Lymphocyte subsets early predict mortality in a large series of hospitalized COVID-19 patients in Spain.

The role of lymphocytes and their main subsets as prognostic factors of death in SARS-CoV-2-infected patients remains unclear, with no information obtained from patients outside China. We aimed to assess whether measuring lymphocyte subpopulations added clinical value to the total lymphocyte counting regarding mortality when they were simultaneously tested at hospital admission. Peripheral blood was analysed in 701 polymerase chain reaction (PCR)-confirmed consecutive patients by lysed-no washed flow cytometry. Demographic and clinical features were registered in electronic medical records. Statistical analysis was performed after a 3-month follow-up. The 112 patients who died were older and had significantly higher frequencies of known co-morbidities than survivor COVID-19 patients. A significant reduction in total lymphocytes, CD3+ , CD4+ , CD8+ and CD19+ counts and CD3+ percentage was found in the group of deceased patients (P < 0·001), while the percentage of CD56+ /CD16+ natural killer (NK) cells was significantly higher (P < 0·001). Multivariate logistic regression analysis showed a significantly increased risk of in-hospital death associated to age [odds ratio (OR) = 2·36, 95% confidence interval (CI) = 1·9-3·0 P < 0·001]; CD4+  T counts ≤ 500 cells/µl, (OR = 2·79, 95% CI = 1·1-6·7, P = 0·021); CD8+  T counts ≤ 100 cells/µl, (OR = 1·98, 95% CI = 1·2-3·3) P = 0·009) and CD56+ /CD16+ NK ≥ 30%, (OR = 1·97, 95% CI = 1·1-3·1, P = 0·002) at admission, independent of total lymphocyte numbers and co-morbidities, with area under the curve 0·85 (95% CI = 0·81-0·88). Reduced counts of CD4+ and CD8+ T cells with proportional expansion of NK lymphocytes at admission were prognostic factors of death in this Spanish series. In COVID-19 patients with normal levels of lymphocytes or mild lymphopenia, imbalanced lymphocyte subpopulations were early markers of in-hospital mortality.

Efficiency of three intracellular extraction methods in the determination of metabolites related to tryptophan and tyrosine in winemaking yeast's metabolism by LC-HRMS.

Yeast nitrogen metabolism produces metabolites, whose origin in wines has scarcely been studied, with an important biological and organoleptic role. The present work focuses on comparing three intracellular extraction methods in order to elucidate efficiency of extraction while measuring the effect of temperature upon the integrity of the compounds related to the metabolism of tryptophan and tyrosine by yeast. Two UHPLC/HRMS methods to measure 16 metabolites were developed and validated. The validation provided optimum values of LOD (7.4·10-6 to 0.1 µg L-1), of LOQ (2·10-5 to 0.02 µg L-1) of precision (11-0.5% RSD) and repeatability (12-0.5% RSD). The removal of interfering molecules enabled matrix effects to be kept at low levels. The results pointed out that the low-temperature methods were more effective, providing better precision for 16 metabolites. The high-temperature extraction method may yield false enhanced compounds concentrations since they originate in cell wall macromolecules degradation.

Determination of hydroxytyrosol produced by winemaking yeasts during alcoholic fermentation using a validated UHPLC-HRMS method.

Hydroxytyrosol (HT) is a phenolic compound of recognized bioactivity that has been described in wines but little is known about its origin. This work demonstrates that yeast involved in wine making, i.e. Saccharomyces cerevisiae strains and the non-Saccharomyces Torulaspora delbrueckii, can synthesise HT, as this compound was identified in the intracellular media of three strains by means of a developed and validated UHPLC-HRMS method with LOQ and LOD of 0.108 and 0.035ngmL-1 respectively. Controlled fermentations were performed with different varieties of grapes (Corredera, Moscatel, Chardonnay, Palomino fino, Sauvignon Blanc, Vijiriega, and Tempranillo) and synthetic must. The Saccharomyces cerevisiae strain QA23 was the most efficient producer of HT from tested yeasts. On the other hand, the grape variety influences HT wine concentrations. Furthermore, the maximum concentration of HT is reached between the fourth and sixth day of fermentation. This work reveals that yeasts have a great potential for the production of HT.

Melatonin and derived l-tryptophan metabolites produced during alcoholic fermentation by different wine yeast strains.

Melatonin is a neurohormone involved in the regulation of circadian rhythms in humans. Evidence has recently been found of its occurrence in wines and its role in the winemaking process. The yeast Saccharomyces cerevisiae is consequently thought to be important in Melatonin synthesis, but limited data and reference texts are available on this synthetic pathway. This paper aims to elucidate whether the synthetic pathway of Melatonin in Saccharomyces and non-Saccharomyces strains involves these intermediates. To this end, seven commercial strains comprising Saccharomyces cerevisiae (Red Fruit, ES488, Lalvin QA23, Uvaferm BC, and Lalvin ICV GRE) and non-Saccharomyces (Torulaspora delbrueckii and Metschnikowia pulcherrima) were monitored, under controlled fermentation conditions, in synthetic must, for seven days. Samples were analysed using a UHPLC-HRMS system (Qexactive). Five out of the seven strains formed Melatonin during the fermentation process: three S. cerevisiae strains and the two non-Saccharomyces. Additionally, other compounds derived from l-tryptophan occurred during fermentation.

Sequential combined therapy with omalizumab and rituximab: a new approach to severe atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD) is a common chronic skin disease, and a significant percentage of AD patients have severe forms. Inflammation based on type 2 helper T cells (T(H)2), autoantibodies, and CD8+ T cells could play a relevant role in this disease. When the patient requires systemic immunosuppressors for disease control, side effects are frequent. We propose a sequential therapeutic strategy with 2 monoclonal antibodies, omalizumab (anti-immunoglobulin [Ig] E) and rituximab (anti-CD20), which might induce clinical benefit with few side effects in selected individuals with AD. METHODS: We report 6 cases of severe AD refractory to conventional therapy. The patients underwent sequential switch therapy with omalizumab and rituximab. Clinical response was assessed by means of the decrease in body surface affected. Immunological parameters and side effects were also monitored. RESULTS: Four patients received omalizumab before a high-dose cycle of rituximab. In the case of recurrences, either low-dose cycles of rituximab or omalizumab were administered. A long-term clinical benefit was observed in 3 out of 4 patients. Two patients first received high-dose rituximab followed by either low-dose rituximab or omalizumab, and one of them achieved a response at 17 months. No severe side effects were recorded. Serum IgE level and B-cell counts decreased with therapy, the latter returning to baseline levels 10 to 11 months after treatment. Specific antibody responses remained protective during the study. CONCLUSIONS: With our proposed switch therapy, 4 out of 6 patients achieved a dramatic clinical improvement. This novel strategy targets different arms of the immune response and might be a good alternative for patients with severe AD.

Flow cytometry analysis with a new FITC-conjugated monoclonal antibody-3E12 for HLA-B*57:01 rapid screening in prevention of abacavir hypersensitivity in HIV-1-infected patients.

BACKGROUND: Rapid screening for the detection of HLA-B*57:01 in the prevention of abacavir hypersensitivity in HIV-1-infected patients is a hallmark for clinical services. OBJECTIVE: The aim of this work was to analyze the utility of flow cytometry with a new FITC-conjugated B-17 monoclonal antibody (mAb3E12) for HLA-B*57:01 screening in a Spanish cohort of 577 HIV-1+ individuals. METHODS: Cryopreserved peripheral blood mononuclear cell samples from HIV-1+ individuals were analyzed by flow cytometry with the mAb 3E12 that recognizes both HLA-B*57 and HLA-B*58 alleles (members of the group specificity, HLA-B17). Patients' DNA samples had been previously typed for HLA-B*57:01 with PCR-SSO or PCR-SSP and additional DNA sequencing (EPI Study). The results obtained by flow cytometry were compared with the results obtained by the DNA-PCR techniques. RESULTS: By flow cytometry, 46 samples (7.97%) were positive for HLA-B17, 530 (91.86%) were negative, and 1 (0.17%) was undetermined. All samples found negative by flow cytometry were negative for HLA-B*57:01 by DNA-PCR. Of the HLA-B17 positive samples, 31 (67.4%) were positive for HLA-B*57:01, 2 (3.25%) were positive for HLA-B*57:03, 11 (26.1%) were positive for HLA-B*58, and 2 (3.25%) were negative for both HLA-B*57 and HLA-B*58 antigens. The undetermined sample was negative for HLA-B*57 and HLA-B*58 alleles by DNA-PCR. CONCLUSIONS: This study shows that flow cytometry with mAb3E12 is a highly sensitive method (no false negatives) to implement prior to DNA-PCR analysis for rapid screening of HLA-B*57:01. Additional confirmation by molecular HLA typing method would be required in less than 10% of the cohort of HIV-1-infected individuals.

Kinetics of functionally distinct T-lymphocyte subsets in heart transplant recipients after induction therapy with anti-CD25 monoclonal antibodies.

T cells are involved in the maintenance of immunocompetence and in the development of alloimmune responses in solid organ transplant recipients. The kinetics of functionally distinct T-cell subsets in peripheral blood has received little attention in the field of heart transplantation. We performed a simultaneous analysis of the maturation, activation, and regulatory profiles of T cells using 4-color flow cytometry in a study of 77 heart recipients. Induction therapy included 2 doses of anti-CD25 monoclonal antibodies (daclizumab). Lymphocyte subsets were prospectively evaluated at different times before and up to 1 year after transplantation in 46 heart recipients. A separate cross-sectional study was performed in 33 heart recipients who had received a transplant more than 1 year previously to evaluate abnormalities persisting in the long term. As compared with baseline values, a decrease in regulatory CD4+ T-cell percentages (CD4+CD127lowCD25highFoxP3+) was observed from day 7 to 12 months after transplantation. Interestingly, T cells expressing the beta chain of IL-2 (CD122+) remained stable during the first 3 months. A significant decrease in the activation status of CD4 T cells was documented from day 7 to 1 year after transplantation, while the activation status of CD8+ T cells remained stable during follow-up. Compared with values for healthy controls (n=36), higher CD8+ terminally differentiated effector memory percentages (CD8+CD45RA+CCR7-) were observed from baseline up to more than 1 year after transplantation. Rejection was associated with higher levels of these cells during the first 6 months after transplant. We characterized the abnormalities in distinct functional T-cell subsets at different times before and after heart transplantation. Some of these abnormalities should be further investigated as biomarkers of clinical complications.

Outcomes of splenectomy in patients with common variable immunodeficiency (CVID): a survey of 45 patients.

Splenectomy has been used in patients with common variable immunodeficiency disorders (CVID), mainly in the context of refractory autoimmune cytopenia and suspected lymphoma, but there are understandable concerns about the potential of compounding an existing immunodeficiency. With increasing use of rituximab as an alternative treatment for refractory autoimmune cytopenia, the role of splenectomy in CVID needs to be re-examined. This retrospective study provides the largest cohesive data set to date describing the outcome of splenectomy in 45 CVID patients in the past 40 years. Splenectomy proved to be an effective long-term treatment in 75% of CVID patients with autoimmune cytopenia, even in some cases when rituximab had failed. Splenectomy does not worsen mortality in CVID and adequate immunoglobulin replacement therapy appears to play a protective role in overwhelming post-splenectomy infections. Future trials comparing the effectiveness and safety of rituximab and splenectomy are needed to provide clearer guidance on the second-line management of autoimmune cytopenia in CVID.

Evaluation of lymphoproliferative responses by carboxy fluorescein succinimidyl ester assay in heart recipients with infections.

The analysis of proliferative responses using 5,6-carboxyfluorescein diacetate succinimidyl ester (CFSE) in flow cytometry is widely used to assess lymphocyte function. The aim of this study was to evaluate nonspecific and specific lymphoproliferative responses using CFSE in heart recipients before and after transplantation and their association with the development of infection. We used four-color flow cytometry to measure the response of peripheral CD3+, CD4+, and CD8+ T cells to phytohemagglutinin mitogen (PHA), tetanus toxoid, hepatitis B, and influenza vaccines using a CFSE proliferation assay in 12 heart recipients and 8 healthy control subjects. Recipients were prospectively evaluated. Immunological studies were performed before and at 3 months after transplantation. A 12-month clinical follow-up examination sought to detect the prevalence of severe infectious complications. Heart recipients (infected [n = 7] and uninfected [n = 5]) disclosed significantly lower percentages of proliferative responses than healthy controls against PHA at both study points. Baseline CD3+, CD4+, and CD8+, antitetanus proliferative responses were significantly lower in infected heart recipients than controls. Patients who developed infections displayed significantly lower percentages of CD3+CFSE and CD8+CFSE cells to PHA mitogen at 3 months after transplantation versus those without infections. In conclusion, nonspecific T-cell reactivity to PHA was lower in heart recipients with posttransplantation infections.

Decreased levels of serum complement C3 and natural killer cells add to the predictive value of total immunoglobulin G for severe infection in heart transplant recipients.

BACKGROUND: Infection remains a source of mortality in heart recipients. We previously reported that post-transplant immunoglobulin G (IgG) quantification can help identify the risk for infection. We assessed whether other standardized parameters of humoral and cellular immunity could prove useful when identifying patients at risk of infection. METHODS: We prospectively studied 133 heart recipients over a 12-month period. Forty-eight patients had at least one episode of severe infection. An event was defined as an infection requiring intravenous antimicrobial therapy. RESULTS: Cox regression analysis revealed an association between the risk of developing infection and the following: lower IgG2 subclass levels (day 7: relative hazard [RH] 1.71; day 30: RH 1.76), lower IgA levels (day 7: RH 1.61; day 30: RH 1.91), lower complement C3 values (day 7: RH 1.25), lower CD3 absolute counts (day 30: RH 1.10), lower absolute natural killer [NK] cell count (day 7: RH 1.24), and lower IgG concentrations (day 7: RH 1.31; day 30: RH 1.36). Cox regression bivariate analysis revealed that lower day 7 C3 levels, IgG2 concentration, and absolute NK cell count remained significant after adjustment for total IgG levels. CONCLUSIONS: Data suggest that early immune monitoring including C3, IgG2, and NK cell testing in addition to IgG concentrations is useful when attempting to identify the risk of infection in heart transplant recipients.

Restoration of humoral immunity after intravenous immunoglobulin replacement therapy in heart recipients with post-transplant antibody deficiency and severe infections.

IgG hypogammaglobulinemia is a risk factor for infection in heart recipients. We assessed reconstitution of humoral immunity after non-specific intravenous immunoglobulin (IVIg) replacement therapy administered to treat secondary IgG hypogammaglobulinemia in heart recipients with severe infections. The study population comprised 55 heart recipients who were administered IVIg (IVIg group) and 55 heart recipients with no severe infectious complications (control group). An event was defined as a severe infection requiring intravenous drug therapy during the first year after transplantation. The IVIg protocol comprised non-specific 5% pasteurized IVIg at a dose of 300-400 mg/kg/months. IgG titers were lower in the IVIg group than in controls at seven d (577 vs. 778 mg/dL, p < 0.001) and at one month (553 vs. 684, p = 0.003). After IVIg therapy, IgG concentrations were similar in both groups at three months (681 vs. 737, p = 0.25) and at six months (736 vs. 769, p = 0.46). At three months, the IVIg group had higher levels of antitetanus toxoid and anti-HBs (ELISA, 2.07 ± 2.11 vs. 0.60 ± 1.24 mg/dL [p = 0.003] and 42 ± 40 vs. 11 ± 31 IU/mL [p = 0.005], respectively) than controls. The mean number of infectious complications was significantly lower after IVIG therapy in the IVIG group. IVIg was associated with restoration of humoral immunity in heart recipients with post-transplant IgG hypogammaglobulinemia and severe infections.

Sublingual therapeutic immunization with a polyvalent bacterial preparation in patients with recurrent respiratory infections: immunomodulatory effect on antigen-specific memory CD4+ T cells and impact on clinical outcome.

Recurrent respiratory tract infections (RRTIs) are common clinical conditions in individuals with alterations of the immune function. A prospective open pilot study in a cohort of patients with RRTIs has been performed to assess whether sublingual immunization with a polyvalent bacterial vaccine could exert an immunomodulatory effect on the antigen-specific immunological responses and have an impact on the clinical outcome. Seventeen patients with RRTIs were recruited. An oral polyvalent bacterial preparation (Bactek®) was administered to all patients daily for 6 months. Immunological assessment was performed at baseline and at the end of immunization. Immunological measurements included: T cell-specific proliferations of CD3+CD4+ and CD3+CD8+ to Bactek® antigens, total immunoglobulin levels, antibodies to pneumococcal polysaccharide and tetanus toxoid and B, T and natural killer (NK) cell subsets. There was a significant increase in the proliferative capacity of CD3+CD4+ T cells specific to Bactek® antigens at month 6 in comparison to baseline (P < 0·0001). A significant increase in total CD3+ T cells was also observed (P < 0·05). No significant differences were observed between baseline and month 6 in levels of total immunoglobulins, specific antibodies and B, T or NK cell subsets. A significant reduction in the patient's rate of RRTIs was observed compared with 1 year prior to initiation of therapy (P < 0·0001). The results demonstrate that long-term administration of a sublingual polyvalent bacterial preparation in patients with RRTIs exerts an immune stimulating effect on CD4+ T helper cell responses to bacterial antigens which could be associated with clinical benefit.

6th International Immunoglobulin Symposium: poster presentations.

The posters presented at the 6th International Immunoglobulin Symposium covered a wide range of fields and included both basic science and clinical research. From the abstracts accepted for poster presentation, 12 abstracts were selected for oral presentations in three parallel sessions on immunodeficiencies, autoimmunity and basic research. The immunodeficiency presentations dealt with novel, rare class-switch recombination (CSR) deficiencies, attenuation of adverse events following IVIg treatment, association of immunoglobulin (Ig)G trough levels and protection against acute infection in patients with X-linked agammaglobulinaemia (XLA) and common variable immunodeficiency (CVID), and the reduction of class-switched memory B cells in patients with specific antibody deficiency (SAD). The impact of intravenous immunoglobulin on fetal alloimmune thrombocytopenia, pregnancy and postpartum-related relapses in multiple sclerosis and refractory myositis, as well as experiences with subcutaneous immunoglobulin in patients with multi-focal motor neuropathy, were the topics presented in the autoimmunity session. The interaction of dendritic cell (DC)-SIGN and alpha2,6-sialylated IgG Fc and its impact on human DCs, the enrichment of sialylated IgG in plasma-derived IgG, as wells as prion surveillance and monitoring of anti-measles titres in immunoglobulin products, were covered in the basic science session. In summary, the presentations illustrated the breadth of immunoglobulin therapy usage and highlighted the progress that is being made in diverse areas of basic and clinical research, extending our understanding of the mechanisms of immunoglobulin action and contributing to improved patient care.

High rate of infection and immune disorders in patients with hepatitis C virus after liver transplantation.

The aim of this prospective study was to analyze the incidence of serious infections and changes in immunological markers after liver transplantation (LT) in a cohort of patients with hepatitis C virus (HCV). This study included 34 patients who had LT, 20 patients with HCV etiology (HCV group), and 14 patients with alcoholic etiology (non-HCV group). Patients with HCV were more likely to have severe infections (80%) in comparison with patients in the non-HCV group (42%) (P=0.05). The HCV group had a 3-fold greater likelihood of early severe bacterial infections than the non-HCV group. At 1 week post LT, the HCV group showed higher values of CD19+ B cells/microL than the non-HCV group (P<0.05). At weeks 4 and 12 post LT, the HCV group had lower values of CD19+ B cells/microL (P<0.05). Our data suggest that HCV recurrence after LT was associated with a high incidence of early severe infections and immunological alterations, which may be related to this increased risk.

Missense mutation Thr309Lys in the coagulation factor XII gene in a Spanish family with hereditary angioedema type III.

BACKGROUND: A new type of hereditary angioedema (type III) affecting mainly women with normal C1-inhibitor level and function has been described. Exposition to estrogens is an important precipitating factor. Recently, a missense mutation in the gene of the blood coagulation factor XII (Hageman factor) has been reported in a few families with this type of hereditary angioedema. AIM: To study a patient and her family with recurrent swelling attacks during pregnancy. METHODS: Complement factors C3 and C4 as well as C1-inhibitor level and function were determined. Genomic DNA was isolated from venous blood samples and screened for mutations in the coagulation factor XII gene. RESULTS: C3 and C4 levels as well as C1-inhibitor level and function were normal. A missense mutation Thr309Lys was identified in factor XII gene with a heterozygotic pattern. This mutation was also identified in the mother of the patient, her daughter and her son. CONCLUSION: These results support that the mentioned mutation in factor XII gene causes hereditary angioedema type III.