1 British Journal of Rheumatology 1998;37: EDITORIALS EXPERT WITNESS REPORTS IN RHEUMATOLOGY ALMOST all medical practitioners will at some stage of It is beyond the scope of this editorial to describe in their careers be asked to provide reports of medical detail what an expert witness report submitted in the evidence for courts, lawyers, insurers or employers. UK should contain; privately run courses abound in The requirements of these reports will vary between this field and the BSR organized a medicolegal course countries and legal systems; they may also depend in the autumn of 1997 which included this topic. upon whether or not the individual who is the subject However, several issues need to be considered. of the report is a patient of the doctor providing it. Should one supply expert witness reports on one s Consultant rheumatologists in the UK are asked by own patients? There seems to be no agreement on lawyers to provide expert witness reports in cases of this point amongst doctors or lawyers. Certainly, there alleged medical negligence, for personal injury claims are hazards in doing so; a report may antagonize a after acute trauma (e.g. in cases of whiplash injury, patient and destroy the clinical relationship. The docalleged precipitation of arthritis or exacerbation of tor s natural inclination to support his patient to the existing arthritis), where injuries are alleged to have hilt may lead to an unpleasant bumping up against occurred as a result of workplace practices and occa- the truth, particularly under cross-examination. sionally in criminal cases. Conversely, some lawyers feel that a specialist who Employers and insurers frequently turn to rheumato- already has a professional relationship with a patient logists for advice about whether or not to grant is likely to be a more enthusiastic expert witness than employees early retirement on medical grounds for one who is indifferent to the outcome of a case. disablement resulting from musculoskeletal conditions. An expert should alter a report at the request of the British insurers and solicitors are becoming well commissioning solicitor only in ways which do not informed about the capabilities of rheumatologists in affect his original opinion, unless the solicitor brings assessing their clients with difficult musculoskeletal to light some fact that necessitates alteration of that diagnoses such as fibromyalgia, work-related upper opinion. limb disorders and algodystrophy, as well as those Far-reaching changes are currently under way in the with more clearly defined conditions such as rheumat- practice of law in Britain which affect doctors supplying oid arthritis. As a result, most rheumatologists will expert witness reports in a number of ways: periodically receive requests for expert witness reports. $ Ordinary witness statements are statements of fact, Legal aid for financial claims for personal injury is e.g. containing only a chronological account of a due to be withdrawn this year; aid for medical patient s diagnosis and treatment, whereas an expert negligence claims is likely to be abolished within a witness report is also a statement of opinion, e.g. about few years. Simultaneously, the use of conditional possible causes of an individual s condition, its probase; solicitors will fund the costs of cases themselves fees is to be expanded from the present rudimentary gnosis or the suitability of treatment given. In the UK, one may decline to provide an expert witness report, and take a proportion (the conditional fee ) of any but not to testify in court if one s report is used in award that their clients win. They will also have to evidence. Expert witness reports should be provided in bear part or all of the financial risk of losing cases Britain only at the written request of a legal practitioner (although the risk of having to pay the other side s (a solicitor), who must make clear to the expert whether costs will be no higher than is currently the case he is acting for the plaintiff (the person or organization with legally aided clients ). Solicitors will thus bringing the legal action for damages) or the defendant need to know from the start in particular cases (against whom the action is being instituted). The whether or not they have a good chance of winning. provider of the expert witness report should write the In cases with medical evidence, they may seek the report bearing in mind that it may eventually have to help of expert advisors to answer this question. The be defended under oath in court, before a judge with medical advisor could be open to suit if he does not little understanding of medical facts and jargon. The deal adequately with the facts, strengths and weak- report may be revised after discussion with the solisolicitor nesses of a case  in a way which allows the citors who commissioned it, after which it is exchanged to make an accurate risk appraisal. with expert witness statements from the other side, for $ The Master of the Rolls, Lord Woolf, has recently comment. When providing reports for employers or published a report  into the workings of the civil insurers, it is important for the expert in the UK to justice system in the UK with the aim of making remember that if he has seen as a patient the individual the process of claiming damages cheaper, faster and who is the subject of his report, that individual is more accessible to members of the public. The role entitled to see the report before its release to the party of the expert medical witness has come under commissioning it . If in doubt, the medical expert scrutiny in his report: I believe there is scope for should consult his defence organization. the joint instructing of a single expert in cases British Society for Rheumatology
2 716 BRITISH JOURNAL OF RHEUMATOLOGY VOL. 37 NO. 7 $ where no controversial medical issue is involved The effect of these changes is that expert witnesses . If this suggestion were taken up, it would must be seen to be truthful, and clearly expert in represent a move from the adversarial British system current practice in their field. They must be forthright of justice toward the inquisitorial system prevalent about their own limitations and the limitations of their in continental Europe; however, this view of one evidence, and must give clear reasons for their opin- opinion per case, rather than the plaintiff and the ions. Although the eminence of an expert will doubtless defence each instructing their own expert(s), has not continue to lend authority to his opinion, that author- been universally welcomed by British solicitors, who ity may be undermined if these criteria are not fulfilled. will not want to invest in opinions which do not Medical negligence work in rheumatology is no favour their clients, since it is illegal for expert different from that in other specialities. In a medical witnesses to receive conditional fees. negligence action in the UK, the task of the expert is to provide information which will help the court to The single expert option accords with the English judicial view of the role of the expert witness as decide whether or not the plaintiff received medical being to help the court, whether he is commissioned care of a standard which was in accordance with a by the plaintiff or the defendant. A set of principles practice accepted as proper by a responsible body of guiding the evidence of expert witnesses [6 ] has medical opinion skilled in that particular art  and received widespread judicial approval in the UK; it if not, whether or not this failure caused harm. is now considered de rigeur for experts to follow However, there are other areas of medicolegal work these seven Cresswell Principles (named after the that particularly concern rheumatologists. These judge who first advocated them). The principles include claims against individuals or organizations for (abridged) are: personal injury, claims against workers compensation insurance funds and claims against permanent health 1. Expert evidence should be independent. insurers for alleged unfitness for work. Workers com- 2. An expert witness should never assume the role pensation insurance (which pays compensation for of advocate. illness or injury suffered as a result of employment) 3. An expert witness should state the facts upon has barely existed in Britain as a separate entity since which his opinion is based and all the facts 1948 when it became part of the state-funded health which could detract from his opinion. and welfare system; in other countries, including the 4. An expert witness should make clear when an USA and Australia, it is covered by separate insurance issue is outside his expertise. systems paid for largely by employers. The use of 5. If inadequate data exist to support an opinion, workers compensation insurance in the UK may then an expert should indicate that his opinion is increase as the Welfare State shrinks and companies provisional. If the expert could not assert that insure against the inability of their employees to work his report contained the whole truth without through illness or injury caused specifically by their some qualification, his report should state that employment. Claims against workers compensation qualification. insurance funds for musculoskeletal conditions are 6. If an expert witness changes his opinion having expensive; according to Hadler , back pain and arm read the report of the other side s expert, he pain not associated with any single specific injuring should transmit this change of view (via legal event account for 20% of workers compensation insurrepresentatives) to the other side and to the court, ance claims (but for 80% of payments) in the USA. without delay. Workers compensation, personal injury and perman- 7. Where expert evidence refers to measurements or ent health insurance claims for inability to work due similar documents, these must be provided to the to fibromyalgia and work-related upper limb disorder opposite party at the time of the exchange of ( RSI ) pose considerable difficulties for insurers because reports. of uncertainties surrounding the diagnosis and prognosis of these conditions. Additionally, in workers In a recent decision , the House of Lords affirmed compensation claims for these diagnoses, it may be some of the Cresswell Principles in medical negligence difficult to ascertain whether the condition occurred as when it pronounced that in cases involving the a result of a specific employment. Rheumatologists are weighing of risks against benefits, judges would have often better placed than other specialists to deal with to be satisfied that the experts had directed their minds such issues. to the question of comparative risks and benefits, Payment for expert witness work is an important and reached a defensible conclusion. Lord Browne- issue which is often dealt with inadequately by both Wilkinson added that if it can be demonstrated doctors and lawyers. The expert in the UK should that the professional opinion is not capable of with- always aim to have a clear contract with the solicitor standing logical analysis, the judge is entitled to hold from the start, in order to maintain professional credibthat the opinion is not reasonable or responsible. ility and to avoid later disagreements. The contract is In such cases, it is the expert s judgement rather than straightforward: the expert agrees to supply a report his knowledge that is under test. However, where to the solicitor to cover the issues requested, on delivery available, scientifically proven facts will form an and payment terms agreed in advance. The expert important part of the expert s defence of his opinions. should develop and use standard agreement terms,
3 EDITORIALS 717 including a payment date and a statement that he does be very tedious. Lastly, the adversarial legal process in not wish his fee to be subject to assessment and the UK contains elements of ruthlessness so the expert taxation by the court (which can sometimes delay and needs to maintain high standards of knowledge and reduce payment). It is important to obtain the soliand judgement, or run the risk of possible public censure citor s written agreement in advance, however apparently ignominy. pressing the need for an early report. The expert In conclusion, although this editorial deals primarily may quote an hourly rate or an overall fee for the with medical reports provided by rheumatologists work; solicitors prefer the latter. However, it is rarely within the legal system of the UK, rheumatologists in possible to estimate precisely the amount of work one other countries may recognize many similarities to the needs to put into a report, particularly if the case is requirements imposed upon them in their medicolegal complex. If the price quoted does not include considtors work; the duty of professional integrity amongst doc- eration of further documentation, meetings with lawyers is universal. and court appearances, this must be made clear. A. BRADLOW Lastly, the contract for providing the report is with Department of Rheumatology, Royal Berkshire and the solicitor, not with the solicitor s client. Recovery Battle Hospitals NHS Trust, Battle Hospital, Reading of payment from a client who cannot or will not pay RG3 1AG is the solicitor s task and should not cause any delay in payment to the expert. A solicitor who breaches a REFERENCES contract with an expert may be reported to the Office 1. Access to Medical Reports Act 1988 Ch 28 s1. for the Supervision of Solicitors in Leamington Spa, 2. Hodgson and others v Imperial Tobacco Ltd and others. Warwickshire. (CA) Independent, 17 February The expert witness working in the UK thus needs 3. Pamplin C. Conditional fees. In: Your witness newsletter to be truthful, concise and an active expert in the field. of the UK Register of Expert Witnesses. Newmarket: JS Publications, 1997: Issue 10. He must give reasons for his opinions, citing published 4. Woolf, Rt Hon the Lord, Master of the Rolls. Access to evidence wherever possible. Reports should be written justice. Final report to the Lord Chancellor on the civil for the intelligent layman, using short sentences, justice system in England and Wales. London: HMSO, avoiding the use of jargon, and explaining all terms, if July necessary in an accompanying glossary. The expert 5. Woolf, Rt Hon the Lord. Medics, lawyers and the court. should agree a contract with the solicitor before under- J R Coll Physicians London 1997;31: taking the work. The careful evaluation of documented 6. The Ikarian Reefer  2 Lloyds Rep 68 at p81. evidence in the preparation of a report (using medical 7. Dyer C. Medical decisions must be logically defensible. Br Med J 1997;315:1327. journals and textbooks to back one s opinions where 8. McNair J in Bolam v Friern Hospital Management possible) should be a rigorous stimulus to learning and Committee  1 WLR 583. expert witness work can be a useful supplement to 9. Hadler NM. Worker s compensation and regional backincome. However, there are no easy reports; picking ache. In: Occupational musculoskeletal disorders. New through the minutiae of evidence is essential, but can York: Raven Press, 1993:157. TREATMENT OF REACTIVE ARTHRITIS WITH ANTIBIOTICS WHEN discussing the causes of inflammatory rheumatic these forms of arthritis. This idea has received strong diseases, the role of microbes is often raised . Among support from the demonstration of bacterial antigens the many rheumatic diseases, the most informative in in the joint by several techniques, suggesting that this connection are reactive arthritis ( ReA) and Lyme locally persisting bacterial antigen indeed drives the arthritis, both of which develop following infection immunopathology (overview in ). For Borrelia burgdorferi, outside the joint. The bacteria which are most frequently the causative agent for Lyme arthritis, and for involved in ReA are Chlamydia trachomatis Chlamydia trachomatis it has repeatedly been shown (following infections of the urogenital tract) and that bacterium-specific DNA and even RNA  can enterobacteria such as Yersinia, Salmonella, Shigella be found in synovial fluid or synovial membrane, or Campylobacter jejuni (following infections of the suggesting that live bacteria are present. The situation gut). Although in most cases ReA is a self-limiting for the enterobacteria is less clear at present. Former disease, its mean duration of between 3 and 6 months, studies failed to find Yersinia DNA by polymerase especially in a young population [2, 3], demands a chain reaction (PCR) [6 ], although Salmonella  and treatment able to shorten the course of the arthritis. Campylobacter DNA  have been detected in this Furthermore, up to 20% of patients run a chronic way in ReA joints. Very recently, Yersinia DNA has course longer than 12 months . also been identified in a patient with ReA using a The clear relationship between a specific bacterium broad-spectrum PCR . and the occurrence of arthritis has prompted the While it has become clear in recent years that Lyme question of whether antibiotics can be used to treat arthritis can be prevented by early treatment of the
4 718 BRITISH JOURNAL OF RHEUMATOLOGY VOL. 37 NO. 7 initial skin infection, and even the arthritis cured in shaped bacteria without DNA can be detected for the majority of cases by appropriate antibiotic treatment, weeks by intracellular antibody staining . Thus, the situation is less clear for ReA. Early studies the persistence of dead bacteria could be sufficient to demonstrated that short-term ( 1 2 weeks) antibiotic stimulate a local immune response, possibly through treatment of ReA does not influence the course and lipopolysaccharide ( LPS), even over the period of duration of the arthritis [ 10, 11]. Therefore, interest weeks and months of the self-limiting form of the has focused on the question of whether arthritis can disease. However, the persistence of high serum levels be prevented by antibiotic therapy of the preceding of IgA class antibodies in patients with ReA  and infection, or ameliorated by long-term antibiotic the continued excretion of Yersinia from the gut in treatment. animals treated adequately  suggests that, at least Two studies from Salmonella outbreaks showed that in some patients, live bacteria might persist outside the antibiotic treatment of the initial infection, mostly joint, e.g. in the intestinal mucosa . It is not clear with quinolones, did not prevent arthritis [12, 13]. at the moment why these bacteria are resistant to the Comparable data are not available for the other enterobacteria. antibiotics. However, in an animal model of Yersinia- The situation for Chlamydia trachomatis is more induced arthritis, treatment with ciprofloxacin could contradictory. ReA can certainly occur even after reduce the incidence of arthritis only when given effective treatment of a C. trachomatis infection of the immediately after infection and before or shortly after urogenital tract [ 19]. However, in a study performed the onset of clinical symptoms . This is of doubtful in the Greenland population, which has a high frequency clinical relevance as patients are rarely seen this early of HLA-B27, of venereal diseases, and of ReA, in their disease. Thus, it seems unlikely that antibiotic the incidence of post-venereal relapse of ReA was treatment of Salmonella or Yersinia enteritis would significantly reduced from 37% in untreated or penicil- prevent arthritis. lin (ineffective for Chlamydia) treated patients to 10% Long-term antibiotic therapy over 3 months with in infections treated short term with erythromycin or tetracycline  or ciprofloxacin [15, 16] has been tested tetracycline, both antibiotics which are highly effective in enterobacteria-induced ReA in placebo-controlled in the treatment of chlamydial infections . double-blinded studies. Lauhio et al.  could find no Therefore, because C. trachomatis tends to persist for effect of treatment with lymecycline in a small group a long time in the urogenital tract and because it can of 11 patients with enteric ReA caused either by cause not only arthritis, but also infertility, patients Yersinia or Campylobacter. Subsequently, Toivanen should be treated by appropriate antibiotics for et al.  also found no effect of antibiotics in 31 days if C. trachomatis is present. Another question is patients with Yersinia-induced arthritis. However, the whether every patient with suspected ReA should be significance of the latter study is limited by the long tested for C. trachomatis in the urogenital tract. disease duration of nearly 5 yr before treatment. In a Although the cost-effectiveness of such an approach very recent study , we also did not see any effect has not been tested, these authors would advocate it. of a 3 month course of ciprofloxacin treatment The possibility of detecting Chlamydia not only in a (1g/day) on the course of the arthritis caused either urogenital smear, but also in the first portion of the by Yersinia or Salmonella in 39 patients, independently morning urine , would be worth considering it. of whether the disease duration was longer or shorter In two of the studies mentioned above, patients with than 3 months. Furthermore, in the animal model of Chlamydia-induced ReA were treated with lymecycline Yersinia-induced arthritis, even a very high dose of  or ciprofloxacin  vs placebo over 3 months. In ciprofloxacin did not influence the course of established the lymecycline study, with a relatively small number arthritis . Interestingly, 15% of the animals treated of 21 Chlamydia-induced arthritis patients, 50% of the with a lower dose, comparable to that used in humans, antibiotic-treated group recovered by 15 weeks vs 39.5 still continued to excrete Yersinia in the faeces. weeks in the placebo group (a statistically significant Thus, long-term antibiotic therapy, even with the currently difference). In the ciprofloxacin study, 66% of patients most effective drugs for enterobacteria (the treated with antibiotics vs 33% in the placebo group quinolones), seems not to be effective in enteric ReA. showed improvement, a difference which was not signi- It could be argued that the number of patients so ficant probably because there were only 15 patients. far investigated was too small, that there are results In another study, patients with Chlamydia-induced for Yersinia but few for Salmonella and Campylobacter, ReA who had a disease duration of >6 months were and none for Shigella, and that all studies have included treated with 200 mg/day of doxycycline either for 2 a rather small proportion of patients with early ReA. weeks or for 4 months . Four out of 15 patients However, the conclusion drawn from the currently (27%) treated long term and 3 out of 17 (18%) treated available data must be negative. The results of the short term went into remission; this difference was not ongoing European study on the treatment of ReA with significant. Furthermore, a recent report demonstrates azithromycin may give additional information. that C. trachomatis persists in the synovial membrane The question arises why antibiotics seem to fail in of patients with ReA despite treatment with adequate enteric ReA despite the detection of the products of antibiotics . Thus, antibiotic treatment has been Yersinia, Salmonella and Shigella in the joint. For demonstrated to have some benefit in Chlamydia- Yersinia, it has been shown in in vitro studies that rod- induced ReA, although the situation remains uncertain.
5 EDITORIALS 719 The positive trend observed for antibiotic treatment in 6. Nikkari S, Merilahti Palo R, Saario R et al. Yersiniasome of the studies would argue for the presence of triggered reactive arthritis. Use of polymerase chain live Chlamydia in the joint and would therefore be in reaction and immunocytochemical staining in the detec- accordance with the detection of chlamydial RNA in tion of bacterial components from synovial specimens. synovial membrane. Arthritis Rheum 1992;35: Nikkari S, Möttönen T, Saario R et al. Demonstration On present information, it does not seem likely that of Salmonella DNA in the synovial fluid in reactive antibiotic treatment for longer than 3 months or use arthritis. Arthritis Rheum 1996;39:S185. of the parenteral route would be more effective. 8. Braun J, Tuszewski M, Eggens U et al. Nested poly- However, one has to consider the possibility that merase chain reaction strategy simultaneously targeting bacteria persist in a latent state where they could be DNA sequences of multiple bacterial species in inflamkilled only by antibiotics in combination with stimula- matory joint diseases. I. Screening of synovial fluid tion of the immune response . Furthermore, the samples of patients with spondyloarthropathies and other possibility remains open, especially in HLA-B27+ arthritides. J Rheumatol 1997;24: chronic cases of ReA, that an autoimmune response 9. Wilkinson NZ, Ward ME, Kingsley GH. Detection of takes over , thus rendering antibiotic treatment bacteria in rheumatoid and reactive arthritis synovial ineffective. There have been reports that antibiotics fluid using a kingdom-specific polymerase chain reaction: might also work through immunosuppression. Howgenesis evidence in support of a role for bacteria in the patho- of inflammatory arthritis. Arthritis Rheum ever, until antibiotic treatment has clearly been shown to be effective, there is little point in discussing how it 1997;40:S270. might or might not work. 10. Popert AJ, Gill AJ, Laird SM. A prospective study of Reiter s syndrome. An interim report on the first 82 In summary, there is increasing evidence that the cases. Br J Venereal Dis 1964;40: pathophysiology might differ in Chlamydia-induced 11. Fryden A, Bengtsson A, Foberg U. Early antibiotic and enteric ReA. Available evidence suggest that antitreatment of reactive arthritis associated with enteric biotics are not effective in enteric ReA, but that they infections: clinical and serological study. Br Med J might work in Chlamydia-induced ReA. However, final 1990;301: proof of their efficacy even in Chlamydia-induced ReA 12. Locht H, Kihlstrom E, Lindstrom FD. Reactive arthritis is missing; further study is required with larger patient after Salmonella among medical doctors study of an numbers, preferably accompanied by PCR testing for outbreak. J Rheumatol 1993;20: Chlamydia in the joints, where this technique has not 13. Mattila L, Leirisalo-Repo M, Pelkonen P, Koskimies S, been applied previously. While the quinolones seem to Granfors K, Siitonen A. Reactive arthritis following be best for enterobacteria, in vitro studies suggest that an outbreak of Salmonella bovismorbificans infection. tetracycline or macrolide antibiotics such as azithromy- J Infect; in press. cin might be superior for killing Chlamydia. To improve 14. Zhang Y, Gripenberg Lerche C, Soderstrom KO, efficacy, even combination antibiotic therapy could be Toivanen A, Toivanen P. Antibiotic prophylaxis and considered. In conclusion, long-term antibiotic treatmodel. Arthritis Rheum 1996;39: treatment of reactive arthritis. Lessons from an animal ment of ReA is not indicated in daily clinical practice, 15. Toivanen A, Yli Kerttula T, Luukkainen R, Merilahti pending the results of further study. Palo R, Granfors K, Seppala J. Effect of antimicrobial J. SIEPER and J. BRAUN treatment on chronic reactive arthritis. Clin Exp Department of Medicine, Rheumatology Section, Univer- Rheumatol 1993;11: sity Hospital Benjamin Franklin, Hindenburgdamm 0, 16. Sieper J, Fendler C, Eggens U et al. Long term antibiotic Berlin, Germany treatment in reactive arthritis and undifferentiated oligoarthritis: results of a double-blinded placebo-controlled REFERENCES randomized study. Arthritis Rheum 1997;40:S Huppertz HI, Heesemann J. Experimental Yersinia infec- 1. Kingsley G. Microbial DNA in the synovium a role in tion of human synovial cells: persistence of live bacteria aetiology or a mere bystander? Lancet 1997;349: and generation of bacterial antigen deposits including 2. Lauhio A, Leirisalo Repo M, Lahdevirta J, Saikku P, ghosts, nucleic acid-free bacterial rods. Infect Immun Repo H. Double-blind, placebo-controlled study of 1996;64: three-month treatment with lymecycline in reactive arth- 18. Toivanen A, Lahesmaa Rantala R, Vuento R, Granfors ritis, with special reference to Chlamydia arthritis. Arthritis Rheum 1991;34:6 14. K. Association of persisting IgA response with yersinia 3. Glennas A, Kvien TK, Melby K et al. Reactive arthritis: triggered reactive arthritis: a study on 104 patients. Ann a favorable 2 year course and outcome, independent Rheum Dis 1987;46: of triggering agent and HLA-B27. J Rheumatol 1994; 19. Keat A, Thomas BJ, Taylor Robinson D. Chlamydial 21: infection in the aetiology of arthritis. Br Med Bull 4. Sieper J, Braun J. Pathogenesis of spondylarthropathies. 1983;39: Persistent bacterial antigen, autoimmunity, or both? 20. Bardin T, Enel C, Cornelis F et al. Antibiotic treatment Arthritis Rheum 1995;38: of venereal disease and Reiter s syndrome in a Greenland 5. Nanagara R, Li F, Beutler A, Hudson A, Schumacher population. Arthritis Rheum 1992;35: HR. Alteration of Chlamydia trachomatis biologic 21. Caul EO, Horner PJ, Leece J, Crowley T, Paul L, Davey behavior in synovial membranes. Suppression of surface Smith G. Population-based screening programmes for antigen production in reactive arthritis and Reiter s Chlamydia trachomatis. Lancet 1997;349: syndrome. Arthritis Rheum 1995;38: Wollenhaupt J, Hammer M, Pott HG, Zeidler H. A
6 720 BRITISH JOURNAL OF RHEUMATOLOGY VOL. 37 NO. 7 double-blind placebo-controlled comparison of 2 weeks antibiotic treatment in chronic Reiter s syndrome/reactive versus 4 months treatment with doxycycline in arthritis. J Clin Rheumatol 1997;3: Chlamydia-induced arthritis. Arthritis Rheum 1997; 24. Yin Z, Braun J, Neure L et al. Crucial role of 40:S143. interleukin-10/interleukin-12 balance in the regulation of 23. Beutler AM, Hudson AP, Whittum-Hudson JA. the type 2 T helper cytokine response in reactive arthritis. Chlamydia trachomatis can persist in joint tissue after Arthritis Rheum 1997;40: