PNH Clone Size Interpreter

Flow Cytometry Triage: Use the clone size from Granulocytes (Neutrophils/Monocytes). RBC clone size often underestimates disease burden due to lysis and transfusions.

Granulocyte Clone Size (%)

Deficient Population

Enter percentage value

Guidelines & Evidence

Verified

Last Review: 2026-07-17

When to Use

When to Screen

Investigating Coombs-negative hemolytic anemia (especially if associated with iron deficiency).

Evaluating unexplained venous thrombosis in unusual sites (e.g., Budd-Chiari, mesenteric veins).

Monitoring patients with Aplastic Anemia (AA) or Myelodysplastic Syndrome (MDS), as PNH clones frequently co-exist.

Testing Standard

High-sensitivity Flow Cytometry using FLAER (fluorescent aerolysin) is the gold standard, capable of detecting clones as small as 0.01%.

How it Works

Clone Size (Neutrophils/Monocytes)

Clone Size	Category	Clinical Correlation
> 50%	Large Clone	High risk of hemolysis, LDH elevation, and thrombosis.
10 - 50%	Moderate Clone	Classical PNH symptoms; significant hemolysis likely.
< 10%	Small / Subclinical	Common in AA/MDS; unlikely to cause primary PNH symptoms.

RBC Type Definitions

RBC Type	Description	GPI Expression
Type I	Normal RBCs	100%
Type II	Partial deficiency	Reduced (1-10%)
Type III	Complete deficiency	Absent

Last Comprehensive Review: 2026-07-17

Recent Journal Updates

British J HaematologyJul 22, 2026

Eradication of PPMI clone and improvement in cytopenia using cryopreserved autologous haematopoietic stem cells

Clinical Context

We think this might be relevant to the clinical guidance for PNH Clone Size & Flow Cytometry Interpreter.

JAMAJul 21, 2026

Correction to Primary Composite Outcome in a Trial of Transfusion Strategy

Clinical Context

We think this has broad domain relevance to PNH Clone Size & Flow Cytometry Interpreter.

WHO NewsJul 15, 2026

New WHO guidelines: up to 45% of dementia risk could be prevented or delayed

Clinical Context

We think this might be relevant to the clinical guidance for PNH Clone Size & Flow Cytometry Interpreter.

PNH Clone Size Interpreter

When to Use

When to Screen

Testing Standard

How it Works

Clone Size (Neutrophils/Monocytes)

RBC Type Definitions

Clinical Pearls

The RBC Trap

Complement Inhibition

The Evidence

Primary Strategy

Paroxysmal nocturnal hemoglobinuria.

Practical guidelines for the high-sensitivity detection and monitoring of paroxysmal nocturnal hemoglobinuria clones by flow cytometry.

Origins & History

Terminology

Recent Journal Updates

PNH Clone Size Interpreter

When to Use

When to Screen

Testing Standard

How it Works

Clone Size (Neutrophils/Monocytes)

RBC Type Definitions

Clinical Pearls

The RBC Trap

Complement Inhibition

The Evidence

Primary Strategy

Paroxysmal nocturnal hemoglobinuria.

Practical guidelines for the high-sensitivity detection and monitoring of paroxysmal nocturnal hemoglobinuria clones by flow cytometry.

Origins & History

Terminology

Recent Journal Updates