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Prof Timothy Cox began his talk at the 5th Conference by describing the distressing symptoms of bone complications and then described the exciting Collaborative Bone Research Project to be undertaken by the four UK Gauchers Centres.
Prof Cox said at the Conference that despite the advent of enzyme therapy and all the success associated with it, sufferers of Gauchers disease often experience painful bone symptoms. There remains a real need to address and understand this problem.
Avascular necrosis means death of the bone when the blood supply is cut off from part of a bone. This can cause painful bone crises and the hip can become distorted. A bone infarction also describes destruction of the bone caused by loss of blood supply.
Osteolysis describes areas of bone rarefication, cortical thinning and distortion often related to local deposits of Gauchers cells in the bone marrow. The condition is associated with an increased risk of fracture which is often recurrent. However the cause is unknown.
Osteoporosis describes the loss of bone substance and mineral content. It is usually generalised throughout the skeleton and increases the liability for bones to fracture. It complicates the diagnosis of Gauchers disease as these symptoms can also be caused by: Hormonal effects eg after women reach menopause. Reduced exercise and weight bearing Direct effect of the inflammatory response to Gauchers tissue.
In addition there are contributing factors to the bone disease:
Although the platelet count is often low in patients with Gauchers disease, other proteins and factors are involved in blood coagulation and may cause minute blood clots in the small blood vessel network (capillaries) that supply bone. Many patients have various abnormalities in blood coagulation which may result from a defect in blood clotting. These blood clots may obstruct the blood flow in the bone and cause the death of part of the bone. It is important that extra care be taken, if patients with Gauchers disease undergo surgery, to prevent excessive loss of blood; dead bone can also serve as a easy site for bacteria to nest in and proliferate.
Cathepsin K is a protein implicated in bone disease and this protein has been isolated as being active in sufferers of Gauchers disease. It contributes to resorption (maintenance) of the bone and it is interesting that treatments are currently being developed to counteract the activities of cathepsin K in generalized osteoporosis in the community. Cathepsin K antagonists might be beneficial in patients with Gauchers disease.
Prof Cox said that research in Cambridge in conjunction with Prof Hans Aerts' colleagues in Amsterdam, has shown that out of a group of patients, about 30% had significantly less vitamin D than normal. This vitamin is essential for the maintenance and health of bone and can be obtained from fatty fish, milk products and from the sun. It increases calcium absorption. 'It is important to discover if a deficiency of Vitamin D is a component of Gauchers disease. In particular Vitamin D deficiency is more common among the Asian population. 'Doctors should perhaps measure Vitamin D in patients at their six monthly investigation to see if extra Vitamin D is needed. Sun lamps may be useful but the patient should refer to their Gauchers Centre specialist first to see if this is necessary.'
Pamidronate, Alendronate, Etidronate, Risidronate and Clodronate are a group of bisphosphonate drugs. They have been found to arrest bone thinning and increase bone density in Gauchers disease and there are reports of their successful use in children with poor bone growth and inadequate absorption of bone.
The Gauchers Association has encouraged the four Gauchers Centres to develop a research project to look at bone disease in patients as this remains a problem for many sufferers and can affect their quality of life.
The objective of the project is to document the extent of disability caused by the the skeletal effects of Gauchers disease in the national group of patients attending the four specialist centres.
This will involve the following :
Where possible, samples of large joints removed at orthopaedic surgery will be retrieved for examination to determine the extent of bone collapse and death. Prof Cox said that to his knowledge this study will present the first of its kind on a national basis to fully document the skeletal effects of Gauchers disease on a cohort of patients in relation to biochemical, radiological and clinical markers of disease activity.
The study should enhance the appropriate therapy and monitor outcome. By focusing on this common affliction of adults and children within the Gauchers community, he felt that their needs would be better recognized and addressed in the clinical setting.
'With my colleagues, I have been struck over the years by the burden placed on patients by bone manifestations and suggest that the time is ripe now for a concerted effort to deal with this difficult and ill-understood problem. 'I would like to thank the Association on behalf of all the physicians for their interest in this imaginative collaboration and for offering its support to the research.'
The project will last for three years and will cost an estimated £162,000. It will require a full time specialist nurse (preferably with degree and research experience) and costs will include: travel and accommodation, costs between centres, IT training, special reagents (chemicals) to measure markers.
The Gauchers Association intends to raise the £162,000 to enable this research into bone disease to proceed. To date £33,000 is in the kitty so another £129,000 is needed. Everyone is encouraged to raise money for this venture which has the potential to help everyone. Please do what you can. Above is our money raising Bone Meter which shows how much has been raised so far.
Gauchers News Contents
Source: Gauchers News March 2002.
© Copyright Gauchers Association 2002