Revaccination of patients with systemic lupus erythematosus or rheumatoid arthritis without an initial COVID-19 vaccine response elicits seroconversion in half of the patients.

OBJECTIVES: To investigate the effect of COVID-19 mRNA revaccination (two doses) on the antibody response in patients with rheumatic diseases (RD) who were initial vaccine non-responders. Further, to examine if B-cell levels or T-cell responses before revaccination predicted seroconversion. METHODS: From a RD cohort vaccinated with the standard two-dose COVID-19 vaccinations, we enrolled cases without detectable antibody responses (n=17) and controls with detectable antibody response (n=29). Blood donors (n=32) were included as additional controls. Samples were collected before and six weeks after completed revaccination. Total antibodies and specific IgG, IgA, and IgM against SARS-CoV-2 spike protein, SARS-CoV-2 neutralising antibodies, and SARS-CoV-2 reacting CD4+ and CD8+ T-cells were measured before and after revaccination. B-cells (CD19+CD45+) were quantified before revaccination. RESULTS: Forty-seven percent of cases had detectable neutralising antibodies after revaccination. However, antibody levels were significantly lower than in controls and blood donors. Revaccination induced an antibody class switch in cases with a decrease in IgM and increase in IgG. No significant difference was observed in T-cell responses before and after revaccination between the three groups. Only 29% of cases had measurable B-cells compared to 100% of controls and blood donors. Fifty percent of revaccinated cases who seroconverted had measurable B-cells before revaccination. CONCLUSIONS: Forty-seven percent of initial non-responders seroconverted after two-dose revaccination but still had lower levels of SARS-CoV-2 antibodies compared with controls and blood donors. RD patients without a detectable serological response after the initial COVID-19 mRNA vaccine had a T-cell response similar to immunocompetent controls and blood donors.

Cholesterol pericarditis.

Cholesterol pericarditis is an extremely rare type of pericarditis characterized by a continuous pericardial effusion containing high amounts of cholesterol crystals. This case report of a 51-year-old male with syncopal episodes and a massive, cholesterol-rich pericardial effusion highlights the interdisciplinary approach and rationale in treating this rare condition of largely unknown pathogenesis.

Rituximab-treated rheumatic patients: B cells predict seroconversion after COVID-19 boost or revaccination in initial vaccine non-responders.

OBJECTIVES: To investigate the effect of either a booster vaccine (one dose) or revaccination (two doses 3 weeks apart) on the antibody response to the COVID-19 mRNA vaccines in patients with rheumatic disease (RD) treated with rituximab (RTX) who had not produced vaccine-reactive antibodies after the initial two vaccine doses. Further, to examine if B cell levels in peripheral blood predicted seroconversion. METHODS: We included 91 RTX-treated RD patients previously vaccinated against COVID-19. Patients were offered revaccination or a single booster vaccination with an mRNA vaccine. Serum total antibodies against SARS-CoV-2 spike protein were measured before and 6 weeks after the last vaccine dose. B cells (CD19+CD45+) were measured by flow cytometry at inclusion. RESULTS: Of RD patients with undetectable SARS-CoV-2 antibody levels before inclusion, seroconversion was seen in 38% 6 weeks after the booster dose and 32% after revaccination. Patients receiving revaccination had significantly higher antibody levels than patients receiving a booster dose (P < 0.001). In both univariate and multivariate logistic regression analysis, only B cells higher than 10/µl before boost or revaccination were associated with seroconversion (P = 0.009 and P = 0.01, respectively). Seroconversion was independent of age, gender, diagnosis, cumulative RTX dose, RTX treatment time and time since last RTX treatment. CONCLUSION: Continuously impaired humoral response to mRNA vaccines was found in most RTX-treated patients after a booster dose or revaccination. Seroconversion was observed in approximately one-third of the patients. Measurable B cells before boosting or revaccination was the strongest predictor of antibody response after boost or revaccination.

COVID-19 vaccination in patients with rheumatic diseases leads to a high seroconversion rate and reduced self-imposed isolation and shielding behaviour.

OBJECTIVES: We investigated the effect of a two-dose messenger ribonucleic acid (mRNA) vaccine on antibody levels against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and patient behaviour and shielding concerning fear of coronavirus disease 2019 (COVID-19) in patients with systemic lupus erythematosus or rheumatoid arthritis. METHODS: Three hundred and three patients and 44 blood donors were included. All patients received two doses of an mRNA vaccine and had total antibodies against SARS-CoV-2 measured before vaccination and 2 and 9 weeks after the second vaccination. Further, patients answered an electronic questionnaire before and after vaccination concerning behaviour, anxiety, and symptoms of depression (Patient Health Questionnaire-9). RESULTS: Significantly fewer patients (90%) had measurable antibodies against SARS-CoV-2 compared to blood donors (100%) after the second vaccination (P < .001). Treatment with rituximab was the strongest predictor of an unfavourable vaccine response, as only 27% had measurable antibodies. Nearly all patients (97%) not treated with rituximab experienced seroconversion. Prednisone and methotrexate had a negative effect on seroconversion, but no effect of age or comorbidity was observed. Patients experienced significant improvement after vaccination in 10 out of 12 questions regarding behaviour and fear of COVID-19, while no change in Patient Health Questionnaire-9 or anxiety was observed. CONCLUSION: We find a very high seroconversion rate among rheumatic patients and reduced self-imposed isolation and shielding after COVID-19 vaccination.

Time Since Rituximab Treatment Is Essential for Developing a Humoral Response to COVID-19 mRNA Vaccines in Patients With Rheumatic Diseases.

OBJECTIVE: We aimed to investigate (1) whether patients with rheumatic disease (RD) treated with rituximab (RTX) raise a serological response toward the coronavirus disease 2019 (COVID-19) mRNA vaccines, and (2) to elucidate the influence of time since the last RTX dose before vaccination on this response. METHODS: We identified and included 201 patients with RDs followed at the outpatient clinic at the Department of Rheumatology, Aarhus University Hospital, who had been treated with RTX in the period 2017-2021 and who had completed their 2-dose vaccination series with a COVID-19 mRNA vaccine. Total antibodies against the SARS-CoV-2 spike protein were measured on all patients and 44 blood donors as reference. RESULTS: We observed a time-dependent increase in antibody response as the interval from the last RTX treatment to vaccination increased. Only 17.3% of patients developed a detectable antibody response after receiving their vaccination ≤ 6 months after their previous RTX treatment. Positive antibody response increased to 66.7% in patients who had RTX 9-12 months before vaccination. All blood donors (100%) had detectable antibodies after vaccination. CONCLUSION: Patients with RDs treated with RTX have a severely impaired serological response toward COVID-19 mRNA vaccines. Our data suggest that the current recommendations of a 6-month interval between RTX treatment and vaccination should be reevaluated.

Isolation, Behavioral Changes, and Low Seroprevalence of SARS-CoV-2 Antibodies in Patients With Systemic Lupus Erythematosus or Rheumatoid Arthritis.

OBJECTIVE: Patients with chronic rheumatic diseases (CRDs), such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA), require special attention during the COVID-19 pandemic as they are considered at risk of severe infections. Our objective was to assess the seroprevalence of SARS-CoV-2 in patients with SLE and RA and to assess patient behavior, disease-related symptoms, and mental health. METHODS: More than 900 participants were included: 405 patients with RA or SLE (CRD patients) and 513 blood donors. All participants had blood SARS-CoV-2 total antibodies measured (sensitivity 96.7%, specificity 99.5%) and answered a questionnaire concerning behavior, anxiety, and symptoms of depression (Patient Health Questionnaire 9). The CRD patients were further asked about physical activity, adherence to medication, and disease-related symptoms. RESULTS: CRD patients had a significantly lower seroprevalence of SARS-CoV-2 antibodies (n = 1 of 365, 0.3%) compared to blood donors (n = 10 of 513, 1.9%; P = 0.03). Almost 60% of patients were unable to exercise as usual, and increased pain and disease activity was experienced by 34% and 24% of patients, respectively. Almost 10% of patients reduced or discontinued their immunosuppressive treatments at their own initiative. Symptoms of moderate depression were present in 19% of patients compared to 6.8% of blood donors (P < 0.001). CONCLUSION: Low seroprevalence in patients with CRDs indicates successful mitigation of exposure to SARS-CoV-2. However, this mitigation appears to occur at the expense of physical activity, experience of increased pain, disease activity, and symptoms of depression. There is a need for care providers to be aware of these negative side effects and for further studies to investigate the possible long-term consequences.

Local and systemic reactogenicity of COVID-19 vaccine BNT162b2 in patients with systemic lupus erythematosus and rheumatoid arthritis.

Vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were launched in December 2020. Vaccination of patients with rheumatic diseases is recommended, as they are considered at higher risk of severe COVID-19 than the general population. Patients with rheumatic disease have largely been excluded from vaccine phase 3 trials. This study explores the safety and reactogenicity of BNT162b2 among patients with rheumatic diseases. Patients with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA), median age 58.8 years, 285 subjects in total, were vaccinated twice with the BNT162b2 (Pfizer/BioNTech). Questionnaires on reactogenicity matching the original phase 3 study were answered seven days after completed vaccination. The majority of SLE and RA patients experienced either local (78.0%) or systemic reactions (80.1%). Only 1.8% experienced a grade-4 reaction. Compared to the original study, we found more frequent fatigue [Odds ratio (OR) 2.2 (1.7-2.8)], headache [OR 1.7 (1.3-2.2)], muscle pain [OR 1.8 (1.4-2.3)], and joint pain [OR 2.3 (1.7-3.0)] in patients. In contrast, the use of antipyretics was less frequent [OR 0.5 (0.3-0.6)]. Patients with SLE and RA experience reactogenicity to the Pfizer-BioNTech BNT162b2 COVID-19 vaccine. Reactogenicity was more frequent in patients, however, not more severe compared with healthy controls.

Impaired Antibody Response to the BNT162b2 Messenger RNA Coronavirus Disease 2019 Vaccine in Patients With Systemic Lupus Erythematosus and Rheumatoid Arthritis.

OBJECTIVE: With a vaccine effectiveness of 95% for preventing coronavirus disease 2019 (COVID-19), Pfizer-BioNTech BNT162b2 (BNT162b2) was the first vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to be approved. However, immunosuppressive therapy was an exclusion criterion in the phase 3 trial that led to approval. Thus, extrapolation of the trial results to patients with rheumatic diseases treated with immunosuppressive drugs warrants caution. METHODS: Patients with systemic lupus erythematosus (SLE; n = 61) and rheumatoid arthritis (RA; n = 73) were included from the COPANARD (Corona Pandemic Autoimmune Rheumatic Disease) cohort, followed since the beginning of the COVID-19 pandemic. Patients received the BNT162b2 vaccine between December 2020 and April 2021. All patients had total antibodies against SARS-CoV-2 measured before vaccination and 1 week after the second vaccination (VITROS Immunodiagnostic Products). RESULTS: Of 134 patients (median age, 70 years), 77% were able to mount a detectable serological response to the vaccine. Among patients treated with rituximab, only 24% had detectable anti-SARS-CoV-2 antibodies in their serum after vaccination. The time since the last rituximab treatment did not seem to influence the vaccine response. No significant difference was observed between patients with RA or SLE when adjusting for treatment, and no correlation between antibody levels and age was detected (r = -0.12; P = 0.18). CONCLUSION: Antibody measurements against SARS-CoV-2 in patients with RA and SLE after two doses of the BNT162b2 vaccine demonstrated that 23% of patients could not mount a detectable serological response to the vaccine. B cell-depleting therapy (BCDT) is of specific concern, and our findings call for particular attention to the patients receiving BCDT.

Similar lipid level changes in early rheumatoid arthritis patients following 1-year treat-to-target strategy with adalimumab plus methotrexate versus placebo plus methotrexate: secondary analyses from the randomised controlled OPERA trial.

To compare changes in low-density lipoprotein cholesterol and other lipids in patients with rheumatoid arthritis (RA) randomised to a 1-year treat-to-target strategy with either adalimumab plus methotrexate or placebo plus methotrexate. Prespecified secondary analyses from the OPERA trial, where 180 early and treatment-naïve RA patients received methotrexate 20 mg once weekly in combination with either placebo or subcutaneous adalimumab 40 mg every other week. Serum lipid levels were measured at baseline and after 1 year. Changes in lipid levels were analysed using mixed linear models based on the intention-to-treat (ITT) population. Overall, 174 patients were included in the ITT population (adalimumab plus methotrexate n = 86; placebo plus methotrexate n = 88). Differences between changes in lipid levels were low-density lipoprotein cholesterol 0.18 mmol/l [95% CI - 0.05 to 0.42], total cholesterol 0.27 mmol/l [- 0.002 to 0.54], high-density lipoprotein cholesterol 0.05 mmol/l [- 0.06 to 0.15], triglycerides 0.11 mmol/l [- 0.08 to 0.29], very-low-density lipoprotein cholesterol 0.03 mmol/l [- 0.05 to 0.12], and non-high-density lipoprotein cholesterol 0.22 mmol/l [- 0.02 to 0.46]. In early RA patients treated to tight control of inflammation over a period of 1 year with either adalimumab plus methotrexate or placebo plus methotrexate, changes in lipid levels were similar. Trial registration number: NCT00660647.

Clinical Value of Ultrasonographic Assessment in Lateral Epicondylitis Versus Asymptomatic Healthy Controls.

BACKGROUND: Ultrasonography (US) is often used in the assessment of lateral epicondylitis (LE). The strength of evidence supporting its role is, however, not well-documented. PURPOSE: To describe and compare the US tendinopathic changes observed in patients with LE and the general population, including any correlation between patient characteristics and US outcomes. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Tendon thickness, color Doppler activity, and bone spur were assessed by US in 264 participants with healthy elbows and 60 patients with chronic LE. In addition to patient characteristics, Patient-Rated Tennis Elbow Evaluation (PRTEE) score, pain, and disability were recorded. RESULTS: Depending on the measurement technique used, mean LE tendon thickness increased by 0.53 mm (10.2%) or 0.70 mm (14.5%) as compared with the contralateral arm and 0.40 mm (7.9%) or 0.41 mm (8.5%) as compared with the general population. Mean color Doppler activity (scale, 0-4) was 3.47 in the LE arm versus 0.13 in the contralateral asymptomatic arm and 0.26 in the general population. Bone spur was observed in 78% of the LE arms as opposed to 45% in the contralateral arms and 50% in the general population. In the LE group and the general population, the prevalence of bone spur increases with age. No correlations were observed with pain, disability, PRTEE, and disease duration. CONCLUSION: Increased common extensor tendon thickness is part of the tendinopathic changes observed in LE. However, given the marked variation in natural tendon thickness and small increases in tendon thickness in patients with LE, this technique cannot be used as a stand-alone diagnostic tool but rather as a supplement to the overall assessment. The contralateral elbow (if asymptomatic) is a better tendon thickness comparator than a general population mean value. Color Doppler activity is an indicator of ongoing tendinopathy and supports the LE diagnosis, but it is not pathognomonic for the condition. Absence of Doppler activity in a patient with suspected LE should raise suspicion of other diagnoses. Identification of a bone spur is of very limited clinical value given the high prevalence in the general population. The important outcomes of pain, disability, PRTEE, and disease duration did not correlate with any of the investigated US techniques.

Social media use among young rheumatologists and basic scientists: results of an international survey by the Emerging EULAR Network (EMEUNET).

OBJECTIVES: To explore perceptions, barriers and patterns of social media (SM) use among rheumatology fellows and basic scientists. METHODS: An online survey was disseminated via Twitter, Facebook and by email to members of the Emerging European League Against Rheumatism Network. Questions focused on general demographics, frequency and types of SM use, reasons and barriers to SM use. RESULTS: Of 233 respondents (47 countries), 72% were aged 30-39 years, 66% female. 83% were active users of at least one SM platform and 71% were using SM professionally. The majority used SM for communicating with friends/colleagues (79%), news updates (76%), entertainment (69%), clinical (50%) and research (48%) updates. Facebook was the dominant platform used (91%). SM was reported to be used for information (81%); for expanding professional networks (76%); new resources (59%); learning new skills (47%) and establishing a professional online presence (46%). 30% of non-SM users justified not using SM due to lack of knowledge. CONCLUSIONS: There was a substantial use of SM by rheumatologists and basic scientists for social and professional reasons. The survey highlights a need for providing learning resources and increasing awareness of the use of SM. This could enhance communication, participation and collaborative work, enabling its more widespread use in a professional manner.

A treat-to-target strategy with methotrexate and intra-articular triamcinolone with or without adalimumab effectively reduces MRI synovitis, osteitis and tenosynovitis and halts structural damage progression in early rheumatoid arthritis: results from the OPERA randomised controlled trial.

OBJECTIVES: To investigate whether a treat-to-target strategy with methotrexate and intra-articular glucocorticosteroid injections suppresses MRI inflammation and halts structural damage progression in patients with early rheumatoid arthritis (ERA), and whether adalimumab provides an additional effect. METHODS: In a double-blind, placebo-controlled trial, 85 disease-modifying antirheumatic drug-naïve patients with ERA were randomised to receive methotrexate, intra-articular glucocorticosteroid injections and placebo/adalimumab (43/42). Contrast-enhanced MRI of the right hand was performed at months 0, 6 and 12. Synovitis, osteitis, tenosynovitis, MRI bone erosion and joint space narrowing (JSN) were scored with validated methods. Dynamic contrast-enhanced MRI (DCE-MRI) was carried out in 14 patients. RESULTS: Synovitis, osteitis and tenosynovitis scores decreased highly significantly (p<0.0001) during the 12-months' follow-up, with mean change scores of -3.7 (median -3.0), -2.2 (-1) and -5.3 (-4.0), respectively. No overall change in MRI bone erosion and JSN scores was seen, with change scores of 0.1 (0) and 0.2 (0). The tenosynovitis score at month 6 was significantly lower in the adalimumab group, 1.3 (0), than in the placebo group, 3.9 (2), Mann-Whitney: p<0.035. Furthermore, the osteitis score decreased significantly during the 12-months' follow-up in the adalimumab group, but not in the placebo group, Wilcoxon: p=0.001-0.002 and p=0.062-0.146. DCE-MRI parameters correlated closely with conventional MRI inflammatory parameters. Clinical measures decreased highly significantly during follow-up. CONCLUSIONS: A treat-to-target strategy with methotrexate and intra-articular glucocorticosteroid in patients with ERA effectively decreased synovitis, osteitis and tenosynovitis and halted structural damage progression as judged by MRI. The findings suggest that addition of adalimumab is associated with further suppression of osteitis and tenosynovitis.

CRP genotype and haplotype associations with serum C-reactive protein level and DAS28 in untreated early rheumatoid arthritis patients.

INTRODUCTION: Single-nucleotide polymorphisms (SNPs) in the CRP gene are implicated in the regulation of the constitutional C-reactive protein (CRP) expression and its response to proinflammatory stimuli. Previous reports suggest that these effects may have an impact on clinical decision-making tools based on CRP, such as the Disease Activity Score in 28 joints (DAS28). We aimed to investigate the possible association between seven CRP SNPs, their haplotypes and the serum levels of CRP, as well as DAS28 scores, in two cohorts of untreated active early rheumatoid arthritis (RA) patients followed during their initial treatment. METHODS: Overall, 315 patients with RA from two randomized controlled trials (the CIMESTRA and OPERA trials) who were naïve to disease-modifying antirheumatic drugs and steroids with disease durations less than 6 months were included. Seven CRP SNPs were investigated: rs11265257, rs1130864, rs1205, rs1800947, rs2808632, rs3093077 and rs876538. The genotype and haplotype associations with CRP and DAS28 levels were evaluated using linear regression analysis adjusted for age, sex and treatment. RESULTS: The minor allele of rs1205 C > T was associated with decreased CRP levels at baseline (P = 0.03), with the TT genotype having a 50% reduction in CRP from 16.7 to 8.4 mg/L (P = 0.005) compared to homozygosity of the major allele, but no association was observed at year 1 (P = 0.38). The common H2 haplotype, characterized by the T allele of rs1205, was associated with a 26% reduction in CRP at baseline (P = 0.043), although no effect was observed at year 1 (P = 0.466). No other SNP or haplotype was associated with CRP at baseline or at year 1 (P ≥ 0.09). We observed no associations between SNPs or haplotypes and DAS28 scores at baseline or at year 1 (P ≥ 0.10). CONCLUSION: CRP genotype and haplotype were only marginally associated with serum CRP levels and had no association with the DAS28 score. This study shows that DAS28, the core parameter for inflammatory activity in RA, can be used for clinical decision-making without adjustment for CRP gene variants. TRIAL REGISTRATION: The OPERA study is registered at Clinicaltrials.gov (NCT00660647). The CIMESTRA study is not listed in a clinical trials registry, because patients were included between October 1999 and October 2002.

Adalimumab added to a treat-to-target strategy with methotrexate and intra-articular triamcinolone in early rheumatoid arthritis increased remission rates, function and quality of life. The OPERA Study: an investigator-initiated, randomised, double-blind, parallel-group, placebo-controlled trial.

OBJECTIVES: An investigator-initiated, double-blinded, placebo-controlled, treat-to-target protocol (Clinical Trials:NCT00660647) studied whether adalimumab added to methotrexate and intra-articular triamcinolone as first-line treatment in early rheumatoid arthritis (ERA) increased the frequency of low disease activity (DAS28CRP<3.2) at 12 months. METHODS: In 14 Danish hospital-based clinics, 180 disease-modifying anti-rheumatic drugs (DMARD)-naïve ERA patients (<6 months duration) received methotrexate 7.5 mg/week (increased to 20 mg/week within 2 months) plus adalimumab 40 mg every other week (adalimumab-group, n=89) or methotrexate+placebo-adalimumab (placebo-group, n=91). At all visits, triamcinolone was injected into swollen joints (max. four joints/visit). If low disease activity was not achieved, sulfasalazine 2 g/day and hydroxychloroquine 200 mg/day were added after 3 months, and open-label biologics after 6-9 months. Efficacy was assessed primarily on the proportion of patients who reached treatment target (DAS28CRP<3.2). Secondary endpoints included DAS28CRP, remission, Health Assessment Questionnaire (HAQ), EQ-5D and SF-12. Analysis was by intention-to-treat with last observation carried forward. RESULTS: Baseline characteristics were similar between groups. In the adalimumab group/placebo group the 12-month cumulative triamcinolone doses were 5.4/7.0 ml (p=0.08). Triple therapy was applied in 18/27 patients (p=0.17). At 12 months, DAS28CRP<3.2 was reached in 80%/76% (p=0.65) and DAS28CRP was 2.0 (1.7-5.2) (medians (5th/95th percentile ranges)), versus 2.6 (1.7-4.7) (p=0.009). Remission rates were: DAS28CRP<2.6: 74%/49%, Clinical Disease Activity Index≤2.8: 61%/41%, Simplified Disease Activity Index<3.3: 57%/37%, European League Against Rheumatism/American College of Rheumatology Boolean: 48%/30% (0.0008

M-ficolin levels reflect disease activity and predict remission in early rheumatoid arthritis.

OBJECTIVE: To assess plasma M-ficolin concentrations in disease-modifying antirheumatic drug (DMARD)-naive patients with early rheumatoid arthritis (RA), to investigate the correlation of M-ficolin concentrations with disease activity markers, and to determine the predictive value of M-ficolin with respect to the Disease Activity Score in 28 joints (DAS28). METHODS: The study group included 180 DMARD-naive patients with early RA who participated in a randomized controlled trial of methotrexate and intraarticular glucocorticoids plus either adalimumab or placebo/adalimumab. One hundred healthy control subjects and 51 patients with chronic RA were also assessed. A sandwich-type time-resolved fluorometric immunoassay was used for quantification of plasma M-ficolin. RESULTS: At baseline, M-ficolin levels were highest in the group of DMARD-naive patients with newly diagnosed active RA, and the level in these patients decreased 26% after 1 year of aggressive treatment. The baseline M-ficolin level correlated with 5 of 7 disease activity markers, including the DAS28 and the Health Assessment Questionnaire (HAQ), and a similar pattern of correlations was observed at 1 year. Multiple logistic regression analysis showed that an elevated M-ficolin level at baseline was the strongest predictor of not achieving either DAS28 remission (odds ratio [OR] 4.18, 95% confidence interval [95% CI] 2.02-8.63) or low disease activity (OR 2.45, 95% CI 1.13-5.28) at 1 year. The presence of a baseline M-ficolin level in the lowest quartile resulted in sensitivity of 29%, specificity of 93%, and positive predictive value of 95% for low disease activity at 1 year. CONCLUSION: In patients with early RA, elevated plasma M-ficolin levels correlated with a high DAS28 and a high HAQ score at baseline and 1 year. A low M-ficolin level was the strongest predictor of remission and low disease activity in a multivariate analysis.

Polymorphisms in the MASP1 gene are associated with serum levels of MASP-1, MASP-3, and MAp44.

INTRODUCTION: MASP-1 is the first protein in the activation of the lectin pathway and MASP-1 is, like its isoforms MASP-3 and MAp44, encoded by the MASP1 gene. Our aim was to explore associations between polymorphisms in MASP1 and corresponding concentrations of MASP-1, MASP-3, and MAp44 in plasma as well as the genetic contribution to the equilibrium between the three proteins. METHODS: Fifteen SNPs were genotyped in the MASP1 gene in 350 blood donors. Corresponding plasma concentrations of MASP-1, MASP-3, and MAp44 were measured. RESULTS: A total of 10 different SNPs showed associations with the concentration of one or some of the three proteins (rs113938200, rs190590338, rs35089177, rs3774275, rs67143992, rs698090, rs72549154, rs72549254, rs75284004, rs7625133), and several of these were in strong linkage. SNPs located in the mutually exclusive splice region had opposite effects on the protein concentrations. Being e.g. homozygote for the minor allele of rs3774275 was associated with an increase in median concentration of 13% in MASP-1(P=0.03), 29% in MAp44 (P<0.001), and a decrease in MASP-3 of 26% (P<0.001) compared to homozygosis for the major allele. Heterozygosis of rs113938200 (p.Asn368Asp in MAp44) was associated with a reduced MAp44 concentration of 61% (P=0.005). Rs190590338 located in the promoter region was associated in the heterozygote form with an increased MASP-1 concentration of 35% (P = 0.002). A multivariate linear regression model including sex, age, M- and H-ficolin, MBL, and the 15 SNPs explained 20-48% of the variation in the concentration of the three proteins and the SNPs investigated contributed with the most explanatory power (12-23%). DISCUSSION: The present study described 10 SNPs, which were associated with the concentration of one or some of the three proteins originating from the MASP1 gene and in a multivariate model it was shown that the SNPs contributed with the most explanatory power to the protein concentrations.

Non-synonymous polymorphisms in the FCN1 gene determine ligand-binding ability and serum levels of M-ficolin.

BACKGROUND: The innate immune system encompasses various recognition molecules able to sense both exogenous and endogenous danger signals arising from pathogens or damaged host cells. One such pattern-recognition molecule is M-ficolin, which is capable of activating the complement system through the lectin pathway. The lectin pathway is multifaceted with activities spanning from complement activation to coagulation, autoimmunity, ischemia-reperfusion injury and embryogenesis. Our aim was to explore associations between SNPs in FCN1, encoding M-ficolin and corresponding protein concentrations, and the impact of non-synonymous SNPs on protein function. PRINCIPAL FINDINGS: We genotyped 26 polymorphisms in the FCN1 gene and found 8 of these to be associated with M-ficolin levels in a cohort of 346 blood donors. Four of those polymorphisms were located in the promoter region and exon 1 and were in high linkage disequilibrium (r(2)≥0.91). The most significant of those were the AA genotype of -144C>A (rs10117466), which was associated with an increase in M-ficolin concentration of 26% compared to the CC genotype. We created recombinant proteins corresponding to the five non-synonymous mutations encountered and found that the Ser268Pro (rs150625869) mutation lead to loss of M-ficolin production. This was backed up by clinical observations, indicating that an individual homozygote of Ser268Pro would be completely M-ficolin deficient. Furthermore, the Ala218Thr (rs148649884) and Asn289Ser (rs138055828) were both associated with low M-ficolin levels, and the mutations crippled the ligand-binding capability of the recombinant M-ficolin, as indicated by the low binding to Group B Streptococcus. SIGNIFICANCE: Overall, our study interlinks the genotype and phenotype relationship concerning polymorphisms in FCN1 and corresponding concentrations and biological functions of M-ficolin. The elucidations of these associations provide information for future genetic studies in the lectin pathway and complement system.