<<**Rheumatoid Arthritis**<< • A chronic systemic inflammatory disorder. • It can affect numerous tissues and organs, but it primarily affects the joints, causing a non-suppurative proliferative and inflammatory synovitis that frequently proceeds to articular cartilage degradation and joint ankylosis. <<**INCIDENCE**<< •Involves about 1% of the population •Females are 3-5 times more affected than males •Less common in African and Asian individuals but tends to be more aggressive. •Majority of patients affected are 40-70 years old. \ ==**Genetic susceptibility**== • HLA-DRB 1 alleles ==**Environmental arthritogen(**==Causing or caused by arthritis) • Microbial agents (i.e viral infections) have been implicated • Citrullinated proteins (CCP) \ <<**Cause and pathogenesis**<< ==Autoimmunity== • There is evidence for both abnormal humoral and cell-mediated immunity. • These antibodies (usually IgM), which react with the Fc components of the IgG, can be detected in the blood as rheumatoid factor • Approximately 25 % of patients have antinuclear antibodies. \n ![k](https://knowt-user-attachments.s3.amazonaws.com/d93cd9f8836544cd8a6486610d9dd9bb.jpeg)CLINICAL FEATURES Swollen, tender and warm joints Symmetrical involvement ‘Morning stiffness’ is a common complaint .Any joint may be affected, mostly Small hand joints Feet joints Wrists, elbows and ankles are often involved. Insidious onset, chronic disease \ ==**Typical findings:**== •chronic inflammation of the synovium •exudation of cells, fluid, and fibrin (rice bodies) into the articular cavity •erosion of cartilage •juxta-articular osteoporosis •bony ankylosis •deformities of the joints \n ![Progression of rheumatoid disease](https://knowt-user-attachments.s3.amazonaws.com/fbd375993d934a809e1a4ad01f4686f9.jpeg) ==**Extra-articular manifestations:**== •subcutaneous rheumatoid nodules •lymphadenopathy •Splenomegaly and neutropaenia (Felty’s syndrome) •anaemia •dry mouth and dry eyes •pneumonitis with interstitial fibrosis and nodules •pericarditis •uveitis and scleritis \ ^^**morphology**^^ symmetric athritis • Synovium-oedematous, thickened, hyperplastic \-**Main histologic features**: ==•synovial cell hyperplasia and proliferation== ==•dense inflammatory infiltrate== ==•increased vascularity due to angiogenesis== ==•fibrinopurulent exudate on synovial and joint surfaces== ==•osteoclastic activity in underlying bone== \n ![A. Joint lesion B. Synovial hypertrophy c. Dense lymphoid aggregate](https://knowt-user-attachments.s3.amazonaws.com/b37135c559d442678670d31b8228513b.jpeg) \ ^^Pannus^^ is A mass of oedematous synovium, inflammatory cells, granulation tissue that grows over the articular surface and causes its erosion ^^Fibrosing ankylosis^^ is When cartilage has been destroyed and the pannus bridges the apposing bones ^^Bony ankylosis^^ is Fusion of bones \ h ![Early rheumatoid dâease. A byer of chronic inflammatory tisue (’pannus', arrowed) has eroded the a1!cuIar„ surface of the ferroral condyb. ](https://knowt-user-attachments.s3.amazonaws.com/a2753612460a4694a2b29c712380a766.jpeg) \n ![](https://knowt-user-attachments.s3.amazonaws.com/0dfe6610f92f4a3aad666d39abb48013.jpeg) ^^**Rheumatoid Nodules**^^ • Develop in about 30% of patients with RA • Not diagnostic of RA **Gross morphology** Firm, non-tender, round to oval • Located on ulnar surface of the forearm, elbow, lumbosacral area • Arise in subcutaneous tissue • Less commonly may be found in the lungs, spleen, pericardium, myocardium, heart valves and aorta ^^**Histopathology**^^ • central area of fibrinoid necrosis • surrounding rim of macrophages, lymphocytes and plasma cells \ ^^**MORPHOLOGY**^^ Blood vessels • Acute necrotising vasculitis (small and large arteries) • Can involve pleura, pericardium, lung • Obliterans endarteritis can occur obstructing digital arteries causing peripheral neuropathy.,ulcers, gangrene • Leukocytoclastic vasculitis -produces purpura, cutaneous ulcers, nail bed infarction • Ocular changes:uveitis, keratoconjuctivitis may be prominent. \ ^^**RADIOLOGICAL FEATURES**^^ • Osteopaenia • Prominent radial deviation of the wrist • Radial deviation of the fingers • Flexion-hyperextension abnormalities of the fingers ( swan neck, botonniere) • Marked loss of the joint spaces • Erosions of the metacarpal and carpal bones \n ![radiological feautures](https://knowt-user-attachments.s3.amazonaws.com/565a5b7d9c524b719d2d00f0698ab279.jpeg) \ ![•Diffuse osteopaenia •Marked loss of joint spaces of the carpal, metacarpal, phalangeal and interphalangeal joints •Periarticular bony erosions •Ulnar drift of fingers](https://knowt-user-attachments.s3.amazonaws.com/7e7600edb2d24cc6b17002521b57dcd0.jpeg) \ ^^**LABORATORY INVESTIGATIONS**^^ • Rheumatoid factor • Anti-CCP antibody • Normocytic normochromic anaemia • Raised ESR and CRP • Auto-antibodies such as ANF may be present \ ^^Rheumatoid factor^^ • Found in only 75 % of patients with RA. • May be present in the serum of patients who do not have RA but who do have : • Systemic Lupus Erythematosus • Sjogren syndrome • infectious mononucleosis • viral hepatitis \n ![Differences between RA and OA](https://knowt-user-attachments.s3.amazonaws.com/6bc63d91268a4dc08d50bfd949bd5523.jpeg) s ![](https://knowt-user-attachments.s3.amazonaws.com/dc0a22ba537d4035852eb46e134cd801.jpeg) ^^**Juvenile Idiopathic Arthritis**^^ \ • Variant of RA • Begins before the age of 16 years • There are several forms which correspond toseparate diseases and different backgrounds • Long term prognosis is variable and 10 % of patients develop a serious functional disability \ ^^**Several forms**^^ • systemic arthritis • oligoarthritis • rheumatoid factor-positive polyarthritis • rheumatoid factor-negative polyarthritis • rheumatoid factor polyarthritis • enthesitis • psoariatic arthritis • undifferentiated arthritis \ ^^**Differences between JIA and adult RA**^^ • Systemic disease is more frequent • Large joints are affected more often than small joints • Rheumatoid nodules and rheumatoid factor are usually absent • Anti-nuclear antibody (ANA) seropositivity is common \ ^^**Juvenile**^^ __Stills disease / systemic arthritis__ • Variant of JIA • Abrupt onset • Features include : \-high spiking fevers \-migratory and transient skin rash \-hepatomegaly \-serositis • Associated with recurrent flares or persistent disease with significant morbidity

pathology of joints part 1