Systemic oxidative stress may be associated with reduced IgG antibody titers against SARS-CoV-2 in vaccinated kidney transplant recipients: A post-hoc analysis of the RECOVAC-IR observational study.

BACKGROUND: Coronavirus disease 2019 (COVID-19) poses an increased risk for severe illness and suboptimal vaccination responses in patients with kidney disease, in which oxidative stress may be involved. Oxidative stress can be reliably measured by determining circulating free thiols (R-SH, sulfhydryl groups), since R-SH are rapidly oxidized by reactive species. In this study, we aimed to examine the association between serum free thiols and the ability to mount a humoral immune response to SARS-CoV-2 vaccination in kidney patients. METHODS: Serum free thiol concentrations were measured in patients with chronic kidney disease stages 4/5 (CKD G4/5) (n = 46), on dialysis (n = 43), kidney transplant recipients (KTR) (n = 73), and controls (n = 50). Baseline serum free thiol and interferon-γ-induced protein-10 (IP-10) - a biomarker of the interferon response - were analyzed for associations with seroconversion rates and SARS-CoV-2 spike (S1)-specific IgG concentrations after two doses of the mRNA-1273 vaccine. RESULTS: Albumin-adjusted serum free thiol concentrations were significantly lower in patients with CKD G4/5 (P < 0.001), on dialysis (P < 0.001), and KTR (P < 0.001), as compared to controls. Seroconversion rates after full vaccination were markedly reduced in KTR (52.1%) and were significantly associated with albumin-adjusted free thiols (OR = 1.76, P = 0.033). After adjustment for MMF use, hemoglobin, and eGFR, this significance was not sustained (OR = 1.49, P = 0.241). CONCLUSIONS: KTR show suboptimal serological responses to SARS-CoV-2 vaccination, which is inversely associated with serum R-SH, reflecting systemic oxidative stress. Albeit this association was not robust to relevant confounding factors, it may at least partially be involved in the inability of KTR to generate a positive serological response after SARS-CoV-2 vaccination.

Viral presence and immunopathology in a kidney transplant recipient with fatal COVID-19: a clinical autopsy report.

COVID-19 is of special concern to immunocompromised individuals, including organ transplant recipients. However, the exact implications of COVID-19 for the immunocompromised host remain unclear. Existing theories regarding this matter are controversial and mainly based on clinical observations. Here, the postmortem histopathology, immunopathology, and viral presence in various tissues of a kidney transplant recipient with COVID-19 were compared to those of 2 nontransplanted patients with COVID-19 matched for age, sex, length of intensive care unit stay, and admission period in the pandemic. None of the tissues of the kidney transplant recipient demonstrated the presence of SARS-CoV-2. In lung tissues of both controls, some samples showed viral positivity with high Ct values with quantitative reverse transcription polymerase chain reaction. The lungs of the kidney transplant recipient and controls demonstrated similar pathology, consisting of acute fibrinous and organizing pneumonia with thrombosis and an inflammatory response with T cells, B cells, and macrophages. The kidney allograft and control kidneys showed a similar pattern of interstitial lymphoplasmacytic infiltration. No myocarditis could be observed in the hearts of the kidney transplant recipient and controls, although all cases contained scattered lymphoplasmacytic infiltrates in the myocardium, pericardium, and atria. The brainstems of the kidney transplant recipient and controls showed a similar pattern of lymphocytic inflammation with microgliosis. This research report highlights the possibility that, based on the results obtained from this single case, at time of death, the immune response in kidney transplant recipients with long-term antirejection immunosuppression use prior to severe illness is similar to nontransplanted deceased COVID-19 patients.

Clinical outcome and humoral immune responses of ß-thalassemia major patients with severe iron overload to SARS-CoV-2 infection and vaccination: a prospective cohort study.

Background: COVID-19 has raised special concern for patients with ß-thalassemia major (ß-TM) due to frequent comorbidities, regular blood transfusions, and iron overload. However, the exact implications of COVID-19 for patients with ß-TM remain uncertain. We aimed to explore the COVID-19 incidence and severity, and the serological response to SARS-CoV-2 infection and vaccination in patients with ß-TM. Methods: Patients with ß-TM (n = 105) and age-matched healthy controls, all individuals of all control groups were health care workers of the hospital, were prospectively enrolled at the haematology department of Al-Shifa hospital in the Gaza Strip from January 1st, 2021 to December 31st, 2021. Data on COVID-19 incidence and severity were analysed, with Alpha, Beta, and Delta SARS-CoV-2 variants dominating at that time. Anti-SARS-CoV-2 IgG antibody levels were measured and compared between study groups. Findings: Patients with ß-TM showed a higher incidence of SARS-CoV-2 infection than the general population (61.9% vs. 7.1%, p < 0.0001). Most patients with ß-TM had asymptomatic (70.8%) or mild disease (26.1%), with no fatalities recorded. COVID-19 illness was more severe among female than male patients with ß-TM. Anti-SARS-CoV-2 IgG antibodies were significantly higher in symptomatic patients with ß-TM than controls post-infection (geometric mean ÷ geometric standard deviation 1299.0 ÷ 3.3 vs. 555.7 ÷ 2.4 AU/mL, p = 0.009) and post-vaccination (8404.0 ÷ 3.9 vs. 2785.6 ÷ 5.0 AU/mL, p = 0.015). Similar responses were observed when comparing splenectomised to non-splenectomised (both asymptomatic and symptomatic) patients with ß-TM post-infection (595.4 ÷ 3.9 vs. 280.7 ÷ 3.5 AU/mL, p = 0.005) and post-vaccination (13,778.2 ÷ 3.2 vs. 4961.8 ÷ 4.1 AU/mL, p = 0.045). Interpretation: This distinctive ß-TM cohort exhibited a high susceptibility to SARS-CoV-2 infection but mild disease course. Our findings support favourable serological responses to SARS-CoV-2 infection and to vaccination in patients with ß-TM, indicating a potential interplay between iron availability and COVID-19-related immunity. Funding: This study was funded by Mr. Hosam and Wasim s. El Helou.

The Disease-Modifying Role of Taurine and Its Therapeutic Potential in Coronavirus Disease 2019 (COVID-19).

Taurine is an amino sulfonic acid that is implicated in numerous physiological functions, including the regulation of oxidative stress, which plays an important role in coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), together with other pathophysiological processes. The recent finding of decreased serum taurine levels in SARS-CoV-2-infected patients, in tandem with its potential modulatory role in COVID-19 due to its antiviral, antioxidant, anti-inflammatory, and vascular-related effects, provides a rationale for considering taurine as a beneficial supplement in patients suffering from COVID-19. Here, we reviewed the potential disease-modifying effects of taurine and combined these with the current knowledge on COVID-19 to clarify the potential role of taurine in this respiratory disease.

SARS-CoV-2 infects the human kidney and drives fibrosis in kidney organoids.

Kidney failure is frequently observed during and after COVID-19, but it remains elusive whether this is a direct effect of the virus. Here, we report that SARS-CoV-2 directly infects kidney cells and is associated with increased tubule-interstitial kidney fibrosis in patient autopsy samples. To study direct effects of the virus on the kidney independent of systemic effects of COVID-19, we infected human-induced pluripotent stem-cell-derived kidney organoids with SARS-CoV-2. Single-cell RNA sequencing indicated injury and dedifferentiation of infected cells with activation of profibrotic signaling pathways. Importantly, SARS-CoV-2 infection also led to increased collagen 1 protein expression in organoids. A SARS-CoV-2 protease inhibitor was able to ameliorate the infection of kidney cells by SARS-CoV-2. Our results suggest that SARS-CoV-2 can directly infect kidney cells and induce cell injury with subsequent fibrosis. These data could explain both acute kidney injury in COVID-19 patients and the development of chronic kidney disease in long COVID.

A Rare Case of Epstein-Barr Virus-Positive T-Cell Lymphoma in the Skin of an Immunocompromised Patient.

ABSTRACT: Immunodeficiency-associated lymphoproliferative disorders are associated with latent infection by Epstein-Barr virus (EBV). Most cases of EBV-positive immunodeficiency-associated lymphoproliferative disorders arise from B cells, although some are of T-cell or natural killer origin. Cutaneous involvement is unusual and sporadically reported in the literature. We describe a rare case of an EBV-positive T-cell lymphoma presenting in the skin of a 32-year-old woman using adalimumab for neurosarcoidosis.

Mild Coronavirus Disease 2019 (COVID-19) Is Marked by Systemic Oxidative Stress: A Pilot Study.

Oxidative stress has been implicated to play a critical role in the pathophysiology of coronavirus disease 2019 (COVID-19) and may therefore be considered as a relevant therapeutic target. Serum free thiols (R-SH, sulfhydryl groups) comprise a robust marker of systemic oxidative stress, since they are readily oxidized by reactive oxygen species (ROS). In this study, serum free thiol concentrations were measured in hospitalized and non-hospitalized patients with COVID-19 and healthy controls and their associations with relevant clinical parameters were examined. Serum free thiol concentrations were measured colorimetrically (Ellman's method) in 29 non-hospitalized COVID-19 subjects and 30 age-, sex-, and body-mass index (BMI)-matched healthy controls and analyzed for associations with clinical and biochemical disease parameters. Additional free thiol measurements were performed on seven serum samples from COVID-19 subjects who required hospitalization to examine their correlation with disease severity. Non-hospitalized subjects with COVID-19 had significantly lower concentrations of serum free thiols compared to healthy controls (p = 0.014), indicating oxidative stress. Serum free thiols were positively associated with albumin (St. ß = 0.710, p < 0.001) and inversely associated with CRP (St. ß = -0.434, p = 0.027), and showed significant discriminative ability to differentiate subjects with COVID-19 from healthy controls (AUC = 0.69, p = 0.011), which was slightly higher than the discriminative performance of CRP concentrations regarding COVID-19 diagnosis (AUC = 0.66, p = 0.042). This study concludes that systemic oxidative stress is increased in patients with COVID-19 compared with healthy controls. This opens an avenue of treatment options since free thiols are amenable to therapeutic modulation.

COVID-19: immunopathology, pathophysiological mechanisms, and treatment options.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), continues to spread globally despite the worldwide implementation of preventive measures to combat the disease. Although most COVID-19 cases are characterised by a mild, self-limiting disease course, a considerable subset of patients develop a more severe condition, varying from pneumonia and acute respiratory distress syndrome (ARDS) to multi-organ failure (MOF). Progression of COVID-19 is thought to occur as a result of a complex interplay between multiple pathophysiological mechanisms, all of which may orchestrate SARS-CoV-2 infection and contribute to organ-specific tissue damage. In this respect, dissecting currently available knowledge of COVID-19 immunopathogenesis is crucially important, not only to improve our understanding of its pathophysiology but also to fuel the rationale of both novel and repurposed treatment modalities. Various immune-mediated pathways during SARS-CoV-2 infection are relevant in this context, which relate to innate immunity, adaptive immunity, and autoimmunity. Pathological findings in tissue specimens of patients with COVID-19 provide valuable information with regard to our understanding of pathophysiology as well as the development of evidence-based treatment regimens. This review provides an updated overview of the main pathological changes observed in COVID-19 within the most commonly affected organ systems, with special emphasis on immunopathology. Current management strategies for COVID-19 include supportive care and the use of repurposed or symptomatic drugs, such as dexamethasone, remdesivir, and anticoagulants. Ultimately, prevention is key to combat COVID-19, and this requires appropriate measures to attenuate its spread and, above all, the development and implementation of effective vaccines. © 2021 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

N-Acetylcysteine and Hydrogen Sulfide in Coronavirus Disease 2019.

Significance: Hydrogen sulfide (H2S) is one of the three main gasotransmitters that are endogenously produced in humans and are protective against oxidative stress. Recent findings from studies focusing on coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), shifted our attention to a potentially modulatory role of H2S in this viral respiratory disease. Recent Advances: H2S levels at hospital admission may be of importance since this gasotransmitter has been shown to be protective against lung damage through its antiviral, antioxidant, and anti-inflammatory actions. Furthermore, many COVID-19 cases have been described demonstrating remarkable clinical improvement upon administration of high doses of N-acetylcysteine (NAC). NAC is a renowned pharmacological antioxidant substance acting as a source of cysteine, thereby promoting endogenous glutathione (GSH) biosynthesis as well as generation of sulfane sulfur species when desulfurated to H2S. Critical Issues: Combining H2S physiology and currently available knowledge of COVID-19, H2S is hypothesized to target three main vulnerabilities of SARS-CoV-2: (i) cell entry through interfering with functional host receptors, (ii) viral replication through acting on RNA-dependent RNA polymerase (RdRp), and (iii) the escalation of inflammation to a potentially lethal hyperinflammatory cytokine storm (toll-like receptor 4 [TLR4] pathway and NLR family pyrin domain containing 3 [NLRP3] inflammasome). Future Directions: Dissecting the breakdown of NAC reveals the possibility of increasing endogenous H2S levels, which may provide a convenient rationale for the application of H2S-targeted therapeutics. Further randomized-controlled trials are warranted to investigate its definitive role.