Rheumatoid Arthritis

Adam Syfrett

Professor Name

Immunology

26 February 2008

RHEUMATOID ARTHRITIS

INTRODUCTION

Rheumatoid arthritis is a chronic systemic inflammatory disease that may affect many tissues and organs , skin , muscles , cardiovascular and respiratory systems . It principally attacks the joint and causes a non-suppurative and inflammatory synovitis which progresses to destruction of the articular cartilage and joint ankylosis . The typical clinical phenotype of RA is a symmetrical deforming small and large joint polyarthritis often associated with systemic disturbance and extra articular disease [Firestein , 356] . Being an autoimmune disease cytokines

and an autoantibody , rheumatoid factor , produced by lymphocytes and plasma cells respectively have been implicated in the pathogenesis of RA these agents and cells have also become the targets of therapeutic agents

EPIDEMIOLOGY

RA occurs throughout the world and in all ethnic groups . The prevalence is lowest in black Africans and Chinese . It is highest in the Pima Indians of Arizona . In Caucasians , it is 1-1 .5 with a higher prevalence in females [Lee , 903]

RA is an autoimmune disease . Concordance rates are higher in monozygotic twins than in zygotic twins . The frequency of the disease is increase in first-degree relatives of patients with RA . The genetic contribution to susceptibility is due to genes in the HLA region : HLA-DR4 is the major susceptibility haptotype in some ethnic groups . It is more likely that genetic factors influence both susceptibility and severity , with DR4 positivity more common in those with severe disease [Firestein , 356]

Female gender is a risk factor and this susceptibility in increased post-partum and by breast feeding . Rheumatoid arthritis is the most common inflammatory arthritis in women and hence an importance cause of potentially preventable disability . No infectious agents have been consistently isolated and there is no evidence of disease clustering [Firestein , 356] . Cigarette smoking is a risk factor for RA and for positivity for rheumatic factor in non-RA subjects

CLINICAL FEATURES

The diagnosis of RA can only be established by an accurate and careful history and physical examination . Only limited help is provided by laboratory tests

The clinical hallmark of inflammatory joint disease is persistent synovitis . The diagnosis of RA can be made in the presence of four or more of the following : morning stiffness[ 1hour] , arthritis of three or more joint areas , arthritis of hand joints , symmetrical arthritis rheumatic nodules , radiological changes , rheumatic factor , duration of 6 weeks or more [Lee , 2003]

The most common presentation is with a gradual onset of symmetrical arthralgia and synovitis of small joints of the hands , feet and wrists The insidious onset has traditionally been considered to be a poor prognosis , possibly because of the delay in presenting for medical advice . A dramatic acute onset with florid morning stiffness polyarthritis and pitting edema , occurs more in the elderly Occasionally the onset is palindromic , with recurrent symmetrical acute episodes of joint pain and swelling . The hand is crucial to the overall patient function and provides a good reflection of overall disease activity . The typical features are symmetrical swelling of the metacarpophalangeal and proximal interphalangeal joints . These...