Musculoskeletal manifestations of Lyme arthritis

Lyme disease is a treatable and curable infectious disease that can be diagnosed with relative confidence with attention to the details of the syndrome and proper use of serologic testing to confirm the clinical diagnosis. Lyme disease should not be a "diagnosis of exclusion," made on the basis of isolated serologic reactivity or because of the presence of symptoms compatible with Lyme disease. The pathogenesis of chronic complaints following infection with B. burgdorferi is often unclear, but such persistent complaints should not automatically be ascribed to ongoing infection. There is no proven role for long-term antibiotics or combination regimens.

Persistence of Yersinia antigens in peripheral blood cells from patients with Yersinia enterocolitica O:3 infection with or without reactive arthritis

OBJECTIVE

To assess the persistence of bacterial antigens in peripheral blood cells from patients with Yersinia enterocolitica O:3-triggered reactive arthritis (ReA).

METHODS

Peripheral blood samples were obtained from 20 patients with Y. enterocolitica O:3 infection (11 with ReA and 9 without). These samples were studied by immunochemical techniques for the presence of Yersinia antigens at the beginning of infection and up to 4 years thereafter. Synovial fluid samples from 6 of the 11 ReA patients were also studied.

RESULTS

The Yersinia antigens lipopolysaccharide and heat-shock protein (HSP) were detected in peripheral blood mononuclear cells and polymorphonuclear phagocytes from all patients studied at the early phase of the disease. They were also found in the synovial fluid cells of patients with Yersinia-triggered ReA. At 4 years after the onset of infection, these bacterial antigens were still detected in the peripheral blood cells of most of the ReA patients studied.

CONCLUSION

This study has, for the first time, directly demonstrated that bacterial antigens persist for a long time in patients who develop ReA after Y. enterocolitica O:3 infection. The finding of bacterial HSP in synovial fluid cells could provide a link to the pathogenesis of ReA, since T cell responses of synovial cells have been shown to be directed against that structure. A close similarity between the bacterial and host HSP might contribute to the development of the relatively common, chronic form of this complication.

Synovial Chlamydia trachomatis in patients with reactive arthritis/Reiter's syndrome are viable but show aberrant gene expression

OBJECTIVE

We used reverse transcription-polymerase chain reaction (RT-PCR) assays to assess expression of genes from Chlamydia trachomatis in synovial tissues of patients with reactive arthritis (ReA)/Reiter's syndrome (RS) to determine viability/metabolic activity of the bacterium in joints of infected patients.

METHODS

Synovial biopsies were obtained from 18 patients with ReA, RS, or other arthritides; nucleic acids from 16 samples were PCR positive for chlamydial chromosomal DNA. RT-PCR assays targeting primary transcripts from C. trachomatis rRNA operons, and mRNA from the bacterial omp1, hsp60, glyQS, and r-protein S5 and L5 genes, were used to characterize viability/metabolic activity. Host actin mRNA was assessed as control in each sample preparation.

RESULTS

RT-PCR of host cell actin mRNA in the 18 patient samples confirmed the quality of all RNA preparations. RNA from 14/16 PCR positive samples was positive by RT-PCR for chlamydial rRNA primary transcripts. Each of these same 14 samples was also RT-PCR positive in assays targeting glyQS, r-protein S5 and L5, and hsp60 mRNA. However, none of the 14 samples showing chlamydial rRNA and mRNA was positive for omp1 transcripts.

CONCLUSION

Synovial chlamydia are viable/metabolically active, since primary rRNA transcripts and mRNA from chlamydial genes specifying components of the bacterial protein synthetic system were present in most patient samples assayed. Expression of omp1, encoding the major outer membrane protein, is strongly attenuated in persistently infecting synovial chlamydia, while that of hsp60, specifying a highly immunogenic heat shock protein of the organism, is not downregulated.

[Reiter syndrome: apropos of a case]

We report the case of a 25 year-old man presenting Reiter's syndrome (urethritis, conjunctivitis and oligoarthritis). This clinical triad is a particular expression of reactive arthritis. A genital or enteric infection can be responsible for the onset. Presence of HLA B27 histocompatibility antigen is a genetic factor favoring the development of Reiter's syndrome. Many organs or systems can be affected. In addition to eradication of the initiating infection, treatment is mainly symptomatic and management is multidisciplinary.

T helper 1 response is dominant and localized to the synovial fluid in patients with Lyme arthritis

Cytokines produced by subsets of CD4+ T helper cells responding to an infection influences the efficiency with which the host is able to mount a protective immune response. In an attempt to elucidate the population of active cells involved in the propagation of Lyme arthritis we have utilized intracellular cytokine staining to analyze the polyclonal immune response at the single cell level. We have determined the Th phenotype in the synovial fluid of patients with a variety of chronic inflammatory arthritides, including patients representative of the spectrum of Lyme arthritis. Th1 cells dominate the immune response in the synovial fluid of patients with Lyme as well as those with rheumatoid or other types of chronic inflammatory arthritis. In addition, the severity of Lyme arthritis directly correlates with the ratio of Th1 to Th2 cells in the synovial fluid, such that the larger the effusion, the higher the ratio (r = 0.67, p < 0.05). These results suggest that Th1 cells play a direct role in the pathogenesis of the inflammatory process seen in Lyme arthritis, and that Th2 cells modulate the pro-inflammatory response generated by Th1 cells in the joint. Finally, we identify Th1 cells specific for outer surface protein A of Borrelia burgdorferi, the agent of Lyme disease. These cells are restricted to patients with Lyme arthritis and are localized to the joint. Furthermore, they persist in patients with prolonged antibiotic treatment-resistant Lyme arthritis, suggesting the possibility of an autoimmune process.

Molecular diagnosis of Ureaplasma urealyticum in an immunocompetent patient with destructive reactive polyarthritis

Polymerase chain reaction (PCR) amplification, which is a useful method for detecting infectious agents in joints, has potential utility in the molecular diagnosis of venereal-associated arthritis. Among pathogens detected by this technique, Ureaplasma urealyticum, which is primarily associated with reactive arthritis (ReA), is also implicated in septic arthritis in immunocompromised patients. We report here a case of destructive polyarthritis, initially suggestive of septic arthritis, in an immunocompetent patient whose PCR positivity for U. urealyticum DNA in one joint, in conjunction with the disease outcome and histologic findings, led to the diagnosis of destructive ReA.

Humoral immune response in Yersinia enterocolitica O:5 induced arthritis in hamsters

Yersinia enterocolitica can cause extraintestinal sequelae such as reactive arthritis. The immunopathogenic mechanisms of this disease have not been completely clarified. Autoimmunity and persistent immune responses against bacterial antigens have been related to Yersinia-induced arthritis. The arthritogenic capacity of Y. enterocolitica O:5 and the kinetics of the development of autoantibodies and Yersinia antigen-specific antibodies were studied in hamsters. The results indicated that Y. enterocolitica O:5 was arthritogenic in the animal model studied. The animals developed septic arthritis on day 2 post-infection (p.i.) and reactive arthritis on day 65 p.i. An important IgG response to types I and II collagen and the persistence of antibodies against lipopolysaccharide and bacterial cellular extract were observed. By immunoblotting, it was obtained that IgG reacted against a large number of bacterial antigens, the strongest being the responses against 88, 76, 63 and 36-33 kDa peptides. From the results obtained, it can be concluded that serovar O:5 was experimentally arthritogenic, and that both autoimmune mechanisms and Yersinia-specific antibodies participated in the development of Yersinia-induced reactive arthritis in the animal model studied.

Long-term prognosis of reactive salmonella arthritis

OBJECTIVES

Reactive joint complications triggered by salmonella gastroenteritis are increasingly reported, but the outcome and long term prognosis of the patients is incompletely known. This study looked at the prognosis of salmonella arthritis in patients hospitalised in 1970-1986.

METHODS

Hospital records from two hospitals in southern Finland were screened for patients with the discharge diagnosis of salmonellosis or reactive, postinfectious arthritis or Reiter's disease. For the patients with confirmed diagnosis of reactive salmonella arthritis, data about the acute disease were collected from the hospital records. A follow up study was performed.

RESULTS

There were 63 patients (28 women, 35 men, mean age 36.5 years) with salmonella arthritis. Urethritis occurred in 27%, eye inflammation in 13%, and low back pain in 44% of the patients. HLA-B27 was present in 88%. More men than women were HLA-B27 positive. HLA-B27 positive patients had higher erythrocyte sedimentation rate (mean 80.9 v 46.5 mm 1st h, p = 0.0180). Also, extra-articular features and radiological sacroiliitis were seen only in HLA-B27 positive patients. A follow up study was performed on 50 patients mean 11.0 (range 5-22 years) later. Twenty patients had recovered completely. Ten patients had mild joint symptoms, 11 patients had had a new acute transient arthritis, and five acute iritis. Eight patients had developed chronic spondyloarthropathy. Radiological sacroiliitis was seen in six of 44 patients, more frequently in male than in female patients (32% v 0%; p = 0.0289). Recurrent or chronic arthritis, iritis or radiological sacroiliitis developed only in HLA-B27 positive patients.

CONCLUSION

Joint symptoms are common after reactive salmonella arthritis. HLA-B27 contributes to the severity of acute disease and to the late prognosis.

Actinomycotic splenic abscesses presenting with arthritis

An 18-month-old Caucasian female began with a high fever. She developed swelling in one finger and one toe. Abdominal ultrasound revealed multiple abscesses in her spleen. Multiple blood culture and splenic abscess aspirations grew no pathogens. She had transient response to multiple antibiotics and splenic abscess drainage, but fever returned along with subcutaneous nodules. Culture of splenic tissue from her second splenic drainage eventually grew one organism identified as Actinomyces naeslundii. Therapy with high dose penicillin followed by amoxicillin p.o. and total splenectomy led to complete recovery.

Ligase chain reaction in detection of Chlamydia DNA in synovial fluid cells

Synovial fluid cells from 12 patients with reactive arthritis (ReA) triggered by Chlamydia trachomatis were studied for the presence of Chlamydia DNA using the ligase chain reaction (LCR) LCx (Abbott) and the polymerase chain reaction (PCR) Amplicor (Roche). In addition, peripheral blood leucocytes from 11 of these patients were analysed by LCR. As controls, seven patients with newly diagnosed rheumatoid arthritis (RA) were included. Chlamydia trachomatis DNA was detectable by LCR in samples of synovial fluid cells from 4/12 patients with C. trachomatis-triggered ReA, and in none by PCR. Chlamydia trachomatis DNA was not detectable in the synovial fluid cells of the seven RA patients by either method, neither was C. trachomatis DNA detectable in the peripheral blood leucocytes of the ReA patients (0/11) or controls (0/6) by LCR. The LCR technique may be useful in the demonstration of Chlamydia DNA in synovial fluid cells.

Reactive arthritis

The complex interactions between the triggering microbe and the defense mechanisms of the host in reactive arthritis have been studied in several laboratories around the world, and interesting observations have been made. Research has also focused on the mediators in the inflammatory process in joints, and these results are helping to slowly build a comprehensive picture about the pathogenetic process in reactive arthritis. For the practicing clinician, some important new findings have emerged. It is known that asymptomatic urogenital infections are quite common as a trigger of reactive arthritis. More aggressive treatment, including disease-modifying drugs as used in the therapy of rheumatoid arthritis, is becoming accepted. The value of antibiotic treatment is being studied, but final conclusions will not be made for perhaps a few years.

Nested polymerase chain reaction strategy simultaneously targeting DNA sequences of multiple bacterial species in inflammatory joint diseases. II. Examination of sacroiliac and knee joint biopsies of patients with spondyloarthropathies and other arthritides

OBJECTIVE

Bacteria play a crucial pathogenetic role in reactive arthritis (ReA) and other forms of spondyloarthropathy (SpA) and in Lyme arthritis. Although there is evidence of local persistence of bacterial antigens no definitive method revealing microbes in peripheral joints has been established. We detected DNA of individual bacteria in synovial material by PCR. Applying molecular technology we screened simultaneously for 8 bacterial genomes in arthritis and sacroiliitis.

METHODS

Sacroiliac (SI) biopsy specimens taken from the SI joint of 8 patients with ankylosing spondylitis (AS, n = 5) and undifferentiated SpA (uSpA, n = 3) by computed tomography guided biopsy were investigated for presence of bacterial DNA. Similarly, synovial membrane samples obtained by office arthroscopy from 15 patients with ReA (n = 5), uSpA (n = 3), undifferentiated oligoarthritis (uOligo, n = 3), and rheumatoid arthritis (RA, n = 4) were screened. Nested PCR was performed for DNA of the following bacteria: Chlamydia trachomatis, C. pneumoniae, Yersinia enterocolitica, Salmonella enteritidis, Campylobacter jejuni, Shigella flexneri, Klebsiella pneumoniae, and Borrelia burgdorferi.

RESULTS

No bacterial DNA was found in the SI biopsies of patients with uSpA and AS. DNA of B. burgdorferi (n = 2) and C. trachomatis (n = 1) was detected in 3 patients with uOligo, but not in patients with ReA or RA. DNA of other microbes including K. pneumoniae was not found. Patients' mean disease duration was 5.3 years (2 mo-8.4 yrs).

CONCLUSION

We found bacterial DNA in peripheral joints of patients with uOligo, while in patients with ReA, AS, and uSpA no bacterial DNA was detected in peripheral or SI joints. The failure to detect bacterial DNA in patients with SpA suggests autoimmune mechanisms operate in later stages of disease.

Nested polymerase chain reaction strategy simultaneously targeting DNA sequences of multiple bacterial species in inflammatory joint diseases. I. Screening of synovial fluid samples of patients with spondyloarthropathies and other arthritides

OBJECTIVE

Bacteria play a crucial pathogenetic role in Lyme arthritis (LA), reactive arthritis (ReA), other forms of spondyloarthropathy (SpA), and possibly in undifferentiated oligoarthritis (uOligo). Polymerase chain reaction (PCR) technology has been applied to detect bacterial DNA of individual microbes in synovial fluid (SF) of patients with arthritides. We screened for DNA sequences of 8 bacterial species simultaneously in SF of patients with inflammatory joint disease.

METHODS

We examined 104 SF samples of 96 patients with ReA (n = 13), undifferentiated SpA (uSpA, n = 10), uOligo (n = 50), juvenile chronic arthritis (JCA, n = 13), and rheumatoid arthritis (RA, n = 10). A nested PCR approach was developed to detect DNA sequences of 8 bacteria: Chlamydia trachomatis, C. pneumoniae, Yersinia enterocolitica, Salmonella enteritidis, Campylobacter jejuni, Shigella flexneri, Klebsiella pneumoniae, and Borrelia burgdorferi. The detection limit was determined at 10 bacterial/sample. Serology and lymphocyte proliferation assay were done in parallel in most patients.

RESULTS

In 12 cases bacterial DNA of B. burgdorferi (n = 7), C. trachomatis (n = 2), C. jejuni (n = 2), and C. pneumoniae (n = 1) was detected in patients with uOligo (n = 9) and JCA (n = 3), while no evidence of bacterial DNA was found in patients with ReA, uSpA, and RA. Shigella flexneri DNA was detected in 4 cases, but the significance of this finding remains uncertain due to the high sequence homology of this species with Escherichia coli. DNA of Y. enterocolitica, S. enteritidis, or K. pneumoniae was not found. A positive serologic response was found in 7/9 PCR positive patients. In 11/96 cases antibodies to 2 or more bacteria were found in parallel (11.5%). Antigen specific lymphocyte proliferation was observed in 5/9 PCR positive patients.

CONCLUSION

Bacterial DNA was detected in peripheral joint of patients with uOligo and JCA, but not in ReA, uSpA, or RA in this study. The detection of bacterial DNA in synovial material by PCR technology gives useful diagnostic information, especially when antibodies against several microbes are present or antibodies are not detectable. Failure to detect bacterial DNA in patients with ReA and uSpA with longstanding disease suggests that in later stages autoimmune mechanisms may operate.

Immune responses towards intestinal bacteria--current concepts and future perspectives

The intestinal mucosa constitutes an important barrier as it separates each individual from a large array of antigens within the bowel lumen. These luminal antigens may either be derived from pathogens or may be derived from harmless constituents such as ingested food or the normal intestinal flora. The dichotomy of potentially harmful and potentially harmless antigens encountered by the mucosal immune system poses the important task that, with regard to bacteria-derived antigens, the gut associated immune system is required to mount an efficient host defense against pathogenic bacteria but to maintain at the same time the regulatory control mechanisms which protect the human organism from hyperresponsiveness, and thus chronic inflammation, towards antigens from the normal intestinal flora. In the present review, we discuss variable host and bacterial factors which are likely to determine whether the immune response to pathogenic or normal intestinal bacteria will have beneficial or detrimental consequences for the human organism. Using infections with the prototype enteropathogens V. cholerae and enteropathogenic E. coli (ETEC), Y. enterocolitica induced reactive arthritis (ReA) and in more detail, inflammatory bowel diseases (IBD) as exemplary clinical situations, we review current hypotheses of how bacteria or their products are encountered by cellular components of the specific immune system and how this may relate to disease pathogenesis and the development of new treatment strategies.

Host-microbe interaction in HLA-B27-associated diseases

The mechanisms leading to the development of HLA-B27-associated diseases, spondyloarthropathies, are unknown. One of them, reactive arthritis, is clearly caused by an infection, and joint inflammation develops soon after or during an infection elsewhere in the body. In other forms of spondyloarthropathies, such as ankylosing spondylitis, association with infection is suggested but it is not as clear. Pathogenetic mechanisms of reactive arthritis are a focus of great interest as causative infections and strong genetic association are known. How HLA-B27 determines the appearance of joint complications after certain infections is not clear. Several theories have been proposed to explain the association, and they usually include the idea that interaction between microbe and host is abnormal and inefficient in HLA-B27-positive subjects in whom reactive arthritis develops.

Evaluation of ELISA to detect Chlamydia trachomatis antigen in urine samples from arthritis patients

OBJECTIVE

To determine whether examination of urine samples using ELISA allows the detection of asymptomatic C. trachomatis infection in arthritis patients.

METHODS

The in vitro sensitivity of IDEIA Chlamydia ELISA to detect C. trachomatis in urine samples was determined by the investigation of serial dilutions of chlamydial elementary bodies. In a clinical study, urine samples from 402 consecutive arthritis patients (182 men and 220 women) in a tertiary care rheumatology clinic were examined for asymptomatic chlamydial infection by ELISA and the results were compared to culture and direct immunofluorescence assay (DFA, MicroTrak) of urogenital swabs.

RESULTS

The in vitro sensitivity of ELISA for detecting purified elementary bodies of C. trachomatis serovar K in urine was 60 infection forming units. Twenty-three of 402 arthritis patients (6%) had asymptomatic chlamydial infection as shown by DFA and culture from urogenital smears. The ELISA method identified only 3 of 17 swab-positive patients among 271 patients when urine specimens were collected during the clinical visit, while the assay detected all 6 swab-positive patients among 131 patients when first-voided early morning urine specimens were used (p < 0.001).

CONCLUSION

It is mandatory to examine only first voided early morning urine samples if ELISA is used instead of DFA or culture from urogenital swabs to detect asymptomatic chlamydial infection in arthritis patients.

[Does reactive arthritis caused by Brucella exist? Apropos of 4 cases]

OBJECTIVES

Arthritis observed in patients with Brucella infection is usually considered to result from live micro-organisms invading the synovia. We observed four cases of brucellosis in which the clinical and laboratory findings suggested a different mechanism: reactive arthritis.

CLINICAL OBSERVATIONS

The diagnosis of brucellosis was made on the basis of serology tests in 3 patients and blood cultures in 1. All 4 patients presented oligoarthritis. The synovial fluid was sterile in 3. Antibiotics were ineffective in reducing joint pain and inflammation whereas local and systemic anti-inflammatory drugs were effective. Three patients also had other manifestations (sausage-shaped toes, talalgia, sacroiliitis) and fulfilled the diagnostic criteria for spondylarthropathy. All patients were positive for antigen HLA-B27.

DISCUSSION

These observations suggest that Brucella should be added to the list of intracellular infectious agents capable of inducing reactive arthritis, despite the lack of all the diagnostic criteria. For some, such as the uretritis or diarrhea observed before joint involvement, it would be difficult to implicate the germ. Brucella serology should be part of the etiology work-up for reactive arthritis in endemic areas.

Survival and degradation of Salmonella enterica serotype Enteritidis in intestinal epithelial cells in vitro

The survival and fate of Salmonella enterica serotype Enteritidis in Henle-407 human intestinal epithelial cells was investigated during prolonged incubation to evaluate the persistence of causative microbes and the relationship to patients developing reactive arthritis. Most of the bacteria were killed and degraded quite soon after infection of the cells, but there were still live bacteria inside the cells for up to 14 days. These results suggest that in patients developing reactive arthritis the salmonellae could persist in the epithelial cells and spread within the host to the joint and be present there at the time of the inflammatory response. Production of marked amounts of nitric oxide was observed as a novel response to salmonella infection in human intestinal epithelial cells. The present experimental procedure appears to be a suitable model to further investigate host-bacteria interaction in HLA-B27 positive cells from patients developing reactive arthritis.

Poststreptococcal reactive rheumatic syndrome

Poststreptococcal reactive arthritis remains a poorly recognized clinical entity that is rarely considered in adults. We describe a case of poststreptococcal rheumatic syndrome in a 63-year-old woman to highlight that prolonged bone pain, night sweats, arthralgia, and laboratory evidence of active inflammation may be the principal manifestations, and that it may occur even in elderly patients. Poststreptococcal rheumatic manifestations can be viewed as a continuum extending from acute rheumatic fever with or without carditis to poststreptococcal reactive rheumatic syndrome with either reactive arthritis or systemic symptoms predominating.

Poststreptococcal reactive arthritis: report of one case

Poststreptococcal reactive arthritis (PSRA) is a clinical syndrome of reactive arthritis. It is associated with recent streptococcal infections, but could not fulfill the revised Jones criteria for acute rheumatic fever (ARF). The incidence of PSRA cardiac complications to develop was as high as the ARF's developing into rheumatic heart disease. A 9-year-old boy presented with limping gait. He had pain in his left knee for 4 days but no fever. His right knee was swelling with a limitation of movement. A throat culture showed positive growth for group A streptococcus, and consequently antistreptolysin-O serum titer and C-reactive protein were elevated. A synovial fluid examination was turbid but sterile. After 3 days the arthralgia subsided rapidly. A cardiac color Doppler and electrocardiogram showed no evidence of valvular disease. Under the threat of high incidence of rheumatic heart disease in PSRA, we treated this patient with prophylactic antibiotics as acute rheumatic fever. A clinic follow up one year later showed neither sequels nor heart murmur on physical examination.

Comparative microbicidal activity of synovial fluid on arthritogenic organisms

There is strong circumstantial evidence to support the concept that local microbial antigens play a key role in the synovitis of reactive arthritis (ReA) patients. It is not at all clear whether these antigens reflect the sequelae of previously viable organisms once resident in the joint. To address the microbicidal activity of synovial fluid (SF) we performed quantitative cultures of arthritogenic organisms (Salmonella typhimurium, Shigella flexneri, Klebsiella pneumoniae) and controls (Escherichia coli, Staphylococcus aureus) in the presence of SF from patients with ReA. There was a dramatic inhibitory effect of SF on the Gram-negative organisms (mean 1.35x10(5) organisms at 3h; 0 organisms at 24 h) in contrast to Staph. aureus (1.61x10(5) at 3h; 5.70x10(5) at 24 h). This SF bactericidal phenomenon was observed in 11/11 ReA patients, 5/8 rheumatoid arthritis (RA) patients and 1/8 osteoarthritis (OA) patients. Using a sandwich ELISA, we measured SF levels of bactericidal/permeability-increasing protein (BPI). BPI was detectable in all ReA SF (range 4.6-333ng/ml)) and RA SF (range 343-2570ng/ml), but was absent in 5/6 OA SF tested. Anti-BPI antibodies, however, did not fully neutralize the bactericidal activity of inflammatory SF. In contrast to the SF effects observed on Gram-negative bacteria, Chlamydia trachomatis cultured within HeLa cells thrived in the presence of SF. Indeed extracellular Chlamydia could easily be passaged through cultured synovial fibroblasts in the presence of SF. These findings indicate that the potent microbicidal activity of SF may account for the failure to recover viable organisms from the joint in ReA. Chlamydia alone amongst these organisms demonstrates resistance to microbicidal effect of SF, which may relate to the pathogenesis of Chlamydia-induced arthritis.

Prediction of diagnosis in acute and subacute oligoarthritis of unknown origin

A total of 146 consecutive patients between 18 and 60 yr of age with oligoarthritis of unknown origin (< or = 6 active joints, < or = 8 weeks duration) were examined by a variety of clinical, laboratory and microbiological investigations, and followed longitudinally for 24 weeks. Reactive arthritis was diagnosed in 46 patients (19 induced by Chlamydia trachomatis, 27 by enterobacteria), 62 had undifferentiated arthritis, eight other inflammatory arthritic diseases, 15 acute sarcoid arthritis and 15 non-inflammatory joint diseases. Group differences were found for many baseline variables, but with considerable overlap between the groups. A set of four clinical and laboratory variables (elevated CRP, genitourinary symptoms, metatarsophalangeal joint involvement. HLA B27) could predict reactive arthritis with a sensitivity of 69.2% and a specificity of 93.5%. A wide range of clinical and laboratory examinations are required to determine the final diagnosis in oligoarthritis, but individual and sets of clinical and laboratory measures may give helpful clues for the correct diagnosis.

Reactive arthritis, diagnosis and treatment: a review

The diagnosis of reactive arthritis (ReA) is easy in typical cases with a history of an infection within 3 weeks in combination with an asymmetric mono or oligoarthritis with or without extra-articular manifestations. Subclinical microbial infections, a possible co-existing inflammatory bowel disease and the fact that in 25% of the cases the microbial agent remains unidentified, make the diagnosis more troublesome. The course of disease is usually self-remittent within 6 months but a less good long-term prognosis is pre-determined by two factors-namely, the presence of HLA-1327 and the recurrence of triggering infections. The finding of microbial fragments in the joint cavity have led to new treatment strategies especially in Chlamydia-triggered ReA. It must, however, be remembered that the antibiotics mostly used (namely, tetracyclines) also possess immunoregulatory and anticollagenolytic potential. In chronic destructive cases, antirheumatic treatment, similar to that used in rheumatoid arthritis, is recommended.

Aetiological agents and immune mechanisms in enterogenic reactive arthritis

Reactive arthritis is triggered by an infection, either of the genitourinary or gastrointestinal tracts; the common triggering bacteria in enteric ReA include salmonella, shigella, yersinia, and campylobacter. It is still not clear how such different bacteria can lead to a similar clinical picture and have a similar association with the MHC class I antigen HLA-B27. Common both to enterogenic and urogenic bacteria is the type of peripheral joint involvement. However, this is not so different from other bacteria-associated arthritides and is probably the consequence of bacteria persistent inside the joint. What is unique to these bacteria is the HLA-B27-association and the nearly exclusively B27-linked clinical manifestations as sacroiliitis and iritis. Shigella-induced ReA has the highest B27-association while in salmonella- and chlamydia-induced ReA a lower association can be found. Mucosal entry of enterogenic bacteria give easy access to macrophages which might be important for the transport into the joint. Although bacteria-specific antibodies are of diagnostic value, the humoral immune response does not explain the immunopathogenesis and MHC-association of this disease. Bacteria-specific T-cells have been constantly found in the synovial fluid from ReA patients and have been further analysed. The identification of immunodominant antigens of these bacteria is of great importance to understand the pathogenesis. Although an antigen shared by all bacteria has not been identified until now progress is being made in this field. We have also to consider the possibility that these bacteria are not only driving the immune response themselves but rather work as a trigger for autoimmunity.

Comparison of peptides eluted from the groove of HLA-B27 from Salmonella infected and non-infected cells

Reactive arthritis (ReA) is associated with the MHC class-I molecule HLA-B27 and caused by certain Gram-negative bacteria. The mechanism by which HLA-B27 confers a higher susceptibility for this disease compared to other MHC Class-I alleles is still not known. We investigated whether infection of human HLA-B27+ cells is able to change the peptide repertoire presented by these HLA-B27 molecules. To this end large quantities of a B-cell line (C1R-B27) transfected with HLA-B2705 were infected with S. typhimurium. Peptides were eluted from the B27 molecules and separated by Reversed Phase Chromatography (RPC). We then compared the peptide profiles obtained from S. typhimurium infected CIR B-cells with that obtained from non infected cells. Apart from a few additional peaks present in the profile derived from the infected batch the peptide profiles were almost identical. A few fractions were subjected to sequencing by Edman degradation. All peptides found were nonameres with arginine (Arg) at position 2 which is in agreement with the previously described HLA-B27 peptide binding motif. The majority of peaks expressed a mixture of at least four different peptides. The analysis of differences between HLA-B27 bound peptides from Salmonella infected and non infected cells might lead to the identification of T-cell epitopes shared by Salmonella and autoantigens.

Antineutrophil cytoplasmic antibodies in reactive arthritis

OBJECTIVE

To study the occurrence of antineutrophil cytoplasmic antibodies (ANCA) in reactive arthritis (ReA).

METHODS

Sera from 22 patients with ReA were analyzed by ELISA for the presence of autoantibodies (IgG and IgA) against a proteinase-3 containing azurophilic granule extract ("alpha-antigen") from human polymorphonuclear leukocytes, myeloperoxidase (MPO), and lactoferrin (Lf), respectively. Rheumatoid factor (RF), antinuclear antibodies (ANA), and HLA-B27 were also tested. Erythrocyte sedimentation rate and serum levels of C-reactive protein were used to assess disease activity. The patients were divided into acute or chronic (> 1 year) disease.

RESULTS

12/22 patients (55%) had IgG ANCA (7 had MPO ANCA, 8 had Lf ANCA, and 4 had alpha-ANCA). Eight patients (36%) had IgA ANCA. One serum was positive only for IgA ANCA. 18/21 patients (86%) were HLA-B27 positive, and none had RF or ANA. The triggering infection was Chlamydia trachomatis in 6 cases. Campylobacter jejuni in 6, Yersinia enterocolitica in 4. In 6 patients the causative microorganism could not be determined. ANCA was more prevalent in chronic disease (6/7, 82%) compared to acute (7/15, 47%). No obvious correlation was seen between ANCA and disease activity.

CONCLUSION

ANCA, predominantly those reacting with Lf and/or MPO preparations, are common in ReA.

Reactive arthritis-associated bacteria can stimulate lymphocyte proliferation in non-exposed individuals and newborns

In reactive arthritis (ReA) a specific T cell response to the triggering bacterial antigen is present in the synovial fluid, while in paired peripheral blood T cells the response is markedly reduced. The proliferative response to ReA-associated bacteria in the peripheral blood of ReA patients was compared with that seen in the blood of healthy adults, who denied exposure to these microbes, and in the umbilical cord blood of newborns, who have clearly not been exposed to bacterial antigen. Peripheral blood mononuclear cells (PBMC) from non-exposed adults and those from umbilical cord blood proliferated to ReA-associated bacteria, whilst little response was seen in ReA PBMC. The response was MHC class II-restricted, required processing of the bacterial antigen, was seen in both CD45RO+ and CD45RA+ subsets, and was not oligoclonal. These T cell responses are similar to those previously demonstrated in non-exposed individuals to malaria, leishmania and trypanosoma antigen, and may reflect the existence of 'natural' T cell immunity to ReA-associated bacteria. The lack of such responses in ReA peripheral blood may suggest that such 'natural' responses may restrict the dissemination or progression of infection.

Sensitivities of PCR, MicroTrak, ChlamydiaEIA, IDEIA, and PACE 2 for purified Chlamydia trachomatis elementary bodies in urine, peripheral blood, peripheral blood leukocytes, and synovial fluid

Routine microbiological diagnosis of Chlamydia-induced reactive arthritis is based mainly on the detection of Chlamydia trachomatis with urogenital swabs or in urine. Because chlamydial antigen, rRNA, and DNA are present in low quantities in the inflamed joint, highly sensitive assays are needed to detect C. trachomatis not only at the primary site of infection but also in peripheral blood and peripheral blood leukocytes, which are suspected carriers for dissemination, and in synovial fluid. To evaluate possible tools for this purpose, the sensitivities of PCR, MicroTrak, Chlamydia EIA, IDEIA, and PACE 2 for the detection of defined numbers of purified C. trachomatis elementary bodies (EB) in urine, peripheral blood, peripheral blood leukocytes, and synovial fluid were determined. In urine, PCR detected 2, MicroTrak and ChlamydiaEIA detected 2 x 10(3), and PACE 2 and IDEIA detected 2 x 10(4) EB per ml. In peripheral blood, only PCR and MicroTrak detected C. trachomatis, with detection limits of 100 and 2 x 10(7) EB per ml, respectively. For peripheral blood leukocytes, the detection limits were 2 EB per ml for PCR and 2 x 10(4) EB per ml for MicroTrak, ChlamydiaEIA, IDEIA, and PACE 2. In synovial fluid, PCR detected 200, MicroTrak and IDEIA detected 2 x 10(5), and PACE 2 detected 10(6) EB per ml. ChlamydiaEIA was unable to detect 2 x 10(6) EB per ml in synovial fluid. In summary, PCR was found to be the most sensitive method. The sensitivities of the other methods tested were at least 1,000 times lower than that of PCR. PCR should therefore be considered a most promising tool for routine diagnosis of Chlamydia-induced arthritis.

Idiopathic granulomatous appendicitis. Report of five cases, one of which presented as migratory arthritis

The clinical presentation of acute appendicitis and the idiopathic granulomatous variety are, as a rule, indistinguishable. Five patients with idiopathic granulomatous appendicitis, treated during past decade, had histological acute and chronic appendicitis abounding with granulomas. Investigations not disclosing a systemic or enteric granulomatous disease and the patients' long-term complete postoperative recovery support the diagnosis of idiopathic granulomatous appendicitis.

Case report: in situ hybridization for detection of inapparent infection with Chlamydia trachomatis in synovial tissue of a patient with Reiter's syndrome

The authors have shown that protein antigens, RNA, and DNA from Chlamydia trachomatis are present in synovial tissues of patients with Reiter's syndrome (RS). However, those studies gave no insight into the host cell type involved or the precise tissue location of the bacteria. To address such issues, the authors developed an in situ hybridization system to detect chlamydia, and they used that system to examine synovial biopsies from a patient with RS and a patient without RS. The in situ system uses a previously described digoxigenin-labeled DNA probe that hybridizes with chlamydial 16S rRNA sequences in paraformaldehyde-fixed samples. Control studies with chlamydia-infected and uninfected HeLa cells confirmed that the in situ system is as sensitive as is direct fluorescence cytology for detection of the organism. Morphology of host and chlamydia cells is preserved after hybridization. Studies using synovial tissue from an osteoarthritis patient produced no in situ hybridization signal, but similar hybridization to tissue from a culture-/direct fluorescence cytology- negative RS patient had a strong intracellular signal for chlamydia within a subsynovial cell layer. These in situ hybridization results confirm the extensive presence of chlamydia in synovia and extend the authors' earlier observation that chlamydia RNA is present in the synovia of patients with RS. The data also confirm their electron microscopy studies, indicating that chlamydia are intracellular in synovial tissue, and they further show that infected host cells are located beneath the synovial lining.

Alteration of Chlamydia trachomatis biologic behavior in synovial membranes. Suppression of surface antigen production in reactive arthritis and Reiter's syndrome

OBJECTIVE

To investigate the biologic state of Chlamydia and its surface antigen expression in the synovial membranes of patients with Chlamydia-associated reactive arthritis/Reiter's syndrome (ReA/RS).

METHODS

Expression of chlamydial lipopolysaccharide (LPS), major outer membrane protein (MOMP), and elementary body (EB) antigens was studied by gold labeling immunoelectron microscopy on 6 synovial membrane and 2 synovial fluid (SF) pellet samples from 6 patients with Chlamydia-associated arthritis. The study findings were compared with 24-hour cultures of HeLa cells infected with Chlamydia trachomatis EB.

RESULTS

Persistent C trachomatis infection was found in all 6 synovial membrane samples from patients who had either early or chronic arthritis. The infection persisted despite antibiotic treatment, including a 1-month course of doxycycline therapy. Most persistent organisms were atypical reticulate bodies (RBs) found in both fibroblasts and macrophages. Specific, but weak, immunogold staining for all 3 antibodies was found on both intracellular RBs and extracellular EBs. In the SF samples, Chlamydia surface antigens were detected only in phagosomes containing degraded electron-dense materials.

CONCLUSION

The synovial membrane biopsies conducted in this study of Chlamydia-associated ReA/RS revealed atypical RBs with diminished MOMP and LPS expression. Such altered organisms may escape immune surveillance and contribute to disease chronicity; moreover, these organisms may be difficult to detect and treat in some ReA/RS patients.