Rheumatoid-nodule-like cutaneous granuloma associated with recombinase activating gene 1-deficient severe combined immunodeficiency: A rare case.

Cutaneous granulomas without detectable infectious etiology rarely occur in children and adults with primary immunodeficiency disorders. These cutaneous granulomas are primarily seen in combined variable immunodeficiency, ataxia-telangiectasia, and severe combined immunodeficiency (SCID) and can emulate the reaction patterns seen in sarcoidosis and granuloma annulare. To date, the literature has described only six cases of non-infectious cutaneous granulomas in SCID. We report an unusual case of cutaneous granuloma, mimicking a sarcoma, in a 40-year old male with recombinase activating gene 1-deficient SCID, who presented with a slow-growing globus mass over the lateral aspect of the right elbow. There was heterogeneous enhancement on MRI, which was concerning for neoplasm but no malignancy was found on frozen or permanent sections. GMS, PAS with diastase, and AFB stains, as well as microbiology cultures, were negative. An AE1/AE3 stain was negative and a CD163 stain highlighted histiocytes. No infectious etiology was identified and histopathology revealed palisaded granulomatous dermatitis, most closely resembling a rheumatoid nodule. Although cutaneous manifestations have been reported in nearly half of primary immunodeficiency disorder cases, non-infectious cutaneous granulomas are exceedingly rare in SCID. To our knowledge, this is the first case report of cutaneous palisaded granulomatous dermatitis mimicking a rheumatoid nodule in a major joint.

Digital-PCR for gene expression: impact from inherent tissue RNA degradation.

Subtle molecular differences indicate the heterogeneity present in a number of disease settings. Digital-PCR (dPCR) platforms achieve the necessary levels of sensitivity and accuracy over standard quantitative RT-PCR (qPCR) that promote their use for such situations, detecting low abundance transcript and subtle changes from gene expression. An underlying requisite is good quality RNA, principally dictated by appropriate tissue handling and RNA extraction. Here we consider the application of dPCR to measures of gene expression in pathological tissues with inherent necrosis, focusing on rheumatoid subcutaneous nodules. Variable RNA fragmentation is a feature of RNA from such tissues. Increased presence of transcript fragmentation is reflected in a proportionate decrease in Agilent DV200 metric and downstream, a reduction in endogenous control genes' expression, measured by RT-dPCR. We show that normalisation of target gene expression to that for endogenous control genes sufficiently corrects for the variable level of fragmented RNA. Recovery of target gene values was achieved in samples comprising as much as 50 percent fragmented RNA, indicating the suitability and appropriate limitation of such data treatment when applied to samples obtained from inherently necrotic tissues.

Expression of the genes facilitating methotrexate action within subcutaneous rheumatoid nodules.

OBJECTIVES: We sought further understanding of the association between methotrexate (MTX) therapy and accelerated development of subcutaneous rheumatoid nodules. The objective was to establish expression of genes involved in the transport, metabolism, and mechanism of action of MTX within nodule tissue. We also examined for differences in gene expression between nodules from patients actively receiving MTX compared to those not receiving MTX. METHODS: Subcutaneous nodule tissues (n=23) were obtained from 21 patients with RA, undergoing elective surgery. Expression of genes important to the transport (SLC19A1, ABCB1, ABCC1, ABCG2), metabolism (FPGS, GGH), and mechanism of action (TYMS, MTR, MTRR) of MTX, including for the adenosine receptors ADORA1, ADORA2A, ADORA2B, ADORA3 and ADORA3variant were quantitated by real-time PCR in each nodule sample. RESULTS: Transcripts for all genes were found in all nodules. Expression of MTR was significantly reduced in nodules from patients receiving MTX therapy. Patterns of gene expression differed, with those metabolising MTX more prominent in nodules from patients receiving MTX when compared to nodules from those not receiving MTX, where genes involved in MTX transport were more prominent. CONCLUSIONS: Genes involved in MTX handling are expressed in rheumatoid nodules, providing further evidence that metabolism of MTX within nodules could exert a local effect. Furthermore the profile of gene expression in nodules differed from that previously observed in rheumatoid synovial membrane. The significant reduction of MTR expression in nodules has implications for MTR- and MTRR-mediated re-methylation reactions. Our data suggest that in contrast to synovium, downstream methylation reactions involving methionine and the biosynthesis of S-adenosylmethionine (SAM) could be reduced in nodule tissue. This could help explain differing responses to MTX in rheumatoid nodules and synovium and warrants further investigation.

The plausible association of MTHFR and ADORA2A polymorphisms with nodules in rheumatoid arthritis patients treated with methotrexate.

OBJECTIVE: The treatment of rheumatoid arthritis (RA) patients with methotrexate (MTX) is linked to the development or progression of rheumatoid nodules. The aim of this study was to determine whether folate and adenosine pathways-related single nucleotide polymorphisms might be predictive of increased nodule formation in RA patients treated with oral MTX. METHODS: A total of 185 Caucasian RA patients were enrolled in this cross-sectional study, all of whom fulfilled the 1987 RA criteria of the American College of Rheumatology; each patient had a history of MTX treatment. RESULTS: A higher frequency of the MTHFR 1298AA genotype was found in 17 (70.8%) of 24 patients with general nodules [odds ratio (OR)=3.08, 95% confidence interval (CI): 1.20-7.69] and in 14 (73.7%) of 19 patients who developed nodules during MTX treatment (OR=3.55, 95% CI: 1.22-10.32). In contrast, a negative association with nodules during MTX treatment (OR=0.29, 95% CI: 0.08-1.10) was found for 19 (79.2%) patients with the TT genotype (rs2298383) in the adenosine A2a receptor gene (ADORA2A). However, the significance did not remain upon correction for multiple testing. The combination of MTHFR 1298AA along with ADORA2A rs2298383 CC or CT genotypes occurring in one-third of RA patients showed a higher frequency of general nodules 15/59 (25.4%) as well as developing nodules during MTX treatment 13/59 (22.0%) in comparison with the overall studied group: 24/185 (13.0%) and 19/185 (10.3%), respectively. CONCLUSION: This exploratory study indicates for the first time a plausible association of adenosine and folate pathways single nucleotide polymorphisms in nodules' etiopathogenesis.

MMP expression in rheumatoid inflammation: the rs11568818 polymorphism is associated with MMP-7 expression at an extra-articular site.

Matrix metalloproteinases (MMPs) contribute to the joint damage in rheumatoid arthritis (RA). Less is known of the involvement of MMPs at extra-articular sites of rheumatoid inflammation. We assessed the relative contribution from MMP-1, MMP-3, MMP-7 and MMP-12 to joint and extra-articular tissue destruction and inflammation by comparing gene expression in joint synovia and subcutaneous rheumatoid nodules from RA patients. Expression of MMP-1 and MMP-3 predominated in synovia, whereas MMP-12 expression was significantly higher in rheumatoid nodules. Markedly higher MMP-7 expression distinguished a subgroup of nodules that featured infiltrating monocyte/macrophage-producing MMP-7 protein. The high MMP-7 expression in nodules was associated with the single-nucleotide polymorphism (SNP) rs11568818 (-181A>G, MMP-7 promoter) and more active inflammation within the nodule lesions. Patients with such nodules had significantly earlier age of RA onset. Our findings indicate that the expression of MMP-1 and MMP-3 occurs relatively independent of the tissue microenvironment with substantial expression also at extra-articular sites. MMP-12 expression reflects the involvement of monocyte/macrophages in rheumatoid inflammation. Evidence for the association between the rs11568818 SNP and increased MMP-7 expression is restricted to nodules, which indicates that consequences of the MMP-7 polymorphism are likely to manifest within aspects of immune/inflammatory activity that are monocyte/macrophage-mediated.

Microchimerism in the rheumatoid nodules of patients with rheumatoid arthritis.

OBJECTIVE: The rheumatoid nodule is a lesion commonly found on extraarticular areas prone to mechanic trauma. When present with inflammatory symmetric polyarthritis, it is pathognomonic of rheumatoid arthritis (RA), an autoimmune disease in which naturally acquired microchimerism has previously been described and can sometimes contribute to RA risk. Since RA patients harbor microchimerism in the blood, we hypothesized that microchimerism is also present in rheumatoid nodules and could play a role in rheumatoid nodule formation. This study was undertaken to investigate rheumatoid nodules for microchimerism. METHODS: Rheumatoid nodules were tested for microchimerism by real-time quantitative polymerase chain reaction (qPCR). The rheumatoid nodules of 29 female patients were tested for a Y chromosome-specific sequence. After HLA genotyping of patients and family members, rheumatoid nodules from 1 man and 14 women were tested by HLA-specific qPCR, targeting a nonshared HLA allele of the potential microchimerism source. Results were expressed as genome equivalents of microchimeric cells per 10(5) patient genome equivalents (GE/10(5)). RESULTS: Rheumatoid nodules from 21% of the female patients contained male DNA (range <0.5, 10.3 GE/10(5)). By HLA-specific qPCR, 60% of patients were microchimeric (range 0, 18.5 GE/10(5)). Combined microchimerism prevalence was 47%. A fetal or maternal source was identified in all patients who tested positive by HLA-specific qPCR. Unexpectedly, a few rheumatoid nodules also contained microchimerism without evidence of a fetal or maternal source, suggesting alternative sources. CONCLUSION: Our findings indicate that microchimerism is frequently present in the rheumatoid nodules of RA patients. Since microchimerism is genetically disparate, whether microchimerism in rheumatoid nodules serves as an allogeneic stimulus or allogeneic target warrants further investigation.

Association of IL4R single-nucleotide polymorphisms with rheumatoid nodules in African Americans with rheumatoid arthritis.

INTRODUCTION: To determine whether IL4R single-nucleotide polymorphisms (SNPs) rs1805010 (I50V) and rs1801275 (Q551R), which have been associated with disease severity in rheumatoid arthritis (RA) patients of European ancestry, relate to the presence of rheumatoid nodules and radiographic erosions in African Americans. METHODS: Two IL4R SNPs, rs1805010 and rs1801275, were genotyped in 749 patients from the Consortium for Longitudinal Evaluation of African-Americans with Early Rheumatoid Arthritis (CLEAR) registries. End points were rheumatoid nodules defined as present either by physical examination or by chest radiography and radiographic erosions (radiographs of hands/wrists and feet were scored using the modified Sharp/van der Heijde system). Statistical analyses were performed by using logistic regression modeling adjusted for confounding factors. RESULTS: Of the 749 patients with RA, 156 (20.8%) had rheumatoid nodules, with a mean age of 47.0 years, 84.6% female gender, and median disease duration of 1.9 years. Of the 461 patients with available radiographic data, 185 (40.1%) had erosions (score>0); their mean age was 46.7 years; 83.3% were women; and median disease duration was 1.5 years. Patients positive for HLA-DRB1 shared epitope (SE) and autoantibodies (rheumatoid factor (RF) or anti-cyclic citrullinated peptide (CCP)) had a higher risk of developing rheumatoid nodules in the presence of the AA and AG alleles of rs1801275 (odds ratio (OR)adj=8.08 (95% confidence interval (CI): 1.60-40.89), P=0.01 and ORadj=2.97 (95% CI, 1.08 to 8.17), P=0.04, respectively). Likewise, patients positive for the HLA-DRB1 SE and RF alone had a higher risk of developing rheumatoid nodules in presence of the AA and AG alleles of rs1801275 (ORadj=8.45 (95% CI, 1.57 to 45.44), P=0.01, and ORadj=3.57 (95% CI, 1.18 to 10.76), P=0.02, respectively) and in the presence of AA allele of rs1805010 (ORadj=4.52 (95% CI, 1.20 to 17.03), P=0.03). No significant association was found between IL4R and radiographic erosions or disease susceptibility, although our statistical power was limited by relatively small numbers of cases and controls. CONCLUSIONS: We found that IL4R SNPs, rs1801275 and rs1805010, are associated with rheumatoid nodules in autoantibody-positive African-American RA patients with at least one HLA-DRB1 allele encoding the SE. These findings highlight the need for analysis of genetic factors associated with clinical RA phenotypes in different racial/ethnic populations.

Matrix metalloproteinase gene polymorphisms in patients with rheumatoid arthritis.

Several genetic factors seem to be involved in the pathogenesis of rheumatoid arthritis (RA). The aim of this study was to analyze whether functional polymorphisms in the promoter region of the MMP-1, -3 and -9 genes were associated with RA. The study population comprises 110 RA patients and 100 healthy controls. The -1607 1G/2G MMP-1, -1171 5A/6A MMP-3, and -1562 C/T MMP-9 polymorphisms were analyzed. The frequency of the 5A allele of MMP-3 gene was significantly higher in the controls when compared with the RA patients (0.45 vs. 0.32, P < 0.01). No significant differences were observed in the allele frequencies for the MMP-1 and -9 polymorphisms between RA patients and controls. Individuals carrying MMP-3 5A allele have significant higher frequency of extra-articular manifestations and rheumatoid nodules than individuals homozygous for 6A allele (P < 0.05). The results presented in this study provide evidence of an association between the MMP-3 gene polymorphism and RA.

Different T cell subsets in the nodule and synovial membrane: absence of interleukin-17A in rheumatoid nodules.

OBJECTIVE: To determine gene expression of the interleukin-17 (IL-17) family members (IL-17A-F) in rheumatoid subcutaneous nodules, and to assess the cytokines involved in regulating IL-17A expression. METHODS: Total RNA was isolated from 19 nodules obtained from 16 different patients with rheumatoid arthritis (RA). Reverse transcription-polymerase chain reaction (PCR) was used to screen for gene expression of the IL-17 subtypes (IL-17A-F) in all nodules. Quantitative real-time PCR was used to measure the expression of interferon-gamma (IFN gamma), IL-6, IL-23, IL-12, and transforming growth factor beta (TGFbeta), relative to GAPDH as control, in a subset of 10 nodules. RESULTS: IL-17A gene expression was present in only 1 of 19 nodules, IL-17B in 17 of 19 nodules, IL-17C in 18 of 19 nodules, IL-17D in 16 of 19 nodules, and IL-17E in 3 of 19 nodules. IL-17F was absent in all samples. Cytokines that stimulate IL-17A production (IL-6, IL-23) as well as those that inhibit IL-17A production (IL-12, IFN gamma, TGFbeta) were present in the majority of nodules. Quantitative real-time PCR showed a similar pattern of gene expression for the individual cytokines between the different nodules. The mean +/- SD expression of IL-6 relative to GAPDH was 2.28 +/- 2.2 ng, and that of TGFbeta was 2.96 +/- 1.14 ng. There was a lower relative expression of IL-23 (0.05 +/- 0.05 ng), while the expression of IFN gamma was 0.67 +/- 0.68 ng and that of IL-12 was 0.48 +/- 0.23 ng. CONCLUSION: IL-17 family members are varyingly expressed in rheumatoid nodules. The paucity of IL-17A in nodules suggests an important difference from that observed in the synovium. The expression of IL-23 below a critical threshold level seems the most likely explanation for the virtual absence of IL-17A. The presence of tissue destruction within the nodule despite the absence of IL-17A suggests that IL-17A may be an important amplifier rather than an absolute requirement for inflammation in RA.

Cigarette smoking, disease severity and autoantibody expression in African Americans with recent-onset rheumatoid arthritis.

OBJECTIVE: To examine the association of smoking with clinical and serological features in African Americans with recent-onset rheumatoid arthritis (RA) and to explore whether this association is dependent on the presence of the HLA-DRB1 shared epitope (SE). METHODS: In African Americans with recent-onset RA (n = 300), we examined the association of cigarette smoking (current versus past versus never and pack-years of exposure) with anti-cyclic citrullinated peptide antibody, rheumatoid factor (RF) (IgM and IgA), rheumatoid nodules and baseline radiographic erosions using logistic and cumulative logistic regression (adjusting for SE status). We also examined for evidence of interaction between smoking status and SE for all outcomes. RESULTS: Although there was no association with RF-IgA seropositivity, current smokers were approximately twice as likely as never smokers to have higher IgA-RF concentrations (based on tertiles; OR = 1.74; 95% CI 1.05 to 2.88) and nodules (OR = 2.43; 95% CI 1.13 to 5.22). These associations were most pronounced in those with more than 20 pack-years of exposure. There was no association of smoking status or cumulative tobacco exposure with anti-cyclic citrullinated peptide antibody, IgM-RF or radiographic erosions. There was also no evidence of a biological or statistical SE-smoking interaction for any of the outcomes examined. CONCLUSIONS: This is the first study to systematically examine the association of cigarette smoking with RA-related features in African Americans. Cigarette smoking is associated with both subcutaneous nodules and higher serum concentrations of IgA-RF in African Americans with RA, associations that may have important implications for long-term outcomes in this population.

Polymorphisms of genes for programmed cell death 1 ligands in patients with rheumatoid arthritis.

To investigate the role of ligands for programmed cell death 1 (PD-L) in the pathogenesis of rheumatoid arthritis (RA), 129 patients with RA and 125 unrelated healthy controls were enrolled in this study. The PD-L1 and PD-L2 polymorphisms were determined by the method of polymerase chain reaction (PCR)/direct sequencing or PCR/reaction fragment length polymorphisms. The genotype distributions of PD-L1 6777 C/G were not significantly different between the patients with RA and healthy controls. There was also no significant difference in the allele frequencies of PD-L1 6777 C/G polymorphisms between the patients with RA and controls. Similar findings could also be found in the phenotypes and alleles frequencies of PD-L2 47103 C/T and 47139 T/C polymorphisms between the patients with RA and controls. The patients with PD-L1 6777 G had higher prevalence of rheumatoid nodule in comparison with those without PD-L1 6777 G (p = 0.005, OR = 4.0, 95% CI = 1.5-10.9). In contrast, the PD-L2 47103 C/T and 47139 T/C polymorphisms were not related to the occurrence of rheumatoid nodule. This study demonstrated that the PD-L1 and PD-L2 polymorphisms were not associated with susceptibility to RA in Taiwan. PD-L1 6777 G was associated with the prevalence of rheumatoid nodule.

Rheumatoid nodule.

Rheumatoid nodules are the most common extra-articular manifestation of rheumatoid arthritis. Dermatologist may be concerned with the diagnosis and management of rheumatoid nodules, although most patients will probably be under the care of a rheumatologist. This article focuses in clinical, pathogenic, diagnostic, and therapeutic aspects of rheumatoid nodules. Classic rheumatoid nodules commonly occur in genetically predisposed patients with severe, seropositive arthritis. However, they may appear in other clinical settings. Accelerated rheumatoid nodulosis, especially involving the hands, has been reported in patients receiving methotrexate, antitumor necrosis factor alpha biologic drugs or leflunomide therapy for rheumatoid arthritis. Rheumatoid nodulosis is characterized by multiple rheumatoid nodules, recurrent joint symptoms with minimal clinical or radiologic involvement, and a benign clinical course. Pseudorheumatoid nodules have been reported in healthy children. Although histologically almost indistinguishable from true rheumatoid nodules, some consider these lesions to be a form of deep granuloma annulare.

Association of polymorphism in the transforming growth factor {beta}1 gene with disease outcome and mortality in rheumatoid arthritis.

OBJECTIVE: To investigate whether polymorphism in the transforming growth factor beta1 (TGFbeta1) gene is associated with disease outcome in rheumatoid arthritis. METHODS: 208 patients with established rheumatoid arthritis were genotyped for the TGFbeta1 T869C polymorphism using an amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) method. Disease severity was assessed by measuring radiographic damage by Larsen score and functional outcome by the health assessment questionnaire (HAQ). Patients were tracked on the NHS central register for notification of death, and the relation between TGFbeta1 polymorphism and mortality was analysed using Cox proportional hazards regression. RESULTS: Patients carrying a TGFbeta1 T allele had a higher mean HAQ score than those without this allele (1.60 v 1.22, p = 0.04). The T allele was also associated with higher five year mean area under the curve (MAUC) erythrocyte sedimentation rate (ESR), and nodular disease. Larsen score was higher in patients with the TT genotype compared with CC + CT genotypes, although this was not significant after correction for disease duration. There was a trend of increasing mortality risk with T allele dose after adjustment for age, sex, and disease duration (hazard ratio = 1.6 (95% confidence interval, 1.1 to 2.4), p = 0.01). CONCLUSIONS: TGFbeta1 T869C gene polymorphism is associated with disease outcome in rheumatoid arthritis. Carriage of the T allele (putatively associated with decreased TGFbeta1 production) was associated with increased inflammatory activity and poor functional outcome, while increasing T allele dose was associated with worse survival.

Lack of association of the HLA-DRB1 shared epitope with rheumatoid nodules: an individual patient data meta-analysis of 3,272 Caucasian patients with rheumatoid arthritis.

OBJECTIVE: The objective of this individual patient data (IPD) meta-analysis was to examine the relationship of rheumatoid nodules to the HLA-DRB1 shared epitope (SE) and to individual SE genotypes. METHODS: English-language studies that enrolled adult non-Hispanic Caucasian patients with rheumatoid arthritis (RA) were identified by searches of Medline and Embase, and by manual searches of medical journals. All authors were contacted for IPD. Meta-analysis was performed to assess the association of SE presence, dose, and genotype with rheumatoid nodules. Meta-analyses adjusted for disease duration and cumulative meta-analyses were also performed to assess the influence of RA duration and year of study publication on the results. RESULTS: A total of 24 studies and 3,272 patients were available for analysis. IPD were obtained for 22 of the studies. There was a nonsignificant association between the presence of the SE (i.e., 1 or 2 alleles versus 0 alleles) and rheumatoid nodules (summary odds ratio [OR] 1.3, 95% confidence interval [95% CI] 0.97-1.6). Analysis by SE genotype, however, demonstrated a weak relationship with inheritance of a single DRB1*0401 SE allele (OR 1.4, 95% CI 1.1-1.8). No other genotypes achieved statistical significance in the adjusted or unadjusted analyses. CONCLUSION: The presence of the HLA-DRB1 SE does not appear to significantly increase the risk of rheumatoid nodules among Caucasian patients with RA. Analysis by DRB1 SE genotype was uninformative, suggesting only a potential (and at most modest) role of the DRB1*0401 SE allele. Results from this IPD meta-analysis implicate other genetic, stochastic, and/or environmental factors in the susceptibility to rheumatoid nodules.

Nodular disease in rheumatoid arthritis: association with cigarette smoking and HLA-DRB1/TNF gene interaction.

OBJECTIVE: To investigate the association of nodular disease in rheumatoid arthritis (RA) with smoking, seropositivity, and polymorphisms at HLA-DRB1 and TNF loci. METHODS: Consecutive patients with RA (n = 420) attending a hospital clinic were examined for the presence of subcutaneous nodules. Rheumatoid factor (RF) status and HLA-DRB1 genotype were determined on every patient, and their smoking history was recorded. TNFa microsatellite polymorphisms were examined in a subgroup of 144 patients. The relationships between smoking, RF status, HLA-DRB1 genotype, TNFa microsatellite polymorphism, and the presence of nodules were examined using chi-square tests and logistic regression analyses. RESULTS: Current smokers were more likely to have nodular disease than those who had never smoked (OR 1.8, 95% CI 1.0-2.9). An association was also found between RF positivity and nodular disease (OR 2.2, 95% CI 1.2-3.8) that remained significant after correction for current smoking. A combination of current smoking and seropositivity increased the risk of nodular disease (OR 3.9, 95% CI 1.7-9.1). Analysis of HLA-DRB1 genotypes in this RA population revealed that only DRB1*0401 homozygotes were associated with nodular disease, and that this was independent of the influence of smoking and seropositivity. Individual TNFa microsatellite alleles were not associated with the presence of nodules, but an interactive effect was found between the TNF a6 allele and homozygosity for DRB1*0401. CONCLUSION: Our data indicate that nodular disease in RA is independently associated with current cigarette smoking, seropositivity, and homozygosity for HLA-DRB1*0401. The latter association involves a possible interaction with the TNF a6 microsatellite allele.

[An unusual case of Heberden arthrosis in a young man]. / Ein ungewöhnlicher Fall einer Heberden-Arthrose bei einem jungen Mann.

Heberden nodes affect mainly middle-aged women. Inheritance is autosomal dominant in female and autosomal recessive in male patients. We report the case of a young man who presented already with 12 years of age with pain in the distal finger joints. There were no other clinical or serological signs for other rheumatoid diseases, like psoriatic or rheumatoid arthritis. Radiologic findings were consistent with Heberden's osteoarthritis of the finger joints. The joint changes remained clinically and radiologically stable during a time period of more than 15 years. The HLA typing revealed the haplotype HLA A1, B8 and DR4, in accordance with former studies which reported a higher frequency of HLA A1, B8 in families with primary osteoarthritis (early onset osteoarthritis of the large joints in combination with Heberden nodes).

Association of oestrogen receptor gene polymorphisms with age at onset of rheumatoid arthritis.

OBJECTIVE: In view of the possible role of oestrogens in the pathogenesis of rheumatoid arthritis (RA), this study investigated the association between oestrogen receptor (OR) gene polymorphisms and RA. METHODS: Pvu II and Xba I restriction fragment length polymorphisms of the OR gene were analysed in 70 male and 240 female patients with RA, and in 300 male and 350 female controls. The absence or presence of restriction sites were represented as P, p (Pvu II) or X, x (Xba I). The distribution of OR genotypes was compared between the RA and control subjects by sex. RA patients were divided into subgroups according to their OR genotypes, then the age at onset, seropositivity, and rheumatoid nodule positivity were compared between the subgroups. RESULTS: The OR genotype frequency of distribution did not have significant differences between the male RA and male controls nor between the female RA and female controls. In women with RA, there was a significant difference of age at onset between the subgroups (uncorrected p = 0.047, corrected p = 0.94). Female patients with the OR genotype PPxx (homozygote of Px) tended to have developed RA at a younger age, whereas those with PPXX and ppxx (lack of Px haplotype) developed RA at an older age. In men with RA, there was no association between the OR genotype and age at onset. In seropositivity and rheumatoid nodule positivity, there was no significant difference between subgroups for either sex. CONCLUSIONS: Some variants of the OR gene are related to the onset of RA in women in certain age periods, suggesting the role of the interaction between the OR gene and serum concentrations of oestrogen at the onset of the disease.

HLA DRB1* alleles in rheumatoid nodulosis: a comparative study with rheumatoid arthritis with and without nodules.

Rheumatoid nodulosis (RN) is a rare condition associating rheumatoid nodules, episodes of arthritis, cystic bone lesions and, generally, positive rheumatoid factors (RF). It is considered a benign variant of rheumatoid arthritis (RA). In this study, we determined the HLA DRB1* alleles of our RN patients and compared the distribution of these alleles to those of 74 healthy controls and 104 RA patients with and without nodules. Four RN patients were observed. All had subcutaneous nodules and RF were negative in three patients. Of the 104 RA patients, 18 had nodules (nodRA). Systemic manifestation (including vasculitis, peripheral neuropathy or lung involvement) were found in seven of these nodRA cases (33.8%) and most had positive RF and erosive changes on X-rays. Only one RN patient had a RA-associated allele (DRB1*0101). The frequencies of the HLA DRB1* alleles encompassing the "rheumatoid" shared epitope were similar to those of other RA series: *0101, 34.6% (P = 0.03 compared with controls); *0401, 26.9% (P < 0.0001); *0404, 12.5% (P = 0.04); *0405, 4.8% (P = 0.8); *1001, 8.6% (P = 0.5). Of the nodRA and seronegative RA patients, 77.7% and 53.3%, respectively, presented the shared epitope. Thus, there was a tendency to decreased expression of the RA-associated alleles in RN (25%) compared with nodRA and seronegative RA patients. This study is restricted by the small number of tested RN patients, but the results suggest that the RA-associated alleles are poorly expressed in RN.