Paroxysmal Nocturnal Hemoglobinuria

Algorithm(s)

PDF algorithm(s) available at www.arupconsult.com.

Hemolytic Anemias Testing Algorithm

Clinical Background

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare hemolytic disorder caused by a stem cell mutation. PNH results in deficient cell-surface glycol phosphatidylinositol (GPI) anchored proteins, including complement pathway regulatory proteins.

Epidemiology

Incidence - 1-4/1,000,000
Age of presentation - median 40 years
Sex - M:F equal

Pathophysiology

Nonmalignant clonal expansion of one or more stem cells that have acquired a mutation of glycol phosphatidylinositol results in the absence of GPI-anchored cell membrane proteins (CD55, CD59)
Pathophysiology of bone marrow failure involves abnormal red blood cell sensitivity to complement lysis
An association exists between acquired aplastic anemia and PNH - virtually all patients with PNH develop bone marrow dysfunction at some point

Clinical Presentation

Chronic hemolysis - patient reports occurrence of dark urine
Symptoms related to anemia (fatigue, pallor, weakness)
Thrombophilia (occurs in up to 40% of patients)
- Thromboses at various sites; most common sites are central nervous system and abdominal veins
- Thromboses are the leading cause of death
Bone marrow failure
Other signs and symptoms may include abdominal pain, iron deficiency anemia, jaundice and smooth muscle dysfunction

Treatment

Minimal signs and symptoms - folic acid and thrombosis prophylaxis
Severe signs and symptoms - allogeneic transplant, monoclonal therapy
Moderate disease - humanized monoclonal antibody

See Also

Hemoglobinopathies

Hemolytic Anemias

Algorithm(s)

PDF algorithm(s) available at www.arupconsult.com.

Hemolytic Anemias Testing Algorithm

Tests

Tests generally appear in the order most useful for common clinical situations

Test name: Sugar Water Test

ARUP #: 0049005

Methodology: Visual Identification of Hemolysis

Use:

Screen for paroxysmal nocturnal hemoglobinuria (PNH)

Follow-up:

Follow with ham test or flow cytometry to confirm PNH

Test name: Acid Hemolysin (Ham Test)

ARUP #: 0049010

Methodology: Visual Identification of Hemolysis

Use:

Confirm PNH and congenital dyserythropoietic anemia (CDA)

Limitations:

Follow-up:

Test name: CBC with Platelet Count & Automated Differential

ARUP #: 0040003

Methodology: Automated Cell Count with Flow Cell Differential

Use:

Definitive test for the diagnosis of PNH

Test name: Reticulocytes, Percent & Number

ARUP #: 0040022

Methodology: Flow Cytometry

Use:

Aid in diagnosis of PNH

Test name: Lactate Dehydrogenase, Serum or Plasma

ARUP #: 0020006

Methodology: Enzymatic

Use:

Aid in diagnosis of PNH

Test name: Bilirubin, Total, Serum or Plasma

ARUP #: 0020032

Methodology: Spectrophotometry

Use:

Aid in diagnosis of PNH

Test name: Haptoglobin

ARUP #: 0050280

Methodology: Immunoturbidimetric

Use:

Aid in diagnosis of PNH

Test name: Paroxysmal Nocturnal Hemoglobinuria Profile, High Resolution - WBC

ARUP #: 0096666

Methodology: Flow Cytometry

Use:

Confirm PNH

Panel detects the absence of phosphatidylinositol-linked membrane proteins CD55 (DAF-decay accelerating factor) and CD59 (MIRL - membrane inhibitor of reactive lysis) on neutrophils (CD16, CD24, CD55 and CD59)

The expression of CD55 and CD59 is decreased or absent in a subpopulation of RBCs in patients with paroxysmal nocturnal hemoglobinuria

A very low percentage of PNH cells may be found in patients with aplastic anemia, myelodysplastic syndromes, refractory anemia, refractory anemia with excess blasts, and myelofibrosis

Presence of PNH cells in these patients may correlate with better prognosis

Since diagnosis of PNH disease requires deficiency of at least two GPI-linked antigens in two different cell lineages, this test may be complemented with a PNH-RBC test (0098564) if clinically indicated

Test name: Paroxysmal Nocturnal Hemoglobinuria Profile, High Resolution - RBC

ARUP #: 0095864

Methodology: Flow Cytometry

Use:

Confirm PNH

Panel detects the absence of phosphatidylinositol-linked membrane proteins CD55 (DAF-decay accelerating factor) and CD59 (MIRL - membrane inhibitor of reactive lysis) on erythrocytes

The expression of CD55 and CD59 is decreased or absent in a subpopulation of RBCs in patients with paroxysmal nocturnal hemoglobinuria

A very low percentage of PNH cells may be found in patients with aplastic anemia, myelodysplastic syndromes, refractory anemia, refractory anemia with excess blasts, and myelofibrosis

Presence of PNH cells in these patients may correlate with better prognosis

Since diagnosis of PNH disease requires deficiency of at least two GPI-linked antigens in two different cell lineages, this test may be complemented with a PNH-WBC test (0096666) if clinically indicated

Limitations:

Recent RBC transfusions may artifactually decrease percentage of PNH cells

Test name: Bone Marrow Services

ARUP #: arup018

Methodology: Microscopic Exam

Use:

Determine results of biopsy

Test name: ADAMTS13 Activity

ARUP #: 0030056

Methodology: Fluorescence Resonance Energy Transfer

Use:

Limitations:

A variety of medical conditions may result in a mild to moderate deficiency of ADAMTS13 activity; recent plasma exchange therapy may raise the observed ADAMTS13 activity

The monoclonal anti-ADAMTS13 antibody is directed against the CUB domain; therefore, certain forms of ADAMTS13 (with mutations in the CUB domains) may not be equivalently measured due to reduced binding to the antibody

Test name: Alpha Thalassemia, HBA1 & HBA2 Gene Deletions

ARUP #: 0051495

Methodology: Polymerase Chain Reaction/Gel Electrophoresis

Use:

Limitations:

Rare alpha globin gene deletions, non-deletion mutations, gene duplications, and mutations of the regulatory region will not be detected

References

General References

Brodsky RA. Advances in the diagnosis and therapy of paroxysmal nocturnal hemoglobinuria.Blood Rev. 2008; 22 (2) 65-74.

Brodsky RA. Narrative review: paroxysmal nocturnal hemoglobinuria: the physiology of complement-related hemolytic anemia.Ann Intern Med. 2008; 148 (8) 587-595.

Craig FE, Foon KA. Flow cytometric immunophenotyping for hematologic neoplasms.Blood. 2008; 111 (8) 3941-3967.

Krauss JS. Laboratory diagnosis of paroxysmal nocturnal hemoglobinuria.Ann Clin Lab Sci. 2003; 33 (4) 401-406.

Parker C, Omine M, Richards S, Nishimura J, Bessler M, Ware R, Hillmen P, Luzzatto L, Young N, Kinoshita T, Rosse W, Socie G. Diagnosis and management of paroxysmal nocturnal hemoglobinuria.Blood. 2005; 106 (12) 3699-3709.

Parker CJ. The pathophysiology of paroxysmal nocturnal hemoglobinuria.Exp Hematol. 2007; 35 (4) 523-533.

Perkins S. Paroxysmal Nocturnal Hemoglobinuria. In Kjeldsberg C, ed. Practical Diagnosis of Hematologic Disorders, 4th ed. Chicago: ASCP Press, 2006. pp. 141-148.

Rosse WF, Nishimura J. Clinical manifestations of paroxysmal nocturnal hemoglobinuria: present state and future problems.Int J Hematol. 2003; 77 (2) 113-120.

Savage WJ, Brodsky RA. New insights into paroxysmal nocturnal hemoglobinuria.Hematology. 2007; 12 (5) 371-376.

Smith LJ. Paroxysmal nocturnal hemoglobinuria.Clin Lab Sci. 2004; 17 (3) 172-177.

References from the ARUP Institute for Clinical and Experimental Pathology Research®

Inoue N, Izui-Sarumaru T, Murakami Y, Endo Y, Nishimura J, Kurokawa K, Kuwayama M, Shime H, Machii T, Kanakura Y, Meyers G, Wittwer C, Chen Z, Babcock W, Frei-Lahr D, Parker CJ, Kinoshita T. Molecular basis of clonal expansion of hematopoiesis in 2 patients with paroxysmal nocturnal hemoglobinuria (PNH).Blood. 2006; 108 (13) 4232-4236.

Medical Reviewers

Lehman, Christopher M., MD. Co-Medical Director, University Hospital Clinical Laboratory; Associate Professor, Clinical Pathology, University of Utah

Perkins, Sherrie L., MD, PhD. Medical Director, Hematopathology at ARUP Laboratories; Professor, Anatomic Pathology, University of Utah

Roberts, William L., MD, PhD. Medical Director, Automated Core Laboratory at ARUP Laboratories; Professor, Pathology, University of Utah

Comprehensive Review: November 2008
Last Update: May 2009