Late-onset ankylosing spondylitis and related spondylarthropathies: clinical and radiological characteristics and pharmacological treatment options.

Ankylosing spondylitis is the prototype of related diseases commonly called spondylarthropathies which include reactive arthritis, psoriatic arthritis, arthritis associated with inflammatory bowel diseases (enteropathic arthritis) and undifferentiated spondylarthropathies. Ankylosing spondylitis and spondylarthropathies are generally observed in young patients but can be observed later in life or in persons >50 years of age. All the spondylarthropathy subgroups are represented in the elderly with some features particular to this age group. Indeed, radiological aspects of ankylosing spondylitis may be difficult to interpret because of the radiological changes induced by aging. Late-onset peripheral spondylarthropathies are characterised by severe disease, marked elevation of laboratory parameters of inflammation, oligoarthritis involving the lower limbs and oedema of the extremities. Psoriatic arthritis is more severe in the elderly and is associated with worse outcomes than in young patients. The clinical presentation of undifferentiated spondylarthropathy is as varied in the elderly as in young and middle-aged adults. Reactive arthritis and enteropathic arthritis are observed in the elderly more rarely. The effects of aging on drug metabolism and pharmacokinetics, together with the existence of co-morbidities and polypharmacy, are responsible for difficulties in the therapeutic management of late-onset ankylosing spondylitis or spondylarthropathies. Indeed, NSAIDs should be used with caution in older patients because of the high risk of serious gastrointestinal complications. Sulfasalazine and methotrexate have been used as disease-controlling drugs but did not prove very effective. Pamidronate and tumour necrosis factor (TNF)-alpha antagonists offer a therapeutic alternative but have not been specifically tested in the elderly. Pamidronate has been tested in young-onset ankylosing spondylitis and spondylarthropathies with conflicting results but can be used in older patients without risk of major adverse effects. TNFalpha antagonists have been adequately evaluated in ankylosing spondylitis and spondylarthropathies and are associated with dramatic improvement in clinical and biological parameters of disease activity. However, the safety profile of these agents in the elderly is not currently known and careful surveillance, in particular for the risk of infection such as tuberculosis, and/or exacerbation of chronic heart failure, is thus required when using these drugs in this age group.