Adipose tissue-derived mesenchymal stem cells (ADSCs) are crucially involved in various biological processes because of their self-renewal, multi-differentiation, and immunomodulatory activities. Some ADSC's characteristics have been associated with the basic theory of Chinese medicine (CM), especially the Meridian theory. CM can improve the biological properties of ADSCs to facilitate their use in injury treatment, restore immune homeostasis, and inhibit inflammatory responses. Therefore, the combination of CM and ADSCs may be a new promising research direction in integrative medicine of China. This review summarizes the association between CM and ADSCs to assess the potential application value of their combination against various diseases.

Immune dysregulation is a key aspect of post-acute sequelae of coronavirus disease 2019 (PASC), also known as long COVID, with sustained activation of immune cells, T cell exhaustion, skewed B cell profiles, and disrupted immune communication thereby resulting in autoimmune-related complications. The gut is emerging as a critical link between microbiota, metabolism and overall dysfunction, potentially sharing similarities with other chronic fatigue conditions and PASC. Immunothrombosis and neurological signalling dysfunction emphasise the complex interplay between the immune system, blood clotting, and the central nervous system in the context of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Clear research gaps in the design of PASC studies, especially in the context of longitudinal research, stand out as significant areas of concern.

SARS-CoV-2 infection has become a major international issue, not only from a medical point of view, but also social, economic and political. Most of the available information comes from the United States, Europe, and China, where the population and the socioeconomic status are very different from Latin American countries. This study evaluates the effect of regional socioeconomic characteristics on mortality due SARS-CoV-2 infection in patients with immune-mediated rheumatic diseases (IMRD) from Argentina, Mexico and Brazil.

Data from three national registries, SAR-COVID (Argentina), CMR-COVID (Mexico) and ReumaCoV-Brasil (Brazil), were combined. Adult IMRD patients with SARS-CoV-2 infection were recruited. National data for each province/state, including population density, number of physicians per inhabitant, income, unemployment, GINI index, Municipal Human Development Index (MHDI), stringency index, vaccination rate and most frequent viral strains per period were assessed as risk factors for mortality due to COVID-19.

A total of 4744 patients were included, 2534 (53.4%) from SAR-COVID, 1166 (24.6%) from CMRCOVID and 1044 (22.0%) from ReumaCoV-Brasil. Mortality due to COVID-19 was 5.4%. In the multivariable analysis, higher number of physicians per 1000 inhabitants and being infected during the vaccination period of each country were associated with lower mortality. After adjustment for socioeconomic factors, there was no association with country of residence and mortality.

These findings corroborate the complex interplay between socioeconomic factors, rheumatic disease activity, and regional disparities as determinants of death due to COVID-19 in Argentina, Brazil and Mexico. Thus, this research provides valuable insights for guiding public health policies and clinical practice in the ongoing fight against the COVID-19 pandemic.

Patients with autoimmune inflammatory rheumatic disease (AIIRD) are at higher risk of severe infections because of their underlying diseases and immunosuppression. Our objective was to elucidate the epidemiological and clinical characteristics of patients with AIIRD presenting with COVID-19 and their relation to disease severity. We explored whether variables, including underlying diagnosis, disease-modifying antirheumatic drugs (DMARDs) and COVID-19 vaccine status, were associated with more severe forms of COVID-19 infection.

Between 1 January 2020 and 30 June 2022, 151 patients with AIIRD and COVID-19 infection were analysed using a binary regression model and a multinomial regression model.

The average age was 61.5 years, and average Charlson Comorbidity Index (CCI) was 2.1; 106 (70.2%) patients were diagnosed with rheumatoid arthritis (RA), and 70 (46.4%) patients were receiving prednisolone. In the multivariable logistic regression model, ages between 50 and 69 years (odds ratio (OR) = 5.85; 95% confidence interval (CI) = 1.35-25.25) and older than 70 years (OR = 5.29; 95% CI = 1.21-23.14), prior prednisolone treatment (OR = 7.09; 95% CI = 2.63-19.11) and vaccination status including one and two doses (OR = 0.19; 95% CI = 0.05-0.69) and three and four doses (OR = 0.09; 95% CI = 0.02-0.35) were all statistically significant factors related to changes in the severity level of COVID-19.

Severity of COVID-19 infection in patients with AIIRD is affected by age, background steroid use and vaccination status. Factors including sex, comorbidity, diagnosis of AIIRDs and use of DMARDs, including conventional synthetic, biologics and targeted DMARDs, were not significantly associated with COVID-19 severity.

Background: Viral infections, including coronavirus disease 2019 (COVID-19), in patients with autoimmune rheumatic diseases (AIRDs) tend to present more severe disease. This study aims to investigate the clinical characteristics and risk factors for severe infection in rheumatologic patients. Methods: We included patients with a diagnosis of AIRD and COVID-19 infection between January 2022 and July 2023. Patients with AIRDs infected with SARS-CoV-2 were matched with control patients of the general population according to age (±5 years) and sex in a 1:1 ratio. Confirmed infection was defined if a patient had a positive polymerase chain reaction (PCR) test. The severity was divided into mild, moderate, severe, and critical according to the guidelines of the United States National Institutes of Health (NIH). Results: A total of 140 individuals (37 males, 103 females; mean age 56.1 ± 11.3 years) with rheumatic disease diagnosed with COVID-19 infection were enrolled in the study. AIRDs included rheumatoid arthritis (RA) (n = 63, 45%), ankylosing spondylitis (AS) (n = 35, 25%), systemic lupus erythematosus (SLE) (n = 26, 8.6%), and systemic sclerosis (SSc) (n = 16, 11.4%). The AIRDs group had more SARS-CoV-2-related dyspnea (38.6%), arthralgia (45.7%), and depression (27.1%) than the control group (p = 0.004). The rate of lung infiltration on radiographic examination was higher in 58 (41.4%, p = 0.005) patients with rheumatic diseases than in those without them. Severe SARS-CoV-2 infection was more common in the AIRDs group than in the control group (22% vs. 12%; p = 0.043). Conclusions: Patients with AIRDs experienced more symptoms of arthralgia, depression, and dyspnea. There was a trend towards an increased severity of the disease in patients with AIRDs. Patients with arterial hypertension, diabetes, chronic lung, and kidney disease, treated with corticosteroids, had a longer duration, and high activity of autoimmune disease had an increased risk of severe COVID-19.

In the context of immune-mediated inflammatory diseases (IMIDs), COVID-19 outcomes are incompletely understood and vary considerably depending on the patient population studied. We aimed to analyse severe COVID-19 outcomes and to investigate the effects of the pandemic time period and the risks associated with individual IMIDs, classes of immunomodulatory medications (IMMs), chronic comorbidities, and COVID-19 vaccination status.

In this retrospective cohort study, clinical data were derived from the electronic health records of an integrated health-care system serving patients in 51 hospitals and 1085 clinics across seven US states (Providence St Joseph Health). Data were observed for patients (no age restriction) with one or more IMID and for unmatched controls without IMIDs. COVID-19 was identified with a positive nucleic acid amplification test result for SARS-CoV-2. Two timeframes were analysed: March 1, 2020-Dec 25, 2021 (pre-omicron period), and Dec 26, 2021-Aug 30, 2022 (omicron-predominant period). Primary outcomes were hospitalisation, mechanical ventilation, and mortality in patients with COVID-19. Factors, including IMID diagnoses, comorbidities, long-term use of IMMs, and COVID-19 vaccination status, were analysed with multivariable logistic regression (LR) and extreme gradient boosting (XGB).

Of 2 167 656 patients tested for SARS-CoV-2, 290 855 (13·4%) had confirmed COVID-19: 15 397 (5·3%) patients with IMIDs and 275 458 (94·7%) without IMIDs. In the pre-omicron period, 169 993 (11·2%) of 1 517 295 people who were tested for COVID-19 tested positive, of whom 23 330 (13·7%) were hospitalised, 1072 (0·6%) received mechanical ventilation, and 5294 (3·1%) died. Compared with controls, patients with IMIDs and COVID-19 had higher rates of hospitalisation (1176 [14·6%] vs 22 154 [13·7%]; p=0·024) and mortality (314 [3·9%] vs 4980 [3·1%]; p<0·0001). In the omicron-predominant period, 120 862 (18·6%) of 650 361 patients tested positive for COVID-19, of whom 14 504 (12·0%) were hospitalised, 567 (0·5%) received mechanical ventilation, and 2001 (1·7%) died. Compared with controls, patients with IMIDs and COVID-19 (7327 [17·3%] of 42 249) had higher rates of hospitalisation (13 422 [11·8%] vs 1082 [14·8%]; p<0·0001) and mortality (1814 [1·6%] vs 187 [2·6%]; p<0·0001). Age was a risk factor for worse outcomes (adjusted odds ratio [OR] from 2·1 [95% CI 2·0-2·1]; p<0·0001 to 3·0 [2·9-3·0]; p<0·0001), whereas COVID-19 vaccination (from 0·082 [0·080-0·085]; p<0·0001 to 0·52 [0·50-0·53]; p<0·0001) and booster vaccination (from 2·1 [2·0-2·2]; p<0·0001 to 3·0 [2·9-3·0]; p<0·0001) status were associated with better outcomes. Seven chronic comorbidities were significant risk factors during both time periods for all three outcomes: atrial fibrillation, coronary artery disease, heart failure, chronic kidney disease, chronic obstructive pulmonary disease, chronic liver disease, and cancer. Two IMIDs, asthma (adjusted OR from 0·33 [0·32-0·34]; p<0·0001 to 0·49 [0·48-0·51]; p<0·0001) and psoriasis (from 0·52 [0·48-0·56] to 0·80 [0·74-0·87]; p<0·0001), were associated with a reduced risk of severe outcomes. IMID diagnoses did not appear to be significant risk factors themselves, but results were limited by small sample size, and vasculitis had high feature importance in LR. IMMs did not appear to be significant, but less frequently used IMMs were limited by sample size. XGB outperformed LR, with the area under the receiver operating characteristic curve for models across different time periods and outcomes ranging from 0·77 to 0·92.

Our results suggest that age, chronic comorbidities, and not being fully vaccinated might be greater risk factors for severe COVID-19 outcomes in patients with IMIDs than the use of IMMs or the IMIDs themselves. Overall, there is a need to take age and comorbidities into consideration when developing COVID-19 guidelines for patients with IMIDs. Further research is needed for specific IMIDs (including IMID severity at the time of SARS-CoV-2 infection) and IMMs (considering dosage and timing before a patient's first COVID-19 infection).

Pfizer, Novartis, Janssen, and the National Institutes of Health.

COVID-19 outcomes, in the context of immune-mediated inflammatory diseases (IMIDs), are incompletely understood. Reported outcomes vary considerably depending on the patient population studied. It is essential to analyse data for a large population, while considering the effects of the pandemic time period, comorbidities, long term use of immunomodulatory medications (IMMs), and vaccination status.

In this retrospective case-control study, patients of all ages with IMIDs were identified from a large U.S. healthcare system. COVID-19 infections were identified based on SARS-CoV-2 NAAT test results. Controls without IMIDs were selected from the same database. Severe outcomes were hospitalisation, mechanical ventilation (MV), and death. We analysed data from 1 March 2020 to 30 August 2022, looking separately at both pre-Omicron and Omicron predominant periods. Factors including IMID diagnoses, comorbidities, long term use of IMMs, and vaccination and booster status were analysed using multivariable logistic regression (LR) and extreme gradient boosting (XGB).

Out of 2 167 656 patients tested for SARS-CoV-2, there were 290 855 with confirmed COVID-19 infection: 15 397 patients with IMIDs and 275 458 controls (patients without IMIDs). Age and most chronic comorbidities were risk factors for worse outcomes, whereas vaccination and boosters were protective. Patients with IMIDs had higher rates of hospitalisation and mortality compared with controls. However, in multivariable analyses, few IMIDs were rarely risk factors for worse outcomes. Further, asthma, psoriasis and spondyloarthritis were associated with reduced risk. Most IMMs had no significant association, but less frequently used IMM drugs were limited by sample size. XGB outperformed LR, with the AUROCs for models across different time periods and outcomes ranging from 0·77 to 0·92.

For patients with IMIDs, as for controls, age and comorbidities were risk factors for worse COVID-19 outcomes, whereas vaccinations were protective. Most IMIDs and immunomodulatory therapies were not associated with more severe outcomes. Interestingly, asthma, psoriasis and spondyloarthritis were associated with less severe COVID-19 outcomes than those expected for the population overall. These results can help inform clinical, policy and research decisions.

Pfizer, Novartis, Janssen, NIH.

Rituximab, which is used in autoimmune rheumatic diseases (ARD), can cause both an increased risk of development of COVID-19 disease and re-infection due to its potent and long-acting immunosuppression. So, we aimed to evaluate the frequency, risk factors and re-infection rates of COVID-19 in ARD patients receiving rituximab.

A single-center retrospective study was performed with patients receiving rituximab for ARD in 12 months before the onset of COVID-19 in Turkey. The data regarding severe acute respiratory syndrome-coronavirus 2 reverse transcription polymerized chain reaction (RT-PCR) test, clinical, laboratory, and mortality data of all patients were collected from medical records. Logistic regression analysis was used for predictors of COVID-19 disease. COVID-19 re-infection was defined as RT-PCR positivity and recurrence of acute COVID-19 symptoms after at least 1 negative RT-PCR in patients with clinical improvement.

Ninety-eight ARD patients with rituximab were evaluated and 23 (23%) of them had COVID-19. The presence of hypogammaglobulinemia increased the risk of COVID-19 disease 8-fold. COVID-19 pneumonia occurred in 13 (57%) and these patients' age was higher than those without pneumonia (59.6 ± 11.8 vs 44.9 ± 14.2 years, P = 0.013). Mortality due to COVID-19 was 13% and COVID-19 re-infection was seen in 20% of survivors.

Regardless of the underlying rheumatic disease and organ involvements, hypogammaglobulinemia in ARD could be a risk factor for COVID-19 development, and advanced age could be for COVID-19 severity. Moreover, COVID-19 re-infection rates are high.

SARS-CoV-2 causes more severe symptoms in most chronic diseases, and rheumatic disease is no exception. This study aims to investigate whether there is an association between the use of immunomodulatory medications, including conventional disease-modifying agents (csDMARDs), glucocorticoids, and biologic DMARDs, and outcomes such as hospitalization and lung involvement in patients with rheumatic disease with COVID-19.

We performed a cross-sectional study on 177 COVID-19 cases with rheumatologic diseases using immunomodulatory drugs as their regular treatment. All patients were evaluated regarding their initial chest computed tomography (CT) scan, COVID-19 symptoms, and comorbidities. We ran predictive models to find variables associated with chest CT-scan involvement and hospitalization status.

CT findings showed lung involvement in 87 patients with chest CT-scan severity score (C-ss) of less than 8 in 59 (33%) and more than 8 in 28 (16%) of our patients. Of all patients, 76 (43%) were hospitalized. Hospitalized patients were significantly older and had more comorbidities (P = 0.02). On multivariate analysis, older age [odds ratio (OR) 1.90, 95% confidence interval (CI) 1.31-3.08] and comorbidity (OR 2.75, 95% CI 1.06-3.66) were significantly associated with higher odds of hospitalization (P = 0.03). On multivariate analysis, older age (OR 1.15, 95% CI 0.94-2.01), pulmonary diseases (OR 2.05, 95% CI 1.18-3.32), and treatment with csDMARDs (OR 1.88, 95% CI 0.37-1.93) were associated with higher C-ss (P = 0.039).

This study found that advanced age and comorbidities, similar to the general population, are risk factors for hospitalization in patients with COVID-19 with rheumatic disorders. Administration of csDMARDs, older age, and pulmonary disorders were linked to increased risk of COVID-19 pneumonia in these individuals.

There is dearth of data regarding the outcomes of coronavirus disease 2019 (COVID-19) among rheumatic and musculoskeletal disease (RMD) patients from Southeast Asia. We report the clinicodemographic profile and identify predictors of COVID-19 outcomes in a large cohort of Indian RMD patients.

This prospective cohort study, carried out at the Postgraduate Institute of Medical Education and Research, Chandigarh (a tertiary care centre in India), included RMD patients affected with COVID-19 between April 2020 and October 2021. Demographic and clinical and laboratory details of COVID-19 and underlying RMD were noted. Predictors of mortality, hospitalization and severe COVID-19 were identified using stepwise multivariable logistic regression.

A total of 64 severe acute respiratory syndrome coronavirus-2-infected RMD patients [age 41.5 (19-85) years; 46 (72%) females] were included. Eighteen (28%) patients had severe COVID-19. Twenty-three (36%) required respiratory support [11 (17%) required mechanical ventilation]. Thirty-six (56%) patients required hospitalization [median duration of stay 10 (1-42) days]; 17 (27%) required intensive care unit admission. Presence of co-morbidities [odds ratio (OR) = 4.5 (95% CI: 1.4, 14.7)] was found to be an independent predictor of COVID-19 severity. Co-morbidities [OR = 10.7 (95% CI: 2.5, 45.4)] and underlying lupus [OR = 7.0 (95% CI: 1.2, 40.8)] were independently associated with COVID-19 hospitalization. Ongoing rheumatic disease activity [OR = 6.8 (95% CI: 1.3, 35.4)] and underlying diagnosis of lupus [OR = 7.1 (95% CI: 1.2, 42.4)] and SSc [OR = 9.5 (95% CI: 1.5, 61.8)] were found to be strong independent predictors of mortality. Age, sex, underlying RMD-associated interstitial lung disease and choice of immunosuppressive therapy were not associated with COVID-19 severity or adverse outcomes.

The presence of co-morbidities was independently associated with COVID-19 severity and hospitalization. Ongoing rheumatic disease activity and the presence of lupus or SSc independently predicted mortality. Age, sex, type of immunosuppressive therapy and presence of RMD-associated interstitial lung disease did not affect COVID-19 severity or outcomes in Indian RMD patients.

COVID-19 has been associated with increased morbidity and mortality, globally. Whether COVID-19-related mortality is increased in patients with systemic rheumatic diseases (SRDs) is still debatable. Although results are somewhat conflicting, there are a handful of nationwide studies published indicating that, in individuals with SRD, there is signal for increased adverse COVID-19-related outcomes and higher mortality. It appears that there are differences in COVID-19-related mortality across various SRDs. Besides, certain disease-specific (disease activity, disease duration, medication received) and/or other features (e.g. comorbidities) seem to also affect COVID-19-related mortality in SRD patients. Herein, we wanted to highlight that a more individualized approach taking into consideration the effect of the aforementioned factors into the risk calculation for COVID-19 adverse outcomes, including mortality, in SRD patients is warranted. A multinational study based on nationwide data, examining all common SRDs and stratifying accordingly, would be of interest, toward this direction. Key Points • It is still debatable whether Covid-19-related mortality is increased in patients with sytemic rheumatic diseases (SRD). • Disease-specific risk factors (e.g. type of SRD, disease activity) should be taken into account in risk assessment for Covid-19-releted outcomes in SRD patients.