Researchers sought to evaluate whether a three-month course of the antibiotic called tetracycline (lymecycline) has an effect on the long-term prognosis of reactive arthritis (ReA). Previous studies do not show antibiotics' effectiveness in preventing or treating ReA, a disease that usually occurs following an infection in a genetically susceptible person. Doctors have not yet determined why some people exposed to certain bacteria develop this disorder and others do not. See the Side Note at the bottom of this page for more information about ReA.

Study Background
In a 1987-88 study with a three-month course of either lymecycline or a placebo, K. Laasila and colleagues from the Helsinki University Central Hospital in Helsinki, Finland, studied a total of 23 patients from the hospital. 17 of the 23 patients volunteered to take part in a follow up study. This entailed a physical examination and an examination of erythrocyte sedimentation rate, C reactive protein, rheumatoid factor, and radiographs of the lumbosacral spine and sacroiliac joints and of symptomatic peripheral joints.

Participant Information
Sixteen of 17 (94%) patients reported some kind of back pain, and 10 of 17 (59%) peripheral joint symptoms during the follow-up.

One of the ways in which to diagnose someone with ankylosing spondylitis (AS) or one of its related diseases is to evaluate whether he/she has changes in the sacroiliac joints (called sacroiliitis) that show on x-rays, although some people with spondylitis do not have x-ray changes. Doctors "grade" the changes to determine the current state of the disease. Grade 0 means normal sacroiliac joints (SI); Grade 1 refers to nonspecific "suspicious" findings; Grade II changes are minimal sacroiliitis and possibly showing minimal erosions; Grade III is called moderate sacroiliitis and it manifests as definite erosions, loss of joint space, etc.; Grade IV changes consist of complete bony ankylosis of the SI joints, translating into a definite diagnosis of AS.

Two of 17 patients had unilateral grade 1 sacroiliitis, one had grade 4, and one had bilateral grade 2. In one patient, the disease had progressed to AS, and in another to chronic spondyloarthropathy. In addition, two patients had small erosions in radiocarpal joints.

Findings
No statistically significant differences were found between placebo and lymecycline groups in the development of chronic arthritis, sacroiliitis, or AS.

Researchers explain that results of the initial study show that long-term treatment with lymecycline in patients with acute ReA decreased the duration of arthritis in those with Chlamydia trachomatis triggered ReA, but not in other patients with ReA.

Ten years after the acute arthritis, one patient had developed AS, three had sacroiliitis and three had radiological changes of the peripheral joints. Long-term lymecycline treatment did not change the natural history of the disease.

Results were published in a recent issue of the Annals of the Rheumatic Diseases.

Side Note
Muhammad Asim Khan, MD, FRCP, Case Western University, Cleveland, Ohio, states in a separate article: "ReA is an episode of…arthritis occurring within one month of a primary infection elsewhere in the body, usually genitourinary infection with Chlamydia trachomatis or…bacteria, such as Shigella, Salmonella, Yersinia, or Campylobacter."

Khan says that ReA is usually an acute illness -- the average duration is four to five months, and two thirds of patients have mild musculoskeletal symptoms that persist for more than one year. Approximately 15% to 30% of patients develop chronic or recurrent arthritis or sacroiliitis or spondylitis, and most of these patients have a positive family history for spondyloarthropathies or are positive for HLA-B27.

Regarding treatment, Khan explains: "Antibiotics are not effective, although prolonged (more than three months) treatment of severe, persistent Chlamydia-induced ReA with lymecycline provided some improvement in one study. Moreover, prompt and effective treatment of Chlamydial infections reduced the risk for sexually acquired reactive arthritis in a Greenland Inuit population that had a high prevalence of both HLA-B27 and Chlamydial infections."

Additional information can be found in Khan's article "Update on Spondyloarthropathies", which was published in the American College of Physicians-American Society of Internal Medicine, 2002.