IMMUNITY DISEASE AN ORPHAN DISEASE

PRIMARY immunodeficiency (PID) is a chronic disease in which the immune defence mechanism fails to function, and patients are exposed to severe infections. Untreated, PID can cause death.

Unlike AIDS, which is the immunodeficiency disease of a secondary nature caused by the HIV virus, PID has been put on the back-burner by the medical fraternity and policymakers for more than three decades.

Although HIV and PID have a similar onset in the mid-1980s, AIDS was recognised as a health threat, and a national policy was drawn up to combat it.

It had the desired effect. HIV notification rate has dropped by 60 per cent last year since its peak in 2002, from 38.4 to 11 per 100,000 population (Malaysian Aids Council).

PID, meanwhile, is treated as an orphan disease, causing untold misery to patients and families. The increase is phenomenal. The number diagnosed in the decade ending 2014 has risen 10 times more than the previous decade.

Not much attention is given to it as PID is considered rare in Malaysia. A disease is considered rare when the prevalence is less common than one per 2,000 population.

PID at the current prevalence is less common than 1:1,200 population.

This is not rare. The estimates of PID is 25,000 patients for a Malaysian population of 31 million. PID is much more common than childhood leukaemia and lymphoma combined.

PID is often under-diagnosed as the level of awareness is low. The number of patients referred to the MyPIN group of doctors between 1987 and 2014 was 202.

MyPIN, or Malaysian Primary Immunodeficiency Network, is a group of healthcare professionals and scientists dedicated to PID, which began in 2007.

On average, only one and two per cent of the expected number of PID patients in a country gets diagnosed. For Malaysia, the estimates could be as much as 25,000 cases.

PID patients are not as privileged as HIV or haemophilia patients, where there are enough sub-specialists to provide consultation.

PID patients have to contend with the only two clinical immunologists available (at private hospitals). The National Specialist Registrar does not recognise them as sub-specialists. Most PID patients are managed by general specialists.

PID patients who need immediate attention are those with antibody deficiency; and, cellular and antibody deficiency or severe combined immunodeficiency (SCID).

Antibody deficiency exposes one to severe infections with dire consequences. The patient needs regular infusion of immunoglobulin replacement therapy (IRT) for life. Thirty-six patients are on IRT in public hospitals.

SCID, considered a paediatric emergency, is a grave condition occurring in early infancy.

The infant is unable to mount an immune response against infections. The infant requires a bone marrow transplant within three months.

Without it, SCID patients rarely live past their first birthday. In credible centres overseas, there is more than a 90 per cent chance of survival. In Malaysia, the diagnosis is often late, and survival rate is low.

There is a need for more clinical immunologists to manage PID patients. The number is at least five times as recognised by NSR.

Services for laboratory diagnostics and clinical care, including for IRT and bone marrow transplants, have to be improved and boosted. There is also a need to promote PID awareness among the medical fraternity and community.

A central registry should also be set up, where the experience of a patient is documented as a referral centre for learning and research.