Central nervous system immune-related disorders after SARS-CoV-2 vaccination: a multicenter study.

Background: COVID-19 vaccines have been approved due to their excellent safety and efficacy data and their use has also permitted to reduce neurological complications of SARS-CoV-2. However, clinical trials were underpowered to detect rare adverse events. Herein, the aim was to characterize the clinical spectrum and immunological features of central nervous system (CNS) immune-related events following SARS-CoV-2 vaccination. Methods: Multicenter, retrospective, cohort study (December 1, 2020-April 30, 2022). Inclusion criteria were (1) de novo CNS disorders developing after SARS-CoV-2 vaccination (probable causal relationship as per 2021 Butler criteria) (2); evidence for an immune-mediated etiology, as per (i) 2016 Graus criteria for autoimmune encephalitis (AE); (ii) 2015 Wingerchuk criteria for neuromyelitis optica spectrum disorders; (iii) criteria for myelitis. Results: Nineteen patients were included from 7 tertiary referral hospitals across Italy and France (one of them being a national referral center for AE), over almost 1 year and half of vaccination campaign. Vaccines administered were mRNA-based (63%) and adenovirus-vectored (37%). The median time between vaccination and symptoms onset was 14 days (range: 2-41 days). CSF was inflammatory in 74%; autoantibodies were detected in 5%. CSF cytokine analysis (n=3) revealed increased CXCL-10 (IP-10), suggesting robust T-cell activation. The patients had AE (58%), myelitis (21%), acute disseminated encephalomyelitis (ADEM) (16%), and brainstem encephalitis (5%). All patients but 2 received immunomodulatory treatment. At last follow-up (median 130 days; range: 32-540), only one patient (5%) had a mRS>2. Conclusion: CNS adverse events of COVID-19 vaccination appear to be very rare even at reference centers and consist mostly of antibody-negative AE, myelitis, and ADEM developing approximately 2 weeks after vaccination. Most patients improve following immunomodulatory treatment.

Extracellular vesicle features are associated with COVID-19 severity.

COVID-19 is heterogeneous; therefore, it is crucial to identify early biomarkers for adverse outcomes. Extracellular vesicles (EV) are involved in the pathophysiology of COVID-19 and have both negative and positive effects. The objective of this study was to identify the potential role of EV in the prognostic stratification of COVID-19 patients. A total of 146 patients with severe or critical COVID-19 were enrolled. Demographic and comorbidity characteristics were collected, together with routine haematology, blood chemistry and lymphocyte subpopulation data. Flow cytometric characterization of the dimensional and antigenic properties of COVID-19 patients' plasma EVs was conducted. Elastic net logistic regression with cross-validation was employed to identify the best model for classifying critically ill patients. Features of smaller EVs (i.e. the fraction of EVs smaller than 200 nm expressing either cluster of differentiation [CD] 31, CD 140b or CD 42b), albuminemia and the percentage of monocytes expressing human leukocyte antigen DR (HLA-DR) were associated with a better outcome. Conversely, the proportion of larger EVs expressing N-cadherin, CD 34, CD 56, CD31 or CD 45, interleukin 6, red cell width distribution (RDW), N-terminal pro-brain natriuretic peptide (NT-proBNP), age, procalcitonin, Charlson Comorbidity Index and pro-adrenomedullin were associated with disease severity. Therefore, the simultaneous assessment of EV dimensions and their antigenic properties complements laboratory workup and helps in patient stratification.

Brain Endothelial Cells Activate Neuroinflammatory Pathways in Response to Early Cerebral Small Vessel Disease (CSVD) Patients' Plasma.

The pathogenesis of cerebral small vessel disease (CSVD) is largely unknown. Endothelial disfunction has been suggested as the turning point in CSVD development. In this study, we tested the effect of plasma from CSVD patients on human cerebral microvascular endothelial cells with the aim of describing the pattern of endothelial activation. Plasma samples from three groups of young subjects have been tested: PTs (subjects affected by early stage CSVD); CTRLs (control subjects without abnormalities at MRI scanning); BDs (blood donors). Human Brain Endothelial Cells 5i (HBEC5i) were treated with plasma and total RNA was extracted. RNAs were pooled to reduce gene expression-based variability and NGS analysis was performed. Differentially expressed genes were highlighted comparing PTs, CTRLs and BDs with HBEC5i untreated cells. No significantly altered pathway was evaluated in BD-related treatment. Regulation of p38 MAPK cascade (GO:1900744) was the only pathway altered in CTRL-related treatment. Indeed, 36 different biological processes turned out to be deregulated after PT treatment of HBEC5i, i.e., the cytokine-mediated signaling pathway (GO:0019221). Endothelial cells activate inflammatory pathways in response to stimuli from CSVD patients' plasma, suggesting the pathogenetic role of neuroinflammation from the early asymptomatic phases of cerebrovascular disease.

Potential role of IgM-enriched immunoglobulin as adjuvant treatment in severe SARS-CoV-2 infection.

BACKGROUND: Severe COVID-19 patients are characterized by a dysregulated host response to an infection, with uncontrolled pro- and anti- inflammatory pathway activation. Consistent proportion of patients require admission in intensive care units and are at risk of progression to severe forms of disease. These patients are generally admitted during later stages of the disease, when effective antiviral and monoclonal antibody are not indicated. We aimed to assess the potential role of IgM-enriched intra venous immunoglobulins (IGAM) preparations in this setting. METHODS: This retrospective, observational case-controlled study was conducted at a single-center University Hospital of Udine in the Friuli Venezia Giulia Region of Italy. Patients referring to the center between March 2020 and April 2021 was included. During the study period, patient who received Pentaglobin® IGAM treatment (N.=56), administered as compassionate use, was compared with a control group (N.=169) to assess, by propensity score analysis, clinical outcome. RESULTS: Untreated controls required, respect to patient treated with IGAM therapy, longer time to hospitalization with no significant differences in death and orotracheal intubation requirement. Significant differences in the two cohort were in: SOFA was higher in treated, while D-dimer and P/F ratio was better in the treatment cohort. Multivariate logistic regression analysis performed on the "matched sample," obtained by a weighting propensity score approach, identify, as significant protective factor for death outcome, the Pentaglobin® treatment (0.820 [0.698-0.963], P=0.016) and low C-reactive protein (1.001 [1.000-1.002], P=0.031) value while the delay of onset hospitalization is associate with a worst outcome (0.983 [0.967-0.999], P=0.041). CONCLUSIONS: The present study offers a significant insight concerning the use of IgM-enriched immunoglobulin preparations in patients with SARS-CoV-2 severe infection and also could identifying the specific immunological and biochemical profile of the patient who can more benefit from this therapeutic option.

Ischemic strokes in COVID-19: risk factors, obesity paradox, and distinction between trigger and causal association.

Background and purpose: Stroke has been described as a COVID-19 complication. However, its occurrence rate, risk factors, and causal relationships are still not well established. Methods: We describe the characteristics of confirmed COVID-19-related strokes among all cases of COVID-19 hospitalized in our health network, from November 1, 2020 to April 30, 2021. Risk factor analysis has been conducted for ischemic stroke (IS), which represents 92% of all confirmed cases of Covid-19-related strokes, and a "causal attribution to infection" classification is provided. Results: In all, 62/4105 hospitalized COVID-19 patients had an acute stroke (1.51%). Severe COVID-19 (OR 2.27-CI 1.06-4.77; p = 0.032), atrial fibrillation (OR 3.65-CI 1.63-7.98; p = 0.001), and ischemic heart disease (OR 4.590-CI 1.714-12.137; p = 0.002) proved to be independent risk factors for IS, while obesity was a protective factor (OR 0.90-CI 0.82-0.97; p = 0.012). COVID-19 had a causal role in 32.1% of IS cases, was a relevant cofactor in 28.6% of cases of IS, and was a possible trigger in 39.3% of events. Conclusion: Our stroke occurrence rate is consistent with other population-based reports (range 0.34-2.7%). Prespecified peculiar clinical and radiological features allow the distinction between "IS caused by COVID-19" and "IS triggered by COVID-19." Clinical history of vascular diseases and risk factors is crucial in determining the risk of IS in patients with COVID-19. However, the protective effect of a BMI > 30 kg/m2 seems to suggest an obesity paradox.

Mycophenolate Interruption Restores Anti-SARS-CoV-2 Vaccine Immunogenicity in Unresponsive Liver Transplant Recipients.

BACKGROUND & AIMS: The fourth dose of anti-SARS-CoV-2 vaccine slightly improved the humoral response among previously seronegative liver transplant (LT) recipients. Mycophenolate (MMF) treatment worsens the vaccination response. This study aimed to evaluate whether temporary MMF interruption might improve the immunogenicity of the fourth anti-SARS-CoV-2 BNT16b2 vaccine dose in nonresponsive LT recipients. METHODS: LT recipients negative for anti-spike glycoprotein-specific immunoglobulin G receptor-binding domain (s-RBD) antibodies after the third vaccine dose were enrolled. Anti-SARS-CoV-2 spike-specific T-cell responses were measured before and 2 months following the fourth vaccine dose, and anti-SARS-CoV-2 s-RBD antibodies also 6 months thereafter. MMF was suspended two weeks before and after vaccination. RESULTS: Five LT recipients were enrolled. After a mean of 78 days after vaccination, all patients tested positive for anti-SARS-CoV-2 s-RBD antibodies. The mean antibody titer was 8944 UI/mL. The positive antibody response was maintained during a mean of 193 days of follow-up. Three patients developed a positive T-cell response. Two patients (one positive for T-cell response) developed a self-limited SARS-CoV-2 infection. CONCLUSIONS: Suspending MMF prior to the fourth dose of the anti-SARS-CoV-2 mRNA vaccine seems feasible and safe. This procedure could restore vaccine-induced immunogenicity in a large portion of previously nonresponsive LT recipients.

The role of asymmetric dimethylarginine (ADMA) in COVID-19: association with respiratory failure and predictive role for outcome.

We aimed to assess the potential role of Asymmetric dimethylarginine (ADMA) in conditioning respiratory function and pulmonary vasoregulation during Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2) infection. Within 72 h from admission, samples from 90 COVID-19 patients were assessed for ADMA, SDMA, L-arginine concentrations. In addition to classical statistics, patients were also clustered by a machine learning approach according to similar features. Multivariable analysis showed that C-reactive protein (OR 1.012), serum ADMA (OR 4.652), white blood cells (OR = 1.118) and SOFA (OR = 1.495) were significantly associated with negative outcomes. Machine learning-based clustering showed three distinct clusters: (1) patients with low severity not requiring invasive mechanical ventilation (IMV), (2) patients with moderate severity and respiratory failure whilst not requiring IMV, and (3) patients with highest severity requiring IMV. Serum ADMA concentration was significantly associated with disease severity and need for IMV although less pulmonary vasodilation was observed by CT scan. High serum levels of ADMA are indicative of high disease severity and requirement of mechanical ventilation. Serum ADMA at the time of hospital admission may therefore help to identify COVID-19 patients at high risk of deterioration and negative outcome.

Antibody, cell-mediated response and infection susceptibility in allogeneic hematopoietic stem cell recipients after COVID-19 mRNA vaccination.

BACKGROUND: Patients undergoing allogeneic stem-cell transplantation (allo-SCT) have reduced responses to vaccines due to immunosuppressive status linked to GvHD prophylaxis and treatment. In our study, we compared humoral responses to anti-SARS-CoV-2 mRNA vaccine, and infection onset, according to patients and transplant features; we also evaluated cellular response in patients without seroconversion. METHODS: We tested antibodies titer after second and third vaccine doses. Antibodies were detected through an immune-enzymatic assay. In a patients' subgroup without seroconversion, we tested cell-mediated responses evaluating interferon-gamma release by T-lymphocytes exposed to virus spike protein. RESULTS: Seroconversion rate increased from 66% at 30 days to 81% at 90 days after the second dose; it was 97% at 150 days after the third dose. We found a significant association between seroconversion after the second dose and two variables: shorter interval between allo-SCT and vaccination; ongoing immunosuppression. Twelve of 19 patients (63%) without antibodies after the second dose did not show cellular responses. Nineteen percent of patients developed SARS-CoV-2 infection after the third dose, with favorable outcome in all cases. Patients within 12 months after allo-SCT showed a significantly higher infection risk. CONCLUSIONS: Our study suggests that an interval shorter than 12 months between allo-SCT and first vaccine dose and/or ongoing immunosuppression were associated with humoral and cellular response deficiency after two doses. Third dose induced an increased and sustained humoral response in the majority of patients. However, patients within 1 year after allo-SCT remained at higher infection risk and may be candidate for prophylaxis with anti-SARS-CoV-2 monoclonal antibodies.

Rapidly evolving Creutzfeldt-Jakob disease in COVID-19: from early status epilepticus to fatal outcome.

We report the case of a 70-year-old man coming to our attention for new onset refractory status epilepticus (NORSE) in a rapidly evolving CJD during SARS-CoV-2 co-infection. Our case report describes a fulminant CJD evolution associated with SARS-CoV-2 infection, which led to patient death after 15 days from admission. First EEG presented continuous diffuse spikes, sharp waves and sharp-and-slow wave complexes, pattern consistent with a non-convulsive status epilepticus (NORSE). Our case supports how CJD with SARS-CoV-2 co-infection could be characterized by an accelerated evolution, as already hypothesize for others microorganism infections, and how the diagnosis might be more challenging due to its uncommon presentations, such as NORSE.

Immunogenicity and safety of a third dose of anti-SARS-CoV-2 BNT16b2 vaccine in liver transplant recipients.

BACKGROUND & AIMS: A strategy to improve the low rate of anti-SARS-CoV-2 mRNA vaccine-induced immunogenicity in liver transplant recipients (LTs) is urgently needed. METHODS: We analysed the rate of positive (≥0.8 U/ml) anti-SARS-CoV-2 receptor domain-binding protein (RBD) antibody response 2 months after a third dose of the BNT16b2 vaccine in 107 LTs who completed the second vaccine dose 7 months earlier. RESULTS: A positive anti-SARS-CoV-2-s-RBD antibody response after the third vaccine dose was detected in 98 (91.6%) LTs compared to 82 (76.6%) after the second vaccine dose (p = .003). The median of anti-SARS-CoV-2 RBD antibody titres increased from 22.9 U/ml 6 months after the second to 3500 U/ml 2 months after the third vaccine dose (p < .001). Fourteen (14.3%) responder patients presented antibody titres <100 U/ml, 57 (58.2%) between 100 and 9999 U/ml and 27 (27.6%) ≥10 000 U/ml. Seropositivity after the second dose was maintained after the third dose. Independent predictors of antibody response failure after the third vaccine dose were taking a higher daily dose of mycophenolate mofetil (MMF, p < .001) and had a lower (<60 ml/min/1.73 m2 ) estimated glomerular filtration rate (p = .007). Nine (9.1%) LTs experienced symptomatic SARS-CoV-2 infection after the third vaccine dose. Median antibody titres were not statistically different between infected and not infected LTs (1325 vs 3515 U/ml, p = .678). CONCLUSIONS: The third dose of the BNT16b2 vaccine increased the number of LTs who developed a positive anti-SARS-CoV-2 s-RBD antibody response. A proportion of patients remained unresponsive, mainly for modifiable factors, such as the use of MMF or multiple immunosuppressants.

Comparison of current methods for anti-dsDNA antibody detection and reshaping diagnostic strategies.

Anti-double-stranded DNA antibodies (anti-dsDNA) are considered a specific marker for systemic lupus erythematosus (SLE). Though the Farr technique was once the reference method for their detection, it has been almost entirely replaced by more recently developed assays. However, there is still no solid evidence of the commutability of these methods in terms of diagnostic accuracy and their correlation with the Crithidia luciliae immunofluorescence test (CLIFT). Anti-dsDNA antibody levels were measured in 80 subjects: 24 patients with SLE, 36 disease controls drawn from different autoimmune rheumatic diseases (14 systemic sclerosis, 10 Sjögren's syndrome, nine autoimmune myositis, three mixed connective tissue disease), 10 inflammatory arthritis and 10 apparently healthy blood donors by eight different methods: fluorescence enzyme immunoassay, microdot array, chemiluminescent immunoassay (two assays), multiplex flow immunoassay, particle multi-analyte technology immunoassay and two CLIFT. At the recommended manufacturer cut-off, the sensitivity varied from 67% to 92%, while the specificity ranged from 84% to 98%. Positive agreement among CLIFT and the other assays was higher than negative agreement. Mean agreement among methods assessed by the Cohen's kappa was 0.715, ranging from moderate (0.588) to almost perfect (0.888). Evaluation of the concordance among quantitative values by regression analysis showed a poor correlation index (mean r2, 0.66). The present study shows that current technologies for anti-dsDNA antibody detection are not fully comparable. In particular, their different correlation with CLIFT influences their positioning in the diagnostic algorithm for SLE (either in association or sequentially). Considering the high intermethod variability, harmonization and commutability of anti-dsDNA antibody testing remains an unachieved goal.

Evaluation of qualitative and semi-quantitative cut offs for rapid diagnostic lateral flow test in relation to serology for the detection of SARS-CoV-2 antibodies: findings of a prospective study.

BACKGROUND: There is limited information to compare the qualitative and semi-quantitative performance of rapid diagnostic tests (RDT) and serology for the assessment of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Therefore, the objective of the study was (a) to compare the efficacy of SARS-CoV-2 antibody detection between RDT and laboratory serology, trying to identify appropriate semi-quantitative cut-offs for RDT in relation with quantitative serology values and to (b) evaluate diagnostic accuracy of RDT compared to the NAAT gold standard in an unselected adult population. METHODS: SARS-CoV-2 antibodies were simultaneously measured with lateral flow immunochromatographic assays (LFA), the Cellex qSARS-CoV-2 IgG/IgM Rapid Test (by capillary blood), the iFlash-SARS-CoV-2 IgG/IgM chemiluminescent immunoassay (CLIA) (by venous blood) and the nucleic acid amplification test (NAAT) in samples from in- and out-patients with confirmed, suspected and negative diagnosis of coronavirus disease 2019 (COVID-19) attending Udine Hospital (Italy) (March-May 2020). Interpretation of RDT was qualitative (positive/negative) and semi-quantitative based on a chromatographic intensity scale (negative, weak positive, positive). RESULTS: Overall, 720 paired antibody measures were performed on 858 patients. The qualitative and semiquantitative agreement analysis performed in the whole sample between LFA and CLIA provided a Kendall's tau of 0.578 (p < 0.001) and of 0.623 (p < 0.001), respectively, for IgM and IgG. In patients with a diagnosis of COVID-19, accordance between LFA and CLIA was maintained as a function of time from the onset of COVID-19 disease and the severity of disease both for qualitative and semi-quantitative assessments. RDT compared to the NAAT gold standard in 858 patients showed 78.5% sensitivity (95% CI 75.1%-81.7%) and 94.1% specificity (95% CI 90.4%-96.8%), with variable accordance depending on the timing from symptom onset. CONCLUSION: The RDT used in our study can be a non-invasive and reliable alternative to serological tests and facilitate both qualitative and a semi-quantitative antibody detection in COVID-19.

Contribution and Effectiveness of Laboratory Testing in the Diagnostic Assessment of Juvenile Ischemic Stroke and Transient Ischemic Attack.

Introduction Strokes in young people require an extensive diagnostic workup to detect their possible several etiopathogenetic mechanisms. There is no consensus indicating what and when it should be tested. The clinical benefit and cost-effectiveness ratio of laboratory tests is unclear as well. Methods In one series of 104 consecutive juvenile ischemic stroke patients, under 45 years old, admitted between January 1, 2012, and December 31, 2017, we considered a wide panel of laboratory biomarkers exploring both the patient's basal status and specific risk factors for thrombotic disorders. To combine conventional and unconventional risk factors, structural defects, and other stroke-related diseases, we defined four categories of etiologic probability. We then studied the contribution of laboratory testing in changing the rate of "definite or probable stroke etiology" and the "proportion of patients with at least one additional risk factor" for stroke. Results The mere clinical assessment clarified stroke etiopathogenesis in 31% of cases. Abnormal values of the panel of biomarkers we considered were found in 30.1% of young ischemic strokes, while 11.5% of patients had unclear or borderline values. The benefit of laboratory assessment consisted of a relevant 14% gain in patients with a "definite or probable stroke etiology." Conclusion Several areas of uncertainty are still pending and herein discussed, such as the low re-testing rate during follow-up and the neglect of some relevant biomarkers. However, our results support the importance of laboratory testing in this setting. An improvement of diagnostic protocols in juvenile ischemic stroke would even increase their effectiveness, and this is still an unsolved issue in the field of cerebrovascular diseases. The same age limit, conventionally considered for juvenile stroke, could be better defined according to the effectiveness of both laboratory and clinical assessment in identifying unconventional stroke risk factors.

The impact of body composition on mortality of COVID-19 hospitalized patients: A prospective study on abdominal fat, obesity paradox and sarcopenia.

BACKGROUND & AIMS: Obesity has been described as a predisposing risk factor to severe forms of COVID-19, but conflicting results are emerging on its real impact on the mortality of COVID-19. We aimed to compare clinical outcomes and mortality among COVID-19 patients according to obesity, metabolic syndrome and adiposity distribution. METHODS: We conducted a prospective observational study of all consecutive adult patients with a confirmed diagnosis of SARS-CoV-2 infection admitted to the Infectious Diseases Clinic at Udine Hospital, Italy, from January 2021 to February 2021. At admission, the study population was submitted to specific anthropometric, laboratory and bioimpedance analysis (BIA) measurements and divided into five groups according to: 1) BMI < or >30 kg/m2; 2) waist circumference (WC) < or >98 cm for women, < or >102 cm for men; 3) presence or absence of metabolic syndrome (MS); 4) visceral adipose tissue (VAT) distribution; and 5) presence or absence of sarcopenia (SP) both based on BIA. We then compared clinical outcomes (ventilatory support, intensive care unit (ICU) admission, ICU length of stay, total hospital length of stay and mortality), immune and inflammatory makers and infectious and non-infectious acute complications within the five groups. RESULTS: A total of 195 patients were enrolled in the study. The mean age of patients was 71 years (IQR 61-80) and 64.6% (126) were male. The most common comorbidities were hypertension (55.9%) and MS (55.4%). Overall mortality was 19.5%. Abdominal adiposity, measured both with WC and with BIA, and SP were significantly associated with need for increased ventilator support (p = 0.013 for WC; p = 0.037, 0.027 and 0.009 for VAT; p = 0.004 and 0.036 for FMI; and p = 0.051 for SP), but not with ICU admission (WC p = 0.627, VAT p = 0.153, FMI p = 0.519 and SP p = 0.938), length of stay (WC p = 0.345, VAT p = 0.650, FMI p = 0.159 and SP p = 0.992) and mortality (WC p = 0.277, VAT p = 0.533, FMI p = 0.957 and SP p = 0.211). Obesity and MS did not discriminate for the intensity of ventilatory outcome (p = 0.142 and p = 0.198, respectively), ICU admission (p = 0.802 and p = 0.947, respectively), length of stay (p = 0.471 and p = 0.768, respectively) and mortality (p = 0.495 and p = 0.268, respectively). We did not find significant differences in inflammatory markers and secondary complications within the five groups. CONCLUSIONS: In patients admitted with COVID-19, increased WC, visceral abdominal fat and SP are associated with higher need for ventilatory support. However, obesity, MS, SP and abdominal adiposity are not sensitive predictive factors for mortality.