Autoantibody-positivity before and seroconversion during treatment with anti-PD-1 is associated with immune-related adverse events in patients with melanoma.

INTRODUCTION: Treatment with the immune checkpoint inhibitor anti-programmed cell death protein-1 (PD-1) often causes immune-related adverse events (irAEs). Since irAEs resemble autoimmune diseases, autoantibodies might play a role and could potentially be used to identify patients at risk. Therefore, we investigated the association between autoantibody-positivity and toxicity as well as clinical response in patients with melanoma treated with anti-PD-1. MATERIALS AND METHODS: This two-center, retrospective study included 143 patients with melanoma treated with anti-PD-1. Toxicities grade ≥2 and recurrences/responses were captured until 6 months after treatment initiation. Autoantibody measurements were performed at baseline and 3 months after treatment initiation, including IgM-rheumatoid factor (RF), antinuclear antibodies (ANA), extractable nuclear antigen, anti-cyclic citrullinated peptide antibodies (anti-CCP2) and anti-thyroid antibodies. RESULTS: 169 irAEs were experienced by 86/143 patients (137 grades 1-2, 32 grades 3-4), the most common being thyroiditis (n=25), dermatitis (n=24), and sicca problems (n=19). Patients with autoantibodies at baseline experienced more irAEs (p=0.001), predominantly associated with anti-thyroid antibodies and thyroid dysfunction. No association was observed between any irAE and anti-CCP2, RF or ANA. In women, baseline and on-treatment anti-thyroid antibody-positivity as well as seroconversion during treatment was associated with thyroid dysfunction. In men, this association was only observed on-treatment. The presence of autoantibodies was not associated with melanoma recurrence (p=0.776) or response (p=0.597). CONCLUSION: The presence of autoantibodies prior to anti-PD-1 therapy is associated with irAEs in patients with melanoma. Both baseline positivity and seroconversion of anti-thyroid antibodies were strongly associated with thyroid dysfunction. This association was stronger in women, with all women who were baseline positive developing thyroid dysfunction.

Antibodies against advanced glycation end-products and malondialdehyde-acetaldehyde adducts identify a new specific subgroup of hitherto patients with seronegative arthritis with a distinct clinical phenotype and an HLA class II association.

OBJECTIVE: In rheumatoid arthritis (RA) around two-thirds of patients are autoantibody positive for rheumatoid factor, anti-citrullinated protein antibodies and/or anti-carbamylated protein antibodies. The remaining seronegative subgroup of patients is clinically heterogeneous and thus far, biomarkers predicting the disease course are lacking. Therefore, we analysed the value of other autoantibodies in RA directed against malondialdehyde-acetaldehyde adducts (MAA) and advanced glycation end-products (AGE). METHODS: In sera of 648 patients with RA and 538 patients without RA from the Leiden Early Arthritis Clinic, anti-MAA and anti-AGE IgG antibody levels were measured using ELISA. Associations between genetic risk factors, acute phase reactants, radiological joint damage, remission and anti-PTM positivity were investigated using regression, correlation and survival analyses. RESULTS: Anti-AGE and anti-MAA were most prevalent in RA (44.6% and 46.1% respectively) but were also present in non-RA arthritis patients (32.9% and 30.3% respectively). Anti-AGE and anti-MAA antibodies were associated with HLA-DRB1*03 within seronegative RA (OR=1.98, p=0.003, and OR=2.37, p<0.001, respectively) and, for anti-AGE also in non-RA arthritis patients (OR=2.34, p<0.001). Presence of anti-MAA antibodies was associated significantly with markers of inflammation, erythrocyte sedimentation rate and C reactive protein, in all groups independent of anti-AGE. Interestingly, the presence of anti-AGE and anti-MAA antibodies was associated with radiological progression in patients with seronegative RA, but not evidently with sustained drug-free remission. CONCLUSIONS: Anti-AGE and anti-MAA were present in around 45% of RA patients and 30% of non-RA arthritis patients, and although not specific for RA, their presence associated with HLA, inflammation and, for RA, with clinical outcomes especially in patients with seronegative RA.

Smoking is associated with the concurrent presence of multiple autoantibodies in rheumatoid arthritis rather than with anti-citrullinated protein antibodies per se: a multicenter cohort study.

BACKGROUND: The contribution of smoking to rheumatoid arthritis (RA) is hypothesized to be mediated through formation of anti-citrullinated protein antibodies (ACPA). In RA, however, autoantibodies such as ACPA, rheumatoid factor (RF), and anti-carbamylated protein antibodies (anti-CarP) often occur together, and it is thus unclear whether smoking is specifically associated with some autoantibodies rather than others. We therefore investigated whether smoking is only associated with ACPA or with the presence of multiple RA-related autoantibodies. METHODS: A population-based Japanese cohort (n = 9575) was used to investigate the association of smoking with RF and anti-cyclic citrullinated peptide antibodies (anti-CCP2) in individuals without RA. Furthermore, RA patients fulfilling the 1987 criteria from three early arthritis cohorts from the Netherlands (n = 678), the United Kingdom (n = 761), and Sweden (n = 795) were used. Data on smoking, RF, anti-CCP2, and anti-CarP were available. A total score of autoantibodies was calculated, and odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated by logistic regression. RESULTS: In the population-based non-RA cohort, no association was found between smoking and one autoantibody (RF or anti-CCP2), but smoking was associated with double-autoantibody positivity (OR 2.95, 95% CI 1.32-6.58). In RA patients, there was no association between smoking and the presence of one autoantibody (OR 0.99, 95% CI 0.78-1.26), but smoking was associated with double-autoantibody positivity (OR 1.32, 95% CI 1.04-1.68) and triple-autoantibody positivity (OR 2.05, 95% CI 1.53-2.73). CONCLUSIONS: Smoking is associated with the concurrent presence of multiple RA-associated autoantibodies rather than just ACPA. This indicates that smoking is a risk factor for breaking tolerance to multiple autoantigens in RA.

Anti-CarP antibodies in two large cohorts of patients with rheumatoid arthritis and their relationship to genetic risk factors, cigarette smoking and other autoantibodies.

INTRODUCTION: In rheumatoid arthritis (RA), several genetic risk factors and smoking are strongly associated with the presence of anticitrullinated protein antibodies (ACPA), while much less is known about risk factors for ACPA-negative RA. Antibodies against carbamylated proteins (anti-CarP) have been described in both ACPA-positive and ACPA-negative RA patients. In this study, we have analysed the relationships among anti-CarP antibodies, ACPA, genetic risk factors (HLA-DRB1 alleles and PTPN22) and smoking in RA. METHODS: Presence of antibodies to carbamylated fetal calf serum (CarP-FCS) and fibrinogen (CarP-Fib) was determined by inhouse ELISAs among RA cases in the Leiden Early Arthritis Clinic (n=846) and in the Swedish Epidemiological Investigation of Rheumatoid Arthritis (n=1985) cohorts. ORs for associations with different HLA-DRB1 alleles, PTPN22 genotypes and smoking were calculated separately for each cohort as well as in meta-analysis in RA subsets defined by the presence/absence of anti-CarP and anticyclic citrullinated peptide (anti-CCP) antibodies. RESULTS: In both cohorts, anti-CarP antibody positivity was mainly detected in the anti-CCP-positive population (49%-73%), but also in the anti-CCP-negative population (8%-14%). No associations between anti-CarP antibodies and HLA-DRB1 shared epitope alleles could be identified, while there were data to support an association between anti-CarP-FCS and HLA-DRB1*03. Further analyses did not reveal any specific associations of anti-CarP antibodies with other HLA-DRB1 alleles, PTPN22 genotypes or smoking. CONCLUSIONS: Anti-CarP antibodies were present in both ACPA-positive and ACPA-negative RA. There were no significant associations among anti-CarP antibodies and HLA-DRB1 alleles, PTPN22 or smoking. These data suggest that different biological mechanisms may underlie anti-CarP versus anti-CCP antibody formation.