PNH CONFIRMATION TEST

The PNH Confirmation Test is a specialized flow cytometry-based diagnostic test used to confirm the presence of Paroxysmal Nocturnal Hemoglobinuria (PNH), a rare acquired blood disorder characterized by destruction of red blood cells, bone marrow dysfunction, and an increased risk of blood clots.

PNH occurs due to acquired mutations in the PIGA gene within hematopoietic stem cells. These mutations result in the absence or deficiency of glycosylphosphatidylinositol (GPI) anchors that normally attach protective proteins such as CD55 and CD59 to blood cell surfaces. Without these protective proteins, red blood cells become vulnerable to destruction by the complement system.

The PNH Confirmation Test uses advanced flow cytometry to identify and quantify populations of blood cells lacking GPI-linked proteins. Modern testing often includes FLAER (Fluorescent Aerolysin) along with markers such as CD55, CD59, CD24, CD14, and CD15, providing highly sensitive detection of PNH clones in red blood cells, granulocytes, and monocytes.

The test is considered the gold standard for diagnosing PNH and is essential for evaluating patients with unexplained hemolytic anemia, thrombosis, bone marrow failure syndromes, or suspected PNH.

Benefits of the Test

• Confirms the diagnosis of PNH
• Detects GPI-anchor deficient blood cells
• Measures the size of PNH clones
• Supports treatment planning and monitoring
• Helps assess thrombotic risk
• Provides highly sensitive and specific results

Why Doctors Recommend This Test

Doctors may recommend a PNH Confirmation Test for:

• Unexplained hemolytic anemia
• Dark-colored urine (especially in the morning)
• Recurrent or unusual blood clots
• Aplastic anemia evaluation
• Bone marrow failure syndromes
• Unexplained low blood counts
• Suspected Paroxysmal Nocturnal Hemoglobinuria
• Monitoring known PNH patients

The test helps identify abnormal blood cell populations characteristic of PNH.

Preparation Before Test

The test requires:

• Peripheral venous blood sample

Preparation generally includes:

• No fasting is required
• Inform your physician about ongoing treatments
• Follow laboratory instructions for sample collection
• Fresh blood samples are often preferred for optimal flow cytometry analysis

Normal Reporting Time

Results are generally available within 3 to 7 working days, depending on laboratory workflow and panel complexity.

Who Should Take This Test?

• Patients with unexplained hemolytic anemia
• Individuals with recurrent thrombosis
• Patients with aplastic anemia
• Individuals with bone marrow failure syndromes
• Patients with unexplained cytopenias
• Individuals referred by hematologists

The PNH Confirmation Test is the definitive laboratory investigation for diagnosing and monitoring PNH.

Clinical Significance

The test helps diagnose and evaluate:

• Paroxysmal Nocturnal Hemoglobinuria (PNH)
• Hemolytic Anemia
• Bone Marrow Failure Syndromes
• Aplastic Anemia
• Unexplained Cytopenias
• PNH-associated Thrombosis

Detection of GPI-deficient granulocytes, monocytes, and red blood cells confirms the presence of a PNH clone.

Important Note

The size of the PNH clone does not always correlate directly with symptom severity. Test results should be interpreted together with complete blood counts, lactate dehydrogenase (LDH) levels, hemolysis markers, clinical symptoms, and bone marrow findings.