Host-microbe interaction in HLA-B27-associated diseases

Efficacy of methotrexate in the treatment of a HLA-B27-positive Japanease patient with reactive arthritis

We report a case of reactive arthritis in a 21-year-old man who was successfully treated with methotrexate. In July 2008, the patient experienced arthritis in the left knee 3 days after being diagnosed as having urethritis by the urology clinic. The patient was treated with loxoprofen sodium and fosfomycin calcium at an orthopedic clinic. Antibiotics induced clinical improvement of urethritis, although arthritis became worse. Even after sulphasalazine and corticosteroid were started, polyarthritis remained persistent. Finally, methtrexate was added ; thereafter, polyarthritis and elevated CRP were resolved. HLA-B270502 was positive. Methotrexate could be one of the choices for sulphasalazine-resistant reactive arthritis.

Yersinia EnterocoliticaO:3 Isolated from Patients with or without Reactive Arthritis Induces Polyclonal Activation of B Cells and Autoantibody ProductionIn Vivo

The mechanisms by which arthritis-provoking pathogens such as Yersinia enterocolitica interact with the human immune system to produce inflammatory synovitis are not well known. One of the immunomodulating mechanisms used against these pathogens is the polyclonal activation of lymphocytes. In this study, we investigated the extent of the B-lymphocyte activation induced in mice by a strain of Y. enterocolitica O:3 (FCF 526) isolated from a patient with arthritis, and compared it with two other strains, a virulent one (FCF 397[+]) isolated from a patient without arthritis and its plasmidless isogenic pair (FCF397[-]). Also we investigated the production of autoantibodies in mice infected with these different strains. SPF Swiss mice were infected intravenously with a suspension of Y. enterocolitica. Spleen cells were taken on days 7, 14, 21 and 28 after infection and the number of cells secreting nonspecific and specific antibodies of IgG1, IgG2a, IgG2b, IgG3, IgM and IgA isotypes were determined by the ELISPOT technique. The presence of autoantibodies in mouse serum was investigated by the dot-blot assay. The pattern of infection of the three bacterial strains were almost the same. We observed a general increase in the number of nonspecific Ig-secreting cells with all three strains, and the greatest increases observed were in the IgG2a and IgG3 isotypes. Only a small fraction of the immunoglobulins detected were antibacterial, suggesting that the rest resulted from polyclonal B cell activation. The strain isolated from the patient with arthritis (FCF526) induced the greatest production of autoantibodies, coinciding with the period in which the greatest activation of nonspecific B lymphocytes was seen. There were no signs of arthritis or inflammation in the joints of the infected animals. Based on our results, we were unable to determine whether there is an association between the arthritogenic capability of Y. enterocolitica and polyclonal activation of B cells.

Reactive arthritis which occurred one year after acute chlamydial urethritis

A 30-year-old Japanese man developed dactylitis with sausage-like fingers in addition to balanitis and stomatitis. One year prior to these symptoms, acute chlamydial urethritis had been successfully treated by levofloxacin. On admission, Chlamydia trachomatis DNA was not detected in the urine sediment by PCR method, however, he was diagnosed to have reactive arthritis based on the clinical findings of asymmetric dactylitis, circinate balanitis, stomatitis and positivity for HLA B27 antigen. He was treated with methotrexate and his arthritis improved. The past chlamydial infection may have been involved in the pathogenesis of reactive arthritis in this patient.

Campylobacter jejuni infection during pregnancy: long-term consequences of associated bacteremia, Guillain-Barré syndrome, and reactive arthritist

Campylobacter jejuni infections are the main cause of foodborne gastroenteritis in the United States and other developed countries. Generally, C. jejuni infections are self-limiting and treatment is not necessary; however, infections caused by this organism can lead to potentially dangerous long-term consequences for some individuals. Bacteremia, Guillain-Barré syndrome (GBS; an acute flaccid paralytic disease), and reactive arthritis (ReA) are the most serious of the long-term consequences of C. jejuni infections. During pregnancy, foodborne infections may be hazardous to both the woman and the fetus. C. jejuni-induced bacteremia during pregnancy may lead to intrauterine infection of the fetus, abortion, stillbirth, or early neonatal death. Infection of a newborn by the mother during the birth process or shortly after birth may lead to neonatal enteritis, bacteremia, and/or meningitis. C. jejuni enteritis is the inducing antecedent infection in approximately 30% of cases of GBS. Thus, pregnant women infected with C. jejuni may contract GBS. GBS during pregnancy does not affect fetal or infant development and does not increase spontaneous abortion or fetal death; however, it may induce spontaneous delivery during the third trimester in severe cases. Reactive arthritis occurs in approximately 2% of C. jejuni enteritis cases and leads to the impaired movement of various joints. Pregnant women with C. jejuni-induced reactive arthritis can be expected to deliver a normal infant. A pregnant patient with GBS or ReA may be unable to care for a newborn infant because of the physical impairment induced by these diseases. Since C. jejuni infections put both fetuses and pregnant women at risk, pregnant women must take special care in food handling and preparation to prevent such infections.

Aetiological agents: their molecular biology and phagocyte-host interaction

Inflammatory joint disease can develop following an extra-articular infection. The term reactive arthritis was coined in order to differentiate this arthritis, which is often characterized by lack of culturable organisms in the joint, from septic arthritides. Bacteria known to trigger reactive arthritis include Campylobacter, Chlamydia, Salmonella, Shigella and Yersinia. Demonstration of bacteria or bacterial macromolecules in the joint has elicited the idea that reactive arthritis is a sterile process induced and maintained by antigenic material in the synovium. Continued synthesis of antigens to maintain synovial inflammation probably requires establishment of persistent bacterial infection in the joint, or at the primary site of infection. In the case of Chlamydia trachomatis, viable, metabolically-active organisms have been demonstrated to exist for extended periods in the joints of patients with reactive arthritis. In this chapter, we review the aetiological agents, and their molecular biology and phagocyte-host interactions, that are involved in reactive arthritis and spondylarthropathy.