Senior Consultant, Bone Marrow Transplant & Haemato-Oncology, BLK-Max Super Speciality Hospital, New Delhi
Part 3 of 11 in Diagnosis and Management of Sickle Cell Disease
Diagnosing Sickle Cell Disease: From Newborn Screening to Confirmatory Testing
November 24, 2024
A peripheral blood smear is central to diagnosing sickle cell disease, since the characteristic sickle-shaped red cells can be seen directly under the microscope.
Confirmatory Laboratory Tests
The sickle solubility test detects the polymerisation of haemoglobin S after a reducing agent is added, but it only tells you that sickle haemoglobin is present, not whether the person has sickle cell disease or is simply a carrier. Distinguishing disease from trait, and telling different sickle cell phenotypes apart, requires looking at clinical severity together with the haemoglobin S percentage, the haemoglobin A percentage, the total haemoglobin level, the mean corpuscular volume and the reticulocyte count. Confirmatory diagnosis relies on haemoglobin analysis using high performance liquid chromatography (HPLC), isoelectric focusing or gel electrophoresis.
Why Newborn Screening Matters
Early diagnosis through neonatal screening is important for reducing the morbidity and mortality of the disease. This is done as a heel-prick test at birth, where a single spot of blood is taken and analysed. A positive result on this screening test is not itself a diagnosis; it must always be followed by a confirmatory laboratory test if sickle cell disease is suspected.
This article is based on a Jivo Masterclass session conducted by Dr. Divya Doval, Senior Consultant, Bone Marrow Transplant & Haemato-Oncology, BLK-Max Super Speciality Hospital, New Delhi. The article has been summarised with the assistance of an AI tool from the original masterclass recording. Watch the full Masterclass recording
This guide is based on a live Jivo Masterclass: Dr. Divya Doval taught doctors across Africa on November 24, 2024.
FROM THE LIVE Q&A
Moderator
What are your absolute indications for bone marrow transplant in sickle cell anaemic children?
Dr. Divya Doval
Our indications are changing every day, because with the advent of haploidentical stem cell transplant, donor availability and outcomes have improved so much that more families are willing to take the risk. For us, indications include any child with a single episode of stroke, a single episode of chest crisis, or multiple episodes of pain requiring hospital admission.
Frequently Asked Questions
What preventive measures are possible to avoid complications such as avascular necrosis?▼
Repeated pain crisis is really the driver, and there is no way around it beyond hydration and treating the pain crisis promptly, because recurrent crises can cause these infarcts in the bones, and unfortunately we sometimes cannot prevent them. Fluids, hydroxyurea and supportive care every time there is a pain crisis are the key measures.
What is the pathophysiology of stress as a factor or trigger of sickle cell disease symptoms?▼
Stress on the body can be anything. Fever is a stress. Dehydration is a stress to the body. Similarly, any hypoxic condition, such as being in a high-altitude area where oxygen levels are lower, contributes to stress on the body.
What is the management of priapism in sickle cell disease patients?▼
The management is first hydration, control of the pain, and all the supportive measures normally used for sickle cell disease, like oxygen, pain management and fluids. If it doesn't settle, we may need blood transfusion, and for refractory cases, a urology review for possible surgical intervention.
Is sickle cell trait a disease?▼
Sickle cell trait itself I don't consider a disease, since it doesn't manifest with any problems in most people. But sickle cell disease has a whole spectrum, and once the pain crises and other manifestations begin, we definitely have to treat it as a disease.
What is the success rate of managing sickle cell disease with stem cell transplant?▼
Stem cell transplant has a very good outcome, especially in younger children. Even with a haploidentical stem cell transplant, we have reported outcomes between 70 to 80 percent overall survival, and matched sibling data was close to 90 percent. It is a one-time treatment and the cure is for life, whereas managing sickle cell disease is an ongoing process, one complication after another, and cognitive dysfunction from silent strokes can build up over time even with careful management. Doing the transplant at a younger age gives a better outcome.
In This Series: Diagnosis and Management of Sickle Cell Disease
- 1.Diagnosis and Management of Sickle Cell Disease
- 2.Sickle Cell Disease Explained: Inheritance, Haemoglobin S and Why Cells Sickle
- 3.Diagnosing Sickle Cell Disease: From Newborn Screening to Confirmatory Testing
- 4.Pain Crisis and Acute Chest Syndrome: The Two Most Common Sickle Cell Emergencies
- 5.Stroke Risk in Sickle Cell Disease: Screening and Preventing a Devastating Complication
- 6.How Sickle Cell Disease Damages the Spleen, Liver, Kidneys and Eyes
- 7.Priapism, Infections and Aplastic Crisis in Sickle Cell Disease
- 8.Hydroxyurea and Newer Drug Therapies for Sickle Cell Disease
- 9.Blood Transfusion and Iron Overload Management in Sickle Cell Disease
- 10.Bone Marrow Transplant and Gene Therapy: Curing Sickle Cell Disease
- 11.Sickle Cell Disease and Pregnancy: Managing a High-Risk Combination