1. PAROXYSMAL
NOCTURNAL
HEMOGLOBINURIA
Dr.Fariha Saleem

2. PAROXYSMAL
NOCTURNAL
HEMOGLOBINURIA
Dr.Fariha Saleem

3. Outline:
 Introduction
 Pathogenesis
 Clinical features and complications
 Investigations
 Treatment

4. Introduction:
 PNH is a clonal non-malignant hematological
disease characterized by the expansion of
hematopoietic stem cells and progeny
mature cells, whose surface lack all the
proteins linked through the glycosyl-
phosphatidyl inositol anchor.
 Acquired somatic mutation in the X- linked
phosphatidylinositol glycan class A gene.

5. PNH
Hemolytic
anemia
Thromboe
mbolism
Bone
marrow
failure

6. History:
 Investigator Year Contribution
 Gull 1866 Described nocturnal and paroxysmal nature of
“intermittent haematinuria” in a young man.
 Strubing 1882 Distinguished PNH from paroxysmal cold
haemoglobinuria and march haemoglobinuria.
Attributed the problem to the red cells.
 van den Burgh 1911 Red cells lysed in acidified serum. Suggested a role
for complement.
 Enneking 1928 Coined the name “paroxysmal nocturnal
haemoglobinuria”.
 Marchiafava 1928- Described perpetual hemosiderinemia.
 and Micheli 1931 Their names became eponymous for PNH
in Europe.
 Ham 1937- Identified the role of complement in lysis of PNH red
 1939 cells. Developed the acidified serum test, also called
the Ham test, which is still used to diagnose PNH.
Demonstrated that only a portion of
PNH red cells are abnormally
sensitive to complement.
 Davitz 1986 Suggests defect in membrane protein anchoring
system responsible
 Hall & Rosse 1996 Flow cytometry for the diagnosis of PNH

7. Epidemiology:
 Rare disease.
 Incidence of PNH in UK = 1.3 newly diagnosed
patients per million per year.
 Observed in all ages but most common in young
adults.
 No evidence of family clustering.

8. Pathophysiology

9. Two kinds of membrane proteins: transmembrane and glycosyl
phosphatidyl inositol (GPI)-linked. The latter are anchored to cell
membranes through a covalent attachment to a glycosyl phospatidyl
inositol moiety. In PNH, GPI cannot be synthesized, leading to a global
deficiency of GPI-linked membrane proteins

10. GPI – anchor:
 GPI (Glycosylphosphatidylinositol)-anchor is a
glycolipid consisting of phosphatidylinositol
(PI), glucosamine (GlcN), mannose (Man) and
ethanolaminephosphate (EtNP).
 Acts as a lipid anchor for various plasma-
membrane proteins.

13.  Synthesis of
Glycosylphosphatidylinositol (GPI)
Anchor
 Synthesized in the endoplasmic reticulum.
 Transferred en bloc to the carboxyl terminus of a
protein that has a GPI-attachment signal
peptide.
 Involves at least 10 reactions and more than 20
different genes.

14.  Synthesis of GPI Anchor: (cont.)
 The first step in GPI anchor biosynthesis is the transfer of
N-acetylglucosamine (GlcNAc) from uridine 5′ diphospho-N-
acetylglucosamine (UDPGlcNAc) to phosphatidylinositol
(PI) to yield GlcNAc-PI.
 This step is catalyzed by GlcNAc:PI α1-6 GlcNAc
transferase, an enzyme whose subunits are encoded by 7
different genes: PIG-A, PIG-C, PIG-H, GPI1, PIG-Y, PIG-P
and DPM2.
 The core is modified with side groups during or after
synthesis.
 The GPI anchored proteins then transit the secretory
pathway to reach their final destination at the plasma
membrane where they reside in 50 to 350-nm

16. Biosynthesis of GPI-anchored proteins
GPI-anchored biosynthesis takes place in the endoplasmic reticulum. PIG-A is one of 7 genes
required for the first step, the transfer of N-acetylglucosamine (GlcNAc) from uridine 5′-
diphospho-N-acetylglucosamide (UDP-GlcNAc:PI ) to phosphatidylinositol (PI) to yield
GlcNAc-PI. After synthesis of the mature GPI precursor, the cognate protein is attached and
then transported to the plasma membrane where the GPI-anchored protein resides in
membrane rafts. PIG-A mutations lead to a defect in the first step in GPI anchor biosynthesis
resulting in intracellular degradation of the cognate protein and a lack of cell surface GPI
anchored proteins.

17.  Failure to synthesize a mature GPI anchor causes the
cognate protein to be degraded intracellularly and
results in an absence of all GPI anchored proteins
from the cell surface.
 To date, all PNH patients have been shown to have
genetic mutations in PIG-A gene located on short arm
of Ch X. (band Xp22)
 More than 180 mutations identified, majority of which
are small insertions/deletions producing frameshifts,
nonsense mutations. Only 2 large deletions identified.
 The remaining mutations are missense or small in-
frame deletions.

18. Schematic representation of the structure and
mutations in the PIGA gene:

23. GPI Linked Proteins:
Rosti, Haematologica, 2000

25. The Role of Complement in
Intravascular Hemolysis:
 PNH red cells are more vulnerable to
complement-mediated lysis due to a
reduction, or complete absence, of two
important GPI-anchored, complement
regulatory proteins. (CD55 and CD59)
 CD59 is a 19,000 molecular weight
glycoprotein that directly interacts with the
membrane attack complex (MAC) to
prevent lytic pore formation by blocking the
aggregation of C9.

26.  CD55, a 68,000 molecular weight glycoprotein,
controls early complement activation by
inhibiting C3 and C5 convertases.
 Of the two, CD59 is more important in
protecting cells from complement.
 All three cell lines are effected by the mutation
but only RBCs are the one to suffer hemolysis.

27. The Role of Complement in
Intravascular Hemolysis:

28. Consequences of Chronic Hemolysis and Free
Hemoglobin:
1. International PNH Interest Group. Blood. 2005;106:3699-3709. 2. Brodsky R Paroxysmal Nocturnal Hemoglobinuria. In: Hematology - Basic Principles
and Practices. 4th ed. R Hoffman; EJ Benz; S Shattil et al, eds. Philadelphia, PA: Elsevier Churchill Livingstone; 2005;419-427. 3. Rother RP et al. JAMA.
2005;293:1653-1662. 4. Socie G et al. Lancet. 1996;348:573-577. 5. Hill A et al. Br J Haematol. 2007;137:181-92. 6. Lee JW et al. Hematologica 2010;95
(s2):Abstract #505 and 506. 7. Hill A et al. Br J Haematol. 2010; May;149(3):414-25. 8. Hillmen P et al. Am. J. Hematol. 2010;85:553-559.
Thrombosis
Fatigue
Renal Failure
Abdominal Pain
Dyspnea
Dysphagia
Hemoglobinuria
Erectile Dysfunction
Normal red blood cells
are protected from
complement attack by
a shield of terminal
complement inhibitors
Without this protective
complement inhibitor
shield, PNH red blood
cells are destroyed
Intact RBC
Complement
Activation
Significant
Impact on
Survival
Significant
Impact on
Morbidity
Free Hgb/Anemia
Pulmonary Hypertension
NO↓

29. Nitric oxide scavenging in PNH:
 Nitric oxide is a major regulator of vascular
physiology and many clinical manifestations of PNH
are readily explained by depletion of nitric oxide at the
tissue level.
 Free hemoglobin in the plasma has enormous affinity
for nitric oxide and serves as a potent nitric oxide
scavenger.
 Haptoglobin is one compensatory mechanism for free
hemoglobin removal, but the concentration of plasma
hemoglobin in PNH exceeds the capacity of
haptoglobin to remove the hemoglobin from the
plasma.

30. Nitric oxide scavenging in PNH
Under normal conditions (A) Nitric oxide synthase (NOS) combines with oxygen (O2) and arginine
to form nitric oxide (NO) and citrulline. (B) Intravascular hemolysis releases free hemoglobin
into the plasma. Oxygen bound Fe2+ from free hemoglobin enters the plasma and converts NO
to inert nitrite and oxidizes hemoglobin to methemoglobin. In addition, intravascular hemolysis
releases erythrocyte arginase, which depletes arginine, the substrate for NOS. Depletion of NO
at the tissue level leads to many of the symptoms of PNH including smooth muscle dystonias.

31. Thrombosis:
 Thrombosis is an ominous complication of PNH
and leading cause of death from the disease.
 Occurs in about 40% of PNH patients and
predominantly involves the venous system.
 Patients with PNH granulocyte clones of greater
than 60% appear to be at greatest risk for
thrombosis.

32.  Mechanism of thrombosis in PNH :
 Nitric oxide depletion has been associated with
increased platelet aggregation, increased platelet
adhesion and accelerated clot formation.
 In an attempt to repair complement-mediated
damage, PNH platelets undergo exocytosis of the
complement attack complex.
 This results in the formation of microvesicles with
phosphatidylserine externalization, a potent in vitro
procoagulant. These prothrombotic microvesicles have
been detected in the blood of PNH patients.

33.  Mechanism of thrombosis in PNH :
(cont.)
 Fibrinolysis may also be perturbed in PNH given that
PNH blood cells lack the GPI anchored urokinase
receptor.
 Tissue factor pathway inhibitor (TFPI), a major inhibitor
of tissue factor, has been shown to require a GPI
anchored chaperone protein for trafficking to the
endothelial cell surface.

34. Effect of GPI- AP deficiency on blood cell
populations:

35. Sites of thrombotic events in
haemolytic PNH:
Blood 2007;110:4123– 8. © American Society of

36. Clonal evolution and cellular
selection:
 ‘ESCAPE THEORY’ of PNH:
 Expansion of abnormal hematopoietic stem cell required
for PNH disease expression.
 In vitro growth studies, demonstrate that there are no
differences in growth between normal progenitors and
PNH phenotype progenitors.
 Close association with AA - PNH hematopoitic cells
cells may be more resistant to the immune attack than
normal hematopoitic cells.
 Evidence in AA is that the decrease in hematopoitic
cells is due to increased apoptosis via cytotoxic T
cells by direct cell contact or cytokines (escape via
deficiency in GPI linked protein???)

37. The dual pathophysiology theory:

39. Bone Marrow Failure Occurrence of PNH blood cells
Anemia
Infections
Gallstones
Bleeding
Inappropriate complement
activation
Extravascular Hemolysis
Low blood cell counts
Blood Clot
Abdominal pain
Bloating
Back pain
Headache
Erectile dysfunction
Esophagospasm
Fatigue
Hemoglobinuria
Kidney failure
Intravascular Hemolysis
The Mechanisms of Disease in PNH

40. Classification of PNH:
Classification of PNH
A Classic PNH
B PNH in the presence of another specified bone marrow
disorder (e.g. PNH/AA or PNH/refractory anemia-MDS)
C PNH sub clinical (PNH-sc) in the setting of another specified
bone marrow disorder (e.g., PNH-sc ⁄ AA)

41. Classification of PNH:
Category Hemolysis GPI - clone Bone marrow
Classical +++ large Erythroid
hyperplasia and
normal or near
normal
morphology
PNH in the
presence of
another specified
bone marrow
disorder
+/++ variable Defined underline
marrow
abnormality
sub clinical - Small population Defined underline
marrow
abnormality

42. Clinical features:
 Fatigue due to anemia. (mild to severe)
 Passing of (very) dark colored urine.
 Attacks of abdominal pain associated with
either diarrhea or constipation.
 Recurrent dysphagia.
 Erectile dysfunction.
 May present as a case of Aplastic Anemia
(AA)

43. Common Symptoms in Patients With PNH:
1. Meyers G et al. Blood. 2007;110(11):Abstract 3683.3. 2. Hill A et al. Br. J. Hematol. 2010;149(3):414-425. 3. Hillmen P et al. Am. J. Hematol. 2010; 85:553-559. 4. International PNH Interest Group. Blood.
2005;106(12):3699-3709. 5. Hillmen P et al. N Engl J Med. 1995;333:1253-8. 6. Nishimura J et al. Medicine. 2004;83(3):193-207.
41% Dysphagia1
47% Pulmonary Hypertension2
66% Dyspnea1
57% Abdominal Pain1
64% Chronic Renal Insufficiency3
47% Erectile dysfunction1
26% Hemoglobinuria4
40% Thrombosis5
89% Anemia6
96% Fatigue, Impaired QoL1
PNH Symptom Incidence Rate (%)

44. Examination findings:
 Pallor.
 Mild jaundice.
 Deep palpation abdominal tenderness.
 Hepatosplenomegaly (rare) : usually occur
when there is thrombosis in the hepatic
vein (Budd-Chiari syndrome) splenic or in
the portal vein.

45. Complications of PNH:
Chronic Kidney Disease
 Renal insufficiency
 Dialysis
 Hypertension
End Organ Damage
 Brain
 Liver
 GI
Anemia
 Transfusions
 Hemosiderosis
Fatigue / Impaired
Quality of Life
 Abdominal pain
 Dysphagia
 Poor physical functioning
 Erectile dysfunction
Pulmonary Hypertension
 Dyspnea
 Cardiac Dysfunction
Thrombosis
Venous
 PE/DVT
 Cerebral
 Dermal
 Hepatic/Portal
 Abdominal ischemia
Arterial
 Stroke/TIA
 MI
1. International PNH Interest Group. Blood. 2005;106:3699-3709. 2. Brodsky R. Paroxysmal Nocturnal Hemoglobinuria. In: Hematology - Basic Principles and Practices. 4th ed. R
Hoffman; EJ Benz;S Shattil et al, eds. Philadelphia, PA: Elsevier Churchill Livingstone; 2005; p. 419-427. 3. Hillmen P et al. N Engl J Med. 1995;333:1253-1258. 4. Rosse W et al.
Hematology (Am Soc Hematol Educ Program). 2004:48-62. 5. Rother R et al. JAMA. 2005;293:1653-1662. 6. Socie G et al. Lancet. 1996;348:573-577. 7. Hill A et al. Br J Haematol.
2007;137:181-92. 8. Lee JW et al. Hematologica 2010. 95 (s2): Abstract #505 and 506. 9. Hill A et al. Br J Haematol. 2010; May;149(3):414-25. 10. Hillmen P et al. Am. J. Hematol.
2010; 85:553–559.

46. Chronic Kidney Disease:
Renal failure: cause of death in 8% to 18% of patients with PNH2
Renal insufficiency prevalence in PNH is 6.6x higher than reported for the general
population1,3
80% of patients with PNH had renal hemosiderosis (median age 32)4
1. Hillmen P, Elebute MO, Kelly R, et al. [ASH abstract]. Blood. 2007;110: Abstract 3678.
2. Nishimura J-I, Kanakura Y, Ware RE, et al. Medicine. 2004;83:193-207. 3. Stevens LA, Coresh J, Greene T, Levey AS. N Engl J Med. 2006;354:2473-
2483. 4. Hill A, Reid SA, Rother RP, et al. [ASH abstract]. Blood. 2006;108: Abstract 979.
64% of Patients With PNH Have Chronic Kidney Disease (CKD)1

47. 47
Chronic
Kidney Disease
Acute Renal Failure
Pulmonary Hypertension
Cardiac
Dysfunction
Stroke / TIA
Ischemic Bowel
DVT
Hepatic Failure
Signal the Underlying Threat of Catastrophic Consequences
Common Symptoms of Hemolysis
FatigueImpaired QoL
Anemia
HemoglobinuriaDyspnea
Dysphagia
Abdominal Pain
Erectile Dysfunction

48. Diagnosis of PNH

49. Who should be screened for
PNH?
 Patients with hemoglobinuria.
 Patients with Coombs-negative intravascular hemolysis , especially
patients with concurrent iron deficiency.
 Patients with venous thrombosis involving unusual sites:
 Budd-Chiari syndrome
 Other intra-abdominal sites (eg, mesenteric or portal veins)
 Cerebral veins
 Dermal veins
 Patients with aplastic anemia (screen at diagnosis and once yearly
even in the absence of evidence of intravascular hemolysis)
 Patients with refractory anemia-MDS.
 Patients with episodic dysphagia or abdominal pain with evidence of
intravascular hemolysis.

50. Laboratory findings:
 Urine : hemoglobinuria.
 Anemia : may be normocytic or macrocytic on
the account of reticulocytosis.
 If MCV is normal rather high, there probably is
superimposed iron deficiency.
 Neutrophills : range from normal to below 1 x
109/L.
 Platelets : range from normal to below 20 x
109/L.
 Lymphocytes : normal count, lymphopenia or
increase in large granular lymphocytes.

51.  LDH : markedly increased.
 Haptoglobin : markedly decreased.
 Serum iron and transferrin saturation index :
may be decreased.
 Serum ferritin : might be normal.
 Coomb’s test : negative.
 Bone marrow aspirate and trephine: may be
cellular with erythroid hyperplasia or
hypoplastic or MDS-like changes in one or
more cell lineages.

52. Diagnostic Tests:
 Complement based tests
 Acidified-serum lysis test (Ham test)
 Sucrose lysis test
 Flow cytometry

53. Thomas Hale Ham (1905-1987)
7th President of the
American Society of Hematology
Acidified-Serum Lysis
test (Ham Test)
 Principle:
 The patient’s red cells are exposed
at 37*C to the action of normal or
patient’s own serum suitably
acidified to the optimum pH for
lysis (pH 6.5 – 7.0)
 First described in 1937
 Patient’s red cells can be obtained
from defibrinated, heprainized,
oxalated, citrated or EDTA blood
but the best is by defibrination.

54. The Acidified-serum lysis test with added magnesium
Test (ml) Controls (ml)
Reagent 1 2 3 4 5 6
Fresh Normal serum 0.5 0.5 0 0.5 0.5 0
Heat-inactivated normal serum 0 0 0.5 0 0 0.5
0.2 mol/L HCl 0 0.05 0.05 0 0.05 0.05
50 % patient’s red cells 0.05 0.05 0.05 0 0 0
50 % normal red cells 0 0 0 0.05 0.05 0.05
MgCl (250 mmol/L; 23.7 g/L) 0.01 0.01 0.01 0.01 0.01 0.01
Lysis (in a positive modified test) Trace
(2%)
+++
(30%)
- - - -

55. PNH Control
S HS S HS
PNH patient
Diagnosis of PNH by the Ham
Test:

56.  Ham Test : (cont.)
 Three populations of red cells are
demonstrated
 Type III cells:
10 – 15 times more sensitive than normal
cells.
 Type II cells :
Medium sensitivity, 3 – 5 times more
sensitive than normal cells.
 Type I cells :

57.  Sensitivity of Ham test:
 Reasonably good at estimating the proportion of
PNH red cells, if they are PNH type III cells and
comprise less than 20% of the total.
 In cases in which the PNH cells are type II and more
than 20% are present, the standard Ham test
significantly underestimates the proportion of PNH
red cells.
 The standard Ham test can be negative when there
are less than 5% PNH type III cells or less than 20%
PNH type II cells.
 With supplementation of Ham tset with
magnesium, the percentage lysis gives a more
accurate estimation of the proportion of PNH cells.

58.  Significance of the Acidified-Serum
Lysis Test:
 Positive Ham test:
 PNH.
 False-positive acidified-serum test:
 congenital dyserythopoietic anaemia type
II.
 Positive test in inactivated serum:
 Markedly spherocytic red cells.

59. Sucrose Lysis Test:
 Principle:
 Red cells absorb complement components from
serum at low ionic concentrations. PNH cells,
because of their greater sensitivity, undergo lysis
but normal red cells do not.
 An iso-osmotic solution of sucrose (92.4g/l) is
required.
 In PNH, lysis usually varies from 10% - 80%.
 Sucrose lysis test can be positive in other
conditions like megaloblastic anemia,
autoimmune haemolytic anemia, myelofibrosis,
leukaemia.

60. Flow Cytometric analysis of GPI-
linked Proteins:
 Flow cytometry is a rapid, sensitive and
reproducible diagnostic tool for the
detection of PNH clones in different
peripheral blood cell populations.
 It was first described in 1985
 ‘Gold Standard’ for diagnosis of PNH

61.  Analysis of RBCs by flow cytometry:
 Quantitation of at least 2 GPI-APs is
recommended to exclude the possibility that the
clinical process is a consequence of an
inherited, isolated deficiency of a single GPI-AP.
 CD59 expression is stronger on RBCs than
CD55 and hence CD59 gives much better
separation of different types of cells.
 Analysis ideally should be performed prior to
transfusion or during a period of transfusion
abstinence.

62. IIIIIIIII III
Counts
CD59
I
Flow Cytometric Analysis of Red Blood Cells
PNH
PNH I PNH IIPNH I + III PNH I + II + III
PNH PNH

63. Testing for PNH in Red Blood Cells:
GPA = glycophorin A.
Data Source - Dahl-Chase Diagnostic Services.
RBC’s with normal CD59 expression
(Type I cells)
clone with complete
CD59 deficiency (Type III cells) and
partial CD59 deficiency
(Type II cells)
clone with complete CD59
deficiency
(Type III cells)
Gating on GPA+ RBC’s

66.  Analysis of Granulocytes:
 In contrast to GPI-AP-deficient red cells, the life
span of PNH granulocytes is normal. So, the
proportion of abnormal granulocytes more
accurately reflects the PNH clone size and is
unaffected by red cell transfusion.
 CD55 is better than CD59 on granulocytes as
against RBCs.
 Other proteins include CD16, CD24, CD55, CD59
and CD67.

67. Flow cytometric analysis of granulocytes in
PNH using a combination of anti-CD15 FITC,
anti-CD24 PE, and anti-CD16 PE:

68. Diagnosis and management of paroxysmal nocturnal hemoglobinuria, blood-2005-
 Recommendations for flow cytometric analysis
in diagnosis and management of PNH:
 For patients with clinical evidence of
hemolysis (classic PNH and PNH/aplastic
anemia)
 At diagnosis, flow cytometric analysis of both
erythrocytes and granulocytes is recommended.
 After establishment of the diagnosis, flow cytometric
analysis is recommended every 6 months for 2
years and yearly thereafter if the parameters are
stable.
 If there is evidence of clinical progression (or
amelioration), more immediate analysis should be
performed.

69. Diagnosis and management of paroxysmal nocturnal hemoglobinuria, blood-2005-04-
1717
 Recommendations for flow cytometric
analysis: (cont.)
 For patients with aplastic anemia or refractory
anemia-MDS without clinical evidence of
hemolysis
 At diagnosis, analysis of erythrocytes and
granulocytes using high-sensitivity flow cytometry.
 Every year, even in the absence of clinical evidence
of hemolysis (including patients treated with
immunosuppressive therapy).

70. FLAER:
 An alternative flowcytometric approach.
 This assay utilizes Aerolysin, the toxin of the
bacterium Aeromonas hydrophila, which binds
directly to the GPI anchor. It is secreted as an
inactive protoxin, proaerolysin, that is converted to
the active form, through proteolytic removal of a C-
terminal peptide. Aerolysin, thus generated binds to
cell surface structures and oligomerizes, forming
channels that result in cell lysis.

71.  Initially, this reagent was used to demonstrate the
resistance of PNH erythrocytes to aerolysin and also
to enrich GPI-negative PNH cells
 Two point mutations were introduced to obtain a
protein that still binds GPI upon activation but lacks
lytic activity.
 By coupling this mutant proaerolysin to a fluorescent
marker (Alexa Fluor 488), a reagent (FLAER) was
produced that stains cells containing GPI proteins but
not PNH cells lacking GPI. As this reagent detects
the GPI anchor itself, it can be used to investigate
all peripheral blood cell types except
erythrocytes, which do not express the

72. Display of FLAER vs CD24 in three PNH
patients:

73. A multiparameter gating strategy for
granulocytes and monocytes:

74. Multiparameter Flow Cytometry analysis of peripheral blood in PNH. (A-D) Aplastic anemia patient
with small (2%) PNH clone; (E-H) classic PNH patient. (A,E) Forward scatter (FSC)/side scatter (SSC)
display showing initial gate to exclude lymphocytes and debris. (B,F) Granulocytes (green) are identified
as bright CD15 and low CD33, whereas monocytes (blue) are bright CD33 and low CD15. (C,G) Population
of GPI anchor protein–deficient granulocytes showing lack of staining with both anti-CD24 and FLAER.
(D,H) Population of GPI anchor protein–deficient monocytes showing lack of staining with both anti-CD14
and FLAER.

75. PNH Patient With an 80% WBC Clone Size and
31% RBC Clone Size Indicating Hemolysis:
Data Source - Dahl-Chase Diagnostic Services.
CD24-Granulocytes
FLAER- GPI Anchor Binding Marker CD59 – GPI Anchored Protein
80.1 % of Granulocytes lack GPI proteins 31.4% RBCs are Type III PNH cells
WBC RBC

76. Antibodies Useful in PNH
Testing:

77. Comparison between FLAER and immunophenotyping for the
diagnosis of PNH
FLAER Immunophenotyping using monoclonal
antibodies against GPI-AP
Sensitive as a single agent and hence
more
economical as screening test
At least two antibodies required
Detection of PNH clone only on leukocytes Detection of PNH clone on all peripheral
blood cells
Better separation of Type I, II, and III cells
on granulocytes
Separation of Type I, II, and III cells on
granulocytes is not always clear
Better estimation of clone size on
granulocytes and monocytes and hence
useful for estimation of small clone of
granulocytes in AA and MDS using
multiparametric assay
Essential for estimation of clone size on
RBCs and monitoring of RBC clone size in
patients on Eculizumab therapy
More robust assay for detection of clone on
granulocytes, can be performed on
samples stored up to 48 h
Analysis on granulocyte needs to be
performed within 8 h of collection, but
analysis on RBCs can be done in samples
stored up to 21–30 d

78. MANAGEMENT OF PNH:
 Supportive:
 Management of haemolysis and anemia
 Management of thrombosis
 Management of marrow failure
 Curative:

79. Supportive management:
 Management of haemolysis and anemia
 Management of thrombosis
 Management of marrow failure

80.  Management of hemolysis and anemia:
 Corticosteroids
 Androgens – in the cases with marrow
impairment
 RBC transfusions
 Iron and folate supplementation

81.  Management of thrombosis:
 Propensity toward thrombosis appears roughly
proportional to the size of the PNH clone.
 The risk of thromboembolic disease appears higher in
white and African-American patients than in patients of
Asian/Pacific Island or Hispanic ancestry even when
adjusted for clone size.
 White and African-American patients with greater than
50% GPI-AP-deficient granulocytes who have no
contraindications are candidates for prophylactic
anticoagulation with warfarin.
 Patients with PNH who have experienced a
thromboembolic event should remain anticoagulated

82.  Management of thrombosis: (cont.)
 LWMH
 Warfarin
 Anti-platelet agents
 Fibrinolytic agents

83.  Management of marrow failure:
 Immunosuppressive therapy
 Antithymocyte/antilymphocyte globulin
 High dose prednisone
 Cyclosporin A
 Alemtuzumab

84. Curative strategies:
 Stem cell transplantation
 Inhibition of complement activation -
Eculizumab

85.  ALLOGENIC BONE MARROW
TRANSPLANTATION:
 Indications:
 Bone marrow failure
Decision on transplantation is based on
underlying marrow abnormality (eg aplastic
anemia)
 Major complication of PNH
Recurrent, life-threatening thromboembolic
disease
Refractory, transfusion-dependent hemolytic

86.  PNH-specific transplant-related
issues:
 The conditioning regimen of cyclophosphamide/ATG
is recommended for patients with PNH/aplastic
anemia.
 For patients with classic PNH, a more
myeloablative regimen is indicated.
 Additional investigation is required to define the role
of nonmyeloablative regimens.
 For syngeneic twin transplants, a myeloablative
conditioning regimen is recommended to prevent

87.  PNH-specific transplant-related issues:
(cont.)
 There are no PNH-specific adverse events
associated with transplantation; severe, acute
graft-versus-host disease (GVHD) occurs in
more than a third of the patients and the
incidence of chronic GVHD is roughly 35%.
 Overall survival for unselected PNH patients
who undergo transplantation using an HLA-
matched sibling donor is 50% to 60%.

88. Inhibition of terminal
complement activation:
Eculizumab :
 Eculizumab is a humanized monoclonal antibody
against C5 that inhibits terminal complement
activation.
 Prevention of C5 cleavage blocks the generation of
the potent proinflammatory and cell lytic molecules
C5a and C5b-9.
 C5 blockade preserves the critical immunoprotective
and immunoregulatory functions of upstream
components that culminate in C3b-mediated
opsonization and immune complex clearance.
 Most effective in Classical PNH.

89. Eculizumab was engineered to reduce immunogenicity and eliminate effecter function.
Human IgG2 and IgG4 heavy-chain sequences were combined to form a hybrid constant
region that is unable to bind Fc receptors or to activate the complement cascade.
Eculizumab exhibits high affinity for human C5, effectively blocking its cleavage and
downstream proinflammatory and cell lytic properties.

90. The complement cascade and
C5 blockade by Eculizumab:

91. Rationale for Eculizumab use in
PNH:

92. Extravascular hemolysis with
eculizumab therapy:

93. Eculizumab: (cont.)
 Treatment with eculizumab decreases or
eliminates the need for blood transfusions,
improves quality of life and reduces the risk of
thrombosis
 Two weeks before starting therapy, all patients
should be vaccinated against Neisseria
meningitides because inhibition of complement
at C5 increases the risk for developing
infections with encapsulated organisms,
particularly N meningitides and N gonorrhoeae

94. Eculizumab: (cont.)
 Dosage :
 I/V, 600 mg weekly for the first 4 weeks, then
900 mg biweekly starting on week 5
 Must be continued indefinitely because it does
not treat the underlying cause of the disease

95. Dosing Schedule of
Eculizumab:
Pretreatment Induction Phase Maintenance Phase
2 weeks
before induction
Week
→
1 2 3 4 5 6 7 8
9 and
every
2 weeks
thereafter
Neisseria
meningitidis
vaccination
SOLIRIS®
dose, mg
→
600 600 600 600 900 X 900 X 900

96. Eculizumab: (cont.)
 Indications for Therapy:
 No widely accepted evidence-based indications for
treatment.
 Eculizumab is usually for patients with disabling
fatigue, thromboses, transfusion dependence,
frequent pain paroxysms, renal insufficiency, or
other end-organ complications from disease.
 Watchful waiting is appropriate for asymptomatic
patients or those with mild symptoms.

97. Eculizumab: (cont.)
 Adverse Affects:
 Most common side effect is headache and it
occurs in approximately 50% of patients, after
the first dose or two, but rarely occurs thereafter.
 Neisserial sepsis is the most serious
complication of eculizumab therapy.
 0.5% yearly risk of acquiring Neisserial sepsis
even after vaccination.
 Patients should be revaccinated against N
meningitidis every 3 to 5 years after starting
treatment.

98. Eculizumab: (cont.)
 Monitoring patients on eculizumab:
 Symptomatic improvement within hours to days
after the first dose of eculizumab.
 Complete blood count, reticulocyte count, LDH, and
biochemical profile weekly for the first 4 weeks and
then at least monthly thereafter.
 LDH usually returns to normal or near normal within
days to weeks after starting eculizumab.
 Reticulocyte count usually remains elevated
because extravascular hemolysis persists and the
hemoglobin response is highly variable.

99.  In patients who are transfusion-dependent, a
marked decrease in red cell transfusions is
observed in virtually all patients, with more
than 50% achieving transfusion independence.
 Breakthrough intravascular hemolysis and a
return of PNH symptoms occur in less than 2%
of PNH patients treated with eculizumab.
 Infections might be a cause.

100. 86% Reduction in LDH:
TRIUMPH and SHEPHERD
P<0.001 at all measured time points.
Hillmen P et al. Blood. 2007;110(12):4123-8.
TRIUMPH placebo patients switched to SOLIRIS® after week 26.
All TRIUMPH patients entered the long-term extension study.
TRIUMPH – Placebo/Extension
TRIUMPH – SOLIRIS®/Extension
SHEPHERD – SOLIRIS®
LactateDehydrogenase(U/L)
0
500
1000
1500
2000
2500
3000
Time, Weeks
0 4 8 12 16 20 24 28 32 36 40 44 48 52
100% response after the
first dose

101. 73% Reduction in Mean Units
Transfused Across all Subgroups: TRIUMPH
*P<0.001.
†Transfusion data obtained during 12 months before treatment; values were normalized for a 6-month period.
1. Hillmen P et al. N Engl J Med. 2006;355;1233-1243. 2. Schubert J. Br. J Haematol. 2008;142(2):263-72.
Overall 4-14 15-25 >25
Pre-treatment Transfusion Strata†
Patients not on SOLIRIS® (n=44)
SOLIRIS (n=43)
*
*
*
*
(n=87) (n=30) (n=35) (n=22)
0
2
4
6
8
10
12
14
16
MedianUnitsTransfused
18
• 51% of SOLIRIS patients achieved transfusion independence vs 0% of patients not on SOLIRIS1
• Patients with concomitant bone marrow dysfunction may continue to require minimal transfusions

102. Patients Report Rapid and Sustained
Improvement Across Broad Range of
Measures
*P<0.05.
†P<0.001.
1. Brodsky R et al. Blood. 2006;108(11): Abstract 3770. 2. Data on file. Alexion Pharmaceuticals.
Moderate
Impact
Small
Impact
Large
Impact
StandardEffectSize(SES)
EORTC
Functioning
EORTC
Symptoms
FACIT-Fatigue†
EORTCFatigue†
GlobalHealth†
Physical†
Role†
Cognitive*
Dyspnea†
Pain*
Insomnia*
Constipation
Nausea
Diarrhea
0
0.2
0.4
0.6
0.8
1
1.2

103. 92% Reduction in Thrombotic
Events:
 63% of patients received concomitant anticoagulants1
 The effect of anticoagulant withdrawal was not studied2
 Events observed in both venous and arterial sites3
PI: There were fewer thrombotic events with SOLIRIS treatment than during the same period of time
prior to treatment.
1. Brodsky R et al. Blood. 2008;111(4):1840-47. 2. SOLIRIS® (eculizumab) [package insert]. Alexion Pharmaceuticals; 2009. 3. Hillmen P, et al. Blood.
2007;110:4123-4128.
39
3
0
5
10
15
20
25
30
35
40
45
Pre-SOLIRIS® Treatment SOLIRIS Treatment
ThromboticEvents(#)
P=0.0001
N=195

104. Eculizumab-Pro’s and Con’s
 Pro’s
 Very effective at
reducing hemolysis
 Well tolerated
 Improvements in
QOL, reduction in
transfusions proven
 Reduction in burden
of disease
 Probable reduction in
clots
 Con’s
 $$$$
 Infusion weekly X5,
then every 2 weeks
 Infection risk:
meningococcal
meningitis
 Burden of treatment
 Plan for lifetime
therapy
 Does not improve
other blood counts

105. Correction of CD59 deficiency:
 An alternative approach to the prevention of
hemolysis in PNH is to restore CD59
(membrane inhibitor of reactive lysis)
expression to the surface of the PNH red cells
and thus reestablish membrane complement
inhibitory activity
 In a recent study, a novel synthetically modified
recombinant human CD59 (rhCD59-P), a
soluble protein that attaches to cell membranes
was assessed for its ability to correct CD59
deficiency on PNH red cells both in vitro
(human red cells) and in vivo

106. In vitro treatment of PNH erythrocytes with rhCD59-P
resulted in levels of CD59 equivalent to normal
erythrocytes and effectively protected erythrocytes from
complement-mediated hemolysis

107. Clinical management of PNH:

108. Impact of PNH on Quality of
Life
59% patients were transfusion-free for at least 12 mo or had never been transfused
76% were forced to modify their daily activities to manage their PNH
17% were unemployed due to PNH
*Moderate to severe; N=29.
Meyers G et al. Blood. 2007;110 (11): Abstract 3683.
~75% of Patients Reported Symptoms as Moderate to Very Severe

109. Paroxysmal Nocturnal Hemoglobinuria:
A Chronic Disabling and Life-Threatening Disease
 5 year mortality: 35%1
 Quality of life
diminished2
 Progressive disease.
The expected survival of an age- and sex-matched control group is shown for
comparison (Hillmen et al 1995). In a patient population where ½ the patients
have <30% clone, 1 in 7 patients died by 5 years.
de Latour et al. Blood. 2008; 112: 3099-3106.
Years After Diagnosis
PatientsSurviving(%)
Actuarial Survival From the Time of
Diagnosis in 80 Patients With PNH1
100
80
60
40
20
0
0 5 10 15 20 25
Age- and Gender-
Matched Controls
Patients with PNH
1. Hillmen P et al. N Engl J Med. 1995;333:1253-1258. 2.Hill A et al. Br J Haematol. 2007;137:181-92.

110.  Poor prognostic factors:
 Development of thrombosis
 Progression to pancytopenia
 MDS or acute leukemia
 Age ≥ 55 years
 Thrombocytopenia at diagnosis
 Aplastic anemia antedating PNH

111. Future Research Topics:
 Many research questions still to be answered:
 Why do PNH cells survive immune mediated
insults better?
 Why clotting?
 Why does the PNH clone expand?
 Better treatments
 Improvement in supportive care and
transplantation