CSIR-CCMB develops India-specific tool to predict Sickle Cell severity

Doctors may soon have a more reliable way to predict how severely sickle cell anaemia (SCA) will affect Indian patients, thanks to a new India-specific disease severity score developed by scientists at the CSIR-Centre for Cellular and Molecular Biology (CCMB).

Potential impact of the India-specific tool

The new tool, developed using clinical data from Indian children, could improve treatment decisions and disease management as existing international scoring systems do not accurately reflect the clinical profile of Indian patients with SCA, whose disease patterns often differ from those seen in African and Western populations.

What is Sickle Cell Anaemia?

SCA is an inherited blood disorder caused by a mutation in the beta globin gene, which produces abnormal haemoglobin causing red blood cells to assume a sickle shape, leading to anaemia, severe pain episodes, organ damage and other complications. India is among the countries with the highest burden of the disease, according to Giriraj R. Chandak, physician-scientist and Sir J C Bose Fellow at CSIR-CCMB.

He and fellow scientists including Suraj S. Nongmaithem, Amitabh Biswas, Swaroop Iyer, Jandhayala Vyshnavi, Archana Wath and Dipty Jain conducted this study.

Early identification helps to alleviate suffering

SCA is caused by a single genetic mutation, yet its severity varies considerably. While some patients experience relatively mild symptoms, others endure repeated hospitalisations and life-threatening complications. An early identification of those at risk of severe clinical course can help devise targeted strategies and alleviate the suffering.

Indian patients are said to have a milder disease profile than many African populations, partly because of higher levels of foetal haemoglobin, which helps reduce disease severity. Complications such as leg ulcers, pulmonary hypertension and ‘priapism’, commonly reported in African populations, are comparatively rare here. However, nutritional deficiencies, infectious diseases and environmental stressors can worsen anaemia.

Researchers analysed the medical records of 171 SCA children aged up to 18 years and receiving treatment at the Government Medical College and Hospital, Nagpur, to develop a more suitable assessment tool. Two experienced paediatricians independently classified the patients into mild, moderate and severe categories based on their clinical condition.

The study found that the widely used Paediatric Severity Score (PSS), developed using international patient data, matched expert clinical assessments in only about 67% of cases. The score was modified adding four clinical features frequently observed among Indian patients — recurrent blood transfusions, severe anaemia requiring hospitalisation and acute febrile illnesses.

Improvement in clinical assessments

The revised model — ‘ISS1’ (India-specific Severity Score), improved clinical assessments to nearly 83%. A second version, ‘ISS2’, replaced the laboratory measurements with easily observable clinical indicators to achieve an overall concordance of about 85%, correctly identifying all patients in the mild category and improving performance in moderate cases. This enables clinicians to decide the management without the need for many laboratory investigations.

The findings highlight the importance of developing population-specific tools rather than relying solely on models designed for different ethnic groups and healthcare settings. It was also found that painful vaso-occlusive crises were the most common complication among the children while frequent blood transfusions, severe anaemia and recurrent fever-related illnesses led to hospital admissions.

“We believe the new scoring systems could help doctors make quicker and more informed decisions on treatment, including the use and dosage of hydroxyurea, one of the primary drugs used to manage SCA. This study adds to the comprehensive efforts by CSIR-CCMB in making a difference in the lives of Indian SCA patients, under CSIR-Sickle Cell Anaemia Mission”, said Dr. Chandak.

This could be applicable to other low- and middle-income countries with similar genetic backgrounds, disease patterns and healthcare challenges. However, further validation in larger and more diverse populations will be needed before the tool can be adopted more widely, added researchers.