What are the limitations of the pnh clone size interpreter?

While the pnh clone size interpreter is highly validated, it should not replace clinical judgment. OpiCalc provides the latest evidence-based limitations for the pnh clone size interpreter to ensure safe bedside use and optimal diagnostic accuracy.

How does the pnh clone size interpreter compare to other Hematology scores?

The pnh clone size interpreter is a gold-standard diagnostic tool. OpiCalc provides side-by-side clinical guidance to help clinicians choose the most specific evidence-based tool for their patient's presentation.

Is the pnh clone size interpreter free to use?

Yes. OpiCalc provides the pnh clone size interpreter completely ad-free and optimized for mobile bedside use, ensuring you can calculate medical risk swiftly and without distraction.

OpiCalc

927 Clinical Tools

OpiCalc

4Ts Score (HIT)aaIPI (Age-adjusted IPI)ABC Score (Massive Transfusion)Absolute Neutrophil Count Age-adjusted D-dimer Threshold aGvHD Grading (Glucksberg/MAGIC)AL Amyloidosis Staging (Mayo)Anti-Xa Monitoring Interpreter Antiphospholipid Syndrome Classification Binet / Rai Staging (CML)Blood Volume Calculator Caprini VTE Risk CISNE Score CLL-IPI Coombs-Negative Haemolysis Checklist Corrected Reticulocyte Count CRS Grading (ASTCT 2019)DAT Interpretation Algorithm Deauville Score Interpreter DIC Score (ISTH)DIPSS (MF)DIPSS-Plus (MF)DOAC Dose Selector DOAC Renal Dose Adjustment DRI (Disease Risk Index)Durie-Salmon Staging (historical)EBMT Risk Score ELN 2022 AML Risk Classification ELTS Score (CML)England & Fraser Index EUTOS Score (CML)Expected Hb Rise per RBC Unit Factor Inhibitor Bethesda Titre Interpreter Febrile Neutropaenia Risk (MASCC)Fibrinogen Replacement FLIPI (Follicular Lymphoma IPI)FLIPI-2 French TTP Score GAPSS (Global APS Score)Haemophilia Severity Classification HbS Percentage Target Calculator HCT-CI (Comorbidity Index)HEP Score Heparin Nomogram (Weight-based)Hepatic Iron Index HERDOO2 Rule HFE Haemochromatosis Risk Estimator ICANS Grading (ASTCT 2019)IMWG Response Criteria (Myeloma)IPI (International Prognostic Index)IPSID / Lugano Classification IPSS-M (Molecular IPSS)IPSS-R (Revised IPSS for MDS)Iron Deficit Calculator (Ganzoni Formula)ISS (Myeloma)ISTH Bleeding Assessment Tool (BAT)ISTH Non-Overt DIC Score ITP Bleeding Score iwCLL Response Criteria (2018)IWG ITP Response Criteria JAK2V617F Allele Burden Interpreter Karnofsky Performance Scale Leucostasis Risk Threshold Lupus Anticoagulant (LAC) Reporting Framework MAGIC aGvHD Biomarker Score MCV-based Anaemia Algorithm Mentzer Index MIPI (MCL IPI)MIPSS70+ v2.0 (MF)Mixing Study Interpretation MRD Assessment Threshold Interpreter mSMART 3.0 (Myeloma)MTP Activation Criteria NCCN-IPI NIH Chronic GvHD Scoring NTDT Iron Burden Estimator Padua RAM PBT (Paediatric BAT)PCNSL MSKCC Score PERC Rule Perioperative Anticoagulation Bridging PESI Score (PE Mortality)PLASMIC Score Platelet Increment Calculator (CCI)PNH Clone Size Interpreter R-IPI (Revised IPI)R-ISS (Revised ISS)Reticulocyte Index (RPI)Revised Geneva Score (PE)Revised Response Criteria (NHL)Revised Zubrod / ECOG Performance Shine & Lal Index Sickle Cell Disease Risk (TCD)SLiM-CRAB Criteria SOKAL Score (CML)Sokal/EUTOS/ELTS Comparison sPESI (Simplified PESI)TACO Risk Score Thalassaemia Transfusion Threshold Thrombocytopaenia Differential Thrombophilia Screening Eligibility Algorithm Time in Therapeutic Range (TTR)TLS Risk Classification Transferrin Saturation Calculator Vienna Prediction Model von Willebrand Factor Activity Interpreter Warfarin Dose Calculator Wells Score (DVT)Wells Score (PE)WHO 2022 AML Classification Mapper WHO Bleeding Scale YEARS Algorithm

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

Clinical Details

Section 1

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%.

Section 2

Formula & Logic

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

Section 3

Pearls/Pitfalls

The RBC Trap

RBC clone size may severely underestimate the true PNH disease burden due to the shortened lifespan of Type III cells and the dilutional effect of recent blood transfusions. Always rely on Neutrophil and Monocyte clone sizes for diagnostic accuracy.

Complement Inhibition

Large clones (> 50%) or symptomatic hemolysis are primary indications for treatment with C5 inhibitors (e.g., Eculizumab, Ravulizumab) or proximal complement inhibitors (e.g., Pegcetacoplan).

Section 4

Evidence Appraisal

Primary Strategy

Paroxysmal nocturnal hemoglobinuria.

Brodsky RA. • Blood. 2014;124(24):3504-11.

View Source

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

Sutherland DR et al. • Cytometry B Clin Cytom. 2012;ICCS/ESCCA consensus.

View Source

Section 5

Literature

Terminology

FLAER (Fluorescently Labeled Aerolysin) binds specifically to the GPI anchor itself, providing a more robust signal than individual antibodies.

Last Comprehensive Review: 2026

Guidelines & Evidence

Clinical Details

Section 1

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%.

Section 2

Formula & Logic

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

Section 3

Pearls/Pitfalls

The RBC Trap

Complement Inhibition

Large clones (> 50%) or symptomatic hemolysis are primary indications for treatment with C5 inhibitors (e.g., Eculizumab, Ravulizumab) or proximal complement inhibitors (e.g., Pegcetacoplan).

Section 4

Evidence Appraisal

Primary Strategy

Paroxysmal nocturnal hemoglobinuria.

Brodsky RA. • Blood. 2014;124(24):3504-11.

View Source

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

Sutherland DR et al. • Cytometry B Clin Cytom. 2012;ICCS/ESCCA consensus.

View Source

Section 5

Literature

Terminology

FLAER (Fluorescently Labeled Aerolysin) binds specifically to the GPI anchor itself, providing a more robust signal than individual antibodies.

Last Comprehensive Review: 2026

Related Hematology Tools

Shine & Lal Index

Corrected Reticulocyte Count

Transferrin Saturation Calculator

Iron Deficit Calculator

HFE Haemochromatosis Risk Estimator

Hepatic Iron Index

DAT Interpretation Algorithm

Coombs-Negative Haemolysis Checklist

PLASMIC Score

French TTP Score

Have feedback about this calculator?Let us know.

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

Clinical Details

Section 1

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%.

Section 2

Formula & Logic

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

Section 3

Pearls/Pitfalls

The RBC Trap

Complement Inhibition

Large clones (> 50%) or symptomatic hemolysis are primary indications for treatment with C5 inhibitors (e.g., Eculizumab, Ravulizumab) or proximal complement inhibitors (e.g., Pegcetacoplan).

Section 4

Evidence Appraisal

Primary Strategy

Paroxysmal nocturnal hemoglobinuria.

Brodsky RA. • Blood. 2014;124(24):3504-11.

View Source

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

Sutherland DR et al. • Cytometry B Clin Cytom. 2012;ICCS/ESCCA consensus.

View Source

Section 5

Literature

Terminology

FLAER (Fluorescently Labeled Aerolysin) binds specifically to the GPI anchor itself, providing a more robust signal than individual antibodies.

Last Comprehensive Review: 2026

Guidelines & Evidence

Clinical Details

Section 1

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%.

Section 2

Formula & Logic

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

Section 3

Pearls/Pitfalls

The RBC Trap

Complement Inhibition

Large clones (> 50%) or symptomatic hemolysis are primary indications for treatment with C5 inhibitors (e.g., Eculizumab, Ravulizumab) or proximal complement inhibitors (e.g., Pegcetacoplan).

Section 4