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Background: Axial spondyloarthropathy(AS) is a chronic inflammatory disease primarily affecting the axial skeleton, often characterized by sacroiliitis. While pulmonary embolism (PE), a potentially lethal condition, has been linked to several autoimmune diseases, limited data exist regarding PE risk among patients with AS. Methods: This retrospective cohort study utilized the Clalit Healthcare Services (CHS) database, including 5825 patients with AS and 28,356 matched controls. Follow-up began at the date of first AS diagnosis for patients and at the matched patient's diagnosis date for controls and continued until PE diagnosis, death, or study end date. Results: Prevalence of PE before AS diagnosis in patients compared to controls was 0.4% vs. 0.2% (p < 0.01). The incidence rate of PE was 11.6 per 10,000 person-years for patients with AS and 6.8 per 10,000 person-years for controls. The adjusted hazard ratio (HR) for PE in patients with AS was 1.70 (p < 0.001). Subgroup analysis demonstrated excess risk for PE in patients with AS regardless of gender and age, with variations among AS treatment categories. Discussion: Our findings highlight a significant association between AS and PE, indicating an increased risk in patients with AS independent of age and sex and suggests a subclinical level of inflammation. Preliminary results suggest a protective role of immunosuppressing drugs. Further research into the impact of treatment strategies should be conducted and could inform clinical management and reduce the life-threatening risk of PE in Patients with AS. [ABSTRACT FROM AUTHOR]

Background: Previous studies demonstrated unclear and vast variability in the association between Ankylosing Spondylitis (AS) and the risk of cancer. Objectives: To assess the risk of overall and site-specific malignancies for AS patients in Israel, while examining the role of comorbidities and immunomodulatory therapy. Methods: We conducted a retrospective electronic data-based study including all AS patients diagnosed between 2002 and 2018, with no history of cancer prior to enrollment, with 5:1 ratio matched-control by age, gender, and place of residence. The odds Ratios (OR) for site-specific malignancies, comparing AS patients and controls, were calculated using logistic regression. Risk factors for malignancies within the AS cohort were evaluated in the same manner. Results: This study comprised 5825 AS patients and 28,356 matched controls. There was a higher overall risk of cancer in AS patients compared to controls (OR = 1.4, 95% CI 1.24–1.6), specifically for solid malignancies (OR = 1.5, 95% CI 1.3–1.7), CNS (OR = 3.72, 95% CI 1.29–10.7), kidney (OR = 2.06, 95% CI 1.12–3.8), and malignancy of unknown primary (OR = 3.06, 95% CI 2.35–3.98). Regarding predictors for malignancy within AS patients, older age at diagnosis (OR = 1.31, 95%,CI 1.25–2.36), diabetes (OR = 1.52, 95% CI 1.18–1.97), IBD (OR = 2.61, 95% CI 1.75–3.89), and treatment with DMARDs (OR = 2.17, 95% CI 1.65–2.83) were associated with a higher risk of solid malignancies, while NSAIDs treatment alone had a protective effect for solid malignancies (OR = 0.78, 95% CI 0.61–0.99). No significant association was found between anti-TNF therapy and the risk of solid or hematologic malignancies within the AS group. Conclusion: AS is associated with an increased risk of overall and site-specific malignancies, with independently higher risk for older age, comorbidity of DM, IBD, and treatment with DMARDs. [ABSTRACT FROM AUTHOR]

The association between the clinical picture of symptomatic women with silicone breast implants (SBI) and dysregulated immunity was in dispute for decades. In the current study, we describe for the first time the functional activity of purified IgG antibodies derived from symptomatic women with SBIs (suffering from subjective/autonomic-related symptoms), both in vitro and in vivo. We found that IgGs, derived from symptomatic women with SBIs, dysregulate inflammatory cytokines (TNFα, IL-6) in activated human peripheral blood mononuclear cells, compared to healthy-women-derived IgGs. Importantly, behavioral studies conducted following intracerebroventricular injection of IgGs derived from symptomatic women with SBIs (who have dysregulated circulating level of IgG autoantibodies directed against autonomic nervous system receptors) into mice brains demonstrated a specific and transient significant increment (about 60%) in the time spent at the center of the open field arena compared with mice injected with IgG from healthy women (without SBIs). This effect was accompanied with a strong trend of reduction of the locomotor activity of the SBI-IgG treated mice, indicating an overall apathic-like behavior. Our study is the first to show the potential pathogenic activity of IgG autoantibodies in symptomatic women with SBIs, emphasizing the importance of these antibodies in SBI-related illness. [ABSTRACT FROM AUTHOR]

Anti-PLA2R antibodies (Ab) are a diagnostic and prognostic biomarker in primary membranous nephropathy (PMN). We assessed the relationship between the levels of anti-PLA2R Ab at diagnosis and different variables related to disease activity and prognosis in a western population of PMN patients. Forty-one patients with positive anti-PLA2R Ab from three nephrology departments in Israel were enrolled. Clinical and laboratory data were collected at diagnosis and after one year of follow-up, including serum anti-PLA2R Ab levels (ELISA) and glomerular PLA2R deposits on biopsy. Univariable statistical analysis and permutation-based ANOVA and ANCOVA tests were performed. The median [(interquartile range (IQR)) age of the patients was 63 [50–71], with 28 (68%) males. At the time of diagnosis, 38 (93%) of the patients had nephrotic range proteinuria, and 19 (46%) had heavy proteinuria (≥8 gr/24 h). The median [IQR] level of anti-PLA2R at diagnosis was 78 [35–183] RU/mL. Anti-PLA2R levels at diagnosis were correlated with 24 h proteinuria, hypoalbuminemia and remission after one year (p = 0.017, p = 0.003 and p = 0.034, respectively). The correlations for 24 h proteinuria and hypoalbuminemia remained significant after adjustment for immunosuppressive treatment (p = 0.003 and p = 0.034, respectively). Higher levels of anti-PLA2R Ab at diagnosis in patients with active PMN from a western population are associated with higher proteinuria, lower serum albumin and remission one year after the diagnosis. This finding supports the prognostic value of anti-PLA2R Ab levels and their possible use in stratifying PMN patients. [ABSTRACT FROM AUTHOR]

Many women with silicone breast implants (SBIs) report non-specific complaints, including hearing impairments. Hearing impairment appears to be associated with a number of autoimmune conditions. The current study aimed to evaluate the prevalence and severity of hearing impairments among women with SBIs and to explore potential improvements in their hearing capability following implant removal. Symptomatic women with SBIs (n = 160) underwent an initial anamnestic interview, and women who reported hearing impairments were selected for the study. These women completed self-report telephone questionnaires regarding their hearing difficulties. Some of these women underwent subjective and objective hearing tests. Out of 159 (50.3%) symptomatic women with SBIs, 80 reported hearing impairments, including hearing loss (44/80; 55%) and tinnitus (45/80; 56.2%). Five out of seven (71.4%) women who underwent an audiologic evaluation exhibited hearing loss. Of women who underwent silicone implant removal, 27 out of 47 (57.4%) reported the improvement or resolution of their hearing complaints. In conclusion, hearing impairment is a frequent complaint among symptomatic women with SBIs, and tinnitus was found to be the most common complaint. A significant reduction in hearing difficulties was observed following silicone implant removal. Further studies using larger populations are needed to verify the occurrence of hearing impairments in these women. [ABSTRACT FROM AUTHOR]

Background: COVID-19 is a heterogenous disease resulting in long-term sequela in predisposed individuals. It is not uncommon that recovering patients endure non-respiratory ill-defined manifestations, including anosmia, and neurological and cognitive deficit persisting beyond recovery—a constellation of conditions that are grouped under the umbrella of long-term COVID-19 syndrome. Association between COVID-19 and autoimmune responses in predisposed individuals was shown in several studies. Aim and methods: To investigate autoimmune responses against neuronal and CNS autoantigens in SARS-CoV-2-infected patients, we performed a cross-sectional study with 246 participants, including 169 COVID-19 patients and 77 controls. Levels of antibodies against the acetylcholine receptor, glutamate receptor, amyloid β peptide, alpha-synucleins, dopamine 1 receptor, dopamine 2 receptor, tau protein, GAD-65, N-methyl D-aspartate (NMDA) receptor, BDNF, cerebellar, ganglioside, myelin basic protein, myelin oligodendrocyte glycoprotein, S100-B, glial fibrillary acidic protein, and enteric nerve were measured using an Enzyme-Linked Immunosorbent Assay (ELISA). Circulating levels of autoantibodies were compared between healthy controls and COVID-19 patients and then classified by disease severity (mild [n = 74], severe [n = 65], and requiring supplemental oxygen [n = 32]). Results: COVID-19 patients were found to have dysregulated autoantibody levels correlating with the disease severity, e.g., IgG to dopamine 1 receptor, NMDA receptors, brain-derived neurotrophic factor, and myelin oligodendrocyte glycoprotein. Elevated levels of IgA autoantibodies against amyloid β peptide, acetylcholine receptor, dopamine 2 receptor, myelin basic protein, and α-synuclein were detected in COVID-19 patients compared with healthy controls. Lower IgA autoantibody levels against NMDA receptors, and IgG autoantibodies against glutamic acid decarboxylase 65, amyloid β peptide, tau protein, enteric nerve, and S100-B were detected in COVID-19 patients versus healthy controls. Some of these antibodies have known clinical correlations with symptoms commonly reported in the long COVID-19 syndrome. Conclusions: Overall, our study shows a widespread dysregulation in the titer of various autoantibodies against neuronal and CNS-related autoantigens in convalescent COVID-19 patients. Further research is needed to provide insight into the association between these neuronal autoantibodies and the enigmatic neurological and psychological symptoms reported in COVID-19 patients. [ABSTRACT FROM AUTHOR]

Background and Objectives: Polymyositis and dermatomyositis (PM/DM) are classified as polygenic autoimmune diseases, whereas inflammatory bowel disease (IBD) is considered a polygenic autoinflammatory disease. In the literature, several cases exist reporting the co-occurrence of both conditions. At the molecular level, PM/DM and IBD share common genetic determinants including interferon regulatory factor and vitamin D receptor susceptibility loci. Accumulating evidence underline several indicators that confer poor prognosis in IBD, including antinuclear antibody positivity and the presence of other autoimmune diseases, therefore the aim of this study is to assess the association between these entities. Materials and Methods: This is a population-based retrospective study using data retrieved from a large electronic medical record in Israel, the Clalit health registry. The sample included PM/DM patients and age- and sex-frequency matched controls. The prevalence of IBD in PM/DM was compared between the two groups and logistic regression was applied to control for confounding variables. Predictors of IBD in patients with PM/DM were also explored. Results: Our study included 12,278 subjects with 2085 PM/DM patients and 10,193 age- and sex- frequency-matched controls. The incidence of IBD in patients with PM/DM was significantly higher even after controlling for various confounding variables (OR of 1.73, 95% CI 1.05–2.86, p-value = 0.033). Anti-nuclear antibodies (ANA) positivity was found to be an independent predictor for IBD diagnosis in patients with PM/DM (OR 3.67, 95% CI 1.01–13.36, p = 0.048). Conclusion: Our analysis reports an association between IBD and PM/DM. Such association could point towards a common pathophysiological background. Further research is needed to further describe the clinical courses and whether a unique therapeutic approach is warranted. [ABSTRACT FROM AUTHOR]

Background: Silicone breast implants (SBIs) has been shown to be associated with an increased risk of autoimmune diseases. In the current study, we aimed to explore the potential association between circulating autoantibodies against the autonomic nervous system and cognitive impairment, memory deficit, and depressive symptoms reported by women with SBIs. Methods: ELISA assays were used to quantify anti-adrenergic receptors (α1, α2, β1, β2), anti-muscarinic receptors (M1-M5), anti-endothelin receptor type A, and anti-angiotensin II type 1 receptor titers in the sera of 93 symptomatic female subjects with SBIs and 36 age-matched healthy female controls. Results: A significant difference was detected in the level of autoantibodies against the autonomic nervous system receptors in women with SBIs who reported memory impairment, cognitive impairment, and sleep disturbance as compared with both women with SBIs who did not complain of these symptoms or with healthy individuals without SBIs. Conclusions: Clinical symptoms such as depression, cognitive impairment, and sleep disturbances were found to be associated with dysregulation of the levels of circulating autoantibodies targeting the autonomous nervous system receptors in women with SBIs. These autoantibodies may have diagnostic significance in diseases associated with breast implants. [ABSTRACT FROM AUTHOR]

(1) Background: Inflammation plays a pivotal role in atherosclerosis, and the association between chronic inflammatory states and ischemic heart disease (IHD) has been shown in several rheumatic diseases. Persistent inflammation might also be a risk factor for IHD in sarcoidosis patients. (2) Methods: Demographic and clinical data of 3750 sarcoidosis patients and 18,139 age- and sex-matched controls were retrieved from the database of Clalit Health Services, Israel's largest healthcare organization. Variables associated with IHD were assessed by a logistic regression model. To assess for variables that were related to increased risk of all-cause mortality, the Cox proportional hazards method was used, and a log-rank test was performed for survival analysis. (3) Results: Both groups were composed of 64% females with a median age of 56 years. An association between sarcoidosis and IHD was demonstrated by a multivariate analysis (adjusted odds ratio (OR) 1.5; 95% confidence interval (CI) 1.36–1.66). Long-term follow-up revealed increased mortality among sarcoidosis patients: 561 (15%) deaths compared to 1636 (9%) deaths among controls (p < 0.001). Survival analysis demonstrated that sarcoidosis patients were also at increased risk for all-cause mortality compared to controls (multivariate model, adjusted HR 1.93; 95% CI 1.76–2.13). [ABSTRACT FROM AUTHOR]

Autoimmune/inflammatory syndrome induced by adjuvants (ASIA) was first introduced in 2011 by Shoenfeld et al. and encompasses a cluster of related immune mediated diseases, which develop among genetically prone individuals as a result of adjuvant agent exposure. Since the recognition of ASIA syndrome, more than 4400 documented cases have been reported so far, illustrated by heterogeneous clinical manifestations and severity. In this review, five enigmatic conditions, including sarcoidosis, Sjögren's syndrome, undifferentiated connective tissue disease, silicone implant incompatibility syndrome (SIIS), and immune-related adverse events (irAEs), are defined as classical examples of ASIA. Certainly, these disorders have been described after an adjuvant stimulus (silicone implantation, drugs, infections, metals, vaccines, etc.) among genetically predisposed individuals (mainly the HLA-DRB1 and PTPN22 gene), which induce an hyperstimulation of the immune system resulting in the production of autoantibodies, eventually leading to the development of autoimmune diseases. Circulating autonomic autoantibodies in the sera of patients with silicone breast implants, as well as anatomopathological aspects of small fiber neuropathy in their skin biopsies have been recently described. To our knowledge, these novel insights serve as a common explanation to the non-specific clinical manifestations reported in patients with ASIA, leading to the redefinition of the ASIA syndrome diagnostic criteria. [ABSTRACT FROM AUTHOR]

In this study, we aimed to examine the effect of vitamin D deficiency on all-cause mortality in ankylosing spondylitis (AS) patients and in the general population. This is a retrospective-cohort study based on the electronic database of the largest health-maintenance organization in Israel. AS patients who were first diagnosed between 2002–2007 were included. Controls were matched by age, gender and enrollment-time. Follow-up continued until death or end of study follow-up on 1 July 2019. Laboratory measures of serum 25-hydroxyvitamin-D levels during the entire follow-up period were obtained. A total of 919 AS patients and 4519 controls with a mean time of follow-up of 14.3 years were included. The mean age at the time of enrollment was 52 years, and 22% of them were females. AS was associated with a higher proportion of vitamin D deficiency (odds ratio 1.27 [95% confidence-interval (CI) 1.03–1.58]). In AS patients, insufficient levels of vitamin D (<30 ng/mL) were significantly associated with increased incidence of all-cause mortality (hazard ratio (HR) 1.59 [95% CI 1.02–2.50]). This association was more prominent with the decrease in vitamin D levels (< 20 ng/mL, HR 1.63 [95% CI 1.03–2.60]; <10 ng/mL, HR 1.79 [95% CI 1.01–3.20]) and among male patients (<30 ng/mL, HR 2.11 [95% CI 1.20–3.72]; <20 ng/mL, HR 2.12 [95% CI 1.19–3.80]; <10 ng/mL, HR 2.23 [95% CI 1.12–4.43]). However, inadequate levels of vitamin D among controls were not associated with an increased all-cause mortality. Our study has shown that vitamin D deficiency is more common in AS patients than controls and is linked to an increased risk for all-cause mortality. These results emphasize the need for randomized-controlled trials to evaluate the benefits of vitamin D supplementation as a secondary prevention of mortality in patients with chronic inflammatory rheumatic disease. [ABSTRACT FROM AUTHOR]

Helminths or their products can immunomodulate the host immune system, and this phenomenon may be applied as the basis of new anti-inflammatory treatments. Previously, we have shown the efficacy of tuftsin–phosphorylcholine (TPC), based on a helminth product, in four animal models of autoimmune diseases: arthritis, colitis, systemic lupus erythematosus, and experimental autoimmune encephalomyelitis. We demonstrated that TPC reduced inflammatory process ex vivo in peripheral blood lymphocytes (PBLs) and in biopsies from giant-cell arteritis. In the present study, we assessed the therapeutic potential of TPC treatment on a chronic colitis murine model. C57BL/6 mice with chronic colitis were treated with TPC after the third cycle of 2% dextran sodium sulfate (DSS). Oral TPC treatment resulted in amelioration of the colitis clinical manifestations exemplified by reduced disease activity index (DAI) score, expansion of mesenteric lymph nodes (MLN) T regulatory cells (shown by Fluorescence Activated Cell Sorting (FACS)), significant reduction in the expression of pro-inflammatory cytokines (IL-1β, IL17, IL-6, TNFα), and elevation in the expression of anti-inflammatory cytokine IL-10 (shown by RT-PCR). This study demonstrated the potential immunomodulatory effects of oral administration of TPC in a chronic colitis murine model. Further clinical trials are needed in order to evaluate this novel approach for the treatment of patients with inflammatory bowel disease. [ABSTRACT FROM AUTHOR]

Hidradenitis suppurativa (HS) is a chronic-relapsing and debilitating disease, which affects the components of the folliculopilosebaceous unit and severely impacts on the perceived health-related quality of life. Among the possible treatments, dietary interventions, such as fasting, have been described to positively impact on HS. However, nothing is known about the effects of circadian, intermittent fasting, such as the Ramadan fasting. A sample of 55 HS patients (24 males (43.6%) and 31 females (56.4%), mean age 39.65 ± 8.39 years, average disease duration 14.31 ± 7.03 years) was recruited in the present study. The "Severity of International Hidradenitis Suppurativa Severity Score System" (IHS4) decreased significantly from 11.00 ± 5.88 (before Ramadan) to 10.15 ± 6.45 (after Ramadan), with a mean difference of −0.85 ± 0.83 (p < 0.0001). At the univariate analyses, the improvement was associated with HS phenotype (with a prominent improvement among those with ectopic type), treatment (with the improvement being higher in patients receiving topical and systemic antibiotics compared to those treated with biologics), the "Autoinflammatory Disease Damage Index" (ADDI), and Hurley scores. At the multivariate regression analysis, only the Hurley score (regression coefficient = 0.70, p = 0.0003) was found to be an independent predictor of change in the IHS4 score after fasting. The improvement in the IHS4 score was not, however, associated with weight loss. In conclusion, the Ramadan fasting proved to be safe and effective in HS patients. Considering the small sample size and the exploratory nature of the present investigation, further studies in the field are warranted, especially longitudinal, prospective and randomized ones. [ABSTRACT FROM AUTHOR]

Although skin manifestations are quite common in systemic sclerosis (SSc), a link between SSc and psoriasis (PsO) has been poorly investigated. We assessed the Clalit medical database in a cohort study to compare the prevalence of PsO between SSc-patients and SSc-free controls. We also evaluated the SSc-related autoantibodies' role in the co-existence of the two conditions. Survival analysis was performed using both univariate (Kaplan–Meier, log-rank test) and multivariate (Cox proportional-hazards technique) analyses. Our cohort of 2,431 SSc-patients was age- and gender-matched with 12,710 controls (case-control match 1:5.2). There were 150 (1.2%) cases of PsO among controls and 47 (1.9%) among SSc-patients (p = 0.0027). A SSc diagnosis was an independent risk factor for PsO with an odds ratio (OR) of 2.16 (95%CI 1.38–3.39, p = 0.0008). Among SSc-patients, 98.6% with PsO were antinuclear antibodies (ANA)-negative. In terms of survival, the mortality rate in SSc-patients with PsO was lower than SSc without PsO (14.9% vs. 26%, p < 0.0001). At the multivariate-analysis, SSc-patients with PsO compared to SSc-patients without PsO had an OR for death of 0.44 (95%CI 0.19–0.99, p < 0.05). SSc is independently associated with PsO. The cases with concurrent PsO and SSc are almost exclusively ANA-negative and may exhibit a better survival. [ABSTRACT FROM AUTHOR]

Intermittent circadian fasting, namely Ramadan, is a common worldwide practice. Such fasting has a positive impact on psoriasis, but no data exist on its role in psoriatic arthritis (PsA)—a disease that is clearly linked to body mass index. We enrolled 37 patients (23 females and 14 males) with a mean age 43.32 ± 7.81 and they fasted for 17 h for one month in 2016. The baseline PsA characteristics were collected and 12 (32.4%) patients had peripheral arthritis, 13 (35.1%) had axial involvement, 24 (64.9%) had enthesitis, and 13 (35.1%) had dactylitis. Three patients (8.1%) were treated with methotrexate, 28 (75.7%) with TNF-α blockers, and 6 (16.2%) with IL-17 blockers. After a month of intermittent fasting, C-reactive protein (CRP) levels decreased from 14.08 ± 4.65 to 12.16 ± 4.46 (p < 0.0001), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) decreased from 2.83 ± 1.03 to 2.08 ± 0.67 (p = 0.0078), Psoriasis Area Severity Index (PASI) decreased from 7.46 ± 2.43 to 5.86 ± 2.37 (p < 0.0001), and Disease Activity index for PSoriatic Arthritis (DAPSA) decreased from 28.11 ± 4.51 to 25.76 ± 4.48 (p < 0.0001). Similarly, enthesitis improved after fasting, with Leeds Enthesitis Index (LEI) decreasing from 2.25 ± 1.11 to 1.71 ± 0.86 (p < 0.0001) and dactylitis severity score (DSS) decreasing from 9.92 ± 2.93 to 8.54 ± 2.79 (p = 0.0001). Fasting was found to be a predictor of a decrease in PsA disease activity scores (DAPSA, BASDAI, LEI, DSS) even after adjustment for weight loss. IL-17 therapy was found to be an independent predictor of decreases in LEI after fasting. These preliminary data may support the use of chronomedicine in the context of rheumatic diseases, namely PsA. Further studies are needed to support our findings. [ABSTRACT FROM AUTHOR]

Background: The correlation between abnormal vitamin serum levels and chronic liver disease has been previously described in literature. However, the association between the severity of folate serum levels (B9), vitamin B12 and nonalcoholic steatohepatitis (NASH) has not been widely evaluated. Therefore, the aim of this study was to investigate the existence of such a correlation in a cohort of NASH patients. Methods: All patients aged 18 years and older who were diagnosed with biopsy-proven NASH at the EMMS hospital in Nazareth during the years 2015–2017 were enrolled in this study. Data regarding demographic, clinical and laboratory parameters was collected. Patients with other liver diseases were excluded. Results: Eighty-three NASH patients were enrolled during the study period. The mean age was 41 ± 11 years and the majority of patients were male. Mean values of folate and B12 were 9.85 ± 10.90 ng/mL and 387.53 ± 205.50 pg/mL, respectively. Half of the patients were presented with a grade 1 steatosis (43.4%), a grade 2 fibrosis (50.6%) and a grade 3 activity score (55.4%). The fibrosis grade was significantly correlated with low folate levels on multivariate analysis (p-value < 0.01). Similarly, low B12 levels were significantly associated with a higher fibrosis grade and NASH activity (p-value < 0.001 and p-value < 0.05 respectively). Conclusion: Our study demonstrated a statistically significant correlation between low levels of folate and vitamin B12 with the histological severity of NASH. These findings could have diagnostic and therapeutic implications for patient management and follow-up. [ABSTRACT FROM AUTHOR]

Background: Tocilizumab is an anti-IL-6 therapy widely adopted in the management of the so-called "cytokine storm" related to SARS-CoV-2 virus infection, but its effectiveness, use in relation to concomitant corticosteroid therapy and safety were unproven despite widespread use in numerous studies, mostly open label at the start of the pandemic., Methods: We performed a systematic review and meta-analysis of case-control studies utilising tocilizumab in COVID-19 on different databases (PubMed/MEDLINE/Scopus) and preprint servers (medRxiv and SSRN) from inception until 20 July 2020 (PROSPERO CRD42020195690). Subgroup analyses and meta-regressions were performed. The impact of tocilizumab and concomitant corticosteroid therapy or tocilizumab alone versus standard of care (SOC) on the death rate, need for mechanical ventilation, ICU admission and bacterial infections were assessed., Results: Thirty-nine studies with 15,531 patients (3657 cases versus 11,874 controls) were identified. Unadjusted estimates ( n = 28) failed to demonstrate a protective effect of tocilizumab on survival (OR 0.74 ([95%CI 0.55-1.01], p = 0.057), mechanical ventilation prevention (OR 2.21 [95%CI 0.53-9.23], p = 0.277) or prevention of ICU admission (OR 3.79 [95%CI 0.38-37.34], p = 0.254). Considering studies with adjusted, estimated, tocilizumab use was associated with mortality rate reduction (HR 0.50 ([95%CI 0.38-0.64], p < 0.001) and prevention of ICU admission (OR 0.16 ([95%CI 0.06-0.43], p < 0.001). Tocilizumab with concomitant steroid use versus SOC was protective with an OR of 0.49 ([95%CI 0.36-0.65], p < 0.05) as was tocilizumab alone versus SOC with an OR of 0.59 ([95%CI 0.34-1.00], p < 0.001). Risk of infection increased (2.36 [95%CI 1.001-5.54], p = 0.050; based on unadjusted estimates)., Conclusion: Despite the heterogeneity of included studies and large number of preprint articles, our findings from the first eight of the pandemic in over 15,000 COVID-19 cases suggested an incremental efficacy of tocilizumab in severe COVID-19 that were confirmed by subsequent meta-analyses of large randomized trials of tocilizumab. This suggests that analysis of case-control studies and pre-print server data in the early stages of a pandemic appeared robust for supporting incremental benefits and lack of major therapeutic toxicity of tocilizumab for severe COVID-19.