Objective The first biomarker associated with the rheumatoid arthritis is rheumatoid factor (RF) and since the earliest reports a role has been proposed in the diagnosis and in the prediction of clinical features and outcome. The study of RF isotypes has further attempted to improve diagnostic accuracy and identify specific subgroups of patients. The main objective of this study is to provide an analysis of the literature on the role of RF isotypes in the diagnosis and prognosis of rheumatoid arthritis (RA). Methods We performed a systematic literature review and meta-analysis on the role of RF isotypes in RA (only in English, from PubMed, search terms: “rheumatoid factor isotypes”, “diagnosis”, “prognosis” and “rheumatoid arthritis”, last search 31 July 2022, two independent assessment of quality and biases, results included in tables and in the meta-analysis). Results Thirty-six articles were examined (7517 patients). Testing all RF isotypes with latex test or nephelometry allows for the highest sensitivity (68.6%, 95% CI 66.2% to 71.0%); nonetheless, the determination of IgA isotype provides the highest specificity (91.4%, 95% CI 90.8% to 92.0%) and the highest positive likelihood ratio (7.7, 95% CI 5.7 to 10.4). When testing IgM isotype the highest diagnostic OR (21.7, 95% CI 16.1 to 29.3) is reached. When analysing anti-citrullinated protein antibodies, RF isotype determination increases diagnostic accuracy. On the other hand, these do not provide relevant prognostic information, as results are conflicting. Conclusions Testing RF allows the highest sensitivity, while IgA isotype the highest specificity and positive likelihood ratio for RA diagnosis. On the other hand, determination of RF isotypes dose not allow prognostic information, as data are limited and heterogeneous.

Objectives To better define the spectrum of new-onset post-COVID-19 and post-COVID-19 vaccine inflammatory rheumatic diseases (IRD) from a large multicentric observational study. Methods Consecutive cases of IRD encountered during a 12-month period and satisfying one of the following inclusion criteria: (a) onset of the rheumatic manifestations within 4 weeks from SARS-CoV-2 infection or (b) onset of the rheumatic manifestations within 4 weeks from the administration of one of the COVID-19 vaccines ws recruited. Results The final analysis cohort comprised 267 patients, of which 122 (45.2%) in the post-COVID-19 and 145 (54.8%) in the postvaccine cohort. Distribution of IRD categories differed between the two cohorts: the post-COVID-19 cohort had a higher percentage of patients classified as having inflammatory joint diseases (IJD, 52.5% vs 37.2%, p=0.013) while the post-vaccine cohort had a higher prevalence of patients classified as polymyalgia rheumatica (PMR, 33.1% vs 21.3%, p=0.032). No differences were detected in the percentage of patients diagnosed with connective tissue diseases (CTD 19.7% vs 20.7%, p=0.837) or vasculitis (6.6% vs 9.0%, p=0.467). Despite the short follow-up period, IJD and PMR patients’ response to first-line therapy was favourable, with both groups achieving a drop in baseline disease activity scores of ~30% and ~70% respectively. Conclusion Our article reports the largest cohort published to date of new-onset IRD following SARS-CoV-2 infection or COVID-19 vaccines. Although causality cannot be ascertained, the spectrum of possible clinical manifestations is broad and includes IJD, PMR, CTD and vasculitis.

The purpose of this study was to evaluate the efficacy and safety of the Moderna-1273 mRNA vaccine for SARS-CoV-2 in patients with immune-mediated diseases under different treatments. Anti-trimeric spike protein antibodies were tested in 287 patients with rheumatic or autoimmune diseases (10% receiving mycophenolate mofetil, 15% low-dose glucocorticoids, 21% methotrexate, and 58% biologic/targeted synthetic drugs) at baseline and in 219 (76%) 4 weeks after the second Moderna-1273 mRNA vaccine dose. Family members or caretakers were enrolled as the controls. The neutralizing serum activity against SARS-CoV-2-G614, alpha, and beta variants in vitro and the cytotoxic T cell response to SARS-CoV-2 peptides were determined in a subgroup of patients and controls. Anti-SARS-CoV-2 antibody development, i.e., seroconversion, was observed in 69% of the mycophenolate-treated patients compared to 100% of both the patients taking other treatments and the controls (p < 0.0001). A dose-dependent impairment of the humoral response was observed in the mycophenolate-treated patients. A daily dose of >1 g at vaccination was a significant risk factor for non-seroconversion (ROC AUC 0.89, 95% CI 0.80–98, p < 0.0001). Moreover, in the seroconverted patients, a daily dose of >1 g of mycophenolate was associated with significantly lower anti-SARS-CoV-2 antibody titers, showing slightly reduced neutralizing serum activity but a comparable cytotoxic response compared to other immunosuppressants. In non-seroconverted patients treated with mycophenolate at a daily dose of >1 g, the cytotoxic activity elicited by viral peptides was also impaired. Mycophenolate treatment affects the Moderna-1273 mRNA vaccine immunogenicity in a dose-dependent manner, independent of rheumatological disease.

Objective Systemic sclerosis (SSc) is associated with an increased risk of cancer. We aimed to assess the prevalence of cancer in our cohort and to explore possible associations with clinical, immunological and treatment characteristics. Methods Our retrospective monocentric cohort study of patients with SSc recorded prevalent and incident cases of malignancy, including those diagnosed within 3 years of the SSc onset (defined as cancer-associated scleroderma) and sought associations with the clinical characteristics and the serum autoantibody profiling performed using RNA and protein immunoprecipitation, Western-blot, immunoblot and ELISA at the time of SSc diagnosis, prior to any specific treatment. Results Among 290 patients with SSc, the overall prevalence of cancer was 20%, with 8% of cases being cancer-associated scleroderma. Both conditions were more frequent in elderly patients and in patients with positive anti-Ro52 or anti-U3-RNP. Cancer-associated scleroderma was significantly more prevalent among patients negative for both anti-centromere (ACA) and anti-topoisomerase-1 (TOPO1) antibodies, especially in the case of diffuse SSc. Immunosuppressants were not significantly associated with cancer. Patients triple negative for ACA, TOPO1 and anti-RNA polymerase III antibodies had a significantly higher risk of breast cancer. Conclusions Cancer surveillance should be particularly careful in patients with diffuse SSc, increased age at disease onset and without classical SSc-related autoantibodies.