Hereditary periodic fever with systemic amyloidosis: is hyper-IgD syndrome really a benign disease?

We report a case of amyloidosis in association with hyperimmunoglobulinemia D syndrome (HIDS). The patient showed typical clinical features of HIDS. He had crescentic glomerulonephritis progressing to end-stage renal disease at age 13 years. Eight years later, he developed an AA-type amyloidosis with extensive involvement of the intestine, respiratory tract, and thyroid gland. These unusual complications of HIDS seriously challenge the assumption that the disease is associated with a good prognosis.

[Cardiac manifestations of rheumatic diseases]

Inflammatory rheumatic diseases potentially involve organs and structures far beyond the musculoskeletal system including skin and blood vessels. A broad spectrum of neurologic, renal, pulmonary, hematologic and cardiac manifestations contributes to the complex clinical picture of connective tissue diseases and vasculitides. Regarding cardiac disease all structures of the heart may be involved. Pericarditis in lupus, mitral valve changes in the antiphospholipid syndrome, myocarditis and coronary artery stenosis in the systemic vasculitides are typical examples in systemic rheumatic diseases. Beyond this, pulmonary hypertension in systemic sclerosis or congenital heart block in newborns of lupus patients are further cardiac issues. Since better treatment options led to better long-term prognosis in connective tissue diseases, cardiovascular complications as a consequence of chronic disease- and therapy-related damage gain increasing attention.

Antiphospholipid syndrome in cardiac surgery—an underestimated coagulation disorder?☆

OBJECTIVE

Antiphospholipid syndrome (APS) is a rare coagulation disorder associated with recurrent arterial and venous thrombotic events. We analysed our experience with five APS patients who underwent cardiac surgery. In three of them the diagnosis of APS had been established before surgery, two patients were diagnosed after surgery.

METHODS

From March 1999 to March 2004 five patients with APS underwent cardiac surgery using cardiopulmonary bypass (CPB). We retrospectively reviewed their clinical data, operative and postoperative courses, and the long-term results.

RESULTS

Procedures performed were heart and lung transplantation (patient 1), endoventriculoplasty and CABG (patient 2), biventricular resection of endoventricular fibrosis and thrombus (patient 3), mitral valve repair repair and coronary artery bypass grafting (CABG, patient 4), and mitral valve replacement with closure of a patent foramen ovale (patient 5). There were three perioperative deaths (patients 1, 2 and 3), two of three patients in whom the diagnosis was known before surgery, survived (patients 4 and 5). In these patients, only half the dose of protamin (patient 4) and no protamin at all (patient 5) was applied to reduce the probability of postoperative thromboembolic complications. At 1 year follow up, only patient 4 had survived, patient 5 had died of the complications of intestinal thromboembolism.

CONCLUSIONS

Patients with APS undergoing cardiac surgery belong to a high risk subgroup. Thus, though rare, APS can be a critical issue in cardiac surgery. Some of the cardiac patients with unexplained perioperative thromboembolic complications, such as graft occlusion, may turn out to have an undiagnosed APS.

Health care and burden of illness in systemic lupus erythematosus compared to rheumatoid arthritis: results from the National Database of the German Collaborative Arthritis Centres

During the past 20 years, outcome studies in the rheumatic diseases have, on the one hand, given increasing evidence of the unfavourable long-term prognosis of rheumatoid arthritis (RA) and on the other hand determined continuous improvement of prognosis in systemic lupus erythematosus (SLE). The aim of the study was to investigate how this translates into the current spectrum of patients with rheumatoid arthritis (RA) or systemic lupus erythematosus (SLE) seen by rheumatologists in Germany and to compare aspects of the burden of disease, disease outcomes and treatment between these two important rheumatic diseases using a large clinical database. Current health care was analysed with data from the German rheumatological database of 10 068 patients with RA and 1248 patients with SLE seen by rheumatologists in 2001. In addition, of a total of 3546 patients with SLE and 24 969 patients with RA seen at the German Collaborative Arthritis Centres between 1994 and 2001, 3465 cases of SLE were matched by age, sex, disease duration and referral status with a corresponding RA case. There were considerable differences in treatment of patients before referral to a rheumatologist and in rheumatologic care. In 2001, patients with SLE were treated by their rheumatologists mainly with antimalarials (AM, 37%), azathioprine (29%) and nonselective NSAIDs (16%). Of them, 61% received at least one immunosuppressive drug (including AM) plus glucocorticoids. In RA, methotrexate was the predominant medication (63%), and 56% received at least one immunosuppressive drug plus glucocorticoids. Matched pairs analysis showed that SLE patients with a short disease duration were almost equally burdened by pain, functional limitations and reduced health status as RA patients. After a disease duration of >10 years, however, patients with RA showed poorer outcomes than those with SLE: RA patients reported significantly more often severe pain (30% in RA versus 17% in SLE) and poor global health status (52 versus 38%), and their disease activity as well as severity was rated higher by the rheumatologists. In conclusion, comparing large groups of RA and SLE patients we found a similar burden in early but not in late disease. Taking into account limitations as to the generalizability of the results (recruitment in rheumatologic care, cross-sectional data, underestimation of SLE-specific outcomes), the discrepancy between the high increase in disease-related negative outcomes with longer disease duration in RA but not in SLE indicates a better long-term prognosis in SLE concerning the items observed. The great disparity in treatment intensity between rheumatologists and nonrheumatologists shows that the involvement of a specialist is needed equally in both diseases.

Krankheitsbezogene Internetnutzung bei Patienten mit entz�ndlich-rheumatischen Systemerkrankungen

OBJECTIVE

On behalf of the "systemic inflammatory rheumatic diseases network" comprehensive, nationwide horizontal and vertical cross-linking of research and care is to be developed for the first time. The quality of scientific work and patient care is to be increased in the medium term through this improved communication and co-operation. Our objective was to determine what hardware and software are available to the patients involved, with a view to the Internet being used as a basis for communication. The ultimate aim was to provide patients with an adequate source of information on care.

METHODS

A survey was carried out among 400 patients attending our outpatient clinics. Data on the hardware and software used and on Internet access and patterns and degree of utilization were collected using a unilateral questionnaire.

RESULTS

326 patients filled in the questionnaire. 163 of those responding had Internet access, with younger and better educated patients using the Internet significantly more frequently. No dependency was noted on gender or marital status. Mean time duration for Internet use was longer in men. 55.8% of the internet users searched for medical questions. Major search topics included up to date therapeutic options (46.6%) and information on specific diseases (28.8%).

CONCLUSION

Internet is an important information medium for patients. Technical requirements and high motivation make communication practicable for about 50% of patients. To ensure acceptance, the Internet platform of the systemic inflammatory rheumatic diseases network needs to be aligned to patients' requirements, bearing in mind the need for extensive high-value, reliable scientific information to be offered on the website.

Differential diagnosis of high serum creatine kinase levels in systemic lupus erythematosus

We report the clinical and bioptic findings for a 57-year-old woman with severe chloroquine-induced myopathy. Since 1989, she had been suffering from systemic lupus erythematosus (SLE) with renal involvement and undergone periods of treatment with azathioprine and cyclophosphamide. Additional therapy with chloroquine (CQ) was started because of arthralgia. At the same time, slightly increased creatine kinase (CK) levels were noted. Myositis was suspected, and the patient was treated with steroids. The CK increase persisted, however, and she developed progressive muscular weakness and muscular atrophy. Routine controls revealed markedly elevated CK levels of 1,700 U/l. The neurological and electrophysiological findings were not typical of myositis. Thus, muscle biopsy of the deltoid muscle was performed in order to exclude polymyositis or toxic myopathy. As it revealed chloroquine-induced myopathy, medication was stopped. Discriminating between primary SLE-induced affection of the musculoskeletal system and drug-induced side effects is important for appropriate treatment of SLE patients.

[Rheumatology online: A survey among the members of the German Rheumatology Society]

OBJECTIVE

On behalf of the "Systemic Inflammatory Rheumatic Diseases Network" comprehensive, nationwide horizontal and vertical cross-linking of research and care is to be developed for the first time. The quality of scientific work and patient care is to be increased in the medium term through this improved communication and co-operation. Our objective was to determine what hardware and software are avail- able to the physicians involved, with a view to the Internet being used as a basis for communication and documentation within the network.

METHODS

A survey was carried out among 723 active members of the German Rheumatology Society (DGRh). Data on the hardware and software used and on Internet access were collected using a unilateral questionnaire.

RESULTS

The response rate among the addressed rheumatologists was 55.3%, with 64.1% of members in private practice replying. Of those responding 85% have Internet access, with rheumatologists in private practice using the Internet significantly less frequently at work than those working at a hospital (42% vs 80%). The latter accordingly reported a higher proportion of medical Internet usage (69% vs 52%, p<0.001). The survey demonstrated that software for private practices and hospitals shows a very variable picture with a multiplicity of systems being used.

CONCLUSION

Use of the Internet for communication in the "Systemic Inflammatory Rheumatic Diseases Network" is practicable in hospitals but clearly restricted in the private practice sector. The widely varying software used in hospitals and private practices underlines the need for standardized, comprehensive documentation systems to be developed. To ensure acceptance and broadly based application, they need to be integrated into the existing computer infrastructure. In this context, Internetbased applications offer new opportunities through the use of system-independent file formats.

Jaccoud's arthropathy in systemic lupus erythematosus: differentiation of deforming and erosive patterns by magnetic resonance imaging

OBJECTIVE

To evaluate alterations of the soft tissues, tendons, and bones as detected by magnetic resonance imaging (MRI) in patients with systemic lupus erythematosus (SLE)-associated arthritis of the finger joints.

METHODS

Both hands of 14 patients with SLE of various activities and durations and with arthritis and/or deformities of the finger joints were examined by MRI and conventional radiography. Coronal T1-weighted spin-echo (with and without gadolinium contrast), axial T2-weighted turbo spin-echo, coronal fat-suppressed short tau inversion recovery, and 3-dimensional double-echo steady-state sequences were acquired and analyzed, and the findings were compared with those from conventional radiographs.

RESULTS

MRI detected periarticular capsular swelling in all 14 patients, joint effusion in 7, edematous tenosynovitis in 6, proliferative tenosynovitis (flexor and/or extensor tendons) in 4, and intraarticular signs of synovial membrane hypertrophy in 10 patients, 9 of whom showed enhancement after administration of contrast medium. Bony erosions were identified in 8 patients by MRI; conventional radiography missed these erosions in 2 of the 8 patients. Four of the 14 patients were designated as Jaccoud's arthropathy index-positive, and all 4 showed severe edematous tenosynovitis and capsular swelling, but no signs of bony erosions despite longstanding disease (mean 21.5 years). Four of the 10 patients with mild deformity exhibited prominent soft tissue pathology, with minimal destruction of bone; the other 6 patients had bony alterations that resembled rheumatoid arthritis.

CONCLUSION

In SLE patients with arthritis of the finger joints, MRI detects characteristic signs of soft tissue pathology (e.g., capsular swelling, edematous and proliferative tenosynovitis, synovial hypertrophy) and bony alterations (e.g., erosions, some of which are missed by conventional radiography). MRI thus helps to distinguish different types of lupus arthritis/Jaccoud's arthropathy, which allows more differentiated treatment strategies and monitoring.

[An example of internet-based quality assurance in rheumatology]

In Germany, patient care and medical progress have become increasingly influenced by quality assurance and quality management and also by a rapid increase in knowledge and information. Thus, modern information management achieves high relevance in medicine, too. The internet provides a fascinating medium with its open architecture and interaction possibilities offering new, trailblazing perspectives. This article shows examples of the current use of the internet for quality assurance at the RheumaNet, which functions as a presentation platform for the competence network for systemic inflammatory rheumatic diseases ('KN-Rheuma') in Germany. The RheumaNet has already contributed to achieving quality assurance by supplying extensive, valuable and reliable scientific information. Other innovative interactive and quality assuring applications have been developed, tested and implemented in the system. Future applications will deal with standardised online documentation modules, and aids for patient self-management are on their way.

Methotrexate treatment for refractory subacute cutaneous lupus erythematosus

Methotrexate is beneficial in rheumatoid arthritis and has been used in small studies of patients with systemic lupus erythematosus. We describe a patient with severe subacute cutaneous lupus erythematosus refractory to therapy with antimalarials and corticosteroids. Treatment with methotrexate resulted in complete clearing of the skin lesions without any side effects.

Relapsing polychondritis in childhood--case report and short review

Relapsing polychondritis (RP) is a disease of unknown etiology and it is characterized by inflammation of the cartilage. While the clinical picture of RP in adults is well described, RP in childhood is poorly documented. We describe a young girl presenting with acute dyspnea, stridor and polyarthritis. The diagnosis of RP was made 2 years after first presentation, when auricular chondritis occurred. Based on a MEDLINE search, reports on RP in childhood were reviewed. The frequency of chondritis and systemic manifestations of RP in children was compared to data in adults and found to be very similar. RP in childhood can be a life-threatening and debilitating disease.

[Combination of antimalarial drugs mepacrine and chloroquine in therapy refractory cutaneous lupus erythematosus]

Antimalarials represent the first line in treatment of cutaneous lupus erythematosus (LE). However, some patients show no improvement on monotherapy with chloroquine or hydroxychloroquine. A 30-year-old female patient had treatment-resistant cutaneous LE exhibiting features of both LE tumidus and subacute cutaneous LE. Previously, the patient had been unsuccessfully treated with chloroquine, hydroxychloroquine, dapsone, and azathioprine, each in combination with variable doses of prednisolone. However, the LE lesions increased during these therapeutic regimens. A combination of chloroquine and mepacrine therapy led to improvement and then total clearing after 4 months of treatment.

[Documentation concepts in MedNet-Rheuma (competence network "Inflammatory-rheumatic systemic diseases")]

Concepts of documentation rely not only on the contents required and technical demands, but the procedures covered and in medical applications especially security aspects are also matters of critical concern. Even though the need for effective documentation (i.e., adequate in content, availability, feasibility and easy to retrieve analysis) is not a question, tasks and aims (for example, quality of patient care) deserve attention and establishing efforts have to be analyzed regarding their structural and personal prerequisites and implications before particular tools for documentation can be developed.

[Arthropathy in beta-thalassemia minor]

CASE REPORT

A 25-year-old Turkish patient presented with a "swelling" of the ankles which now persisted for 5 years. He had previously been diagnosed as having HLA-B27 negative spondylarthropathy with peripheral joint involvement. The symptoms failed to respond to different therapies. Serological markers and radiological procedures revealed beta-thalassemia minor.

DISCUSSION

Symptoms, diagnostic procedures and differential diagnostic options are discussed.

Polymorphisms of the xenobiotic-metabolizing enzymes CYP1A1 and NAT-2 in systemic sclerosis and lupus erythematosus

The etiology of systemic autoimmune diseases, such as systemic lupus erythematosus (SLE) and systemic sclerosis (SSc) is still unknown. In several cases, however, xenobiotics (i.e. drugs and occupational agents) were identified as etiologic agents and associations with certain polymorphic alleles of xenobiotic-metabolizing enzymes have been reported. Cytochrome P4501A1 (CYP1A1) and N-acetyltransferase 2 (NAT-2) are xenobiotic-metabolizing enzymes of phase 1- and phase 2-metabolism, respectively. CYP1A1 may activate drugs and other chemicals to reactive metabolites. NAT-2 is the most important enzyme in acetylation of aromatic amines, and thus may be responsible for detoxification of many of these compounds. Two polymorphisms of the human CYP1A1 gene, a point mutation in the 3' flanking region of the gene (Msp1) and a mutation in exon 7 leading to an isoleucine-valine-exchange in the heme-binding region of the enzyme, have been described and may lead to a higher basal and inducible enzyme activity. With respect to NAT-2, several alleles which combine for the two phenotypes "fast" and "slow" acetylators have been described. We analyzed the gene frequencies of the CYP1A1 polymorphisms and the phenotypes of NAT-2 in patients suffering from idiopathic SLE or SSc. CYP1A1 polymorphisms were analyzed in genomic DNA by PCR, whereas NAT-2 phenotypes were measured by the caffeine method. For CYP1A1 polymorphisms, 106 patients have been typed until now. The SLE group (n = 68) exhibited a significant increase (p < 0.05) in the mutant Val-allele (OR = 2.59) when compared to controls (n = 184). However, no significant differences in allele frequencies for MspI in the SLE group and for both CYP1A1 polymorphisms in the SSc group could be observed. Regarding the NAT-2 phenotype, patients suffering from SLE (n = 88) 75% and SSc (n = 26) 80.2%, respectively, were slow acetylators compared to 55% slow acetylators in the healthy German population (p < 0.05). The observed increased frequencies of the CYP1A1 mutant Val-allele and the slow actylator phenotype in idiopathic autoimmune disease support our concept that in slow acetylators non-acetylated xenobiotics may accumulate and are subsequently metabolized by other enzymes into reactive intermediates. Thus, enhanced formation of reactive metabolites could alter self-proteins presented to the immune system thus stimulating autoreactive T cells which induce autoimmunity.

Cerebral microembolism, a disease marker for ischemic cerebrovascular events in the antiphospholipid syndrome of systemic lupus erythematosus?

OBJECTIVES

We investigated whether the detectability of microembolic Doppler signals (MES) in the intracranial circulation may help to define the individual cerebrovascular risk in systemic lupus erythematosus (SLE) with antiphospholipid syndrome (APS).

MATERIAL AND METHODS

Retrospective cross-sectional study of 70 patients with SLE with or without APS, and 30 controls with a history of cerebral ischemia of unknown cause. Of all patients, 38 had a clinical history of APS and 32 did not.

RESULTS

15 patients with APS (39%) showed MES. In contrast, all patients without APS and 29 of 30 controls were microemboli-negative. MES were more strongly associated with cerebrovascular symptoms than with APS, antiphospholipid antibodies, or cardiac pathology. The time elapsed since the last ischemic cerebrovascular symptom was significantly shorter in microemboli-positive patients than in microemboli-negative patients (P<0.001).

CONCLUSION

MES may be related to disease activity in patients with SLE and APS. Their detection may help to assess individual cerebrovascular risk and contribute to therapeutic decision making and therapeutic monitoring.

Detection of cerebral microemboli in APS--introducing a novel investigation method and implications of analogies with carotid artery disease

Patients with antiphospholipid syndrome (APS) are prone to thromboembolism. So far, the only predictive parameters for further complications are their number in patient's history and perhaps the titre of aPL. Derived from clinical investigation of stroke and obvious analogies between cerebrovascular ischemia (CVI) in patients with carotid artery disease (CAD) and patients with APS, a novel non-invasive method is introduced using transcranial Doppler (TCD) long-term monitoring to detect high energy ultrasonic signals (so called 'microemboli') in the cerebral vasculature. In patients with CAD, these microemboli proved to correlate with past and impending symptoms of CVI permitting therapeutic stratification by their detectability. In SLE and APS. this technique enabled identification of very similar signals in cerebral bloodstream of APS patients. Microemboli were highly associated with the history of CVI and the titre of aPL. Detection of microemboli offers new possibilities in risk estimation, therapeutic stratification and in studying pathophysiology of APS.

RheumaNet--a novel Internet-based rheumatology information network in Germany

Knowledge transfer in medicine has traditionally been achieved through personal communication, the medical literature, conferences and continuous medical education. However, many of these methods of communication have the problem of currentness, and the latest knowledge is mostly transferred with a certain delay. In particular, chronic disease management is frequently burdened by missing, incomplete or delayed communication. We present the implementation of a novel, Internet-based information system (RheumaNet) to facilitate rapid communication and information transfer between the 21 German Multipurpose Arthritis Centres (MACs). Medical information, agendas, urgent notifications, guidelines, etc., can be exchanged easily via electronic mail, file transfer protocol or the World Wide Web. RheumaNet allows interactive on-line communication as a common platform for joint projects or remote consultation. It supports a set of 'core documentation' that has been used by all German MACs for several years. RheumaNet was used for the organization, on-line presentation and evaluation of the 1997 annual meeting of the German Rheumatology Society and is currently appointed to establish its public representation in the 'Web'. An on-line version of the 'Quality Assurance Textbook' of German rheumatology is achieved with database-derived 'dynamic' Web pages, allowing easy access to any information within it. Advances in the future include the development of on-line patient information bulletin boards, on-line questionnaires, the coordination of rehabilitation and educational tools for medical students, and professional training.

High levels of circulating early apoptic peripheral blood mononuclear cells in systemic lupus erythematosus

Increased in vitro apoptosis and altered expression of apoptosis-related molecules have been reported in systemic lupus erythematosus (SLE). It was speculated that autoantigens released from apoptizing cells may contribute to the etiopathogenesis of SLE by both activation of autoreactive lymphocytes and the formation of immune complexes. Conflicting data about the level of cellular apoptosis from animal models for SLE and human SLE indicate different pathomechanisms. In the present study we analysed the count of circulating early apoptotic cells and its correlation with the clinical activity in SLE compared with the amount in primary systemic vasculitis (PSV). The percentage of early apoptotic cells determined by Annexin V-FITC binding cells was significantly increased in peripheral blood of SLE patients compared with normal healthy donors (NHD) and PSV (NHD 5.62%, SLE 13.68%, PSV 8.69%). Analysis of lymphocytes revealed significantly increased counts in the T cell populations (NHD 5.15%, SLE 12.22%, PSV 10.01%), whereas the increase in B cells did not reach significance level (NHD 9.20%, SLE 18.95%, PSV 16.59%). Apoptotic cell count revealed no correlation to SLAM-Score or to immunosuppressive therapy, corticosteroid-dosage or absolute lymphocyte count. The general increase of circulating apoptotic cells may indicate an impaired clearance in SLE patients, independent of clinical activity or therapeutic interventions. Autoantigens from apoptotic cells may contribute to both activation of autoreactive lymphocytes and formation of immune complexes.

The p68 autoantigen characteristic of rheumatoid arthritis is reactive with carbohydrate epitope specific autoantibodies

OBJECTIVE

The autoantigen p68 is a target of autoantibodies as well as autoreactive T cells with a high specificity in rheumatoid arthritis (RA). The binding characteristics of the autoantibodies to their antigen were now analysed biochemically and cytologically.

METHODS

Deglycosylation techniques as well as lectin and sugar competition experiments were performed to p68 to discover if the antibodies detected a glycoepitope, Its antigenicity was investigated applying anti-p68 antibodies derived from RA patients in comparison with polyclonal rabbit anti-p68 antibodies.

RESULTS

p68 specific antibodies from RA patients did not to bind to p68 that had been deglycosylated by alkaline beta-elimination, O-glycosidase or periodate treatment. In contrast, binding of p68 specific antibodies raised in rabbit was unaffected by either deglycosylation protocol. Furthermore, lectins specific for the carbohydrate N-acetylglucosamine competed with p68 specific antibodies from RA patients for antigen bindings. N-acetylglucosamine by itself also competed with patient derived anti-p68 antibodies for p68 binding. Again, rabbit and anti-p68 antibodies did not elicit these competitive effects. Applying cytoimmunofluorescence, p68 was present in the cytoplasm or endoplasmic reticulum and also in low abundance on the cell surface. Under heatshock conditions, p68 was detectable in the nucleus.

CONCLUSIONS

Autoimmunity to p68 during RA is carried by anti-carbohydrate autoantibodies. The carbohydrate modification of p68 appears to be N-acetylglucosamine, which may reflect the regulation of intracellular localisation of the antigen. It is hypothesised that a shift in glycosylation pattern accompanied by an unphysiological localisation of the antigen could trigger antigenicity of p68 during the pathogenesis of IRA.

Cerebral microemboli in patients with antiphospholipid syndrome

CNS involvement is one of the hallmarks underlying poor prognosis in SLE and for therapeutic strategies it is difficult to assess which patients are at risk. As detectability of cerebral microembolic signals (MES) using long-term transcranial Doppler ultrasonography (TCD) proved to be predictive of past and future thromboembolic events in patients with carotid artery stenosis, we investigated whether MES might be similarly useful in patients with antiphospholipid syndrome (APS). Our study population consisted of 46 SLE patients and five with primary APS (pAPS). Twelve of the 46 patients with SLE, 10 of them with secondary APS (sAPS), and four of five patients with pAPS had a history of cerebrovascular ischaemia (CVI). MES in the middle cerebral artery were detected in 14 of 16 patients with and in one of 35 without CVI (P < 0.001). Antiphospholipid antibodies (aPL) were positive in 12 of 15 patients with and 18 of 36 without MES, and the rate of MES correlated to the titre of aPL. MES from APS patients resembled in their energy distribution those from patients with symptomatic carotid disease and were significantly different from those associated with artificial heart valves. In conclusion, cerebral MES are detectable in APS patients and correlate with a history of CVI. Whether this innovative method may provide individual risk assessment in APS patients has to be addressed in prospective studies.

Rheumatoid arthritis: autoreactive T cells recognising a novel 68k autoantigen

OBJECTIVE

A 68k autoantigen has been identified by specific antibodies from patients with rheumatoid arthritis (RA). This study considered whether or not this antigen is a target for T cells and thus may play a part in T cell mediated immunopathology of active RA.

METHODS

The 68k antigen was isolated and used in a nitrocellulose bound form to stimulate T cells. Proliferation of T lymphocytes of peripheral blood as well as synovial fluid was measured.

RESULTS

Peripheral blood T cells specifically proliferating against the 68k antigen were detected in 19 of 27 patients with RA (70%). For T cells isolated from peripheral blood, proliferation peaked on day 10. When T cells were isolated from actively inflamed synovial fluid, the proliferation kinetics shifted to a peak on day 3. Blockade of HLA class II antigens resulted in an increase of proliferation in the case of HLA-DP. Applying HLA-DP specific antibodies capable of inhibiting antigen presentation mediated by this molecule, T cells of 17 of 27 RA patients (63%) proliferated to a higher extent than with the 68k antigen alone. The phenomenon that an increased proliferation occurred upon blockade of a particular HLA class II family member was also demonstrated for DQ and DR: the 68k antigen likewise stimulated T cells restricted for DP or DQ, respectively.

CONCLUSIONS

The novel 68k antigen is a target of both T and B cellular immune responses and as such could play a part in the immune dysfunction of RA. The finding that blocking of certain HLA class II molecules functioning in antigen presentation (for example, via HLA-DQ) results in a higher instead of lower proliferation in vitro, may argue for the presence of antigen specific suppressive T cells.