Sickle cell disease, as one of the lesser known deadly ailments, is gaining prevalence in India. Bone marrow transplant is the only option available for now
As the increase in sickle cell disease (SCD) patients poses a formidable challenge, odds have dramatically lessened in its treatment. The increasing success rate of bone marrow transplants, the only treatment for the disorder, has raised hopes for the sickle-cell patient population in India.
Swollen hands and feet; episodes of intense pain in the chest, abdomen, joints or bones; and frequent infections, are some of the leading symptoms of sickle cell anaemia (SCA). Because the disease causes the body to have a shortage of red blood cells, it is also characterised by chronic fatigue. In infants, children and teenagers, SCA can cause delayed growth and puberty. Various type of independent acute conditions are named sickle cell crisis. The sickle cell crisis lasts between five and seven days. Certain body and weather conditions may precipitate the acute spell.
It is a very debilitating disease. As has been found in one of the Indian Council of Medical Research surveys, about 20 per cent of the children with sickle cell disease, died by the age of two; and 30 per cent of children with SCD, especially among the tribal community, die before they even reach adulthood.
It has not been easy to tackle this disease in the absence of availability of easy transplant options — though things have changed for the better. Bone marrow is the only treatment and curative option available for symptomatic sickle patients; earlier odds were stacked against them. As medicine advances, the treatment has become easier too.
SCD is a red cell disorder. lack of matched sibling/related donor limits the option of bone marrow transplant (BMT). The option of unrelated donor for BMT is also difficult as there are not many voluntary marrow donors. In such a scenario, Haploidentical Stem Cell Transplant (HPC) is the only alternative. So far, HPC, in disease like SCD, was very limited due to poor success rates. With improved strategies, we can get better results with relatively less complications, in this relatively newer process.
In India, there is a huge sickle population in Madhya Pradesh, Chhattisgarh, Bihar, Maharashtra and some parts of West Bengal. With the only option of BMT as a cure, patients suffering from SCD in India and across the world can be hugely benefitted.
SCD is the most prevalent inherited blood condition worldwide, resulting from single DNA mutation within the Beta globin haemoglobin. Due to recent population movements, there has been a gene flow from high allele frequency areas of sub-Saharan Africa, west Asia, and India to Europe and parts of America. This has led to sizeable sickle cell population emerging in previously unaffected areas of the world. Each year, approximately 300,000 children are born with SCA or one of its variants, and nearly 80 per cent of these births occur in poor socio-economic countries.
SCD has high prevalence in India, especially in the central and western regions, and poses a considerable health burden. With increasing control on infant mortality and infectious diseases, genetic diseases are assuming a proportionately greater importance; Beta thalassemia, Sickle cell disease, and Haemoglobin E disease contribute significantly to morbidity and mortality in India.
SCD is a group of blood disorders that comes to the patient from its parents. The most common type of them is known as SCA. It results in an abnormality in the oxygen-carrying protein haemoglobin stored in red blood cells, resulting into a rigid, sickle like shape under certain circumstances. Normally, red blood cells are flexible and round and move easily through blood vessels. In SCA, the distorted red blood cells become rigid and sticky and can get stuck in small blood vessels, which can slow or block blood flow and oxygen to parts of the body.
Problems in SCD typically manifest at around five to six months of age. A host of health disorders may develop, such as attacks of pain — also known as sickle cell crisis — anaemia, swelling in the hands and feet, bacterial infections, stroke and others, which precipitate due to loss of immunity. As the patient grows older, the pain spells may linger for longer periods. The average life expectancy in the developed world is 40 to 60 years.
SCD can be traced two abnormal copies of the haemoglobin gene, one from each parent. This gene occurs in Chromosome 11. Several sub-types exist, depending on the exact mutation in each of haemoglobin gene. In this scenario, an attack can be set off by temperature changes, stress, dehydration and high altitude. A person, with a single abnormal copy, does not usually have symptoms and is said to have only sickle cell trait. Such people are also referred to as carriers. Diagnosis is done by blood test. Some countries test all newborns at birth for the disease. Diagnosis is also possible during the pregnancy period.
The care of people with SCD may include infection prevention with vaccination and antibiotics, high fluid intake, folic acid supplementation, and pain medication. Other measures may include blood transfusion and medication. These are only symptomatic treatments but cure is only through transplanting bone marrow cell. Only a small proportion of people has been cured through transplant route. With the advent of the new protocol, the number of transplants may increase in the future.
The sickle cell mutation was first described in India among the tribal groups in south India, but the prevalence of sickle allele is high in both tribal and non-tribal populations. The real story of the SCD emergence in India is still not known and most of our understanding and knowledge of the natural history of the disease comes from developed countries, where effective interventions have resulted in significant reductions in mortality. There are reports that provide interesting insights into SCD in India, but most of these are inconclusive and based in a single institution or region. Although, knowledge about SCD in India is increasing, yet it is very difficult to establish the burden of this problem accurately in the absence of screening programmes, nationwide reporting system or registries.
With increased awareness about diseases like Thalassemia, we have been able to prevent the disease to a great extent. Sickle cell disease makes life very difficult, so urgent measures to stem it are called for.
(The writer is senior consultant and director Hamato Oncology and marrow transplant, BlK Super Specialty Hospital)