Single-cell characterisation of tissue homing CD4 + and CD8 + T cell clones in immune-mediated refractory arthritis.

BACKGROUND: Immune-mediated arthritis is a group of autoinflammatory diseases, where the patient's own immune system attacks and destroys synovial joints. Sustained remission is not always achieved with available immunosuppressive treatments, warranting more detailed studies of T cell responses that perpetuate synovial inflammation in treatment-refractory patients. METHODS: In this study, we investigated CD4 + and CD8 + T lymphocytes from the synovial tissue and peripheral blood of patients with treatment-resistant immune-mediated arthritis using paired single-cell RNA and TCR-sequencing. To gain insights into the trafficking of clonal families, we compared the phenotypes of clones with the exact same TCRß amino acid sequence between the two tissues. RESULTS: Our results show that both CD4 + and CD8 + T cells display a more activated and inflamed phenotype in the synovial tissue compared to peripheral blood both at the population level and within individual T cell families. Furthermore, we found that both cell subtypes exhibited clonal expansion in the synovial tissue. CONCLUSIONS: Our findings suggest that the local environment in the synovium drives the proliferation of activated cytotoxic T cells, and both CD4 + and CD8 + T cells may contribute to tissue destruction and disease pathogenesis.

Myocardial T1 mapping by cardiac magnetic resonance imaging shows early myocardial changes in treatment-naive patients with active rheumatoid arthritis and positive autoantibodies.

OBJECTIVES: We aimed to study whether myocardial changes are already detectable by cardiac magnetic resonance (CMR) imaging at the time of rheumatoid arthritis (RA) diagnosis. METHODS: This single-centre prospective study included 39 treatment-naive patients with early rheumatoid arthritis (ERA, symptom duration <1 year) without any history of heart disease, and 38 age- and sex-matched healthy volunteers. The disease severity was assessed with clinical evaluation (Disease Activity Score-28 for Rheumatoid Arthritis with CRP (DAS28-CRP) score) and serological testing (rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPA)). The ERA patients were classified into group A (DAS28-CRP score ≥3.2, positive RF and ACPA; n=17) and group B (not fulfilling the group A criteria). The ERA patients and healthy controls underwent 1.5T CMR. RESULTS: Group A patients had significantly higher myocardial global T1 relaxation times than the healthy controls, 987 [965, 1003] ms vs. 979 [960, 991] ms (median [IQR]; p=0.041). A significant difference in T1 was found in the basal, mid inferior and mid anterolateral segments. In a multivariate analysis, prolonged global T1 relaxation time was independently associated with female sex (95% CI [5.62, 51.31] ms, p=0.016), and group A status (95% CI [4.65, 39.01] ms p=0.014). CONCLUSIONS: At the time of diagnosis, ERA patients with a higher disease activity (DAS28-CRP score ≥3.2) and both positive RF and ACPA showed prolonged T1 relaxation times in basal myocardial segments. These segments could be most susceptible to the development of myocardial fibrosis, and a segmental reporting style could be useful when estimating the first signs of myocardial fibrosis.

Corrigendum: Adult-Onset Anti-Citrullinated Peptide Antibody-Negative Destructive Rheumatoid Arthritis Is Characterized by a Disease-Specific CD8+ T Lymphocyte Signature.

[This corrects the article DOI: 10.3389/fimmu.2020.578848.].

Adult-Onset Anti-Citrullinated Peptide Antibody-Negative Destructive Rheumatoid Arthritis Is Characterized by a Disease-Specific CD8+ T Lymphocyte Signature.

Rheumatoid arthritis (RA) is a complex autoimmune disease targeting synovial joints. Traditionally, RA is divided into seropositive (SP) and seronegative (SN) disease forms, the latter consisting of an array of unrelated diseases with joint involvement. Recently, we described a severe form of SN-RA that associates with characteristic joint destruction. Here, we sought biological characteristics to differentiate this rare but aggressive anti-citrullinated peptide antibody-negative destructive RA (CND-RA) from early seropositive (SP-RA) and seronegative rheumatoid arthritis (SN-RA). We also aimed to study cytotoxic CD8+ lymphocytes in autoimmune arthritis. CND-RA, SP-RA and SN-RA were compared to healthy controls to reveal differences in T-cell receptor beta (TCRß) repertoire, cytokine levels and autoantibody repertoires. Whole-exome sequencing (WES) followed by single-cell RNA-sequencing (sc-RNA-seq) was performed to study somatic mutations in a clonally expanded CD8+ lymphocyte population in an index patient. A unique TCRß signature was detected in CND-RA patients. In addition, CND-RA patients expressed higher levels of the bone destruction-associated TNFSF14 cytokine. Blood IgG repertoire from CND-RA patients recognized fewer endogenous proteins than SP-RA patients' repertoires. Using WES, we detected a stable mutation profile in the clonally expanded CD8+ T-cell population characterized by cytotoxic gene expression signature discovered by sc-RNA-sequencing. Our results identify CND-RA as an independent RA subset and reveal a CND-RA specific TCR signature in the CD8+ lymphocytes. Improved classification of seronegative RA patients underlines the heterogeneity of RA and also, facilitates development of improved therapeutic options for the treatment resistant patients.

Activity of rheumatoid arthritis correlates with oral inflammatory burden.

To study oral health in patients with rheumatoid arthritis (RA) with emphasis on disease activity and treatment of RA. In this prospective cohort study 81 RA patients [53 early untreated RA (EURA) and 28 chronic RA (CRA) patients with inadequate response to synthetic disease modifying antirheumatic drugs (DMARDs)], underwent rheumatological [Disease Activity Score (28-joint) DAS28] and dental examinations [Total Dental Index (TDI), Decayed Missing Filled Teeth (DMFT) and Decayed Missing Filled Surfaces (DMFS)]. For controls, 43 volunteers were examined. After the examinations, EURA patients started treatment with synthetic DMARDs, oral and intra-articular glucocorticoids. CRA patients were candidates for biological DMARDs. The patients were re-examined mean 16 months later. Results were analyzed with descriptive statistics and logistic regression. TDI was higher in both RA groups at baseline compared to controls [EURA: 2 (2-3); CRA: 2 (1-3); controls 1 (1-3), p = 0.045]. DMFT [rs 0.561 (p = 0.002)] and DMFS [rs 0.581 (p = 0.001)] associated with DAS28 at baseline in CRA patients. After follow-up, DAS28 associated positively with DMFT [rs 0.384 (p = 0.016)] and DMFS [rs 0.334 (p = 0.038)] in EURA patients; as well as in CRA patients DMFT [rs 0.672 (p = 0.001)], DMFS [rs 0.650 (p = 0.001)]. RA patients already in the early phase of the disease had poorer oral health compared to controls. The caries indices associated with the activity of RA in both patient groups. Oral status may thus contribute to the development and further relate to the activity of RA.

Anti-rheumatic medication and salivary MMP-8, a biomarker for periodontal disease.

OBJECTIVE: To investigate the impact of anti-rheumatic medications on salivary matrix metalloproteinase (MMP)-8 levels and MMP-8/TIMP (tissue inhibitor of MMPs)-1 ratio in patients with rheumatoid arthritis (RA) and periodontal findings during a 1-year follow-up. MATERIALS AND METHODS: Salivary MMP-8 was measured by an immunofluorometric assay and TIMP-1 by an enzyme-linked immunosorbent assay of 53 patients with early untreated RA (ERA), naïve to synthetic disease modifying anti-rheumatic drugs (DMARDs), of 28 patients with chronic RA (CRA), candidates for biologic DMARDs and of 43 age- and sex-matched controls. Periodontal health was evaluated by bleeding on probing (BOP), pocket depth (PD), and periodontal inflammatory burden index (PIBI). Examinations were conducted twice for RA patients and once for controls. RESULTS: Salivary MMP-8 level and MMP-8/TIMP-1 ratio associated positively with PIBI in patients with chronic RA (MMP-8: p < 0.001 at baseline, p = 0.002 after follow-up; MMP-8/TIMP-1 ratio p < 0.001, p = 0.003, respectively) and in controls (MMP-8: p = 0.010, MMP-8/TIMP-1 ratio: p = 0.010). Salivary MMP-8 levels were highest at the early stage of RA. The used DMARDs, synthetic or biologic, did not affect salivary MMP-8 concentrations. CONCLUSIONS: The use of synthetic or biologic DMARDs did not affect salivary MMP-8 levels in RA patients regardless the duration of RA.

Inflammatory biomarkers in saliva and serum of patients with rheumatoid arthritis with respect to periodontal status.

OBJECTIVE: To study prospectively the association of salivary and serum matrix metalloproteinase (MMP)-8, tissue inhibitor of MMPs (TIMP)-1 and interleukin (IL)-6 with periodontal and systemic inflammation in rheumatoid arthritis (RA). We hypothesized that biomarker concentrations reflect inflammation. METHODS: Fifty three early untreated RA (ERA) and 28 chronic RA (CRA) patients, underwent rheumatological and dental examinations at baseline and one year later after starting first conventional or biological disease modifying antirheumatic drug. We included 43 control subjects. Saliva and serum samples were analyzed for MMP-8, TIMP-1 and IL-6. Periodontal health was assessed by bleeding on probing (BOP), pocket depth (PD) and periodontal inflammatory burden index (PIBI); RA disease activity was assessed by disease activity score DAS28. Joint destruction was analyzed by the modified Sharp-van der Heijde (SHS) method. RESULTS: Serum MMP-8 (p < .001; p < .001) and IL-6 (p < .001; p = .002) were significantly higher in CRA vs. other study groups during the study. Salivary MMP-8 (p = .010) and IL-6 (p = .010) were significantly higher in ERA vs. other study groups at baseline. Salivary MMP-8 was associated with periodontal parameters. CONCLUSION: Elevated serum concentrations of MMP-8 and IL-6 in CRA patients reflected chronic RA, while elevated salivary concentrations of MMP-8 levels in ERA patients reflected increased periodontal inflammation. Key messages Concentrations of inflammatory biomarkers in serum and saliva were different between patients with RA and healthy controls. Concentrations of MMP-8 and of IL-6 in serum were elevated in patients with chronic RA reflecting joint inflammation and the burden of established RA. Concentrations of MMP-8 in saliva was elevated already at the early stage of RA and the level of salivary MMP-8 was associated with poor periodontal health both in patients with early and in those with chronic RA.

Serum Epstein-Barr virus DNA, detected by droplet digital PCR, correlates with disease activity in patients with rheumatoid arthritis.

OBJECTIVES: To study the prevalence of asymptomatic activation of Epstein-Barr virus (EBV) in patients with rheumatoid arthritis (RA) and to analyse the correlation of serum EBV DNA with the disease activity. METHODS: The level of EBV DNA was determined by droplet digital PCR assay from the serum of 46 DMARD naive early RA (ERA) and 22 chronic RA (CRA)-patients at study onset. Follow-up samples from 31 ERA and 16 CRA patients were obtained after starting or modifying the anti-rheumatic treatment. EBV DNA was also measured from 33 healthy controls and 9 patients with adult onset Still's disease (AOSD). Disease activity was assessed by the disease activity score (DAS28). RESULTS: At baseline, EBV DNA was detected in the serum of 7 of the 46 ERA patients all of whom had moderate or high disease activity. In the follow-up samples, 11 of 31 patients were EBV DNA positive. At baseline EBV positive patients had significantly higher disease activity (p=0.036) and the concentration of EBV DNA correlated significantly with DAS28 (rs=0.333, p=0.024). EBV DNA was detected in 3 of 22 CRA patients at study onset and in 8 of 16 in the follow-up samples. At follow-up EBV positive patients had significantly higher DAS28 (p=0.027) and the concentration of EBV DNA correlated significantly with DAS28 (rs=0.724, p=0.002). Only one of the healthy controls and none of the AOSD patients were positive for EBV DNA. CONCLUSIONS: Active RA is associated with a lytic EBV infection which may have a role in the pathogenesis of RA.

One-Year Follow-up Study Detects Myocardial Changes with Cardiovascular Magnetic Resonance Tagging in Active Rheumatoid Arthritis.

RATIONALE AND OBJECTIVES: To evaluate the effects of 1 year of medical treatment on myocardial function in active rheumatoid arthritis (RA). MATERIALS AND METHODS: Thirty-nine female patients with RA without any known cardiovascular disease underwent a cardiovascular magnetic resonance (CMR) examination before and after 1 year of antirheumatic treatment. The population comprised untreated active early RA (ERA) and chronic RA patients, who were grouped accordingly. The CMR protocol included volumetric determinations, late gadolinium enhancement imaging, myocardial tagging, and native T1 mapping. DAS28-CRP disease activity scores were calculated before and after the treatment. RESULTS: Results are reported as median (quartile 1-quartile 3). Time to peak diastolic filling rate improved in ERA (495 [443-561] ms vs 441 [340-518] ms, P = .018). Peak diastolic mean mid short-axis circumferential strain rate of all six segments was improved (82 [74-91] %/s vs 91 [77-100] %/s, P = .05), particularly in the anterior segment (82 [63-98] %/s vs 86 [77-109] %/s, P = .013). DAS28-CRP decreased in ERA (3.8 [3.2-4.1] vs 1.6 [1.4-2.2], P < .001). In chronic RA, no statistically significant improvement was detected. CONCLUSIONS: Early treatment of active RA is important, as myocardial function detected with CMR tagging improved in ERA in parallel with decreasing inflammatory activity.

Baseline JAK phosphorylation profile of peripheral blood leukocytes, studied by whole blood phosphospecific flow cytometry, is associated with 1-year treatment response in early rheumatoid arthritis.

BACKGROUND: We found recently that baseline signal transducer and activator of transcription 3 phosphorylation in peripheral blood CD4+ T cells of patients with early rheumatoid arthritis (RA) is associated with treatment response to synthetic disease-modifying antirheumatic drugs (DMARDs). This prompted us to study the baseline phosphorylation profiles of Janus kinases (JAKs) in blood leukocytes with respect to treatment response in early RA. METHODS: Thirty-five DMARD-naïve patients with early RA provided blood samples for whole blood flow cytometric determination of phosphorylation of JAKs in CD4+ and CD8+ T cells, CD19+ B cells, and CD14+ monocytes. Treatment response was determined after 1 year of treatment with synthetic DMARDs, with remission defined as absence of tender and swollen joints and normal erythrocyte sedimentation rate. Exact logistic regression was used to investigate the association of baseline variables with treatment response. Ninety-five percent CIs of means were estimated by bias-corrected bootstrapping. RESULTS: High JAK3 phosphorylation in CD4+ and CD8+ T cells, CD19+ B cells, and CD14+ monocytes and low JAK2 phosphorylation in CD14+ monocytes were significantly associated with remission following treatment with synthetic DMARDs. CONCLUSIONS: Baseline JAK phosphorylation profile in peripheral blood leukocytes may provide a means to predict treatment response achieved by synthetic DMARDs among patients with early RA.

Periodontitis in early and chronic rheumatoid arthritis: a prospective follow-up study in Finnish population.

OBJECTIVES: To investigate the association between rheumatoid arthritis (RA) and periodontitis with special emphasis on the role of antirheumatic drugs in periodontal health. DESIGN: Prospective follow-up study. Patients with early untreated RA and chronic active RA were examined at baseline and 16 months later. Controls were examined once. SETTINGS AND PARTICIPANTS: The study was conducted in Finland from September 2005 to May 2014 at the Helsinki University Hospital. Overall, 124 participants were recruited for dental and medical examinations: 53 were patients with early disease-modifying antirheumatic drug (DMARD) naїve RA (ERA), 28 were patients with chronic RA (CRA) with insufficient response to conventional DMARDs. After baseline examination, patients with ERA started treatment with synthetic DMARDs and patients with CRA with biological DMARDs. Controls were 43 age-matched, gender-matched and community-matched participants. OUTCOME MEASURES: Degree of periodontitis (defined according to the Center for Disease Control and Prevention and the American Academy of Periodontology). Prevalence of periodontal bacteria (analysed from plaque samples), clinical rheumatological status by Disease Activity Score, 28-joint count (DAS28), function by Health Assessment Questionnaire (HAQ) and treatment response by European League Against Rheumatism (EULAR) criteria. RESULTS: Moderate periodontitis was present in 67.3% of patients with ERA, 64.3% of patients with CRA and 39.5% of control participants (p=0.001). Further, patients with RA had significantly more periodontal findings compared with controls, recorded with common periodontal indexes. In the re-examination, patients with RA still showed poor periodontal health in spite of treatment with DMARDs after baseline examination. The prevalence of Porphyromonas gingivalis was higher in patients with ERA with periodontal probing depth ≥4 mm compared with patients with CRA and controls. Antirheumatic medication did not seem to affect the results. CONCLUSIONS: Moderate periodontitis was more frequent in patients with RA than in controls. Patients with ERA and CRA exhibited poorer periodontal health parameters when compared with controls. There was no association between antirheumatic treatment and periodontal parameters.

STAT6 and STAT1 Pathway Activation in Circulating Lymphocytes and Monocytes as Predictor of Treatment Response in Rheumatoid Arthritis.

OBJECTIVE: To find novel predictors of treatment response to disease-modifying antirheumatic drugs (DMARDs), we studied activation of STAT (signal transducers and activators of transcription) 6 and 1 in circulating leukocytes of patients with rheumatoid arthritis (RA). METHODS: 19 patients with untreated recent-onset RA, 16 patients with chronic RA irresponsive to synthetic DMARDs and 37 healthy volunteers provided blood samples for whole blood flow cytometric determination of intracellular STAT6 and STAT1 phosphorylation, expressed as relative fluorescence units, in response to IL-4 and IFN-γ, respectively. Phosphorylation was restudied and treatment response (according to European League Against Rheumatism) determined after 1-year treatment with synthetic DMARDs in recent-onset RA and with biological DMARD in synthetic DMARD-irresponsive RA. Estimation-based exact logistic regression was used to investigate relation of baseline variables to treatment response. 95% confidence intervals of means were estimated by bias-corrected bootstrapping and the significance between baseline and follow-up values was calculated by permutation test. RESULTS: At baseline, levels of phosphorylated STAT6 (pSTAT6) induced by IL-4 in monocytes were higher in those who achieved good treatment response to synthetic DMARDs than in those who did not among patients with untreated RA (OR 2.74, 95% CI 1.05 to 9.47), and IFN-γ -stimulated lymphocyte pSTAT1 levels were higher in those who achieved good treatment response to a biological drug than in those who did not among patients with chronic RA (OR 3.91, 95% CI 1.12 to 20.68). During follow-up, in recent-onset RA patients with good treatment response to synthetic DMARDS, the lymphocyte pSTAT6 levels decreased (p = 0.011), and, consequently, the ratio of pSTAT1/pSTAT6 in lymphocytes increased (p = 0.042). CONCLUSION: Cytokine-stimulated STAT6 and STAT1 phosphorylation in circulating leukocytes was associated with treatment response to DMARDs in this pilot study. The result, if confirmed in larger studies, may aid in developing personalized medicine in RA.

Cardiac magnetic resonance imaging reveals frequent myocardial involvement and dysfunction in active rheumatoid arthritis.

OBJECTIVES: In rheumatoid arthritis (RA), cardiac involvement is common and often subclinical. We used cardiovascular magnetic resonance (CMR) to identify myocardial abnormalities in patients with active RA, free of clinical cardiac disease. METHODS: Sixty female patients with active RA aged <70 years and 21 sex- and age-matched control subjects underwent either 1.5T or 3T CMR imaging for analyses of T1 relaxation times, late gadolinium enhancement (LGE), and the volumes, and function of both ventricles. RESULTS: Determined using 1.5T CMR, the native left ventricular (LV) septal T1 time averaged 1011 (range 973-1046) ms in 20 patients with RA vs. 976 (range 970-988) ms in 10 control subjects (p=0.045). With 3T CMR, the T1 time measured 1173 (range 1154-1187) ms in 29 RA patients vs. 1053 (range 942-1148) ms in 9 control subjects (p=0.002). Myocardial LGE was detected in 55% of the RA patients. LV ejection fraction averaged 58 (range 56-61)% vs. 66 (61-74)% (p<0.001) in the RA (n=60) and control groups (n=21), respectively, and corresponding means for LV peak filling rate were 2.99 (range 2.32-3.33) s-1 vs. 3.39 (range 2.96-3.70) s-1 (p=0.012). The end-diastolic volumes of either ventricle were enlarged in RA compared to the control group (p<0.05 for both). CONCLUSIONS: In active RA, myocardial T1 relaxation times are prolonged suggesting diffuse inflammation or fibrosis. Local myocardial scars and inflammation, visible as LGE, are also common, as are impairments of LV systo-diastolic function.

Constitutive STAT3 Phosphorylation in Circulating CD4+ T Lymphocytes Associates with Disease Activity and Treatment Response in Recent-Onset Rheumatoid Arthritis.

The aim of the present study was to examine constitutive signal transducer and activator of transcription 3 (STAT3) phosphorylation in circulating leukocytes as a candidate biomarker in rheumatoid arthritis (RA). 25 patients with recent-onset, untreated RA provided samples for whole blood flow cytometric determination of intracellular STAT3 phosphorylation, expressed as relative fluorescence units. The occurrence of constitutive STAT3 phosphorylation was evaluated by determining proportion of STAT3-phosphorylated cells among different leukocyte subtypes. Plasma levels of interleukin (IL)-6, IL-17 and IL-21 were measured by immunoassay, radiographs of hands and feet were examined and disease activity score (DAS28) was determined. Biomarkers were restudied and treatment response (according to European League Against Rheumatism) was determined after 12 months of treatment with disease-modifying antirheumatic drugs. At baseline, constitutive phosphorylation of STAT3 occurred in CD4+ T cells of 14 (56%) patients, CD8+ T cells of 13 (52%) patients, in CD19+ B cells of 7 (28%) patients, and in CD14+ monocytes of 12 (48%) patients. STAT3 phosphorylation levels of CD4+ T cells associated with DAS28, and those of all leukocyte subtypes studied associated with erosive disease. The presence of constitutive STAT3 phosphorylation in CD4+ T lymphocytes, pSTAT3 fluorescence intensity of CD4+ and CD8+ T cells and C-reactive protein (CRP) levels at baseline associated with good treatment response. In conclusion, constitutive STAT3 phosphorylation in circulating CD4+ T cells is common in recent-onset untreated RA and associates with good treatment response in patients characterized by high disease activity and the presence of systemic inflammation.

Outcomes of switching anti-TNF drugs in rheumatoid arthritis--a study based on observational data from the Finnish Register of Biological Treatment (ROB-FIN).

The aim of this study was to assess, based on observational data from the Finnish Register of Biological Treatment, the outcomes of switching an initial tumor necrosis factor (TNF) blocker to another in the treatment of rheumatoid arthritis (RA). RA patients, who started biological therapy with a TNF blocker between May 1999 and April 2009 and who switched to another TNF blocker, were studied (n=479). The outcomes were assessed according to the reason for and type of the switch. Outcome assessments included American College of Rheumatology 50 responder index (ACR50) response at 3 months after the switch, treatment duration of the second TNF blocker, and swollen joint counts, CRP and DAS28 score at the 3 months, best and last observations of the first and second TNF blocker, respectively. In those who switched due to lack of effectiveness (LOE), the disease activity parameters fell significantly from baseline upon use of infliximab or adalimumab, but had increased prior to the switch. Switching to another TNF blocker (etanercept or adalimumab) restored the response initially achieved with the first TNF blocker. The disease activity parameters fell significantly from baseline upon use of etanercept, and were maintained but not further improved after switching to adalimumab. TNF blocker switching seemed to be most beneficial in secondary LOE (defined as loss of ACR50 response). In those who switched due to adverse events (AE) or other reasons, a similar degree of response as had been achieved with the first agent was also achieved and maintained with the second agent. The results suggest that a second TNF blocker can restore the response in cases of secondary LOE and maintain it after switching due to an AE.

Causes of death in patients with rheumatoid arthritis from 1971 to 1991 with special reference to autopsy.

Rheumatoid arthritis (RA) patients have premature mortality, mostly attributed to cardiovascular diseases (CVDs). We studied causes of death (CoDs) and contribution of autopsy to them in RA patients treated at a single hospital responsible for primary to tertiary RA treatment in Helsinki. In 1971-1991, 960 RA patients died. The leading CoDs were CVDs, RA, and infections. Over 1971-1991, RA and renal deaths declined, but other CoDs showed no change. Autopsied patients died more frequently than nonautopsied of coronary heart disease (CHD) and gastrointestinal disorders, but less frequently of RA, renal, and endocrinologic diseases. Our finding of autopsied patients having CHD more frequently as a CoD may indicate that CHD, which may be asymptomatic in RA, may be overlooked during lifetime.

Amyloidosis is frequently undetected in patients with rheumatoid arthritis.

Prevalence of AA amyloid in rheumatoid arthritis (RA) is still unclear. The objective of this retrospective study was whether dedicated re-examination of autopsy tissues from RA patients increases the detection rate of amyloid compared to routine examination. Amyloid was re-examined in tissue samples and detection rate compared with original reports of 369 consecutively autopsied RA patients and 370 non-RA patients matched for sex, age, and year of autopsy between 1952 and 1991. Re-examination of 90% of the 739 cases showed doubling of the prevalence of amyloid compared with the original reports: from 18 to 30% in RA and from 2 to 4% in non-RA patients. In RA patients, cardiac amyloid was as frequent as renal amyloid. In RA patients with amyloid at re-examination, amyloidosis had been diagnosed before autopsy in 37%, and these patients had more inflammation and longer disease duration than RA patients without amyloid. Only 56% of RA patients with renal amyloid were known to have proteinuria. In conclusion, this autopsy study shows that amyloid in RA is a common finding which remains frequently undetected. In patients with active and long-lasting RA, a systematic search for amyloid may enable early diagnosis of amyloidosis, which will require effective suppression of inflammation.