Eosinophil-associated diseases: the allergist's and clinical immunologist's perspective.

Summary: Eosinophil-associated diseases (EADs) refer to heterogeneous conditions in which eosinophils are believed to play critical pathological roles. They encompass common respiratory conditions, such as asthma, chronic rhinosinusitis with nasal polyps (CRSwNP), less common primary eosinophilic disorders of gastrointestinal tract, and rare conditions including eosinophilic granulomatosis with polyangiitis (EGPA) and hypereosinophilic syndrome (HES). A literature search was carried out in January 2024 in the MEDLINE and Scopus databases using the PubMed search engine (PubMed, National Library of Medicine, Bethesda, MD). We focused on blood eosinophilia and hypereosinophilia. A diagnostic workup is proposed. From allergist's point of view, we focused the review on 4 groups of eosinophilic disorders of specific interest. Our increased understanding of type 2 inflammation and biology has recently led to development of highly effective precision targeted therapies that are now approved for a growing number of eosinophilic disorders. Novel targeted biologics have a major impact on treatment strategies and have resulted in major advances in our understanding of the pathogenesis of these disorders. In the context of EADs, according to the heterogeneity of eosinophilic disorders a multidisciplinary approach should be adopted. Allergists and Clinical Immunologists play an important role as they have a clear understanding of the eosinophilic inflammation and the role of cytokines and are trained to recognize and characterize type 2 (T2) inflammation and its associated pathologies.

Global cardiovascular risk, COVID-19 severity and post-COVID-19 syndrome: a clinical study.

OBJECTIVE: Post-COVID-19 is a syndrome defined by signs and symptoms present until 12 weeks after COVID-19, lasting for more than 8 weeks, not explained by an alternative diagnosis. The present study aimed to assess whether the cardiovascular risk (CVR) of patients with COVID-19 correlates with symptoms and changes in respiratory function parameters in post-COVID-19. The association between CVR and the severity of acute disease was also considered. PATIENTS AND METHODS: Between 21/04/21-01/09/21, we enrolled 1,782 consecutive patients with COVID-19. We divided these subjects into (i) 4 levels, based on the severity of COVID-19 (home care; hospitalized/no oxygen therapy; hospitalized/oxygen therapy; hospitalized/NIV-ICU), (ii) 2 levels, according to CVR calculated with the European Society of Cardiology SCORE tables (low-intermediate risk; high or very high risk). All subjects underwent a 3-month follow-up considering post-COVID-19 symptoms. RESULTS: In post-COVID-19 patients, high or very-high CVR was associated with (i) increased risk of hospitalization for COVID-19 (p<0.0001), (ii) higher prevalence of severe clinical manifestations and ICU admission (p<0.0001), (iii) development of post-COVID-19 (p<0.0001) and (iv) increased risk of a larger post-COVID-19 burden of disease. CONCLUSIONS: We found a statistically significant association between CVR, severity of COVID-19, and post-COVID-19 syndrome three months after the end of acute disease.

Increased expression of the ectoenzyme CD38 in peripheral blood plasmablasts and plasma cells of patients with systemic sclerosis.

Objective: CD38 is a type II glycoprotein highly expressed on plasmablasts and on short- and long-lived plasma cells, but weakly expressed by lymphoid, myeloid, and non-hematopoietic cells. CD38 is a target for therapies aimed at depleting antibody-producing plasma cells. Systemic sclerosis (SSc) is an immune-mediated disease with a well-documented pathogenic role of B cells. We therefore analyzed CD38 expression in different subsets of peripheral blood mononuclear cells (PBMCs) from a cohort of SSc patients. Methods: Cell surface expression of CD38 was evaluated on PBMCs from SSc patients using eight-color flow cytometry analysis performed with a FacsCanto II (BD). Healthy individuals were used as controls (HC). Results: Forty-six SSc patients (mean age 56, range 23-79 years; 38 females and 8 males), and thirty-two age- and sex-matched HC were studied. Twenty-eight patients had the limited cutaneous form and eighteen the diffuse cutaneous form of SSc. The mean disease duration was 7 years. Fourteen patients were on immunosuppressive therapy (14 MMF, 5 RTX). The total percentages of T, B and NK cells were not different between SSc and HC. Compared to HC, SSc patients had higher levels of CD3+CD38+ T cells (p<0.05), higher percentage (p<0.001) of CD3+CD4+CD25+FOXP3+ regulatory T cells, lower percentage (p<0.05) of CD3+CD56+ NK T cells. Moreover, SSc patients had higher levels of CD24highCD19+CD38high regulatory B cells than HC (p<0.01), while the amount of CD24+CD19+CD38+CD27+ memory B cells was lower (p<0.001). Finally, the percentages of circulating CD38highCD27+ plasmablasts and CD138+CD38high plasma cells were both higher in the SSc group than in HC (p<0.001). We did not observe any correlations between these immunophenotypes and disease subsets or duration, and ongoing immunosuppressive treatment. Conclusions: The increased expression of CD38 in peripheral blood plasmablasts and plasma cells of SSc patients may suggest this ectoenzyme as a candidate therapeutic target, under the hypothesis that depletion of these cells may beneficially downregulate the chronic immune response in SSc patients. Validation of this data in multicenter cohorts shall be obtained prior to clinical trials with existing anti-CD38 drugs.

The value of admission Troponin I to predict outcomes in suspected infections in elderly patients admitted in Internal Medicine: results from the SOFA-T collaboration, a multi-center study.

Elderly patients affected by suspected infection and declining clinical conditions can be admitted to stepdown units (SDU), but a risk stratification is necessary to optimize their management. Admission troponin I (aTnI) has a prognostic role, however, one of the most commonly used stratification tools, the Sequential Organ Failure Assessment score (SOFA), does not consider myocardial injury. With this paper, we aimed to evaluate the prognostic accuracy of a new score, named SOFA-T, considering both SOFA score and aTnI in a cohort of elderly patients admitted to the stepdown beds of two Internal Medicine departments. Patients aged > 65 years admitted in SDU of two different hospitals of the same region in a 12-months timeframe were retrospectively assessed obtaining age, sex, days of admission, in-hospital death, SOFA, aTnI and comorbidities. The best aTnI cutoff for in-hospital death was calculated with ROC curve analysis; dichotomous variables were compared with chi-squared test; continuous variables were compared with t test or Mann-Whitney test. We obtained a cohort of 390 patients. The best aTnI cutoff was 0.31 ng/ml: patients with increased aTnI had higher risk of in-hospital death (OR: 1.834; 95% CI 1.160-2.900; p = 0.009), and higher SOFA (6.81 ± 2.71 versus 5.97 ± 3.10; p = 0.010). Adding aTnI to SOFA increased significantly the area under the curve (AUCSOFA = 0.68; 95% CI 0.64-0.73; AUCSOFA-T = 0.71; 95% CI 0.65-0.76; p = 0.0001), with a slight improvement of the prognostic performance. In elderly patients admitted to SDU for suspected infection, sepsis or septic shock, aTnI slightly improves the accuracy of SOFA score of the in-hospital death prediction.

Nonneutralizing human antibody fragments against hepatitis C virus E2 glycoprotein modulate neutralization of binding activity of human recombinant Fabs.

Evidence from clinical and experimental studies indicates that hepatitis C virus E2 (HCV/E2) glycoprotein is the major target of a putatively protective immune response. However, even in the presence of a vigorous production of anti-HCV/E2 antibodies, reinfection can occur. Dissection of the human immune response against HCV/E2 indicated that blocking of binding of HCV/E2 to target cells [neutralization of binding (NOB) activity] varies widely among antibody clones. Moreover, in vivo, simultaneous binding of antibodies to distinct epitopes can induce conformational changes and synergies that may be relevant to understanding the anti-HCV immune response. In this study, human recombinant Fabs were generated by affinity-selecting a phage display repertoire library with antibody-coated HCV/E2. These Fabs, which share the same complementarity-determining region DNA sequences, had higher affinity than other anti-HCV/E2 Fabs but showed no NOB activity even at the highest concentrations. Binding of Fabs to HCV/E2 caused conformational changes modifying Fab-binding patterns and reducing, with a negative synergistic effect, Fab-mediated NOB activity. These data suggest that some antibody clones have the potential to modify HCV/E2 conformation and that, in this state, binding of this glycoprotein to its cellular target is less prone to inhibition by some antibody clones. This can explain why high anti-HCV/E2 antibody titers do not directly correlate with protection from infection. Information on the interactions among different antibody clones can contribute to understanding virus-host interplay and developing more effective vaccines.