Screening for Sickle Cell Disease
A full hemoglobinopathy screen using high performance liquid chromatography (HPLC), capillary electrophoresis, mass spectrometry, or gel electrophoresis is the recommended laboratory test to screen for sickle cell disease. 1
Screening Algorithm
Initial Assessment:
- Determine if patient is at risk for sickle cell disease based on ethnicity
- Consider screening for all patients except those of solely northern or eastern European, Jewish, or South-East Asian heritage 1
- Avoid repeated unnecessary screening if previously tested
Laboratory Testing Options:
Preferred Method: Full hemoglobinopathy screen
- HPLC
- Capillary electrophoresis
- Mass spectrometry
- Gel electrophoresis
Alternative Initial Approach:
- Rapid sickle solubility test to detect HbS
- If positive, proceed to full hemoglobinopathy screen
Rationale and Evidence
The full hemoglobinopathy screen is highly sensitive, reliable, and reproducible for detecting both homozygous and heterozygous states of HbS and other hemoglobinopathies 1. This comprehensive testing is crucial because:
- It distinguishes between different sickle cell genotypes (HbSS, HbSC, HbS β-thalassemia)
- It quantifies the percentages of different hemoglobin types
- It helps determine disease severity and appropriate management
Important Caveats
Do not use sickle solubility test alone as it cannot differentiate between heterozygous, compound heterozygous, or homozygous states 1
Sickle solubility tests may yield false negatives in:
- Neonates
- Heavily transfused patients 1
- Patients with low hemoglobin S percentage
Point-of-care testing options like HemoTypeSC have shown high sensitivity (100%) in some studies for detecting HbSS and HbSC genotypes 2, but these should be confirmed with standard laboratory methods
Clinical Implications
Early and accurate diagnosis of sickle cell disease is critical for:
- Preventing acute complications through prophylactic measures
- Initiating appropriate transfusion protocols when needed
- Monitoring for chronic complications
- Guiding perioperative management
The Association of Anaesthetists recommends that all at-risk patients be screened for hemoglobinopathies before surgery 1, highlighting the importance of accurate screening methods to reduce morbidity and mortality associated with surgical procedures in patients with sickle cell disease.