Immunogenetic heterogeneity of rheumatoid arthritis

Chronic inflammatory joint disease revealing borderline leprosy

Musculoskeletal symptoms are not infrequent in leprosy and, when inaugural, may be difficult to differentiate from other conditions, most notably rheumatoid arthritis. We report the case of a 24 year-old man with a 5 year history of intermittent inflammatory arthritis and fever. Physical findings and radiographs were normal initially. Several years later, he had severe wasting of the hand muscles, stocking-glove sensory loss, burn scars on the hands, and plantar ulcers. Electrophysiological test results indicated sensory-motor neuropathy with predominant demyelination. Laboratory tests showed inflammation without immunological abnormalities. A prominent endoneurial inflammatory infiltrate composed of mononuclear cells was seen on a nerve biopsy specimen, suggesting leprosy. A family study then revealed that the patient's aunt had been diagnosed with leprosy. Dapsone, clofazimine, and rifampin were given. The joint manifestations and laboratory tests for inflammation improved. However, no changes were noted in the neurological symptoms.

Genetic epidemiology of rheumatoid arthritis

Building on the spectacular success of molecular genetics in defining the biological basis of many rare single gene disorders over the past decade, epidemiologists have turned their attention to unravelling the complex genetic mysteries of common disorders, such as rheumatoid arthritis (RA). As a prelude to any such endeavour it is obviously important to establish that there is a significant genetic component to the disease. The classical approaches of twin and other family recurrence risk studies, coupled with prevalence studies in different ethnic and migrant populations, have been used to estimate the environmental and genetic contributions to RA. However, developing a consensus on these estimates has proved difficult, thereby providing an early warning to the unwary investigator that the road to gene discovery in RA is likely to be a rough ride.

Prognostic use of human leukocyte antigen genotyping for rheumatoid arthritis susceptibility, disease course, and clinical stratification

HLA markers of the class II region are important for determination of the predisposition to RA, clinical manifestations, and rate of progression of joint destruction in this autoimmune disease. Furthermore, evidence emerges indicating that HLA markers also have an impact on treatment outcome in RA. Currently, several immunopathogenetic models of HLA-dependent influences in RA are under debate. These models insufficiently explain the graded influence of HLA-DR and HLA-DQ on manifestation and joint destruction, however. Currently, there is not enough evidence to unequivocally identify a primary susceptibility locus or to pinpoint the HLA-dependent mechanism in RA. Overall, the influence of HLA class II markers on disease susceptibility is rather restricted, and, in turn, their utility in establishing the diagnosis of RA is of limited use. Although relative risks are higher for the association of particular genotypes with extra-articular forms of RA, HLA genotyping may not contribute to prognostication in individual patients but may aid in disease stratification. In contrast, HLA genotyping in early RA, particularly when combined with the determination of RFs and determination of the presence of bony erosions, is of value to identify patients at risk for poor outcome. In turn, these patients may benefit from early aggressive therapy, and HLA genotyping should be useful to aid in risk stratification in patients and thus helpful for the choice of treatment. Lastly, disease and risk stratification based on HLA markers along with the elucidation of HLA-dependent mechanisms may facilitate the development of specific immunotherapy modalities.

Autoimmune keratolysis in a patient with leukocytoclastic vasculitis: unusual erythema elevatum diutinum with granulomatous pattern

PURPOSE

Leukocytoclastic vasculitis (LCCV) is an immune complex-mediated, small vessel disease that is clinically characterized by the presence of palpable purpuric lesions, most often in association with rheumatic diseases. Ocular manifestations of LCCV are rare.

METHODS

We describe a patient with an unusual granulomatous pattern of erythema elevatum diutinum (EED) associated with autoimmune keratolysis.

RESULTS

We studied a 64-year-old man with decreased visual acuity and nodular lesions in both hands. Ocular examination revealed bilateral superior corneal melting with perforation in the left eye and conjunctival thickening in both eyes, in association with a severe inflammatory reaction. Histopathologic examination of the conjunctiva revealed granulomatous vasculitis with neutrophilic infiltrate, giant cells, and fibroblastic proliferation. A punch biopsy taken from his skin showed similar characteristics that suggested EED; however, there were no giant cells.

CONCLUSION

To our knowledge, autoimmune keratolysis secondary to cutaneous LCCV (EED) has not been described previously, and there has been no description of granulomatous reaction (in the conjunctiva) in EED.

Delay in diagnosis: indeterminate leprosy presenting with rheumatic manifestations

BACKGROUND

Rheumatic complications are common in leprosy (Hansen's disease) and can be the primary complaint delaying accurate diagnosis.

OBJECTIVE

Such a case is reported here: a 61-year-old woman with indeterminate leprosy presented with symmetric arthritis and purpura. Despite biopsy and evaluation by several physicians, leprosy was not suspected. After 2 years of progressive symptoms, a second biopsy revealed lepromatous leprosy.

CONCLUSION

In this case, lack of clinical suspicion and unfamiliarity with the histology of indeterminate leprosy delayed diagnosis and treatment. Leprosy should be considered in the differential diagnosis of patients presenting with unusual rheumatic and persistent cutaneous manifestations.

HLA markers in a community-based rheumatoid arthritis series

We wanted to investigate whether rheumatoid arthritis (RA) patients, defined by the American College of Rheumatology (ACR) 1987 criteria and selected from one community by the help of the official Finnish data registers, share the common HLA susceptibility genes. The HLA frequencies of 88 RA patients representing 85% of the prevalent cases of RA in the community were compared with those of 188 healthy controls. Fifty-four per cent of the index cases with RA had DR4 compared with 30% of the healthy controls (P <0.001). The 'RA susceptibility sequence' was found in 75% of the DRB1 genes in the index cases, but it did not correlate with the severity of the disease. The frequency of DR3 was not increased in RA patients but it was associated with features of severe disease, that is, with a high erythrocyte sedimentation rate (P<0.05), extra-articular disease (P<0.01) and prostheses in large joints (P<0.05). According to our results community-based RA patients satisfying the new ACR criteria show the common DR4 association. DR3 was the only HLA allele which showed some disease-modifying effect correlating with the severity of RA.

HLA markers and prediction of clinical course and outcome in rheumatoid arthritis

OBJECTIVE

To evaluate HLA markers as early prognostic factors for disease severity in rheumatoid arthritis (RA).

METHODS

HLA genotyping was carried out in a retrospective analysis of 66 RA patients and in a prospective study of 55 RA patients and 87 healthy controls using polymerase chain reaction-based methods for HLA-DRB1 specificities, DR4 alleles, and their linked DQB1 alleles, as well as HLA-B27. The clinical course of RA was assessed by clinical and radiologic scores. The impact of HLA markers was evaluated by epidemiologic means in addition to modeling using multiple logistic regression analysis.

RESULTS

Shared epitope-positive (HVR3+) DR4 alleles and the HVR3 amino acid cassette QKRAA were associated with RA in both longstanding (relative risk [RR] 3.34 and 3.19) and recent-onset (RR 2.1 and 2.37) RA. In longstanding RA, radiologic evidence of severe joint destruction (Larsen score > 1.62) was seen more often in HVR3 shared epitope-positive patients than in epitope-negative patients (odds ratio [OR] = 25.67, chi 2 = 13.59, P = 0.0003). Moreover, rank sum analysis of Larsen indices indicated significantly higher ranking for the presence of the RA-associated HVR3 cassettes (QKRAA, QRRAA) when expressed on a DR4 allele (P < 0.0001). In the prospective study, DR4-positive patients had a significantly increased risk (OR = 13.75, P = 0.00083) of developing bony erosions. In addition, HVR3 epitope-positive DR4-positive individuals had significantly higher Larsen indices than did epitope-negative patients (P = 0.0083). In particular, the presence of the HVR3 epitope on DR4 resulted in an increased a posteriori likelihood (0.91) of developing early erosive disease compared with an a priori risk of 0.62. Conversely, the likelihood decreased to a minimum of 0.35 when the HVR3 epitope was absent.

CONCLUSION

While the contribution of HLA typing to establishing the diagnosis of RA is limited, HLA-DR genotyping and DR4 subtype determination provide valuable markers for the prognosis of joint destruction in RA.

Factors associated with the development of vasculitis in rheumatoid arthritis: results of a case-control study

OBJECTIVE

To investigate those characteristics of patients with rheumatoid arthritis (RA) that are associated with the development of rheumatoid vasculitis (RV).

METHODS

Demographic and clinical data of 69 patients who had been diagnosed as having RV were compared with those of 138 contemporaneous control patients with RA who were not suspected to have vasculitis. Vasculitis was confirmed histologically in 96% of the subjects with RV.

RESULTS

Variables associated with the development of RV were: 1) male gender, presence of increased serum concentrations of rheumatoid factor, joint erosions, subcutaneous nodules, number of disease modifying antirheumatic drugs previously prescribed, treatment (ever) with D-penicillamine or azathioprine; 2) presence of nail fold lesions and any other extrarticular feature one year before the time of diagnosis of RV; 3) treatment with corticosteroids at the time of diagnosis of RV.

CONCLUSIONS

The development of RV is associated with male gender, extra-articular features, and a severe course of RA as indicated by the presence of joint destruction and need for intensive treatment with antirheumatic drugs. The strongest association was found with the presence of increased concentrations of rheumatoid factor.

Clinical expression of rheumatoid arthritis in Chilean patients

In populations such as Northern Europeans in which the HLA-DR4 subtypes DW14 and Dw4 show strong association with rheumatoid arthritis (RA), these alleles and the double allelic dose of the shared epitope are considered severity markers. The clinical expression of RA varies in different populations, which may be determined by variation in the prevalence of these markers. In the present study we analyzed the expression of RA in 112 consecutive Chilean patients and its relation to the prevalence of genetic factors, prompted by our previous observation that DR4 is weakly associated to RA in this population. Mean age was 50 +/- 14 years; 90% were seropositive and 87% were female, with a disease duration of 10 +/- 8 years. Extra-articular manifestations were found in 38% of patients, rheumatoid nodules in 27%, vasculitis in 8%, and Sjogren's syndrome in 29%. Functional capacity (ACR, 1991) I or II: 82%.15% of patients stopped working. Hand radiographs scored according to Steinbrocker in 89 patients: I, 21%; II, 15%; III, 43%; IV, 21%. In this series, patients with less formal education seemed to have more benign arthritis. In 97 controls and in 65 (56%) RA patients the presence of DRB1 alleles corresponding to DR1 and DR4 serotypes, to DR4-Dw subtypes, and homozygocity, were determined by polymerase chain reaction followed by specific oligonucleotide hybridization. The shared epitope was present in 53% of RA patients and in 30% of controls (P = .0048, odds ratio [OR] = 2.64). A double allelic dose of the epitope was present in 15% of RA patients compared with 4% of controls (P = .026, OR = 4.23). In a subgroup of 31 erosive RA patients we did not find a significant association of disease severity with the shared epitope in a single or double allelic dose. None of the DR4 subtypes that associate with RA in other populations was found significantly more prevalent in our patients. The severity of RA in our study compared with published series was intermediate between British patients with severe RA and Greek patients with milder disease. This may be due to the high prevalence of Dwl3*0403 in our population.

Class II antigens and disease susceptibility

The role for HLA typing in autoimmune disease is changing with the recognition that HLA markers can identify patients with poor prognosis in some autoimmune disease. Aggressive therapeutic intervention in patients with such HLA prognostic markers has the potential to improve or prevent progressive disease outcomes in a select group of patients.

Tumor necrosis factor alpha-308 gene variants in relation to major histocompatibility complex alleles and Felty's syndrome

The location of the human TNF genes within the MHC complex has prompted much speculation about the role of TNF alleles in the etiology of MHC-associated autoimmune diseases. On sequencing the 5' regulatory region of the human TNFA gene a G (TNFA-308G) to A (TNFA-308A) transition polymorphism at position -308 was discovered. We have developed a simple PCR assay to facilitate the screening of the -308 polymorphism at the DNA level. In view of the possible linkage between the TNFA-308A allele and a certain MHC type, TNFA-308 genotypes in HLA-typed healthy individuals (n = 88) were determined. A statistically significant association between the TNFA-308A allele and HLA-DR3, DQB1*0201, DQA1*0501, A1, B8, and the NcoI 5.5-kb RFLP of the TNFB gene was observed. In addition, we determined the frequency of the TNFA-308A allele in patients with FS (n = 13), an HLA-DR4-associated disease. In this study, no association was found of Felty's syndrome with the TNFA-308A allele, indicating that this allele does not appear to be a susceptibility factor for FS.

Elderly-onset rheumatoid arthritis

Elderly-onset rheumatoid arthritis (EORA), defined as rheumatoid arthritis (RA) with onset at age 60 years or over, differs slightly at presentation from younger-onset RA (YORA) by a more equal gender distribution, a higher frequency of acute onset with systemic features, more frequent involvement of the shoulder, and higher disease activity. Longitudinal studies have showed more disease activity, radiographic damage, and functional decline in patients with EORA than in those with YORA. These differences were only found in seropositive patients. Seropositive EORA was reported to be associated with HLA-DR4, in contrast to seronegative EORA. Possible heterogeneity in the pathogenesis of seronegative EORA is supported by the recognition of subsets that overlap with the clinical manifestations of other syndromes such as polymyalgia rheumatica and remitting seronegative symmetrical synovitis with pitting edema. In addition, crystal-induced arthritis and inflammatory osteoarthritis may be difficult to distinguish from EORA. The efficacy and toxicity of second-line drugs is similar in both age groups, but in the elderly caution is needed with the use of nonsteroidal antiinflammatory drugs and prednisone.

The effect of methylprednisolone pulse therapy on methotrexate treatment of rheumatoid arthritis

We randomly assigned 30 active rheumatoid arthritis (RA) patients who started oral methotrexate (MTX, 7.5 mg/week) treatment, into 3 groups. Group I received no additional corticosteroids; Group II was treated with 3 oral pulses of 100 mg prednisolone and Group III with 3 intravenous pulses of 1000 mg methylprednisolone (MP) on alternate days during the first week. Parameters of disease activity were measured at the start, after 10 days and at regular intervals up to 1 year. In Group I maximal improvement occurred after 18 weeks and in Group III after 6 weeks. This effect was sustained during the study. The initial effects in Group II were not as strong as in Group III and of shorter duration. No serious side effects were noticed. Our results suggest, that MP-pulse therapy seems to be useful in bridging the gap between the introduction of MTX and the response to this drug. Furthermore, we found that patients who were HLA-DR4-positive showed a better clinical response after 1 year than HLA-DR4-negative patients.

Absence of an association between HLA-DRB1*04 and rheumatoid arthritis in newly diagnosed cases from the community

OBJECTIVES

To determine HLA-DR4 and DR1 allele frequencies in a series of patients with newly diagnosed early inflammatory arthritis.

METHODS

HLA-DR1 and DR4 frequencies were determined by oligonucleotide typing of 208 patients classified as having either rheumatoid arthritis (RA) or undifferentiated inflammatory polyarthritis.

RESULTS

The frequency of occurrence of DR4 in these patients with RA did not differ significantly from that in controls in the United Kingdom (42 v 37%). HLA-DR1 was increased in the group with inflammatory polyarthritis (25 v 18%).

CONCLUSIONS

The frequency of DR4 is not increased in newly diagnosed community based patients with RA. This supports the hypothesis that DR4 is less important as a marker for susceptibility to RA than it is for disease persistence or severity.

Susceptibility to relapsing polychondritis is associated with HLA-DR4

OBJECTIVE

To determine the frequency of HLA class II antigens in Caucasian central European patients with relapsing polychondritis (RP).

METHODS

HLA class I, DR, and DQ specificities were identified in 41 patients with RP, and the frequencies were compared with those in 204 healthy, unrelated control subjects. HLA typing was performed using the standard complement-dependent microcytotoxicity assay. HLA-DR genotyping of 12 DR4-positive RP patients and 57 controls was performed by allele-specific oligonucleotide probing after amplification of genomic DNA by polymerase chain reaction.

RESULTS

A significant increase in DR4 antigen frequency was found in the patients (56.1%) as compared with that in healthy controls (25.5%) (Pcorr < 0.001). Genotyping of DR4-positive patients and controls revealed no predominance of any DR4 subtype.

CONCLUSION

There are important clinical similarities and overlaps between RP and rheumatoid arthritis (RA). In RA, the association with DR4 has been well established. Our findings show that although there is a DR4 association with RP, the situation is sufficiently distinct from that of RA to imply considerable differences in pathogenesis of the two conditions.

The prognostic value of HLA DR4 and B27 antigens in early rheumatoid arthritis

The prognostic significance of HLA DR4 and B27 antigens was investigated in a 3-year follow-up of 87 patients with early rheumatoid arthritis (RA). The frequencies of DR1, DR4 and also of B27 were increased and the frequencies of DR2, DR3 and DR7 decreased compared with the normal Finnish population. During the follow-up with antirheumatic treatment, a similar improvement in clinical variables and laboratory measure assessing disease activity was found in both DR4-positive and DR4-negative RA patients. Despite clinical improvement a fast radiological progression in peripheral joints was observed but the presence of DR4 or B27 had no impact on the progression of joint damage. In some patients cervical changes developed early in the course of RA but were not related to DR4 or B27 positivity. The earlier observation of increased prevalence of HLA B27 in the Finnish RA patients was confirmed but the presence of B27 did not modify the clinical picture of RA.

HLA Class ii sequence polymorphisms and susceptibility to rheumatoid arthritis in greeks. the hla–drβ shared-epitope hypothesis accounts for the disease in only a minority of greek patients

OBJECTIVE

In Northern Europeans, rheumatoid arthritis (RA) is strongly associated with a relatively conserved pentapeptide sequence of HLA-DR beta found notably in the HLA-DR4 subtypes Dw4 and Dw14 and in DR1. A previous serologic study of HLA class II polymorphism in a Greek population with RA failed to show significant associations with any antigen.

METHODS

We characterized HLA-DRB polymorphisms in Greek patients with RA and in control subjects by restriction fragment length polymorphism analysis. Allelic DRB subtypes were examined by polymerase chain reaction amplification and oligonucleotide hybridization.

RESULTS

DNA analysis in the RA patients showed that although individual HLA-DR allelic associations were weak, a relatively conserved HLA-DR beta motif was significantly associated with RA in this population of Greek patients. The third hypervariable region amino acid sequences QRRAA, QKRAA, or RRRAA were found in the HLA-DR beta 1 of 43.5% of the RA patients versus 15.5% of the controls (uncorrected P = 0.00004).

CONCLUSION

Sequences shown to influence susceptibility to RA in patients in the UK also play a role in patients in Greece. However, 57% of Greek patients lack the putative HLA-DR beta motif, which suggests that considerable immunogenetic heterogeneity underlies disease susceptibility in this population.

Homozygosity for the HLA-DRB1 allele selects for extraarticular manifestations in rheumatoid arthritis

Seropositive rheumatoid arthritis is genetically linked to a group of HLA-DRB1 alleles sharing a sequence motif within the third hypervariable region. Controversy exists over the role of the distinct allelic variants in affecting not only the risk to develop disease, but also in modifying the expression of the disease. We have stratified 81 patients according to their patterns of disease manifestations and identified the HLA-DRB1 alleles by polymerase chain reaction amplification and subsequent oligonucleotide hybridization. To identify precisely the allelic combinations at the HLA-DRB1 locus, homozygosity was confirmed by locus-specific cDNA amplification and subsequent sequencing. Our study demonstrated a high correlation of allelic combinations of disease-associated HLA-DRB1 alleles with the clinical manifestations. Characteristic genotypes were identified for patients who had progressed toward nodular disease and patients who had developed major organ involvement. Rheumatoid nodules were highly associated with a heterozygosity for two disease associated HLA-DRB1 alleles. Homozygosity for the HLA-DRB1*0401 allele was a characteristic finding for RA patients with major organ involvement. Our data suggest a role of the disease-associated sequence motif in determining severity of the disease. The finding of a codominant function of HLA-DRB1 alleles suggests that the biological function of HLA-DR molecules in thymic selection might be important in the pathogenesis of RA.

The search for laboratory measures of outcome in rheumatoid arthritis

A large number of laboratory tests have been developed within the past decade to measure factors involved in the immune inflammation of RA. These can be divided into genetic markers, general measures of inflammation, autoantibodies and tissue-specific markers. In general, it is simpler to prove the power of a certain test to measure the disease process than to predict outcome. Apart from RF positivity and CRP/ESR, few, if any, tests have proven to be of importance in independent studies from different centres. Among the promising candidates for future work are detailed analysis of the HLA-D region genes, sulphoxidation status, the autoantibody against RA33 nuclear antigen, soluble IL-2 receptor measuring lymphocyte activity, hyaluronate/hyaluronan or PIIINP from synovial tissue, the combined use of COMP and proteoglycan epitope tests for cartilage matrix, and pyrodinoline cross-linking for collagen from bone and cartilage. The ideal setting for testing such markers are prospective cohort studies starting early in the disease, and since many such studies have been initiated recently, one can expect much new information in coming years. Attention needs to be devoted to the kinetics of marker metabolism, since many are degraded or removed at very fast rates from the circulation, making serum assays less informative.

Rheumatoid arthritis in south-east Europe

The clinical, serological and immunogenetic studies of RA in mediterranean countries and other small tribal groups have added some more information that is valuable in understanding the pathogenesis of RA. However, the immunogenetic studies seem to be more helpful in understanding the mechanisms of initiation of disease and its dissimilarities in different ethnic groups than in discovering its cause. It should also be stressed that, in addition to genetic factors, other factors may influence disease expression. This proposal was supported by a study from Africa which revealed an increasing incidence and severity of RA in rural compared with urbanized African populations (Brighton, 1987). Thus, the variability factor influencing disease expression may lie in the environment (Woodrow, 1988).

Worldwide trends in the socioeconomic impact and long-term prognosis of rheumatoid arthritis

Rheumatoid arthritis (RA), once considered a benign and nonprogressive disease, is a debilitating condition with serious physical, emotional, and economic consequences. It afflicts approximately 1% of the adult population worldwide; prevalence increases with age, with twice as many women as men affected. In the United States, age, lack of formal education, and lower socioeconomic class correlate with both the incidence and poor prognosis of RA. The patient with RA faces increasing functional disability, the likelihood of work disability within 10 years after the onset of the disease, and a drastic reduction in earnings. Compared with individuals without the disease, patients with RA incur higher medical care costs, increased hospitalization, and a greater number of physician visits. As in the general population, the leading cause of death among patients with RA is cardiovascular disease, and deaths due to malignancy occur at a comparable incidence; however, patients with RA are at greater risk of mortality due to infection, renal disease, respiratory conditions, and gastrointestinal disease. Life expectancy is shorter among patients with RA than in the general population, and survival rates are comparable to those for Hodgkin's disease, diabetes mellitus, stroke, and three-vessel coronary artery disease. Efforts must be made to develop improved therapeutic strategies and rehabilitative programs to improve the quality of life of patients with RA.

Strong primary selection for the Dw4 subtype of DR4 accounts for the HLA-DQw7 association with Felty's syndrome

Felty's syndrome (FS) is a rare complication of rheumatoid arthritis (RA) previously shown to be strongly associated with HLA-DR4 and less significantly with HLA-DQw7. To map more precisely the HLA locus responsible for susceptibility to FS, we have examined HLA-DR4 and DQ beta-chain polymorphisms in FS patients and controls using restriction fragment length polymorphism analysis and polymerase chain reaction amplification in conjunction with oligonucleotide probing. The increased frequency of DR4 in FS (93% vs. 32% controls) was due almost entirely to enrichment for the Dw4 subtype (88% vs. 20% controls) with a secondary increase of the Dw14 subtype. Dw10 and Dw13 subtypes of DR4 were absent from the patient group. Increase in DQw7 frequency among DR4 FS patients could be accounted for by linkage disequilibrium between Dw4 and DQw7 alleles. Whereas susceptibility to RA is strongly associated with a conserved HLA-DR beta epitope associated with several DRB1 alleles, it is primarily the Dw4 allele which is associated with progression to Felty's syndrome. The finding that amino acid sequence variation at the DR4B1 locus rather than DQB1 is associated with development of FS will have important implications for the development of novel immunotherapies which are major histocompatibility complex allele-dependent.

Association of HLA-DR4 with a more progressive disease course in patients with rheumatoid arthritis. Results of a followup study

The association between HLA-DR antigens and rheumatoid arthritis (RA) was investigated in a well-characterized cohort of RA patients who were followed from the beginning of the disease (mean followup 6 years). The frequencies of HLA-DR antigens in patients with possible or probable RA (n = 49) were similar to those in controls. In patients with definite RA (n = 134), the frequencies of DR1, DR4, and DRw53 were increased, whereas the frequencies of DR2, DR3, DRw6, DRw13, and DRw52 were decreased, compared with controls. Comparison of HLA-DR frequencies in patients with definite RA subclassified according to the severity of the disease at the end of the followup period revealed a difference only in the frequency of DR4, which was increased in patients with progressive RA (59.2%) compared with those who had mild RA (34.8%). Further analysis showed that, compared with DR4-negative RA patients, DR4-positive patients had more swollen joints, higher scores on the Ritchie articular index, the Health Assessment Questionnaire, and the Steinbrocker functional classification, more radiologic abnormalities, and more use of second-line drugs. Also, the rate of progression of radiologic abnormalities, functional classification, and use of second-line drugs was higher in DR4-positive patients. We conclude that DR4 is associated with a more severe disease course, and is a prognostic marker in early RA.

Pregnancy and the risk of developing rheumatoid arthritis

There have been conflicting reports on, and no plausible biologic explanation for, a protective effect of oral contraceptive (OC) use on the development of rheumatoid arthritis (RA). Therefore, we investigated aspects of behavior related to OC use that could explain the preventive effect of OC on the onset of RA. In the present case-control study, past pregnancy, age at first pregnancy, and pregnancies with adverse outcome were studied as possible risk factors for RA. Interview information on reproductive variables was obtained from 135 young adult women with confirmed definite or classic RA of recent onset, and from 378 control patients with soft tissue rheumatic disorders or osteoarthritis. All patients had at least 2 years of followup to confirm the consistency of the diagnosis. We found a decreased risk of RA in women who had been pregnant. The risk of RA in women who had ever been pregnant compared with women who had never been pregnant was 0.49 (95% confidence interval 0.27-0.91). The earlier the first pregnancy, the lower the risk of RA. Pregnancy with adverse outcome (i.e., gestation less than 25 weeks) did not substantially change the risk of RA (relative risk 0.73, 95% confidence interval 0.50-1.07). The protective effect of pregnancy was independent of OC use, the presence of HLA-DR4, or a family history of RA. Immune modulation by female hormonal influences could be an explanation for the results of the present study.

DQw7 and the C4B null allele in rheumatoid arthritis and Felty's syndrome

DQ beta and C4 null alleles have been defined in patients with rheumatoid arthritis, Felty's syndrome, and in control subjects. Comparison of DR4 positive subjects shows that rheumatoid disease without extra-articular features has no preferential associations with either DQ beta or C4 null variants. In Felty's syndrome there are significant associations with both the class II major histocompatibility complex (MHC) DQw7 allele (86% of DR4 positive patients with Felty's syndrome and 53% of DR4 positive controls) and the class III MHC C4B null allele (50% of patients with Felty's syndrome and 20% of DR4 positive controls). DQw7 and the C4B null allele are in linkage disequilibrium and the B44-Bf *S-C4A*3-C4B*Q0-DR4-DQw7 haplotype accounts for five of 24 DR4 positive haplotypes assigned in subjects with Felty's syndrome. The results were not accounted for by articular disease severity and suggest that articular and extra-articular forms of rheumatoid disease may be immunogenetically heterogeneous.

Diminished incidence of severe rheumatoid arthritis associated with oral contraceptive use

It has been suggested that the negative association between rheumatoid arthritis (RA) and oral contraceptive (OC) use might be limited to the more severe forms of RA. To investigate this further, we studied 121 consecutive female patients with definite RA, 52 female patients with probable RA, and 378 female controls. All patients had RA symptoms of recent onset. After a mean followup period of 6 years, patients with definite RA were classified as having either a severe disease course (n = 76) or a mild disease course (n = 45). The negative association between OC use prior to the onset of RA symptoms and the development of RA was limited to those patients with definite RA who had a severe disease course. We therefore conclude that OC use prior to the onset of RA symptoms is only associated with a reduction in the incidence of severe RA. This may explain the divergent results of previous studies.

Reduction of the risk of rheumatoid arthritis among women who take oral contraceptives

Discrepant results among investigations of the association between oral contraceptive use and rheumatoid arthritis (RA) have been ascribed to shortcomings in the study methods. In the present study, we obtained detailed information on oral contraceptive use in 135 young women with confirmed definite or classic RA of recent onset and in 378 controls with soft tissue rheumatism or osteoarthritis. All patients had at least 2 years of followup to confirm the consistency of the diagnosis. Oral contraceptive use at any time before disease onset was reported by 70% of the RA patients and 85% of the controls; the latter figure corresponded to general population data for The Netherlands. This yielded a relative risk for RA of 0.39 among those who had ever used oral contraceptives and 0.58 for those using oral contraceptives at the time of symptom onset. The preventive effect of oral contraceptive use on the risk of RA was found to be independent of the dose, duration of use, or presence of HLA-DR4. The strongest protection was seen in women with a family history of RA and in women ages 31-40 at symptom onset. The conflicting results in the literature are discussed, and a possible biologic mechanism for this phenomenon is suggested.

DR4 prevalence related to the age at disease onset in female patients with rheumatoid arthritis

The prevalence of HLA-DR4 in relation to age at disease onset was calculated in 226 consecutive female patients with definite or classical rheumatoid arthritis (RA). A slight increase in the prevalence of DR4 with age at RA onset was found. This appeared to be due to the low percentage of rheumatoid factor (RF) positivity in the youngest age groups; the DR4 prevalence in the RF positive patients was constant for all decades--that is, approximately 60%. A previously reported declining trend of DR4 prevalence in women with RA in relation to age of RA onset may be due to the disease heterogeneity of the patients included in that study.

Rheumatoid arthritis

The results of family and twin studies suggest that RA may result from an interaction between an oligogenic susceptibility and unknown environmental factors. Part of this genetic predisposition is accounted for by genes within the MHC where there is a well-documented association with HLA-DR4. Studies of DR and other MHC variants have shown different associations with particular subgroups. One subgroup is Felty's syndrome where there is a strong association with DR4, as well as associations with DQ-beta and C4B null variants when DR4-matched Felty's and RA subjects are analysed. These DQ-beta and C4B null variants may characterize a single haplotype which is associated with extra-articular disease. A further rheumatoid subgroup characterized by circulating antibodies to native type II collagen, shows an association with HLA-DR3 and 7. Genes on chromosome 14 may also influence susceptibility to RA, probably by interaction with MHC genes and there are different Gm associations for DR4-positive and collagen-antibody-positive rheumatoid subgroups. HLA and Gm markers so far identified only account for a small part of the total genetic predisposition to RA and a third or further loci may also be involved. Possible candidates include T-cell alpha- and beta-chain genes and immunoglobulin light chain genes. One present concept of the genetic predisposition to RA is of several independent immunogenetic pathways each including interactions at two or more loci.

Perivascular infiltration in normal skin of patients with rheumatoid arthritis: association with rheumatoid factors and HLA-DR antigens

The relation between immunohistological findings in biopsy specimens of apparently normal skin, HLA antigens, and rheumatoid factors (RF) was studied in 120 patients with rheumatoid arthritis (RA), selected for treatment with D-penicillamine. Perivascular infiltration (PVI) of more than three mononuclear cells was present in 77 (68%) of 114 patients, accompanied usually by the presence of IgM or C3, or both, in immunofluorescence studies. The number of perivascular cells was associated significantly with the titre of circulating RF. A weak relation of both perivascular cellular infiltration and RF with HLA-DR3 and DR4 did not reach statistical significance. It is concluded that the histological presence of perivascular inflammation is associated mainly with deposition of RF. It is suggested that the first is merely an epiphenomenon of the latter. PVI was not prognostic for the occurrence of the clinical syndrome of rheumatoid vasculitis. For practical purposes skin biopsies do not appear to be useful in the evaluation of individual patients with RA.

Complement C4B-null alleles in Felty's syndrome

C4A and C4B allotypes were compared in 20 patients with Felty's syndrome (FS), 52 patients with rheumatoid arthritis (RA), and 55 control subjects. Nineteen of the FS patients had HLA-DR4. A C4B-null allele was more frequent in the patients with FS (60%) than in either the RA patients (15%) or the control subjects (26%). Only the differences between patients with FS and those with RA remained statistically significant when DR4 positive subjects were compared. The C4B null allele may identify individuals within the rheumatoid population who are at risk of developing particular systemic complications.

Polymyalgia rheumatica: a syndrome associated with HLA-DR4 antigen

HLA class II antigens were determined in 65 patients with biopsy-proven giant cell arteritis (GCA). An increase in DR4 antigen frequency was found in the patients (40%) compared with that in 200 healthy controls (20%) (Pcorr less than 0.05). DR4 was significantly more frequent in GCA patients with polymyalgia rheumatica (PMR) than in those without PMR (58.8% versus 19.3%) (P less than 0.005). HLA-DR4 frequency in GCA patients without PMR was similar to that in the control population (20%). Patients with severe, disabling PMR had DR4 more frequently (90%) than did those with moderate symptoms who required medical care because of cranial arteritis manifestations (41.6%) (P less than 0.05). We conclude that, in GCA patients, association with DR4 is mainly related to the manifestation of the disease as PMR. We discuss clinical and immunogenetic similarities between PMR and other DR4-associated rheumatic disorders. Common immunopathogenic mechanisms leading to clinical overlap among them are suggested.

Immunopathological abnormalities in the normal skin of patients with rheumatoid arthritis in relation to clinical and serological findings: a one year follow up study

Fifty two patients with seropositive rheumatoid arthritis (RA) were studied over a period of one year to investigate possible relationships among changes of circulating immune complexes (CIC), deposits of immunoglobulins and complement around the cutaneous blood vessels, clinical activity of the disease, and the presence of extra-articular manifestations (EAM). The presence or absence of IgM and C3 in and around the cutaneous blood vessels correlated significantly with the presence or absence of extra-articular features in cross sectional and longitudinal studies. Patients with evidence of these cutaneous immune deposits also had a greater prevalence of CIC as determined by the Clq binding assay (ClqBA) or polyethylene glycol (PEG) assay for IC containing IgM (IgM IC). Although the degree of perivascular mononuclear cell infiltration around the blood vessels in the papillary dermis was related to the patients' clinical state at the initial assessment, it did not correlate with the later changes in the activity of the joint disease or the occurrence of EAM. Thus the deposition of immunoglobulin or complement, or both, seems to be independent of cellular infiltration. The meaning of these cellular infiltrates is not yet fully understood. Our study has shown that many patients with RA who appeared to have only joint disease in fact had subclinical systemic disease as reflected by a positive skin biopsy or CIC. Moreover, the disappearance of IgM deposits from the skin correlated with the disappearance of EAM and improvement of joint disease.