Rheumatoid arthritis etiology classification

Historical reference

In 1969, Finnish rheumatologists proved the connection between arthritis and colitis caused by bacteria of the genus Yersinia. It differed from acute infectious arthritis in that microbes were not detected in the synovium. The Finns proposed to isolate it into a separate nosological form and gave it the name - reactive arthritis.

Science does not stand still, and ten years later a new microbiological research method was invented - immunocytochemical. With its help, it was discovered that in reactive arthritis, the cells of the synovial membrane contain bacterial particles. In the 90s of the last century, PCR analysis began to be used in laboratories. It allows you to detect microbial DNA in synovial fluid.

Epidemiology[ | ]

Arthritis is a widespread disease in the human population. In the United States alone, more than 42 million people suffer from arthritis, and one in six are disabled as a result of the disease. It should be noted that among the causes of disability in this country, arthritis ranks first. Arthritis has “about the same effect on the U.S. economy as a moderate economic downturn,” with the disease costing Americans more than $64 billion annually, the Centers for Disease Control and Prevention reports. These losses are associated with treatment costs and decreased productivity. In developing countries such as Brazil, India, Indonesia, China, Malaysia, Mexico, Thailand, the Philippines and Chile, according to studies cited by the World Health Organization, arthritis and similar diseases cause “no less harm there than in rich countries.” countries."

Over time, the number of people suffering from arthritis is gradually increasing. In Canada, it is believed that the number of patients will increase by 1 million over the next ten years. [ source not specified 3855 days

] Although arthritis is not as widespread in Africa and Asia as in Europe, the number of people suffering from this disease is growing rapidly in these parts of the world. Due to the prevalence of arthritis, the World Health Organization declared the period from 2000 to 2010 the “Decade to Fight Bone and Joint Diseases.” During this time, doctors and healthcare workers are focusing their efforts on making life easier for those suffering from musculoskeletal diseases, including arthritis.

Causes

Scientists do not yet know why some people's joints respond to infection and others do not. It is believed that reactive arthritis occurs in carriers of the HLA-B27 antigen. This antigen is a receptor for bacteria. It binds to them and promotes their transport to various tissues of the body, including the synovium. Most often these are pathogens of intestinal infections:

• shigella;
• Yersinia;
• salmonella;
• blastocysts;
• campylobacter;
• clostridia.

Half as often are pathogens of sexually transmitted infections (chlamydia, gonorrhea, etc.).

Enterocolitic reactive arthritis most often develops after dysentery, urogenital - against the background of chlamydia.

The presence of pathogenic microorganisms or parts thereof is a powerful irritant to the immune system. Moreover, immune cells attack not only foreign agents, but also cells of their own joints and other organs that have been in contact with the infectious agent. Because of this, autoimmune inflammation develops in them.

Reactive Arthritis Clinic

Most often, the disease affects the joints of the legs - big toe, ankle, knee, heel tendons. If the inflammation concerns the hands, then the wrist and elbow joints suffer.

In general, reactive arthritis is characterized by:

• damage to a few joints (from one to three);
• asymmetry;
• night pain;
• involvement of tendons and ligaments in the process;
• concomitant urethritis or conjunctivitis;
• sausage-shaped fingers;
• damage to the plantar surface of the feet and nails.

As with all arthritis, the joints swell, the skin over them turns red and becomes hot.

Conjunctivitis is clinically manifested by redness of the sclera, a feeling of sand in the eyes, urethritis - frequent painful urination.

There is a special form of reactive arthritis, in which inflammation of the joints is combined with conjunctivitis and urethritis at the same time. It is called Reiter's syndrome (triad).

With both ordinary reactive arthritis and Reiter's syndrome, the plantar surfaces of the feet change. At first they become covered with red spots. In the center of the spots, zones of increased keratinization are formed - hyperkeratosis, in other words, hardening of the skin. Gradually they spread to the entire sole. Thickened skin peels off.

Toenails also react to inflammation. They thicken, turn yellow and collapse. Damage to the soles and nails does not cause pain, so a person does not attach any importance to them.

In rare cases, other systemic manifestations are observed:

• enlarged lymph nodes (especially inguinal);
• balanitis (inflammation of the skin of the head of the penis);
• iritis (inflammation of the iris);
• formation of ulcers on the oral mucosa;
• glomerulonephritis;
• heart damage (myocarditis, aortic valve insufficiency, pericarditis);
• polyneuritis;
• pleurisy.

Clinical picture[ | ]

All types of arthritis are accompanied by pain, the nature of which depends on the type of arthritis. Arthritis is also characterized by redness of the skin, limited mobility in the joint, and changes in its shape. Disease-prone joints often crack unnaturally when stressed. A person with arthritis may have difficulty using physical force.

Elements of the medical history determine the diagnosis. Important elements are the time of onset and rate of development of the disease, the presence of morning stiffness, pain, “locking” of the joint due to inactivity, etc. X-rays and tomograms are used for more accurate diagnosis.

How does reactive arthritis occur?

The disease occurs acutely 2 weeks to a month after the infection. Symptoms persist, on average, from 3 to 6 months, rarely - up to a year or longer. Then, in most cases, stable remission or complete recovery occurs.

In 15-20% of patients the process becomes chronic. This happens with urogenital reactive arthritis, especially often with Reiter's syndrome. Frequent relapses may be caused by untreated chlamydial infection and re-infection.

Relapses, as a rule, are more severe - an increasing number of joints become inflamed, the eyes, mucous membranes, skin, and urethra are affected.

Over a long period of time, reactive arthritis can transform into rheumatoid arthritis, the treatment of which requires much more effort.

Diagnostic principles

It is not easy to distinguish reactive arthritis from other joint pathologies. Usually the doctor assumes its presence if the patient is young, the inflammation of the joints is asymmetrical, and is accompanied by night pain. When arthritis is combined with damage to the eyes, feet, genitourinary organs, and intestines, making a diagnosis is not difficult.

Often the clinical picture of the disease is blurred, atypical or too similar to other diseases (for example, sausage-shaped deformation of the fingers is also characteristic of psoriatic arthritis). Then additional research methods come to the rescue.

All patients with suspected reactive arthritis are required to undergo blood tests. They most often find:

• increased ESR;
• increased levels of CRP, seromucoid, sialic acids;
• leukocytosis;
• normochromic anemia;
• HLA-B27 antigen.

Antinuclear and rheumatoid factors are absent in the blood, which indirectly confirms the diagnosis.

In a general urine test for urogenital reactive arthritis, a large number of leukocytes are detected, a small number of erythrocytes (microhematuria), and protein are detected. Urine culture can identify the causative agent of infection. To diagnose chlamydia, scrapings from the urethra and cervical canal are also taken.

To detect intestinal infection, serological methods are used - determination of antibodies to Yersinia, Salmonella, and Campylobacter in the blood. Salmonella and Shigella can be detected by bacteriological analysis of feces.

There is a rule: every patient with reactive arthritis should be examined for gonorrhea and HIV infection.

If there is a need to differentiate reactive arthritis from septic arthritis, examine the synovial fluid. It has signs of inflammation: poor formation of a mucin clot, low viscosity, increased content of leukocytes (5-10 thousand per μl, in septic conditions - 20-100 thousand), among which segmented neutrophils predominate.

To exclude other rheumatic diseases, x-rays of the sacroiliac joints are taken. In the picture, with a long course of arthritis, you can see sacroiliitis on the right or left. The asymmetry of the lesion speaks in favor of the infectious nature of the disease.

Treatment

Modern laboratory methods make it possible not only to identify the causative agent of the disease, but also to determine which antibiotics can cope with it. For inflammation caused by chlamydia, azithromycin, clarithromycin, doxycycline, and fluoroquinolones are usually prescribed. The course of treatment lasts from 10 to 30 days, sometimes up to 3 months.

The need for antibiotic treatment of reactive arthritis that occurs after an intestinal infection has not been proven.

To suppress inflammation in the joints and relieve the patient of pain, NSAIDs are used; if the process is highly active, glucocorticoid hormones are used.

It would seem that treatment should not be difficult: they prescribed an antibiotic and defeated the disease. But in reality everything turns out to be more complicated. Even if the bacteria are no longer in the body, disturbances in the functioning of the immune system remain. Therefore, during long-term exacerbations, patients are prescribed immunomodulators (methotrexate, azathioprine, sulfasalazine). Recently, they have been used less and less, since their effectiveness in seronegative spondyloarthritis is highly questionable.

Reactive arthritis is relatively benign and does not lead to severe dysfunction of the joints. Therefore, as a rule, there is no need for surgical treatment.

Prevention[ | ]

With age, the risk of arthritis only increases, so prevention should begin at a young age.

Arthritis is caused by:

• overweight;
• poor nutrition;
• frequent injuries and fractures;
• heavy load on joints associated with working conditions.

To prevent arthritis it is necessary [ source not specified 2891 days

]:

1. monitor your weight, as excess weight increases wear and tear on your joints;
2. lift weights correctly, without bending the spine left or right, avoiding injuries and unnecessary stress on joints and muscles;
3. exercise regularly, as a well-developed “muscle corset” reduces the load on the joints;
4. eat a balanced diet, including polyunsaturated fatty acids (fatty fish, fish oil) and calcium (dairy products, fish), also exclude animal fats (a source of “bad” cholesterol), eat more vegetables and fruits. Omega-3 unsaturated fatty acids alleviate the symptoms of arthritis (in particular, due to the synthesis of anti-inflammatory molecules - resolvins [8]). A study of 2112 patients with radiographically confirmed osteoarthritis of the knee found that higher magnesium intake corresponded to a significant reduction in the risk of osteoarthritis (P=0.03)[9]
5. reduce your intake of sugar and other easily digestible carbohydrates from carbonated drinks;
6. do not smoke or drink alcohol - this also affects the joints negatively;
7. maintain correct posture, which reduces stress on joints;
8. properly organize the workplace so that it is comfortable to sit, without having to lean forward, throw your head back, or strain your back and neck;
9. take breaks from work that involves prolonged sitting/standing. Do light exercises during breaks.