Comparative Analysis of Lymphocyte Populations in Post-COVID-19 Condition and COVID-19 Convalescent Individuals.

Reduced lymphocyte counts in peripheral blood are one of the most common observations in acute phases of viral infections. Although many studies have already examined the impact of immune (dys)regulation during SARS-CoV-2 infection, there are still uncertainties about the long-term consequences for lymphocyte homeostasis. Furthermore, as persistent cellular aberrations have been described following other viral infections, patients with "Post-COVID-19 Condition" (PCC) may present similarly. In order to investigate cellular changes in the adaptive immune system, we performed a retrospective analysis of flow cytometric data from lymphocyte subpopulations in 106 patients with confirmed SARS-CoV-2 infection who received medical care at our institution. The patients were divided into three groups according to the follow-up date; laboratory analyses of COVID-19 patients were compared with 28 unexposed healthy controls. Regarding B lymphocyte subsets, levels of IgA + CD27+, IgG + CD27+, IgM + CD27- and switched B cells were significantly reduced at the last follow-up compared to unexposed healthy controls (UHC). Of the 106 COVID-19 patients, 56 were clinically classified as featuring PCC. Significant differences between PCC and COVID-19 convalescents compared to UHC were observed in T helper cells and class-switched B cells. However, we did not detect specific or long-lasting immune cellular changes in PCC compared to the non-post-COVID-19 condition.

Metagenomic next-generation sequencing as a diagnostic tool in the clinical routine of an infectious diseases department: a retrospective cohort study.

BACKGROUND: Metagenomic next-generation sequencing (mNGS) of circulating cell-free DNA from plasma is a hypothesis-independent broadband diagnostic method for identification of potential pathogens. So far, it has only been investigated in special risk populations (e.g. patients with neutropenic fever). PURPOSE: To investigate the extent to which mNGS (DISQVER® platform) can be used in routine clinical practice. METHODS: We collected whole blood specimens for mNGS testing, blood cultures (BC), and pathogen-specific PCR diagnostics. Clinical data and pathogen diagnostics were retrospectively reviewed by an infectious disease expert panel regarding the adjustment of anti-infective therapy. RESULTS: In 55 selected patients (median age 53 years, 67% male) with heterogeneous diagnoses, a total of 66 different microorganisms and viruses were detected using mNGS (51% viruses, 38% bacteria, 8% fungi, 3% parasites). The overall positivity rate of mNGS was 53% (29/55). Fifty-two out of 66 (79%) potential pathogens detected by mNGS were found in patients with primary or secondary immunodeficiency. The concordance rates of BC and pathogen-specific PCR diagnostics with mNGS testing were 14% (4/28) and 36% (10/28), respectively (p < 0.001). An additional bacterial pathogen (Streptococcus agalactiae) could only be detected by BC. Therapeutic consequences regarding anti-infective therapy were drawn from 23 pathogens (35% of detections), with 18 of these detections occurring in patients with immunodeficiency. CONCLUSIONS: We conclude that mNGS is a useful diagnostic tool, but should only be performed selectively in addition to routine diagnostics of infectious diseases. The limited number of patients and the retrospective study design do not allow any further conclusions.

COVID-19 treatment strategies with drugs centrally procured by the German Federal Ministry of Health in a representative tertiary care hospital: a temporal analysis.

Introduction: To ensure the fastest and earliest possible treatment, the German Federal Ministry of Health (BMG) initiated central procurement and nationwide distribution of new drugs against COVID-19. A single centre was used for a retrospective temporal analysis of this procedure. Methods: A descriptive analysis of hospitalization and treatment of COVID-19 patients with drugs centrally procured by the BMG at St. Georg Hospital, Leipzig, Germany, for the period from 1 March 2020 to 28 February 2023 was employed considering the approval status, evolving guidelines and recommendations of medical societies. Results: In total, 3,412 patients ≥18 years (54.9% men) with PCR-confirmed SARS-CoV-2 infection were admitted. The mean age was 64 years during the reporting period and 66.1/70.6 years during the first and second COVID-19 waves, respectively. 964 patients (28.2%) received COVID-19 therapy with drugs procured centrally by the BMG. Remdesivir was the most commonly used (63%). SARS-CoV-2 neutralizing monoclonal antibodies represented 23% of the therapies. Peroral antivirals (nirmatrelvir/ritonavir and molnupiravir) were used in 14% of COVID-19 patients, with molnupiravir being insignificant (five prescriptions). Conclusions: Specific therapeutic approaches were mainly based on antiviral therapy in the early phase of COVID-19 to prevent severe disease progression in vulnerable patient groups. Most drugs had not been approved at the time of central procurement; therefore, prescriptions were given on a case-by-case basis after careful risk-benefit assessments. All available neutralizing monoclonal SARS-CoV-2 antibodies lost efficacy during the pandemic due to different circulating immune escape variants. Remdesivir and nirmatrelvir/ritonavir remained effective therapies in the early phase of COVID-19.

Clinical outcomes of hospitalized COVID-19 patients treated with remdesivir: a retrospective analysis of a large tertiary care center in Germany.

PURPOSE: The benefits of antiviral treatment with remdesivir in hospitalized patients with COVID-19 remain controversial. Clinical analyses are needed to demonstrate which patient populations are most likely to benefit. METHODS: In a retrospective monocentric analysis, patients with COVID-19 treated between July 1, 2020 and June 30, 2021 at Hospital St. Georg, Leipzig, Germany were evaluated. The primary endpoint was time to clinical improvement, and the secondary endpoint was 28-day mortality. Propensity score matching was used for the endpoint analysis. RESULTS: A total of 839 patients were fully evaluated, 68% of whom received specific COVID-19 drug therapy. Remdesivir was used in 31.3% of the patients, corticosteroids in 61.7%, and monoclonal antibodies in 2.3%. While dexamethasone administration was the most common therapeutic approach during the second pandemic wave, combination therapy with remdesivir and corticosteroids predominated during the third wave. Cox regression analysis revealed that combination therapy was not associated with faster clinical improvement (median: 13 days in both matched groups, HR 0.97 [95% CI 0.77-1.21], P = 0.762). By contrast, 28-day mortality was significantly lower in the corticosteroid-remdesivir group (14.8% versus 22.2% in the corticosteroid group, HR 0.60 [95% CI 0.39-0.95], P = 0.03) in the low-care setting. This effect was also demonstrated in a subgroup analysis of patients with remdesivir monotherapy (n = 44) versus standard of care (SOC). CONCLUSION: In COVID-19 patients with only mild disease (low-flow oxygen therapy and treatment in a normal ward) who received corticosteroids and/or remdesivir in addition to SOC, early administration of remdesivir was associated with a measurable survival benefit.

Evaluation of the systemic and mucosal immune response induced by COVID-19 and the BNT162b2 mRNA vaccine for SARS-CoV-2.

BACKGROUND: The currently used SARS-CoV-2 mRNA vaccines have proven to induce a strong and protective immune response. However, functional relevance of vaccine-generated antibodies and their temporal progression are still poorly understood. Thus, the central aim of this study is to gain a better understanding of systemic and mucosal humoral immune response after mRNA vaccination with BNT162b2. METHODS: We compared antibody production against the S1 subunit and the RBD of the SARS-CoV-2 spike protein in sera of BNT162b2 vaccinees, heterologous ChAdOx1-S/BNT162b2 vaccinees and COVID-19 patients. We monitored the neutralizing humoral response against SARS-CoV-2 wildtype strain and three VOCs over a period of up to eight months after second and after a subsequent third vaccination. RESULTS: In comparison to COVID-19 patients, vaccinees showed higher or similar amounts of S1- and RBD-binding antibodies but similar or lower virus neutralizing titers. Antibodies peaked two weeks after the second dose, followed by a decrease three and eight months later. Neutralizing antibodies (nAbs) poorly correlated with S1-IgG levels but strongly with RBD-IgGAM titers. After second vaccination we observed a reduced vaccine-induced neutralizing capacity against VOCs, especially against the Omicron variant. Compared to the nAb levels after the second vaccination, the neutralizing capacity against wildtype strain and VOCs was significantly enhanced after third vaccination. In saliva samples, relevant levels of RBD antibodies were detected in convalescent samples but not in vaccinees. CONCLUSIONS: Our data demonstrate that BNT162b2 vaccinated individuals generate relevant nAbs titers, which begin to decrease within three months after immunization and show lower neutralizing potential against VOCs as compared to the wildtype strain. Large proportion of vaccine-induced S1-IgG might be non-neutralizing whereas RBD-IgGAM appears to be a good surrogate marker to estimate nAb levels. A third vaccination increases the nAb response. Furthermore, the systemic vaccine does not seem to elicit readily detectable mucosal immunity.

Urinary Proteomics Associates with COVID-19 Severity: Pilot Proof-of-Principle Data and Design of a Multicentric Diagnostic Study.

SARS-CoV-2 infection results in a mild-to-moderate disease course in most patients, allowing outpatient self-care and quarantine. However, in approx. 10% of cases a two- or three-phasic critical disease course with starting from day 7 to 10 is observed. To facilitate and plan outpatient care, biomarkers prognosing such worsening at an early stage appear of outmost importance. In this accelerated article, we report on the identification of urinary peptides significantly associated with SARS-CoV-2 infection, and the development of a multi-marker urinary peptide based test, COVID20, that may enable prognosis of critical and fatal outcomes in COVID-19 patients. COVID20 is composed of 20 endogenous peptides mainly derived from various collagen chains that enable differentiating moderate or severe disease from critical state or death with 83% sensitivity at 100% specificity. Based on the performance in this pilot study, testing in a prospective study on 1000 patients has been initiated. This article is protected by copyright. All rights reserved.

The German National Registry of Primary Immunodeficiencies (2012-2017).

Introduction: The German PID-NET registry was founded in 2009, serving as the first national registry of patients with primary immunodeficiencies (PID) in Germany. It is part of the European Society for Immunodeficiencies (ESID) registry. The primary purpose of the registry is to gather data on the epidemiology, diagnostic delay, diagnosis, and treatment of PIDs. Methods: Clinical and laboratory data was collected from 2,453 patients from 36 German PID centres in an online registry. Data was analysed with the software Stata® and Excel. Results: The minimum prevalence of PID in Germany is 2.72 per 100,000 inhabitants. Among patients aged 1-25, there was a clear predominance of males. The median age of living patients ranged between 7 and 40 years, depending on the respective PID. Predominantly antibody disorders were the most prevalent group with 57% of all 2,453 PID patients (including 728 CVID patients). A gene defect was identified in 36% of patients. Familial cases were observed in 21% of patients. The age of onset for presenting symptoms ranged from birth to late adulthood (range 0-88 years). Presenting symptoms comprised infections (74%) and immune dysregulation (22%). Ninety-three patients were diagnosed without prior clinical symptoms. Regarding the general and clinical diagnostic delay, no PID had undergone a slight decrease within the last decade. However, both, SCID and hyper IgE- syndrome showed a substantial improvement in shortening the time between onset of symptoms and genetic diagnosis. Regarding treatment, 49% of all patients received immunoglobulin G (IgG) substitution (70%-subcutaneous; 29%-intravenous; 1%-unknown). Three-hundred patients underwent at least one hematopoietic stem cell transplantation (HSCT). Five patients had gene therapy. Conclusion: The German PID-NET registry is a precious tool for physicians, researchers, the pharmaceutical industry, politicians, and ultimately the patients, for whom the outcomes will eventually lead to a more timely diagnosis and better treatment.