Rheumatoid arthritis – Causes, Symptoms And Diagnosis
Rheumatoid arthritis is defined as a persistent inflammatory disease affecting peripheral joints symmetrically, altering the cartilage, eroding the bone and leading to ankylosis. Rheumatoid arthritis affects 1% of the general population, is more common in women than in men, the women / men ratio is 3 / 1, and most often is diagnosed between 35 and 50 years.
Rheumatoid Arthritis Causes
The exact cause of rheumatoid arthritis is unknown, but pathogenic, is accepted the existence of genetic predisposition, against which environmental antigens or endogenous antigens can cause immune mechanism which is responsible for the appearance of the inflammation in the peripheral joints.
- Genetic predisposition. Rheumatoid arthritis is four times more common in first degree relatives of patients with seropositve rheumatoid arthritis and 10% of patients with rheumatoid arthritis have a first-degree relative with the same disease. Major genetic risk for rheumatoid arthritis is HLA DR4 in populations of northern Europe and HLA DRB 10402 in populations of southern Europe.
- Possible antigens. There is evidence on the viral nature of antigens that can trigger a immune response in rheumatoid arthritis (Epstein Barr virus, retroviruses) or bacterial antigens (Mycoplasma arthritis, Mycobacterium tuberculosis, Proteus mirabilis).
- Pathogenic immune process. It is supported both by the cellular argument, consisting in the presence in the synovium of a large number of lymphocytes T helper (CD4 +) and by the humoral argument: the production of local rheumatoid factor, the circulating immune complexes of IgM and IgG and the complement activation.
Rheumatoid Arthritis Symptoms
In the onset period:
The first sign is morning joint stiffness, with a progressive duration, relevant when is exceeding 60 minutes. Joint pain occur at short intervals, especially in active movements, and swollen joints (arthritis). Joint pain and arthritis are symmetrical and most commonly interested are metacarpophalangeal joints, proximal interphalangeal (especially the finger 2 and 3) and corresponding joints from the leg. Sometimes rheumatoid arthritis, can have a onset with the inflammation of radiocarpal or of carpal joints. In 10% – 20% of cases, the onset is acute, passing sometimes in one night, from the period of apparent health, to the clinical picture of acute generalized rheumatoid arthritis.
In the period of clinical symptoms, there are articular events and extraarticular events.
Articular manifestations. The most frequent are interested the small joints of hands, the wrists, knees and feet. In time the disease can affect the ribs, shoulders, sterno-clavicular joints, hips and ankles. In general, it might be interested any joint in the body.
- Hands. Proximal interphalangeal joint swelling, give the fingers the appearance of spindle. It is one of the early and characteristic signs. Late, will appear the deformation of the fingers;
- Fists. Radio carpal joint is constantly affected in rheumatoid arthritis. Functional is found a reduction of mobility in wrist, both in terms of flexion, and extension;
- Knees. Inflammation with edema in the knee joint, is frequently a sign of rheumatoid arthritis;
- Feet and ankles. The most common are interested metatarsophalangeal joints, with valgus deformity of the toe, causing pain in walking.
Extraarticular manifestations of rheumatoid arthritis. All extraarticular complications occur almost exclusively in patients with seropositve rheumatoid arthritis.
- Skin: subcutaneous nodule, with hard consistency and diameter about 1 cm. They occur in the joint structures, especially in areas of pressure: elbow, hand, foot, etc.;
- Muscle: swelling and eventually atrophy, especially in the interosseous muscles of hand and of foot;
- Cardiac manifestations represented by pericarditis (more frequent) and rhythm disturbances, valvular stenosis or regurgitation;
- Respiratory manifestations: pleuritis, pulmonary fibrosis;
- Ophthalmologic manifestations are rare. A particular form of rheumatoid arthritis is Sjogren’s syndrome: rheumatoid arthritis, with dry corneas, dry mouth, which may be associated with hypertrophy of the parotid glands.
Felty syndrome is defined by the triad: rheumatoid arthritis, splenomegaly and neutropaenia.
- Rheumatoid factor positive in 80% of cases, is useful for diagnosis in a titer which is higher then 1 / 80. Rheumatoid factor is dividing rheumatoid arthritis into two classes: seropositive rheumatoid arthritis (with rheumatoid factor) and seronegative rheumatoid arthritis (without rheumatoid factor). Positivity rheumatoid factor occurs at a variable interval of time from onset of clinical disease. Usually when there are extraarticular manifestations, rheumatoid factor is present in high titers. Rheumatoid factor is present in 6% – 8% of the general population and can occur with other autoimmune diseases, which may reduce its specificity.
- Antinuclear antibodies, occurring in 30% – 40% of cases.
- Nonspecific inflammation tests: ESR accelerated, fibrinogen and C-reactive protein are increased.
- Synovial fluid examination, shows the presence of leukocytes between 5.000/mm³ and 20.000/mm³, low or normal glucose, low complement and the presence of polymorphonuclear.
- Anemia characteristic for chronic inflammation.
- Radiological changes in rheumatoid arthritis is evolving in stages, as follows:
- Stage I (early): the presence or not of osteoporosis, but without bone erosion;
- Stage II (moderate): the presence of osteoporosis, with or without bone destruction, with or without mild cartilage damage, but without the presence of joint deformities;
- Stage III (severe): the presence of osteoporosis accompanied by bone destruction and cartilage damage, joint deformation accompanied by dislocations, but no bone ankylosis;
- Stage IV (terminal): the presence of stage III criteria, plus fibrosis and joint stiffness .
7. Other osteoarticular imagistic examinations include bone scan and MRI, which can reveal early inflammatory changes that can not be highlighted on a standard radiography.
Rheumatoid arthritis Diagnosis
Because the diagnosis of rheumatoid arthritis is not always easy, American College of Rheumatology proposed a series of diagnostic criteria:
- Morning stiffness lasting at least one hour, at least 6 weeks;
- Arthritis of three or more joints of the hand or foot, involving the simultaneous three joints, manifested by swelling, lasting at least 6 weeks;
- Hand arthritis, at least one area of the hand joints with arthritis (metacarpophalngeal , wrist, interphalangeal joint), lasting at least 6 weeks;
- Symmetrical arthritis, involving the same joints simultaneously;
- Rheumatoid nodules;
- Rheumatoid factor present;
- Radiological changes typical for rheumatoid arthritis, which should include bone erosion or decalcification of the bone.
The diagnosis of rheumatoid arthritis requires the presence of at least four of the seven criteria listed.
To give a full diagnosis of rheumatoid arthritis should be taken into account the functional classification of the disease:
- Class I: Any activity is possible;
- Class II: normal activities are possible, despite the pain and discomfort represented by limiting the mobility of one or more joints;
- Class III: low functional capacity, are possible only a few of the normal activities (is possible Self-care);
- Class IV: immobilization in bed or wheelchair, usually self-care measures are impossible.