated Pediatric ICU Nursing Staff

• The Institute for Transfusion Medicine, now Vitalant

• Joan Sevcik, RN and our talented and highly skilled Therapeutic Apheresis Staff

ACKNOWLEDGEMENTS

Thank you!

jkiss@itxm.org

ADAMTS13 Testing: More Questions Than Answers?

Yara Park, MD

University of North Carolina

www.aabb.org

This Session Will Be Interactive!

To Interact:

Type the above URL in your device web browser

Connect with your Smart Phone, Tablet, and/or

Laptop

www.aabb.org 3

Go to a Red Sox game

Boston Common

New England Aquarium

Throw tea in the harbor

What is your favorite thing to do in Boston?

ADAMTS13 and…Trauma?!?

Jay S. Raval, MD

Associate Professor

Pathology and Laboratory Medicine

Disclosures

• Speaker / Advisory Board Member

– TerumoBCT, Inc.

• Apheresis applications consultant/speaker

– Alexion, Inc.

• Myasthenia gravis advisory board

– Ablynx, Inc.

• Investigator in Phase III trial for caplacizumab in TTP

• No relevant conflicts of interest

Lethal Triad

Hypothermia

CoagulopathyAcidosis

Kashuk JL et al. J Trauma 1982

Acute Traumatic

Coagulopathy

TRAUMA

• Independent of the

“Lethal Triad”

• Attributed to

– hypoperfusion

– increased circulating thrombomodulin

– abnormal protein C activation

• Deranged hemostasis and suprafibrinolytic state

Hess JR et al. J Trauma 2008Brohi K et al. Ann Surg 2007Kushimoto S et al. J Intens Care 2017

Acute Traumatic

Coagulopathy(ATC)

Trauma

• Leading cause of morbidity and mortality worldwide– 1 in 10 deaths

– Expected to increase

• ATC develops in approximately 1/3rd of patients– Predictive of mortality, organ dysfunction, death

• ATC pathophysiology and mechanisms incompletely understood

Soreide K. Br J Surg 2009Alberdi F et al. Med Intensiva 2014Mathers CD et al. PLoS Med 2006Rhee P et al. Ann Surg 2014Kushimoto S et al. J Intens Care 2017

Gonzalez E et al. Semin Thromb Hemost 2010

ADAMTS13 Domain Structure

N-Terminus C-Terminus

Plautz W et al. Transfusion 2018

Image courtesy of Dr. Matthew D. Neal

2015

• Post-hoc analysis of patient samples from a prospective, double-blind, randomized, parallel-group, controlled trial assessing vasopressin efficacy in resuscitation of those with hemorrhagic shock

• University Hospital, San Antonio, TX

• 17 patients w/ severe hemorrhagic shock and serum samples at time of arrival (time 0 hrs)

– 20 control patients

Furmaga W et al. Clinica Chimica Acta 2015

Biomarker Investigation

• Assessment of various molecules to determine which may help predict– Mortality (24 hours)

• 5 patients

– Multi-Organ Dysfunction Syndrome (MODS)• 1 patient

• ADAMTS13 was chosen because it is involved in both coagulation and systemic inflammation cascades– Both activated during hemorrhagic shock

Furmaga W et al. Clinica Chimica Acta 2015

Furmaga W et al. Clinica Chimica Acta 2015

259 x

✔

✔

Furmaga W et al. Clinica Chimica Acta 2015

Early 2018

• Prospective study assessing a variety of biomarkers associated with ADAMTS13 and vWF in pediatric trauma patients

• University of Alabama, Birmingham, AL

• Correlate findings with mortality and coagulation abnormalities

• 106 patients with severe trauma and citrated plasma samples at time 0 and 24 hrs– 52 controls

Russell RT et al. Thromb Haemost 2018

Russell RT et al. Thromb Haemost 2018

Russell RT et al. Thromb Haemost 2018

Russell RT et al. Thromb Haemost 2018

Russell RT et al. Thromb Haemost 2018

Our Collaborative Group’s Work:Late 2016-current

• Hypothesized that an ‘ultra-large vWF burst’ occurs after severe trauma

• Released into the bloodstream by activated, damaged endothelium

• vWF burst results in a dysregulation of the circulating vWF multimer composition

• ADAMTS13 activity would be decreased and insufficient to cleave the ultra-large vWF burst, leading to organ injury

Methods

• Obtained patient data and samples enrolled in a pragmatic, multicenter, cluster-randomized, phase 3 superiority trial (PAMPer) that compared the administration of thawed plasma with standard-care resuscitation during air medical transport

• 37 trauma patients with citrated plasma samples at time 0 and 24 hours– Clinical data abstracted from the RCT database and

electronic medical records

Sperry JL et al. N Engl J Med 2018

Time 0 Hrs

Time 24 Hrs

Circulating vWF Multimer Distribution

TOP of Gel

(LARGEST Multimers)

BOTTOM of Gel

(smallest Multimers)

Circulating vWF Multimer Distribution:Time 0 Hrs

TOP of Gel

(LARGEST Multimers)

BOTTOM of Gel

(smallest Multimers)

Circulating vWF Multimer Distribution:Time 24 Hrs

TOP of Gel

(LARGEST Multimers)

BOTTOM of Gel

(smallest Multimers)

Multivariate Analysis:Correlations w/ Time 0 Hrs ADAMTS13 Activity

• Laboratory Markers of Coagulopathy– Presentation INR (=-0.63, p<0.0001)– TEG activated clotting time (=-0.36, p=0.044)– TEG maximum amplitude (=0.36, p=0.047)

• Clinical Markers of Coagulopathy– Overall blood product transfusion requirement in the

first 24 hours (=-45, p=0.008) – PRBC requirements (=-0.43, p=0.011)– Platelet transfusion (=-0.34, p=0.049)– Plasma requirements (=-0.45, p=0.007)

• Injury Severity Score (=-0.34, p=0.043)

Conclusions

• ADAMTS13 activity and antigen acutely decrease in trauma

– Sustained depressions for 24 hrs (or longer)

• Acute dysregulation of physiologic distribution of circulating vWF multimers

• More severely injured patients have larger ADAMTS13 decreases

• Association between decreased ADAMTS13 and coagulopathy / poorer survival

ARS Question

• What accurately summarizes your medical opinion about ADAMTS13 and Trauma?– A) I didn’t believe there was a reasonable

association before, but now I do

– B) I didn’t believe there was a reasonable association before, and I still don’t

– C) I’d support further investigations into this important clinical area

– D) A and C

– E) I’m just going to hope for a TTP patient instead

Thank you

• Neal Lab (UPMC)

– Dr. Matthew D. Neal

– Dr. Mitch Dyer

– Mr. William Plautz

• NIH/DOD/TACTIC

• PAMPer Investigators

• Special Coagulation Lab (UNC)

– Dr. Marian A. Rollins-Raval

– Mr. Preston Parker

– Ms. Cathy Sohier

ADAMTS13 Testing: More Questions

Than Answers?

10/14/2018

Faculty Disclosures

The following faculty have no relevant financial relationships to disclose:

– Yara Park MD

The following faculty have a relevant financial relationship:

– Jay Raval MD

Terumo BCT, Inc.: Consultant

– Joseph Kiss MD

Ablynx NB: Consultant

– Ravi Sarode MD

Octapharma: Consultant

Siemens: Grant/Research Support

Alexion: Honoraria

Ablynx: Honoraria

www.aabb.org 2

Learning Objectives

• Recognize the utility of ADAMTS13 testing in patients with thrombotic thrombocytopenic purpura and other thrombotic microangiopathies

• Identify the different non-thrombotic microangiopathy patient populations that may have deficiencies of ADAMTS13 activity and discuss the significance of these deficits

• Explain the rationale for therapeutic plasma exchange in thrombocytopenia-associated multiple organ failure patients with decreased ADAMTS13 activities

www.aabb.org 3