Seronegative spondyloarthritis is a group of inflammatory diseases that occur with damage to the joints and spine and have etiological, pathogenetic and clinical similarities. The clinic of disease may include joint syndrome, chronic inflammatory bowel diseases, skin manifestations, lesions from the eyes, cardiovascular system and kidneys. The diagnosis is based on diagnostic criteria accepted in rheumatology, consisting of clinical, radiological, genetic signs and evaluation of the effectiveness of treatment. The main therapy is carried out with nonsteroidal anti-inflammatory drugs.
Meaning
In 1976, Moll and Wright identified the main diagnostic criteria by which a number of diseases began to be grouped into one group called “seronegative spondyloarthritis”. Then these criteria were expanded and supplemented by other researchers. Currently, pathology includes Bekhterev’s disease (ankylosing spondyloarthritis), Reiter’s disease, psoriatic arthritis, arthritis in chronic intestinal diseases (Crohn’s disease, Whipple’s disease, ulcerative colitis), reactive arthritis, Behcet syndrome, juvenile chronic arthritis and acute anterior uveitis.
Causes
Modern rheumatology continues to search and study the causes of the development of this disease. There is a connection between these diseases and the effects on the body of infectious agents, primarily pathogens of intestinal and genitourinary infections (dysentery, salmonellosis, yersiniosis, food toxicoinfections, chlamydia, etc.).
Along with this, most patients have a genetically determined predisposition to the development of one of the variants of this pathology, confirmed by the presence of the HLA-B27 antigen. This antigen is similar to the surface antigenic structure of chlamydia, klebsiella, shigella and other microorganisms. Therefore, infection with these bacteria leads to the production of autoantibodies with the formation of circulating immune complexes that cause an autoimmune inflammatory process in the tissues of the joints and spine with the development of seronegative spondyloarthritis.
Symptoms
Articular syndrome, as a rule, has a clinical picture typical for each of the seronegative spondyloarthritis. Thus, with Bekhterev’s disease, bilateral sacroiliitis, pain in the spine, a typical change in posture, impaired mobility of the spine in all directions are observed. Psoriatic arthritis is more often manifested by inflammation of the distal interphalangeal joints, and spondyloarthritis develops only in 5% of patients. In reactive arthritis, there is a connection with the infections preceding it.
- Eye damage is the most common extra-articular syndrome of seronegative spondyloarthritis. It is manifested by anterior uveitis, iritis, iridocyclitis and can be complicated by the development of cataracts, corneal dystrophy, glaucoma, optic nerve lesions, leading to decreased vision and blindness.
- Skin lesions in seronegative spondyloarthritis, depending on the disease, are manifested by psoriatic plaques or pustules, elements of nodular erythema or may be absent altogether. Psoriasis-like nail changes, ulcerative lesions of the oral mucosa, keratodermia are possible.
- Inflammatory bowel diseases are detected in about 17% of patients with seronegative spondyloarthritis. They are chronic in nature and closely correlate with the activity of the inflammatory process in the joints. In many cases, inflammatory processes in the intestine are in the subclinical stage and are detected only during an instrumental examination.
- Heart damage in seronegative spondyloarthritis usually has no connection with the activity of arthritis. There are cases when the patient addresses cardiological complaints, and articular manifestations of seronegative spondyloarthritis are detected during the examination. Most often, with seronegative spondyloarthritis, there is a violation of AV conduction and aortitis. The latter leads to a reverse flow of blood from the aorta with the development of aortic heart disease.
- Kidney lesions are noted in 4% of patients with seronegative spondyloarthritis. They are manifested by nephrotic syndrome, microhematuria, proteinuria and rarely provoke the occurrence of renal failure.
Diagnostics
Polymorphism of symptoms and the presence of overlapping clinical signs between diseases significantly complicate the diagnosis of seronegative spondyloarthritis. In addition to a rheumatologist, such patients should be examined by an oculist, a cardiologist, a gastroenterologist, if necessary, a dermatologist and a urologist.
Laboratory examination of the blood of patients with seronegative spondyloarthritis shows nonspecific inflammatory signs, an increased content of CRP. A typical sign of seronegative spondyloarthritis is the absence of ANF and RF in the blood of patients.
An X-ray examination of the joints, arthroscopy, diagnostic puncture of the joint with subsequent examination of the synovial fluid is performed. Radiography of the spine can reveal bilateral sacroiliitis, calcification of the ligaments of the spinal column, paravertebral ossification.
The study of the cardiovascular system includes ECG, rhythmocardiography, Echo-СG, MRI of the heart, aortography. During the diagnosis of seronegative spondyloarthritis, a study of the intestine is necessarily carried out: coprogram, irrigoscopy, colonoscopy, radiography of the barium passage, etc. With kidney damage, proteinuria and microhematuria are detected in the clinical analysis of urine. In such cases, ultrasound and CT of the kidneys, urography are performed.
Differential diagnosis of seronegative spondyloarthritis is carried out with rheumatism, rheumatoid arthritis, palindromic rheumatism, hydroxyapatite arthropathy.
Diagnostic
A. Clinical manifestations:
- Lower back pain of a nocturnal nature and/or stiffness in the lumbar region in the morning (1 point).
- Arthritis of one or more joints with asymmetry of the lesion (2 points).
- Transient pain in the buttocks (2 points).
- Thickening of the toes and hands, giving them a sausage-like appearance (2 points).
- Local soreness at the ligament attachment points (2 points).
- Eye damage (2 points).
- The development of cervicitis or urethritis, unrelated to gonorrhea, which was noted during the last month before the onset of symptoms of arthritis (1 point).
- Diarrhea that was observed during the last month before the onset of arthritis symptoms (1 point).
- The presence of the patient at present or according to the anamnesis of psoriasis and/or chronic enterocolitis and/or balanitis (2 points).
B. Radiological criteria of seronegative spondyloarthritis:
- Identification of signs of unilateral sacroiliitis in stages 3-4 or bilateral in stages 2-4 (3 points).
С. Genetic determinism of seronegative spondyloarthritis:
- Detection of HLA-B27 in a patient or the presence of such diseases as psoriasis, uveitis, Reiter’s syndrome, chronic enterocolitis in his relatives (2 points).
D. Effectiveness of NSAID treatment:
- Reduction of pain intensity within 2 days from the start of therapy (1 point).
The disease is reliably diagnosed as seronegative spondyloarthritis if the total score is 6 or more. The clinical picture of seronegative spondyloarthritis can be so polymorphic that in a number of patients it is not possible to fit it into the framework of one specific disease from this group. Such cases are referred to as “undifferentiated seronegative spondyloarthritis”.
Treatment
The basic therapy of seronegative spondyloarthritis is carried out with drugs from the group of nonsteroidal anti-inflammatory drugs (NSAIDs), which include: diclofenac, indomethacin, phenylbutazone. According to many authors, diclofenac is the most effective against seronegative spondyloarthritis, combining a pronounced anti-inflammatory effect and a relatively low risk of side effects. The most common complication of NSAID therapy is gastrointestinal lesions, often of an erosive and ulcerative nature, which can cause the development of a perforated stomach ulcer or gastrointestinal bleeding.
In modern rheumatology, studies on the use of immunological drugs in the treatment of seronegative spondyloarthritis are widely conducted. Currently, infliximab, which is an antibody to one of the main mediators of the inflammatory process, is allowed for use. A number of authors point to the effectiveness of the fourth—generation immunomodulator imunofan in the complex treatment of seronegative spondyloarthritis.