The HEALTH | May-June. 2026

• Polycythaemia vera( PV) is a rare chronic blood cancer caused by the excessive production of red blood cells.

• Symptoms can include headaches, fatigue, itching after warm showers, enlarged spleen and burning pain in the extremities.

• Current treatment strategies focus on reducing clotting risks, controlling symptoms and preventing disease progression.

For patients living with polycythaemia vera( PV), these symptoms are part of a rare chronic blood cancer that quietly disrupts the body’ s blood production system and increases the risk of potentially life-threatening complications.

According to Assoc. Prof. Dr Nor Rafeah Tumian, a consultant in Internal Medicine and Clinical Haematology at the Faculty of Medicine, UKM, Hospital Canselor Tuanku Muhriz( HCTM), PV is a myeloproliferative neoplasm characterised by uncontrolled production of red blood cells in the bone marrow.

“ This condition is primarily driven by an acquired genetic mutation in the Janus kinase 2( JAK2) gene, most commonly the V617F variant, which causes the bone marrow stem cells to remain constantly inverted,” she said.

Excessive red blood cell production thickens the blood, a condition known as hyperviscosity, which slows blood flow and impairs oxygen delivery to vital organs. As a result, patients face a significantly increased risk of arterial and venous thrombosis, including strokes, heart attacks and pulmonary embolisms.

Dr Nor Rafeah explained that over 95 per cent of PV patients carry a JAK2 mutation, making it an important marker for distinguishing the disease from other causes of elevated haemoglobin levels, such as smoking or sleep apnea.

RARE BLOOD DISORDER

Beyond clotting complications, PV also causes systemic inflammation and a range of symptoms that can significantly affect quality of life. Patients may develop splenomegaly, in which the spleen enlarges as it works harder to filter excess blood cells.

Other symptoms include transient visual disturbances, abdominal discomfort, burning pain in the extremities( erythromelalgia), and aquagenic pruritus- intense itching triggered by warm showers.

“ If untreated, PV can progress to more aggressive malignancies such as myelofibrosis or acute myeloid leukaemia,” she noted.

Although PV remains rare, local data suggest it is not insignificant in Malaysia. A retrospective national registry of 1,010 patients with myeloproliferative neoplasms from 2009 to 2015 found that 38.1 per cent had PV, with a mean age of 54

BEYOND THICKENED BLOOD: Dr Nor Rafeah Tumian( pictured) believes that emerging therapies targeting the JAK2 mutation are offering new hope for PV patients years and a male predominance.

The registry also showed a higher proportion of cases among the Chinese population, followed by Indians and Malays. However, Dr Nor Rafeah noted that this may partly reflect differences in healthcare access across regions.

Patients over the age of 60, particularly those with cardiovascular risk factors, such as hypertension, diabetes or a history of blood clots, face the highest risk of severe complications.

Despite advances in treatment, PV remains generally incurable, requiring lifelong management to reduce thrombotic risk, control symptoms and prevent progression to more aggressive blood cancers.

Current treatment strategies in Malaysia follow a risk-stratified approach, with standard first-line therapy comprising therapeutic phlebotomy and low-dose aspirin.

During phlebotomy, 250 to 500 mL of blood is removed via a specific needle and blood collection system.

However, Dr Nor Rafeah stressed that although phlebotomy and aspirin remain essential, they do not directly address the underlying disease process in PV.

For high-risk patients or those with persistent symptoms, cytoreductive therapies are often used to suppress excessive blood cell production.

Hydroxyurea remains the most commonly used first-line drug in Malaysia, while interferon formulations and JAK1 / 2 inhibitors, such as ruxolitinib, offer additional treatment options for patients who are resistant or intolerant to conventional therapy.

TARGETING THE MUTATION

She explained:“ Clinical studies show that early intervention with interferons can lead to superior control of blood counts, deeper molecular responses, and less myelofibrosis or thrombosis, thereby potentially modifying the disease course.”

The field of haematology is now shifting towards therapies designed not only to manage symptoms but also to alter the underlying biology of the disease.

Among the emerging therapies attracting attention is rusfertide, an investigational treatment that mimics hepcidin, a hormone that regulates iron. By limiting iron availability to the bone marrow, the therapy helps slow red blood cell production and reduce the need for repeated phlebotomies.

Clinical trials have shown promising results, with many patients maintaining controlled haematocrit levels while reporting reduced fatigue and other symptoms.

At the same time, artificial intelligence( AI) is beginning to reshape the diagnostic landscape in haematology. AI-powered systems can analyse blood smears and blood count data with growing precision, helping clinicians detect abnormalities earlier than conventional methods.

Looking ahead, Dr Nor Rafeah believes the future of haematology will increasingly centre on precision medicine, with targeted therapies and AI-driven diagnostics playing a greater role as treatment moves beyond symptom control towards sustained remission or even cure.- The HEALTH

UNDERSTANDING PV: The infographic highlights the common symptoms and thrombotic risks of PV