Diagnostic Value of Oral Prednisolone Test for Rheumatoid Arthritis (TryCort)

Rheumatoid arthritis is an inflammatory joint disease often leading to progressive joint destruction. To prevent disability caused by inflamed joints early diagnosis is important. Early diagnosis might be a challenge because the diagnosis is mostly based on clinical signs like swelling of small joints. In clinical practice a therapy with prednisolone is started although the patients do not have an exact diagnosis. In this cases the prednisolone might serve as a diagnostic test for an inflammatory process. The objective of this study is to investigate the diagnostic value of oral prednisolone test for rheumatoid arthritis.

Rheumatoid arthritis is with a prevalence of 2% an important inflammatory joint disease which often leads to impaired functioning and reduced quality of life. Early diagnosis is an important step forward to prevent progressive joint destruction. The classification criteria for rheumatoid arthritis published in 2010 are based on clinical signs (such as swelling) and laboratory findings (such as rheumatoid factor) (Aletaha D 2010). Because its diagnosis is based on clinical signs the early diagnosis for rheumatoid arthritis might be a challenge in daily clinical care. In clinical practice a therapy with prednisolone is started although the patients do not have an exact diagnosis. It has been shown that the start of early low-dose prednisolone decreases the rate of joint destruction after two years of therapy (Kirwan JR 1995, Wassenberg S 2005). Thus, prednisolone might have effects comparable to that of disease-modifying antirheumatic drugs. The objective of this study is to investigate the diagnostic value of oral prednisolone test for rheumatoid arthritis. The hypothesis is that in patients with rheumatoid arthritis the prednisolone test will be positive in 80% of the patients whereas positive in just 20% of patients with osteoarthritis of the hand. Positive prednisolone test is defined as a 30% improvement of the symptoms in finger and wrist on a numeric rating scale from 0-100. Patients with suspicious of rheumatoid arthritis will undergo a prednisolone test with 20 mg per day for 3 days after 2 days of therapy with paracetamol 500 mg twice. After this period the patients will be asked to rate their benefit in improving pain and reducing swelling of wrist and finger joints on a numeric rating scale (0-100 % improvement in steps of 20%). A positive response In addition, demographics and clinical parameter including the compound measure for disease activity DAS-28 will be collected. A patient with a positive prednisolone test will receive standard care for rheumatoid arthritis onward. Patients with a negative prednisolone test will receive standard care for hand and finger osteoarthritis onward. At week 12 all patients will be seen again to reassess the former diagnosis.

Patients with suspicious of rheumatoid arthritis will undergo a prednisolone test with 20 mg per day for 3 days after 2 days of therapy with paracetamol 500 mg twice for 2 days.

Positive prednisolone test: change of more than 40% (on a NRS 0-100%) in painful joints after 3 days of therapy with prednisolone 20 mg/d

Positive prednisolone test: change of more than 40% (on a NRS 0-100%) in painful joints after 3 days of therapy with prednisolone 20 mg/d

Inclusion Criteria: pain in wrist and fingers without known diagnosis since more than 6 weeks, minimum of pain on a numerical rating scale 4 (out of 10) Exclusion Criteria: rheumatoid arthritis psoriatic arthritis psoriasis vulgaris vasculitis gouty arthritis Current glucocorticoidmedication

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