Rhonda L Witte, BSc

The immune system is an elegant example of nature's work. When functioning properly, it protects us against what is "foreign" and does not attack the "self". Throughout an individual's life, changes occur within the immune system which make defense mechanisms less effective. Immunogerontology--the study of the aging immune system--is an up and coming field of research that will help build our knowledge, not only about the aging immune system, but also about the immune system in general.

The Immune System

Our immune system can be broken down into two interacting components: innate (natural) immunity and acquired (specific) immunity.¹ Innate and acquired immunity differ regarding the effector cells and molecules that carry out their specific and essential functions. Natural immunity is composed of defense systems that are present before exposure to foreign macromolecules and infectious microbes. Physical barriers (i.e. the skin) phagocytic cells and eosinophils, a specific class of lymphocytes called natural killer cells, and a range of blood-borne molecules (i.e. soluble proteins of the complement cascade) make up the natural immune system.² Acquired immunity requires stimulation by exposure to foreign molecules and includes sub-types of lymphocytes (e.g. B- and T-cells), cutaneous and mucosal immune responses and antibodies which circulate to find their target.

Thomas Tsirakis, BA

Bipolar disorder is a recurrent and potentially incapacitating illness affecting a person's mood and behaviour, which manifests itself in different ways throughout its course (Table 1). The first episode of bipolar disorder may be manic, hypomanic (milder form of mania with elevated mood), mixed (both mania and depression), or depressive. Due to the extremely variable nature of the illness, it may present itself differently from patient to patient in terms of the severity and duration of episodes. Often, the type of episode an individual experiences may also follow a seasonal pattern (e.g. hypomanic in the summer and depressed in the winter.) With proper intervention, some people recover completely between episodes and may experience years of symptom-free relief, while others may experience continuous low-grade depression and mild mood swings throughout the course of their lives.

Bipolar disorder is classified according to the symptoms that an individual experiences. In Bipolar I Disorder, an individual will have one or more manic episodes, or mixed episodes, lasting at least one week. Many also experience at least one major depressive episode. In Bipolar II Disorder, a person will have one or more major depressive episodes accompanied by at least one hypomanic episode but no manic episodes.

Eleanor Brownridge

Since access to assistive devices is not a federally-mandated program, financial assistance for canes, wheel chairs and braces for patients with arthritis varies considerably from province to province. In fact, the majority of provincial health plans cover none of these aids.

The Ontario Ministry of Health does have an Assistive Devices Program (ADP) which covers a portion of the cost of manual and power wheelchairs, scooters and walkers, back supports, and specialized canes for people with long-term disabilities. ADP pays up to 75 percent of a predetermined price, with the patient paying the remaining 25 percent directly to the vendor at the time of purchase. For those on social assistance, the program will cover 100 percent of the cost. "To access this program, your patient must have a valid Health Card and the device must be authorized by a physiotherapist or occupational therapist registered with the program," says Robert Jankowski, a public information officer with ADP. There are currently over 5,000 registered authorizers working in hospitals, home care agencies or private practice. Physicians or patients can call 1-800-268-6021 to obtain the name of local health professionals authorized to access this program or speak with the local CCAC/Home Care Coordinator for further information.

Hand deformity typical of rtheumatoid arthiritis

Novel Biological Therapy for Rheumatoid Arthritis Looks Promising

Ruwaida Dhala, BSc, MSc

Rheumatoid arthritis (RA) is the most common autoimmune disease worldwide. RA primarily affects joints of the extremities, particularly the fingers. The disease is characterized by chronic inflammation of the synovial joints resulting in joint destruction and deformity. RA occurs both in children and adults. The peak incidence of RA is between the ages of 30 and 50 and occurs more frequently in women than in men.¹ The clinical manifestations of the disease include peri-articular soft tissue swelling, joint pain and joint stiffness. Like most autoimmune diseases, there is a genetic susceptibility to RA (see related article on Unravelling the Genetic Mystery of Arthritis). T cells appear to be important in disease initiation whereas monocytes are implicated in disease progression.

Naushad Hirani, BSc, MD*

The seronegative arthritides, also commonly referred to as the spondylo-arthropathies because of their predilection for involving the spine, are inflammatory diseases that can be distinguished from the more common rheumatoid arthritis and osteoarthritis based on several general characteristics. In addition to being, by definition (with rare exceptions), rheumatoid factor negative (as opposed to rheumatoid arthritis), they also have distinct patterns of articular and extra-articular involvement, and most exhibit an association with the HLA-B27 gene.

The main conditions encompassed by this classification include Psoriatic arthritis (PSA), Reactive arthritis or Reiter's syndrome, and Inflammatory bowel disease-associated arthritis, although Ankylosing spondylitis⁼ (AS) is the prototypical seronegative disease. The key features of each of the seronegative arthritides are summarized in Table 1. From a geriatric standpoint, most of these conditions are not diagnostic challenges, as they are generally diseases that present in young or middle-aged people. However, an understanding of the group of diseases is helpful for the management of patients in the chronic state, and particularly in the case of distinguishing PSA from rheumatoid arthritis. Many of the features of the seronegative arthritides can be illustrated by first considering AS.

Extracts from the leaves of the Ginko biloba tree and Vitamin E are just two of the therapies being investigated for the treatment of Alzheimer's Disease

Try Combining Donepezil and Vitamin E for Alzheimer's

Neil Fam, BSc, MSc

Alzheimer's Disease (AD) is a chronic neurodegenerative disorder characterized clinically by a gradual onset of progressive memory loss with deterioration in patients' social and occupational function. Changes in mood, behaviour and perception are also problematic aspects of the disease. Neuropathologically, AD is associated with the formation of amyloid plaques and neurofibrillary tangles, with impaired synaptic function and neuronal cell death. In particular, patients with AD suffer the loss of cholinergic, noradrenergic and dopaminergic neurons. Loss of acetylcholine neurotransmission in brain areas involved in learning and memory is thought to underlie many of the cognitive symptoms of AD. This concept forms the basis of current therapeutic strategies which aim to increase available acetylcholine levels in the brain by inhibition of acetylcholinesterase.

Dr. A. Mark Clarfield is the Chief of Academic Affairs at the Sarah Herzog Hospital in Jerusalem and a staff geriatrician of the Division of Geriatric Medicine, Sir Mortimer B. Davis-Jewish General Hospital, McGill University, Montreal. We regret that Dr. Clarfield's articles are not available on-line.

Hannah Hoag, BSc

There are about 100 different forms of arthritis. Gout, lupus, and ankylosing spondylitis are members of the arthritis family, as are the better known osteoarthritic and rheumatic versions. Between birth and death, nearly 3.5 million Canadians are affected by some form of the disease. Osteoarthritis and rheumatoid arthritis (RA) are 2 forms of chronic arthritis that are observed in, but not restricted to, the aging population. Arthritis can be defined, most simply, as an inflammation of the joint, however, the severity of the condition varies significantly. Pain can be mild or severe, and the disease can remain isolated to one joint or have systemic effects. With so many variant forms of the disease, it is not surprising that the causes of arthritis are somewhat unclear. However, the importance of the interplay between cartilage, the immune system, heredity, and the environment has been recognized in the onset of disease. Much of current research has been devoted to understanding normal immune function and how dysfunction causes arthritis.

Osteoarthritis is identified as being of either primary or secondary origin. Primary osteoarthritis is viewed as a consequence of the aging process.¹ Over 85% of people over the age of 70 suffer from osteoarthritis. Secondary osteoarthritis is not associated with the aging process but due to other factors such as injury, obesity, and changes in cartilage chemistry.

Nariman Malik, BSc

Osteoarthritis is the most prevalent rheumatic disease.¹ It affects primarily the elderly and is rarely seen in individuals younger than 40. Osteoarthritis was believed to be an unavoidable consequence of aging, however, it is now believed to be a degenerative process that results from the interaction of metabolic, mechanical, genetic and other factors.

The disease is a heterogeneous disorder that affects different joints.² Each affected joint has different clinical manifestations, prognoses, and patterns of progression. The prevalence of osteoarthritis increases with age. It is more common in women than in men.² Women present more with osteoarthritis of the hand while men present more with problems of weight-bearing joints.³ In general, the management of osteoarthritis is coordinated by the family physician.² If there is any doubt about the diagnosis or any complications, a rheumatologist or geriatrician should be consulted. Physiotherapists and occupational therapists are key members of the multidisciplinary management team critical to the long-term management of this chronic illness.

Pathogenesis

Osteoarthritis is a disorder of the hyaline articular cartilage on the bony surface of joints (see Figure 1).² Hyaline articular cartilage is composed of type II collagen, proteoglycans, as well as chondrocytes and water.

Rhonda Witte, BSc

It is one thing to know how the body changes with age, but it is another to understand the effects of these changes on the body. Decreased kidney size? A smaller liver? They may sound like minor changes, but it is crucial to understand the significance of such age-related changes in terms of selecting appropriate drug therapy. Geriatric clinical pharmacology is not a large part of the general practice of medicine but with an increasing elderly population, greater knowledge in this area is required.¹ What must be kept in mind is that it is not just about what drugs should be prescribed to the elderly--it is about the right drugs that should be prescribed to a geriatric patient on an individual basis.

Pharmacokinetics

Fundamental to geriatric medicine is the understanding of age-related changes in pharmacokinetics. Such changes have profound impacts upon drug usage in the elderly population. When ignored, severe complications and even death can result from pharmacotherapy. What makes the situation even more complicated is that pharmacokinetic changes vary with the individual. Therefore, each patient must be treated with a highly individualized approach² and one patient's situation cannot set the standard for other patients to follow.

Pharmacokinetics refers to time-dependent changes of drug concentration and their metabolites in the body, or more simply, what the body does to a drug.