Paroxysmal Nocturnal
Hemoglobinuria
Sharing Hope NORD/ PNH Regional Meeting
Ramon V. Tiu, MD
Assistant Professor of Molecular Medicine
Cleveland Clinic Taussig Cancer Institute
March 1, 2014
San Antonio, Texas
Objectives
1. Overview of PNH
• Historical Background, Epidemiology of PNH, Pathogenesis of PNH, Clinical
Manifestations in PNH, Classification of PNH
2.
3.
4.
5.
6.
7.
Diagnosis of PNH
Thrombosis in PNH
Treatment of PNH
Other Long term complications of PNH
Updates in PNH
Other Issues in PNH
Overview of
PNH
Historical Background
(selected timelines)
• 1866 – Dr. William Gull published important observations on the clinical
feature of PNH but did not distinguish it from paroxysmal cold
hemoglobinuria
• 1882 – paper of Dr. Paul Strubing that clearly described PNH and
distinguished it from paroxysmal cold hemoglobinuria and mrch
hemoglobinuria
• 1939 – Dr. Thomas Hale Ham reported evidence that complement mediates
abnormal lysis of PNH RBCs in acidified serum
• 1950s – Louis Pillemir discovered the alternative pathway of complement
• 1993 – Kinoshita and colleagues found that PNH is a consequence of
mutant PIG-A gene
Parker CJ. Hematol Am Soc Hematol Educ Program.2008
Overview of
PNH
Epidemiology of PNH
• A type of bone marrow failure syndrome
• A rare disease (1-2 per million annual rates)
• However mortality rates in this disease is high
Overview of
PNH
Genetic defect in PNH and effect on
disease phenotype
• Somatic mutation in the PIGA gene, rarely mutation in
PIG-T gene
• This leads to loss in GPI link
proteins which anchors
important proteins to the
surface of cells
• This results in absence of
CD55 and CD59 which makes
the RBC prone to hemolysis
Krawitz Blood 2013. Luzzatto L Blood 2013;122:1099-1100
Overview of
PNH
The Complement Pathway
Jozsi M. Book Chapter. An Update on Glomerulopathies.
Overview of
PNH
Classification of PNH
3 groups
1. Classic PNH
2. PNH in the setting of a BM disorder (MDS, AA, MF)
3. Subclinical PNH – very small GPI negative clones with no obvious
clinical significance (In this context, using the term PNH may be
misleading since none of the clinicl manifestions of this condition
are present. Some have proposed the term “acquired GPI-AP
deficiency.”
Parker CJ et al. Blood. 2005; Risitano A & Rotoli B. Biologics: targets & Therapy. 2008
Overview of
PNH
•
•
•
•
•
•
•
•
•
Clinical Manifestations of Patients
with PNH
Thrombosis
Fatigue
Dysphagia
Abdominal Pain
Erectile dysfunction
Pulmonary HTN
Pain symptoms
Other symptoms related to Anemi
Other symptoms related to thrombocytopenia or neutropenia if these
abnormalities are present
Standard Diagnostic Test for PNH
 Flow cytometry performed on peripheral blood
 Granulocytes and at least one additional cell line should
be evaluated
– Red blood cells (RBCs)
– Monocytes
 Quantitative results
– Optimal-High sensitivity analysis: ≥0.01%
– Routine analysis: ≥1%
 Easy to understand PNH reports
 Use more than one reagent against GPI-anchored proteins
Borowitz MJ et al. for International Clinical Cytometry Society. Part B Clin Cytometry. 2010;78B:211-230.
9
Testing for PNH in Red Blood Cells
Normal RBC’s with normal
CD59 expression
(Type I cells)
PNH clone with complete
CD59 deficiency
(Type III cells)
Gating on GPA+ RBC’s
PNH clone with complete
CD59 deficiency (Type III cells)
and partial CD59 deficiency
(Type II cells)
GPA = glycophorin A.
Data Source - Dahl-Chase Diagnostic Services.
10
Why Look Beyond RBCs for PNH?
 Granulocytes provide more accurate representation of
PNH clone size
 Percentages of PNH RBCs may be affected by
– Hemolysis
– Blood transfusion
PNH reports should provide quantitative results expressing
clone size on both granulocytes and red blood cells
Borowitz MJ et al. for International Clinical Cytometry Society. Part B Clin Cytometry. 2010;78B:211-230.
11
PNH Patient With an 80% WBC Clone Size and 31% RBC Clone
Size Indicating Hemolysis
RBC
CD24- Granulocytes
WBC
FLAER- GPI Anchor Binding Marker
80.1 % of Granulocytes lack GPI proteins
Data Source - Dahl-Chase Diagnostic Services.
CD59 – GPI Anchored Protein
31.4% RBCs are Type III PNH cells
12
Important to Monitor Granulocytes and RBCs Over Time
FLAER-GPI Anchor Marker
Mar 09
FLAER-GPI Anchor Marker
May 09
CD24-Granulocytes
CD24-Granulocytes
CD14-Granulocytes
Dec 08
CD24-Granulocytes
CD24-Granulocytes
Sept 08
FLAER-GPI Anchor Marker
FLAER-GPI Anchor Marker
Gran clone: 3.8%
Gran clone: 7.6%
Gran clone: 14.2%
Gran clone: 23.3%
RBC clone: 0.8%
RBC clone: 1.6%
RBC clone: 1.8%
RBC clone: 2.4%
CD59 –GPI Anchor Protein
CD59 –GPI Anchor Protein
3 Months
CD59 –GPI Anchor Protein
CD59 –GPI Anchor Protein
6 Months 9 Months
PNH Clone Expanded in <1 Year
13
Diagnosis of
PNH
When to test
• A patient with unusual sites of thrombosis especially in a young
patient
• Persistent coombs negative hemolytic anemia
• A patient with aplastic anemia
• Patient with unexplained cytopenias
Thrombosis in
PNH
Frequency of blood clots in PNH
• Thrombosis of arterial and venous blood vessels are common in PNH
• Frequency of DVT/ PE (venous)= 40%
• Frequency of strokes/ hearts attacks (arterial) = 15%
• Major cause of death in 40-67% of PNH patients
Hillmen P et al. Blood. 2007; Hill A et al . Blood. 2013.
Thrombosis in
PNH
Location of blood clots in PNH
DVT and Pulmonary embolism –
But can occur anywhere in PNH
most common types of blood clots
in
1. Medscape reference website: http://emedicine.medscape.com/article/300901-overview#aw2aab6b2b2aa
PNH
2. Mynyp.org website: https://mynyp.org/My_Health/tests/NonInvasiveFlowStudies.aspx
Signs and symptoms suggestive of
Thrombosis in
the presence of a blood clot in a PNH
PNH
patient
• Symptoms associated with blood clots (depends on the
location)
Limbs
Lungs
Deep Vein Thrombosis
Pulmonary embolism
• Swelling of the leg most of
the time just one leg or one
limb
• sudden onset of difficulty
breathing
• Pain in one leg or one
limb
• Painful swelling of one leg
or one limb
• chest pain
• coughing up blood
• pain when taking a deep breath
Signs and symptoms suggestive of
Thrombosis in
the presence of a blood clot in a PNH
PNH
patient
• Symptoms associated with blood clots (depends on the
location)
Cerebral Vein Thrombosis
Abdominal venous thrombosis
• difficulty speaking
• sudden onset of abdominal pain
• difficulty in moving your limbs
• abdominal bloating
• weakness on one side of the body
• rapid weight gain
• blurring of vision
• an enlarged spleen can indicate
portal vein thrombosis
• headaches
Thrombosis in Proposed mechanisms of blood
PNH
clot formation in PNH
• Activation of Platelets
• Intravascular hemolysis: depletion of NO, toxicity of free hemoglobin,
and red cell microvesicles
• Deficiency or absence of other GPI-linked (or associated) proteins: uPAR, heparan sulfate, TFPI, and proteinase-3
• Other complement-mediated procoagulant mechanisms
(independent of hemolysis)
Hill A et al. Blood. 2013
Thrombosis in Tests used to identify bood clots in
PNH
PNH
• Blood clots in the arms and lower extremity (deep vein thrombosis):
duplex ultrasound
• Blood clots in the lungs (Pulmonary embolism): Spiral CT of the chest, CT
pulmonary angiography, pulmonary angiography, D-dimer,
Echocardiography, Troponin T, Brain natriuretic peptide
• Blood clots in the head (Central vein occlusion, strokes): CT scan or MRI of
the head
• Blood clots in the abdomen: US with flow or CT-scan of the abdomen/
pelvis
• Blood clots in the heart (Angina or heart attack): EKG and cardiac enzymes
Thrombosis in
PNH
Management of an acute/ recurrent
thrombotic episode
• Early management:
• Start anti-coagulation in the form of unfractionated heparin or low molecular
weight heparin (enoxaparin)
• Maintenance with Coumadin
• No data on the use of newer anti-coagulants in patients with PNH
• Long Term management:
• Consider initiating eculizumab therapy
Thrombosis in
PNH
Management of Thrombosis
prophylaxis
• Prophylactic Coumadin (but risks and benefits must be carefully
weighed)
• There is no clear consensus on whether eculizumab should be started
just on the premise of thrombosis prophylaxis
• Can we safely stop anti-coagulation in a patient who had a history of
blood clots
Treatment in
PNH
Management of Hemolysis and
anemia
Brodsky R A Blood 2009;113:6522-6527
Treatment in
PNH
Eculizumab therapy
(mechanism of action)
Brodsky R A Blood 2009;113:6522-6527
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26
27
28
29
30
Treatment in
PNH
Eculizumab therapy
(Important reminders while on therapy)
Recommendation for Persons Aged 2 Through 54 Years with Reduced Immune
Response (ACIP guidelines 2010)
Data indicate that the immune response to a single dose of meningococcal conjugate vaccine
is not sufficient in persons with certain medical conditions. Persons with persistent
complement component deficiencies (e.g., C5--C9, properidin, factor H, or factor D) or
asplenia should receive a 2-dose primary series administered 2 months apart and then
receive a booster dose every 5 years. Adolescents aged 11 through 18 years with HIV
infection should be routinely vaccinated with a 2-dose primary series. Other persons with HIV
who are vaccinated should receive a 2-dose primary series administered 2 months apart. All
other persons at increased risk for meningococcal disease (e.g., microbiologists or travelers
to an epidemic or highly endemic country) should receive a single dose.
Advisory Committee on Immunization Practices 2010.
Adverse Reactions Reported in ≥ 5% of
SOLIRIS® Treated Patients in TRIUMPH
Patients, n (%)
Reaction
SOLIRIS®
(n=43)
Placebo
(n=44)
Headache
19 (44)
12 (27)
Nasopharyngitis
10 (23)
8 (18)
Back pain
8 (19)
4 (9)
Nausea
7 (16)
5 (11)
Fatigue
5 (12)
1 (2)
Cough
5 (12)
4 (9)
Herpes simplex virus infections
3 (7)
0
Sinusitis
3 (7)
0
Respiratory tract infection
3 (7)
1 (2)
Constipation
3 (7)
2 (5)
Myalgia
3 (7)
1 (2)
Pain in extremity
3 (7)
1 (2)
Influenza-like illness
2 (5)
1 (2)
SOLIRIS® (eculizumab) [package insert]. Alexion Pharmaceuticals; 2009.
32
Treatment in
Management of Bone Marrow Failure
PNH
• Aplastic Anemia is a rare bone marrow failure syndrome
• PNH and Aplastic Anemia can occur together in the same patient
either at the original time of diagnosis or with PNH preceding the
diagnosis of Aplastic Anemia or developing later in a patient with
Aplastic Anemia
• The co-occurrence of PNH and Aplastic Anemia can complicate the
natural history of PNH and management
Overview
Epidemiology of AA
•
•
Diagnosis of AA
2-4 per 1 million individuals per year
(US)
2-3 fold higher in Asia
•
•
•
Hypocellular bone marrow (<30%)
cytopenias
normal karyotype by metaphase cytogenetics
(In general)
Decision to treat - Based on Disease Severity
Moderate AA
Severe AA
Very Severe AA
1) <30% BM cellularity
1) <30% BM cellularity
And depressed counts but did not
reach criteria for severe AA
And at least 2 of the ff:
And at least 2 of the ff:
Subset
Chronic moderate AA: >3 months
1)
2)
3)
1)
<30% BM cellularity
ANC <0.5 x 109/L
Plt count <20 x 109/L
Retic count <60 x 109/L
Needs Treatment
?
1) ANC <0.2 x 109/L
2) Plt count <20 x 109/L
3) Retic count <60 x 109/L
Needs Treatment
Natural Disease History by Disease Severity without treatment
sAA and vsAA
Moderate AA
0
1
2
3
Camitta B et al. Blood. 1976
Bacigalupo A et al. BJH 1988
4
5
6
7
Gluckman et al. BJH, 1982
8
9
10
Overview
How to treat AA?
Severe AA or Very Severe AA
Age <40 years old
With Matched Sibling Donor
Bone Marrow Transplant
Age ≥40 years old
No Matched Sibling Donor
Immunosuppression
Non-Transplant Pharmacologic
Treatments (sAA)
Anti-Thymocyte Globulin/ Anti-Lymphocyte Globulin
•
Polyclonal purified IgG fraction of sera
from animals like rabbit, horse or
rarely goats that are immunized with
human thymocytes or T cell lines
•
Mainstay in the treatment of severe AA
or very severe AA
•
Combined with cyclosporine or
tacrolimus for the treatment of AA
•
Results in 70-80% overall response
rate in the frontline setting
•
Can be used in the salvage setting
•
Available as rabbit or horse
Thymus
T cell Lines
Polyclonal IgG
T cells
B cells
Monocytes
Dendritic
Cells/ APCs
Mohty M & Gaugler B. Leuk & Lymph 2008
ATG + Cyclosporine
G
A Mechanism of Action
B
Virus
Stem cells
CD28
TCR
Stem cells
T cells
APC
Virus
Cell-Cell Contact
Unknown Antigens
Virus
Calcineurin
Inhibitors
•Cyclosporine
•Tacrolimus
Treatment Options
C
D
T cell
Activation
Stem cells
Effector Mechanisms
Cellular Damage
Depleting Agents
• ATG/ALG
E
F
IL-2, IL-4, IL-6
IL-1, IL-6
Naïve
T cells
Cytokine Release
Activated
T cells
T cell
Effector
Differentiation T cells
T cell
Expansion
Expanded Effector
T cells
Non-Transplant Pharmacologic
Treatments (sAA)
How can we improve these results?
How
100can we improve these results?
Strategies Employed
100
75
ATG + CsA
70-80%
75
1) Use a different ATG
90%
50 CsA
ATG
% +
60-80%
ATG Alone
2) Add Additional Agents
25
40-50%
%
50
~35%
3) Use a completely different
~58%
Agent/ Pathway
~10-15%
0
Response
Rate
ATG Alone
Relapse
Rate
Clonal
Evolution
Overall
Survival
25
40-50%
~35%
~6-15%
0
4 Goals in sAA
Treatment
11 year follow-up
Response
Rate
Relapse
Rate
Clonal
Evolution
Overall
Survival
Frickhofen N et al. Blood. 2003
Other Long term
complications in
PNH
Clonal evolution to MDS/AML
• A fairly sizable proportion of patients with aplastic anemia may later
develop PNH (20-40%).
• Patients with PNH may often have bone marrow failure and some will
develop aplastic anemia.
• Patients with PNH may develop myelodysplastic syndrome and or
acute myelogenous leukemia (<5%).
• Patients with MDS may have a small PNH clone present and these
patients may respond better to immunosuppressive therapy with ATG
and/or cyclosporine.
Updates in
PNH
New information on disease
pathogenesis
• Genetic Variants in C5 lead to poor response to eculizumab in PNH
• 345 Japanese patients (11 had poor response)
• All 11 had a single missense C5 heterozygous mutation c2654GA
predicting for a ;olymorphism pArg885His
• Cannot undergo eculizumab blockade
Nishimura JG et al. NEJM 2014
Updates in
PNH
New therapies on the horizon
Compstatin/ Peg cp40
• A peptidic C3 inhibitor
• A 13 residue cyclic peptide that specifically binds to C3 and C3b
• Smaller protein molecule so has less likelihood of promoting antigenicity
• Demonstrates dose dependent inhibition of hemolysis and opsonization
• Impairs all initiation, amplification and terminal pathway of complement
Risitano A et al. Blood. 2013
Updates in
PNH
New therapies on the horizon
TT30
• It is a novel recombinant protein that is designed to control both intravascular and
extravascular hemolysis of PNH RBCs.
• It is a 65 kDa fusion protein consisting of the iC3b/C3dg-binding domain of
complement receptor 2 (CR2; ie, the short consensus repeats [SCRs] 1-4), and the
CAP inhibitory domain of factor H (fH; ie, SCR1-5), a complement inhibitor present in
human blood whose primary role is to control fluid phase tickover
• fH selectively inhibits the activation of CAP and the CAP C3 convertase, without
affecting complement activation and C3 convertase activity arising from the classic
pathway (CCP) and mannose/lectin (CMP) pathway.
• fH both prevents formation and promotes the decay of the CAP C3 convertase and
also prevents its formation by acting as a cofactor with factor I (fI) to cleave C3b into
the inactive fragment iC3b.
Risitano A et al. Blood. 2012
Complement cascade modulation on normal and PNH RBCs, with or without complement
inhibitors.
Risitano A M et al. Blood 2012;119:6307-6316
©2012 by American Society of Hematology
Other issues
in PNH
Pregnancy
• 23 women: 19 with PNH, 4 with AA/PNH
• 38 pregnancies
• 11 miscarriages
• Pregnancy: 6 hemolysis, 6 hemorrhage
• Labor:
5 hemolysis, 3 hemorrhage, 1 thrombosis, 1 sepsis
• No maternal deaths
• Uncomplicated in one-third of pregnancies
De Gramond et al., Lancet 1987;1:868
Other issues
in PNH
Surgery
 Use of blood thinners for a short period of time after completing surgeries
that puts patients at high risk for blood clots (e.g. hip surgeries, knee
surgeries).
 Certain patients with PNH accompanied by aplastic anemia may have lower
ability to compensate for blood loss that occurs as part of the surgery and
therefore close monitoring of counts and administration of appropriate
transfusions may be necessary
 In a case of a patient who is undergoing cardiac surgery where
extracorporeal machine is used. G-CSF administration and red blood pack
transfusions, perioperative platelet substitution, fluid management, and
antibiotic prophylaxis were utilized successfully
1.
Knobloch K et al. Interactive Cardiovascular and Thoracic Surgery. 2003; 2(4):647-649.
Conclusions
 PNH patients are at risk for thrombosis
 Eculizumab can decrease thrombotic events. Blood thinners are used to treat
blood clots and can be used to prevent blood clots in certain circumstances
 Other potential long term problems in PNH includes kidney damage, hemolysisassociated pulmonary HTN, pain symptoms, fatigue, development of AA or MDS
 It is important to discuss with your PNH specialist any plans for pregnancy and
surgery.
 The treatment for PNH has improved significantly over the years and this has lead
to better outcomes and quality of life.
 There are a lot of new advances in the field of PNH that may lead to better
therapies in the future
THANK YOU