Introduction Covid-19 infection poses a serious challenge for immune-compromised patients with inflammatory autoimmune systemic diseases. We investigated the clinical-epidemiological findings of 1641 autoimmune systemic disease Italian patients during the Covid-19 pandemic. Method This observational multicenter study included 1641 unselected patients with autoimmune systemic diseases from three Italian geographical areas with different prevalence of Covid-19 [high in north (Emilia Romagna), medium in central (Tuscany), and low in south (Calabria)] by means of telephone 6-week survey. Covid-19 was classified as (1) definite diagnosis of Covid-19 disease: presence of symptomatic Covid-19 infection, confirmed by positive oral/nasopharyngeal swabs; (2) highly suspected Covid-19 disease: presence of highly suggestive symptoms, in absence of a swab test. Results A significantly higher prevalence of patients with definite diagnosis of Covid-19 disease, or with highly suspected Covid-19 disease, or both the conditions together, was observed in the whole autoimmune systemic disease series, compared to “Italian general population” (p = .030, p = .001, p = .000, respectively); and for definite + highly suspected diagnosis of Covid-19 disease, in patients with autoimmune systemic diseases of the three regions (p = .000, for all comparisons with the respective regional general population). Moreover, significantly higher prevalence of definite + highly suspected diagnosis of Covid-19 disease was found either in patients with various “connective tissue diseases” compared to “inflammatory arthritis group” (p < .000), or in patients without ongoing conventional synthetic disease-modifying anti-rheumatic drugs treatments (p = .011). Conclusions The finding of a higher prevalence of Covid-19 in patients with autoimmune systemic diseases is particularly important, suggesting the need to develop valuable prevention/management strategies, and stimulates in-depth investigations to verify the possible interactions between Covid-19 infection and impaired immune-system of autoimmune systemic diseases. Key Points• Significantly higher prevalence of Covid-19 is observed in a large series of patients with autoimmune systemic diseases compared to the Italian general population, mainly due to patients’ increased susceptibility to infections and favored by the high exposure to the virus at medical facilities before the restriction measures on individual movement.• The actual prevalence of Covid-19 in autoimmune systemic diseases may be underestimated, possibly due to the wide clinical overlapping between the two conditions, the generally mild Covid-19 disease manifestations, and the limited availability of virological testing.• Patients with “connective tissue diseases” show a significantly higher prevalence of Covid-19, possibly due to deeper immune-system impairment, with respect to “inflammatory arthritis group”.• Covid-19 is more frequent in the subgroup of autoimmune systemic diseases patients without ongoing conventional synthetic disease-modifying anti-rheumatic drugs, mainly hydroxyl-chloroquine and methotrexate, which might play some protective role against the most harmful manifestations of Covid-19.

ObjectivePostacute COVID-19 syndrome (PACS) is an emerging entity characterised by a large array of manifestations, including musculoskeletal complaints, fatigue and cognitive or sleep disturbances. Since similar symptoms are present also in patients with fibromyalgia (FM), we decided to perform a web-based cross-sectional survey aimed at investigating the prevalence and predictors of FM in patients who recovered from COVID-19.MethodsData were anonymously collected between 5 and 18 April 2021. The collection form consisted of 28 questions gathering demographic information, features and duration of acute COVID-19, comorbid diseases, and other individual’s attributes such as height and weight. The American College of Rheumatology (ACR) Survey Criteria and the Italian version of the Fibromyalgia Impact Questionnaire completed the survey.ResultsA final sample of 616 individuals (77.4% women) filled the form 6±3 months after the COVID-19 diagnosis. Of these, 189 (30.7%) satisfied the ACR survey criteria for FM (56.6% women). A multivariate logistic regression model including demographic and clinical factors showed that male gender (OR: 9.95, 95% CI 6.02 to 16.43, p<0.0001) and obesity (OR: 41.20, 95% CI 18.00 to 98.88, p<0.0001) were the strongest predictors of being classified as having post-COVID-19 FM. Hospital admission rate was significantly higher in men (15.8% vs 9.2%, p=0.001) and obese (19.2 vs 10.8%, p=0.016) respondents.ConclusionOur data suggest that clinical features of FM are common in patients who recovered from COVID-19 and that obesity and male gender affect the risk of developing post-COVID-19 FM.

This review focuses on the new perspectives which can provide insight into the crucial pathways that drive cartilage-bone physiopathology. In particular, we discuss the critical signaling and effector molecules that can activate cellular and molecular processes in both cartilage and bone cells and which may be relevant in cross talk among joint compartments: growth factors (bone morphogenetic proteins and transforming growth factor), hypoxia-related factors, cell-matrix interactions [discoidin domain receptor 2 (DDR2) and syndecan 4], signaling molecules [WNT, Hedgehog (Hh)]. With the continuous progression of our knowledge on the molecular pathways involved in cartilage and bone changes in osteoarthritis (OA), an increasing number of potentially effective candidates for OA therapy are already under scrutiny in clinical trials to ascertain their possible safe use in an attempt to identify molecules active in slowing or halting OA progression and reducing joint pain. We then review the principal molecules currently under clinical investigation.