Reactive arthritis

Introduction to reactive arthritis The term reactive arthritis (ReA) was first proposed by Aho in 1974. Since then, a series of clinical and laboratory studies have been carried out on this disease, and its name has gradually been recognized. Currently, reactive arthritis refers to acute non-suppurative arthritis secondary to infection in other parts of the body. Reactive arthritis after intestinal or genitourinary infection is most common. In recent years, there have been many reports on streptococcal infection and reactive arthritis after infection with Chlamydia pneumoniae, and are considered to be two different types of reactive arthritis. basic knowledge The proportion of illness: 0.006% Susceptible people: no special people Mode of infection: non-infectious Complications: balanitis prostatitis iridocyclitis

Causes of reactive arthritis

(1) Causes of the disease

Common microorganisms that cause reactive arthritis include the intestines, genitourinary tract, pharyngeal and respiratory infections, and even viruses, chlamydia and protozoa.

Most of these microorganisms are negative for Gram staining and have the property of adhering mucosal surfaces to host cells.

Studies have found that many of the patients with reactive arthritis can detect the DNA and RNA of Chlamydia trachomatis and the antigenic components of Shigella, and Chlamydia heat shock protein (HSP), Yersinia HSP60 and Its polypeptide fragments can induce T cell proliferation in patients with reactive arthritis. These findings suggest that T cells in peripheral blood of patients may be induced by the antigenic components of the above bacteria. Recently, studies have suggested that the tendon attachment point on the bone may be One of the sites where the initial immune and pathological reactions of reactive arthritis occur, and is the pathological basis for the development of tendonitis.

In recent years, a large number of studies have proved that B-type hemolytic streptococcal infection is closely related to the pathogenesis of reactive arthritis. In addition to reactive arthritis caused by intestinal and genitourinary tract infections, type B hemolytic streptococcus infection is reactive. Another common cause of arthritis, the most discussed topic at present, is how to distinguish between reactive arthritis (PSReA) and rheumatic fever after streptococcal infection, Birdi et al in 2001 in 16 hospital affiliated hospitals in Canada for children with rheumatism, heart A survey of specialists with diseases and infectious diseases found that these physicians have different diagnostic criteria, treatment methods and preventive measures for reactive arthritis after streptococcal infection. Some children with reactive arthritis after diagnosis of streptococcal infection Carditis occurs after a few months, and many people who diagnose atypical rheumatic fever are reactive arthritis after streptococcal infection.

Recently, Kocak et al. diagnosed arthritis/arthralgia after infection with Streptococcus hemolyticus, but did not meet the revised criteria for diagnosis of Jones rheumatic fever. Respiratory arthritis (PSReA) after streptococcal infection, clinically, except for arthritis In addition, these patients may still have skin erythema, tendonitis, orchitis, etc., studies have suggested that about 6% of streptococcal infection patients with reactive arthritis can develop carditis during the course of the disease, it is generally believed that these streptococcus Patients with reactive arthritis after infection should still be given prophylactic antibiotics to avoid further joint damage to streptococcal infection or the presence of carditis.

(two) pathogenesis

Reactive arthritis caused by intestinal and genitourinary tract infections has been shown to be associated with the susceptibility gene HLA-B27, whereas reactive arthritis caused by streptococcus, viruses, and spirochetes is generally free of HLA-B27 factors, but whether There is no conclusion about other genes.

In recent years, studies have found that patients with reactive arthritis have a HLA-B27 positive rate of 65% to 96%, and HLA-B27 carriers have a 50-fold increased chance of developing reactive arthritis. However, the HLA-B27 gene is neither a response. The only cause of sexual arthritis is not the necessary condition. The negative person of this gene also suffers from reactive arthritis. Family studies have found that all of the HLA-B27 positive family members infected with dysentery do not have reactive arthritis. The patients with reactive arthritis are not all HLA-B27 positive, but the clinical symptoms of HLA-B27 positive patients are significantly more serious than those with negative genes, and HLA-B27 positive patients are prone to develop chronic reactive arthritis. It is suggested that the susceptibility to reactive arthritis in HLA-B27-positive patients is related to the type of pathogenic bacteria. For example, the positive rate of HLA-B27 in Salmonella-producing patients is 20% to 33%, and that in Mycoplasma is 40%-50. %, Yersinia caused 70% to 80%, and Shigella caused 80% to 97%.

The study of the role of HLA-B27 in the pathogenesis of reactive arthritis found that the neutrophil activity of this gene-positive patient is enhanced and may enhance the immune response to pathogenic bacteria. At the same time, HLA-B27 can prolong intracellular The survival time of the pathogen, thereby increasing the reactivity of T cells to the pathogen and its antigenic peptide.

In recent years, the hypothesis that HLA-B27 is pathogenic by molecular mimics has been questioned because, although Klebsiella pneumoniae and HLA-B27 share a common amino acid sequence, this sequence is not limited to pathogenic bacteria, and The bacterial antigenic peptide does not induce specific T cells or B cells, and therefore it is difficult to confirm that these bacteria play a role in the pathogenesis of reactive arthritis by a molecular simulation mechanism.

In addition to HLA-B27, there have been many studies on the relationship between other genes and reactive arthritis. It has been shown that HLA-B51, B60, B39 and B7 may increase the susceptibility to reactive arthritis, HLA-B60 and HLA. -B27 has a synergistic effect in the pathogenesis of reactive arthritis, while HLA-B39 and HLA-B7 can be found in patients with HLA-B27 negative, may directly participate in the pathogenesis of reactive arthritis, and another study found that the chain In patients with reactive arthritis, the frequency of HLA-DRB1*01 gene is increased after cocci infection, compared with HLA-DRB1*16 positive in patients with typical acute rheumatic fever after streptococcal infection. The results of several years of experimental research, however, further conclusions need more research to confirm.

Reactive arthritis prevention

1. Eliminate and reduce or avoid the disease factors, improve the living environment, improve the development of good habits, prevent infection, pay attention to food hygiene, and rational diet.

2. Pay attention to exercise, increase the body's ability to resist disease, do not fatigue, excessive consumption, quit smoking and alcohol.

3. Early detection and early diagnosis and early treatment, establish confidence in the fight against disease, adhere to treatment.

Reactive arthritis complications Complications balanitis prostatitis iridocyclitis

1. Some patients with reactive arthritis may have whirlpool balanitis, cystitis and prostatitis. In women, there may be cervicitis and salpingitis.

2. There may be conjunctivitis, scleritis, keratitis, and even corneal ulcers. In addition, there may be endophthalmitis such as iritis and iridocyclitis.

3. Reactive arthritis can cause heart block, aortic regurgitation, central nervous system involvement and exudative pleurisy.

Symptoms of Reactive Arthritis Common Symptoms Hypothermia Muscle Joint Movement During Knee Pain Exacerbation of Ankle Pain Muscle Tendonitis

Reactive arthritis is a systemic disease. It is generally more acute and has clinical manifestations of different severity. It can be transient single joint involvement, severe polyarthritis, or even obvious systemic symptoms or ophthalmia. And extra-articular manifestations such as heart involvement.

In most cases, there are intestinal, genitourinary or respiratory infections, and bacteriological evidence of these infections, days to weeks before arthritis, but a small number of patients have no clear history, clinically, reactive arthritis can be caused The pathogenic bacteria species exhibit different clinical and laboratory characteristics.

1. General symptoms Common systemic symptoms are fatigue, general malaise, myalgia and hypothermia, and a small number of patients may have moderate fever.

2. Joint symptoms The main manifestations of reactive arthritis are joint involvement, which varies in severity. Lightness can only cause joint pain, while severe cases show obvious polyarthritis and even limited activity. The typical performance is progressive. Aggravated asymmetry of single joint or oligoarthritis, the most common joint involvement of the lower extremities, such as the knee, ankle and hip joints, shoulders, elbows, wrists and small joints of the hands and feet can also be affected, local joint swelling, pain, increased skin temperature Or with skin erythema, the small toe of the small joints is more common, in some patients, there may be lower back and ankle pain.

3. Tendonitis Tendonitis is one of the common symptoms of reactive arthritis. It is characterized by local pain and tenderness of the tendon at the point of attachment of the tendon. It is most susceptible to Achilles tendon, plantar tendon, tendon attachment point and paraspinal involvement. In severe cases, the activity may be limited due to local pain or muscle atrophy may occur.

4. Skin mucosa Skin mucosal lesions are more common in reactive arthritis. The most characteristic manifestations are the skin and purulent keratosis of the palms and soles. This skin damage and the nails appearing in some patients are thick and thick. It can be similar to psoriasis skin manifestations, mainly in reactive arthritis after sexual intercourse such as gonococcal infection, and other types of reactive arthritis are rare, the reason is not clear.

Some patients with reactive arthritis may have whirlpool balanitis, cystitis and prostatitis, which are characterized by frequent symptoms such as urinary frequency, urgency, dysuria and hematuria. In women, cervicitis and salpingitis may still occur.

Nodular erythema was found only in some patients, mainly Yersinia infection. Clinical studies have found that the expression of HLA-B27 may be unrelated to the occurrence of nodular erythema.

Oral ulcers are another common manifestation of reactive arthritis, mostly superficial painless small ulcers, which can occur in the ankle, tongue, lips and buccal mucosa.

5. Intestinal lesions Intestinal infection is one of the predisposing factors of reactive arthritis. Patients may have a history of diarrhea from several days to several weeks before onset. Some cases have intestinal symptoms in the presence of arthritis. Intestinal mucosa congestion, erosion or similar ulcerative colitis and Crohn's disease-like appearance, in this period of patients with more bacteria-free growth.

6. Urinary tract manifestations Patients may have symptoms of urinary tract infections such as frequent urination, urgency, and dysuria, and most often occur before arthritis, but many patients may have no obvious symptoms.

7. Eye damage Eye damage is common in reactive arthritis, and may be the first symptom of the disease. Patients may have conjunctivitis, scleritis, keratitis, and even corneal ulcers. In addition, there may be endophthalmitis such as iritis and Iris ciliary body inflammation, therefore, can show signs of photophobia, tearing, eye pain, internal eye involvement, visual acuity decline, patients with eye damage should routinely perform eye examination, and corresponding local treatment, such as cortisone drops Eye drops, dilated, etc., in order to avoid permanent eye damage.

8. Visceral involvement in reactive arthritis can cause heart block, aortic regurgitation, central nervous system involvement and exudative pleurisy, cardiac conduction block in patients with reactive arthritis, and installation of pacemakers Case reports, individual patients may have proteinuria and microscopic hematuria during the course of the disease, but generally no serious kidney damage.

Examination of reactive arthritis

Laboratory tests are not specific for the diagnosis of reactive arthritis, but have a certain significance in judging the extent of the disease, estimating the prognosis and guiding medication. The main laboratory tests include:

1. Hematology ESR and C-reactive protein can be significantly increased in acute phase reactive arthritis, and can be reduced to normal in patients with chronic phase. White blood cells can be seen in blood routine examination, lymphocyte count is increased or mild anemia occurs. The patient can see elevated white blood cells or microscopic hematuria in the urine, and proteinuria rarely occurs.

2. Bacterological examination of the middle urine, throat and throat swab culture can help to find reactive arthritis-related pathogens, but due to the culture method, bacterial characteristics and timing of the different materials, often negative culture results, therefore, determination Anti-bacterial and bacterial protein antibodies in serum are important for identifying bacterial types. Currently, in the diagnosis of reactive arthritis, microorganisms that can be used for routine antibody detection include Salmonella, Yersinia, Campylobacter, Chlamydia, Neisseria gonorrhoeae, Borrelia burgdorferi, type B hemolytic streptococcus, in addition, the method of PCR detection of chlamydia and virus is also very meaningful in the diagnosis of reactive arthritis.

3. HLA -B27 determination of HLA-B27 positive for the diagnosis of reactive arthritis, disease judgment and even prognosis have a certain reference significance, however, HLA-B27 negative can not exclude reactive arthritis, recently, there are several studies on HLA The relationship between the B27 subtype and the condition was analyzed, but there is no consistent conclusion.

4. The rheumatoid factor, anti-peripheral factor and anti-nuclear antibody of autoantibodies and immunoglobulin- reactive arthritis patients are negative, while serum immunoglobulin IgG, IgA, IgM can be increased. These indicators are helpful for reactivity. Diagnosis and differential diagnosis of arthritis.

5. Joint fluid examination: joint fluid examination is of great significance in the diagnosis of reactive arthritis and the identification of other types of arthritis. In the synovial fluid of reactive arthritis, there may be increased white blood cells and lymphocytes, mucin-negative, joint fluid culture. Negative, using PCR, indirect immunofluorescence and electron microscopy techniques can detect bacterial protein components in the synovial and synovial fluid of some patients.

Diagnostic identification of reactive arthritis

Diagnostic criteria

1. The diagnosis of typical reactive arthritis- responsive arthritis mainly depends on the history and clinical features, laboratory and imaging abnormalities, and has reference significance for diagnosis, but it is not specific, and it is more acute for the onset of lower extremity arthritis. The possibility of reactive arthritis should be considered first. If the history of pre-infection of patients is combined and other arthritis is excluded, the diagnosis can be generally determined. Clinically, in addition to the characteristics of arthritis, it is necessary to pay attention to whether the patient has mucosal skin damage or nail lesions. Ophthalmitis and visceral involvement, the classification criteria for reactive arthritis proposed by Kingsley and Sieper in 1996 have a certain significance for the diagnosis of this disease.

HLA-B27 positive, extra-articular manifestations (such as conjunctivitis, iritis, skin, carditis and NS lesions) or the clinical manifestations of typical spondyloarthropathy (low back pain, tendonitis, etc.) are not necessary for reactive arthritis .

In 1999, Sieper and Braun published the diagnostic criteria they recommended at the Third International Respiratory Arthritis Symposium and proposed a multicenter collaborative study that highlighted laboratory tests for precursor infections.

2. Atypical reactive arthritis The diagnosis of typical reactive arthritis is generally not difficult, but in atypical cases, careful history and physical examination, history of intestinal and urinary tract infections in transient or mild patients or The history of unclean sexual contact is often helpful for diagnosis. Need to ask carefully, the author found that many patients have no obvious knee pain, but the physical examination has knee joint effusion, indicating that careful physical examination is very meaningful for finding signs and prompting diagnosis.

3. Reactive arthritis after streptococcal infection After the infection of type B hemolytic streptococcus, reactive arthritis (PSReA) has gradually been recognized by most people, it is not equivalent to acute rheumatic fever, the characteristics of this disease include:

1 history of infection with type B hemolytic streptococcus.

2 non-walking arthritis / joint pain.

3 nodular erythema or erythema multiforme.

Four patients had transient liver damage.

5 no carditis performance.

6 anti-streptolysin "O" and anti-deoxyribonuclease B increased.

7 throat swab culture positive.

The positive rate of 8HLA-DRB1*01 increased, and Table 6 lists the common clinical manifestations of 30 cases of PSReA.

4. Laboratory examination of urine, stool, throat swab and reproductive tract secretion culture is of great significance for the diagnosis and identification of pathogenic bacteria types, ESR, C-reactive protein, joint fluid and autoantibody examination for the diagnosis of reactive arthritis Non-specific, however, contributes to the estimation of the condition and the differential diagnosis of other joint diseases. The diagnosis of typical cases does not require HLA-B27. In atypical patients, HLA-B27 positive indicates the possibility of reactive arthritis, but Negative does not exclude the diagnosis of this disease.

Differential diagnosis

According to the history and clinical features, the diagnosis of reactive arthritis is more difficult, but for atypical and chronic cases, attention should be paid to the identification of other joint diseases.

1. Ankylosing spondylitis This disease is mostly a slow onset, the following low back pain is mainly, can be ascending, patients may be accompanied by asymmetric lower extremity joint pain or swelling, hip, knee, sputum common, can also Involving the upper limb joints, ankylosing spondylitis has a slow history of low back pain and arthritis, which is different from the acute process of reactive arthritis. In addition, the ankle arthritis of ankylosing spondylitis is mostly symmetrical, and the spinal column is ascending. Although the disease may also have ophthalmia, skin mucosal damage and HLA-B27 positive, but according to the course of the disease, clinical manifestations and characteristics of ankle arthritis are not difficult to identify with reactive arthritis.

2. Classification of undetermined spondyloarthropathy classification Undetermined spondyloarthropathy has clinical or laboratory characteristics of spondyloarthropathy, but does not meet the diagnosis of a certain disease, the disease may be an early stage of some kind of spondyloarthropathy or its setback It may also be an independent disease. Patients may have low back pain, or swelling of individual joints such as hips, knees, and ankles. X-ray examination may show mild ankle changes, and patients may be positive for HLA-B27. However, according to the medical history, the clinical features are not consistent with the diagnosis of spinal arthropathy such as reactive arthritis and ankylosing spondylitis. The follow-up of such patients should be followed to observe the evolution of the disease to give timely treatment.

3. Suppurative arthritis septic arthritis is caused by the infection of the joint cavity itself. The general incidence is more urgent, often involving single joint, which is characterized by local redness, swelling, heat, pain, and similar reactive arthritis, but This disease has many other parts of the body infection (such as sepsis), joint puncture is purulent joint fluid, blood routine shows obvious white blood cells, neutrophil increased, etc., no ophthalmia, skin mucosal damage and ankle arthritis, etc. Anti-infective treatment is effective. If you pay attention to the history of the disease and the characteristics of arthritis, and combined with auxiliary examination such as joint puncture, it is generally not difficult to diagnose.

4. Tuberculosis rheumatism tuberculosis is the pathological basis of the disease. The disease has nothing to do with intestinal and genitourinary tract infection. Patients may have systemic symptoms such as low fever, night sweats, fatigue, and tuberculin test. Knee, ankle, shoulder, elbow and other body joints can be affected, and often accompanied by nodular erythema, the disease is effective by anti-tuberculosis treatment.

5. Gouty arthritis Acute gouty arthritis episodes can be similar to reactive arthritis, but the former is often associated with diet and fatigue, the joint pain is severe, the skin is dark red, and can be relieved within a few months. The disease has nothing to do with intestinal or urinary tract infections, no ophthalmia, ankle arthritis, HLA-B27 positive, etc., increased blood uric acid level is found in most patients, uric acid reduction treatment is effective, according to medical history, clinical and laboratory characteristics is not difficult Identification with reactive arthritis.

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