Introduction
What is Psoriatic Arthritis?
Why is the Psoriatic Arthritis Clinic Special?
What have we learnt in the Psoriatic Arthritis Clinic?
Are there new therapies for patients with Psoriatic Arthritis?
Are hereditary factors important in Psoriatic Arthritis?
      Current Studies

 The Psoriatic Arthritis Clinic is located at The Centre for Prognosis Studies in The Rheumatic Diseases, The Toronto Hospital, Western Division.
 This Newsletter aims to update our patients on advances in research and treatment for patients with Psoriatic Arthritis.
 

WHAT IS PSORIATIC ARTHRITIS?

Psoriatic Arthritis is an inflammatory arthritis associated with psoriasis.  The arthritis presents with pain, swelling and stiffness in the affected joints, and occasionally with a reddish discoloration over these joints.  It may also affect the neck and the back, causing pain, stiffness and limitation of movement.  Psoriasis is a common skin disease which affects 1-3% of the population.  Psoriatic Arthritis may develop in as many as one third of the patients with psoriasis, thus Psoriatic Arthritis is a relatively common condition.  Psoriatic Arthritis was considered a mild form of arthritis and physicians have tended not to treat it very aggressively.  The cause of the disease and the reason for its persistence are not well understood.
 

WHY IS THE PSORIATIC ARTHRITIS CLINIC SPECIAL?

The Psoriatic Arthritis Clinic was started in 1978 by Dr. Dafna Gladman.  It was developed because there was not a lot of information about this condition. As noted in the following sections, we have learnt a lot since its inception. The Clinic now takes place on Wednesday afternoons, between 12:30 and 4:30 PM.  Patients are evaluated by a physician, usually a Rheumatology trainee, who is particularly interested in this disease.  All patients are then reviewed by Dr. Gladman, both in order to provide the continuous specialized care, and to assure that the information which is collected is accurate.  The patients are evaluated in a standard way, according to a specially designed format, which includes a complete history, physical examination, blood and urine tests and x-rays at regular intervals.  This information is then entered into a computer database.  In this way, different patients can be compared, and knowledge about the disease is enhanced.  The Clinic numbers over 470 patients who have been followed longitudinally.  This Clinic constitutes the largest and the most comprehensively studied group of Psoriatic Arthritis patients in the world.  Various Centres around the world have invited Dr. Gladman to speak and share what we have learnt about this disease..
 
 

WHAT HAVE WE LEARNT  IN THE PSORIATIC ARTHRITIS CLINIC?
 

 A great deal of knowledge has been gained at the Psoriatic Arthritis Clinic.  The recognition that the disease may result in a destructive form of arthritis in about one fifth of the patients has changed the approach of rheumatologists all over the world towards this disease.  This information could not have been gathered in any other way. The availability of the computer database allows us to study the patterns of the disease and its progression, which cannot be identified when a physician looks after a small number of patients and does not have the information readily at hand. We have confirmed that the methods we use to assess active inflammation and joint deformities, as well as the interpretation of the x-ray changes are reliable. This allows us to continue with our studies of prognosis.  Indeed, since we published the results of our initial study in 1987, several other Centres in the world have become interested in the study of Psoriatic Arthritis, and are using our definitions and methods in their patient populations.

 In addition to active joint inflammation and the development of joint deformity and damage, we have realized that the patients perception of their health and quality of life is an important outcome. Our patients have helped us evaluate the quality of life in Psoriatic Arthritis.  We found that these measures are important factors in the overall assessment of patients with Psoriatic Arthritis, as they provide additional information about the patients which is not reflected in our measures of clinical activity and damage. We have now incorporated these measures into our regular assessments.  When we evaluate the results of new therapies, we want to assure that we assess their effect on patients' quality of life and not only the traditional clinical measures.

 A major investigation into the prognostic factors of this disease has been carried out over the past few years, a project supported initially by Ontario Ministry of Health, and more recently by the Medical Research Council of Canada.  The results of this investigation have taught us that patients who present with a significant degree of inflammation at their first visit to the Clinic are at risk for progression of their disease and development of deformities.  This suggests that we need to be more aggressive with our therapy earlier in the course of this disease.  We have recently found that there are certain genetic markers, present on the membranes of white blood cells, which also serve as indicators of progression, and these may be more important than the clinical features, which may change with time.  These markers are known as HLA antigens.  Many people may recognize this term in conjunction with organ transplantation.  Although HLA antigens were initially identified in the context of transplantation, it soon became clear that they were important in the immune response, the ability of our bodies to fight off infections.  Certain of these markers are more likely to occur in patients with psoriasis and psoriatic arthritis than in the general population, and thus are thought to play a role in the development of the disease.  It turns out that some of these markers are also important in the progression of the disease.  This information is crucial, since these markers may identify those individuals destined to develop a more severe form of Arthritis and allow a more rational approach to the treatment of individual patients.  Further studies, supported by The Medical Research Council are in progress to identify the role of medications on disease progression.

 ARE THERE ANY NEW THERAPIES FOR PATIENTS WITH PSORIATIC ARTHRITIS?

A number of medications have been tested in our Psoriatic Arthritis Clinic.  These include the retinoic acid analogue, Tegison, an anti-inflammatory drug called Meclomen, Gold therapy, Methotrexate therapy, Sulfasalazine (Salazopyrine) therapy and Fish Oil.  Other investigators around the world have studied several of these medications as well.  Recently a controlled trial of Sulfasalazine proved its efficacy in Psoriatic Arthritis.  A pilot study of a new medication is promising, and we are currently considering this and another new therapy in Psoriatic Arthritis, and hope to begin formal studies once the protocols have been completed.

Are we any further ahead understanding the cause of Psoriatic Arthritis?

 There has been some evidence to support a role for immunological factors in the development of Psoriatic Arthritis.  We and others have found some abnormalities in the immune function (defense mechanisms) in patients with both psoriasis and Psoriatic Arthritis.  We have also identified several patients whose psoriasis and arthritis were precipitated by injury, suggesting that this may be a factor in the development of the disease.
 
 

ARE HEREDITARY FACTORS IMPORTANT IN PSORIATIC ARTHRITIS?

We know that about 40% of patients with Psoriatic Arthritis have relatives with either Psoriasis or Psoriatic Arthritis suggesting some hereditary contribution to its development.  The discovery of the HLA genes on chromosome 6 which have a role in the susceptibility to certain diseases, as well as in the immunologic response, has facilitated genetic studies in this disease.  We and others have shown that there is an association between Psoriasis and Psoriatic Arthritis and certain HLA antigens, and that there are certain antigens which identify those patients with psoriasis more likely to develop arthritis.  As mentioned earlier, certain HLA antigens have actually been found to predict progression of psoriatic arthritis, and some have been associated with certain disease manifestations. There are now new techniques to identify these genes and their variability in more detail.  Our HLA laboratory has been moved to The Toronto Hospital, and in now located within the Regional HLA Laboratory directed by Professor Judy Wade.  This is an exciting move since the combined expertise of Professors Wade and Gladman will advance these studies tremendously. We have already reported on one HLA gene, at the C locus, associated with Psoriatic Arthritis which is more easily detected with the new molecular techniques and is associated with an earlier age of onset of Psoriasis. Moreover, there are several new genes that have recently been identified which may be relevant in Psoriatic Arthritis.  We are currently studying these genes as well.  We have been awarded a research grant from The Arthritis Society and plan to extend our family studies, including re-testing some of the families we have previously studied, for further genetic markers.  We hope the patients and their families will continue to support our efforts, and agree to participate in this very important endeavour, which may very well identify the gene responsible for psoriasis and Psoriatic Arthritis.

Several areas of investigations are ongoing at the Psoriatic Arthritis Clinic in addition to the above mentioned genetic studies.

For Study Details ........

We have learnt a lot about Psoriatic Arthritis since the Clinic inception in 1978. We wish to thank our patients for helping our endeavours, and hope that they will continue to participate in these investigations, which will ultimately help us develop better treatment approaches to this disease.
 
 

If you are interested in participating in any of these studies, or would like further information, please inquire.

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