Vaccination programs against SARS-CoV-2 constitute the mainstay of public health interventions against the global COVID-19 pandemic. Currently available vaccines have shown 90% or better rates of protection against severe disease and mortality. Barely a year after vaccines became available, the Omicron variant and its unprecedented speed of transmission has posed a new challenge. Overall, Omicron presents increased immune escape, transmissibility, and decreased pathogenicity. Vaccines do not offer a full protection against SARS-CoV-2 acquisition, since “breakthrough” infections may occur in fully vaccinated individuals, who may in turn spread the virus to others. Breakthrough infections may be causally related to the viral profile (viral variant and load, incubation period, transmissibility, pathogenicity, immune evasion), immunity characteristics (mucosal versus systemic immunity, duration of immunity, etc.), host determinants (age, comorbidities, immune status, immunosuppressive drugs) and vaccination properties (platform, antigen dose, dose number, dose interval, route of administration). Determining the rate of breakthrough infections may be challenging and necessitates the conduction of population-based studies regarding vaccine effectiveness as well as neutralizing antibody testing, a surrogate of immune protection. In this review, we analyze the causes of breakthrough infections, their clinical consequences (severity of infection and transmission), methods of determining their incidence as well as challenges and perspectives. Long COVID as well as multi-inflammatory syndrome in adolescents may be significantly reduced in breakthrough infections. The need for universal pancoranavirus vaccines that would aim at protecting against a plethora of SARS-CoV-2 variants as well as emerging variants is discussed. Finally, novel vaccine strategies, such as nasal vaccines, may confer robust mucosal and systemic protection, reducing efficiently transmission.

Uromodulin is a kidney-specific glycoprotein which is exclusively produced by the epithelial cells lining the thick ascending limb and early distal convoluted tubule. It is currently recognized as a multifaceted player in kidney physiology and disease, with discrete roles for intracellular, urinary, interstitial and serum uromodulin. Among these, uromodulin modulates renal sodium handling through the regulation of tubular sodium transporters that reabsorb sodium and are targeted by diuretics, such as the loop diuretic–sensitive Na⁺-K⁺-2Cl⁻ cotransporter type 2 (NKCC2) and the thiazide-sensitive Na⁺/Cl⁻ cotransporter (NCC). Given these roles, the contribution of uromodulin to sodium-sensitive hypertension has been proposed. However, recent studies in humans suggest a more complex interaction between dietary sodium intake, uromodulin and blood pressure. This review presents an updated overview of the uromodulin's biology and its various roles, and focuses on the interaction between uromodulin and sodium-sensitive hypertension.

For several years, blood pressure control and blocking of the renin-angiotensin system (RAS) represented the cornerstones of chronic kidney disease (CKD) treatment. Cardiovascular outcome trials with sodium-glucose co-transporter-2 (SGLT-2) inhibitors in patients with type 2 diabetes mellitus (DM) suggested that these agents can effectively delay the progression of CKD in these individuals. A major nephroprotective effect of canagliflozin was also shown in a renal outcome trial in patients with proteinuric diabetic CKD. The Study-to- Evaluate-the-Effect- of-Dapagliflozin-on-Renal-Outcomes-and-Cardiovascular- Mortality-in-Patients-With-Chronic-Kidney-Disease (DAPA-CKD) is a recent milestone in the field, as it included patients with both diabetic and non-diabetic proteinuric CKD and showed impressive reduction in the primary renal outcome of CKD progression, as well as the risk of hospitalization for heart failure and all-cause mortality on top of standard- of-care treatment. These benefits were consistent for patients with diabetic and non-diabetic CKD, including patients with ischemic or hypertensive nephropathy and glomerulonephritides (IgA nephropathy, focal segmental glomerulosclerosis and membranous nephropathy). Based on the above, relevant guidelines should accommodate their recommendations to implement treatment with SGLT-2 inhibitors for CKD patients.

Background: Chronic kidney disease (CKD) is often characterized by increased prevalence of cardiovascular risk factors and increased incidence of cardiovascular events and death. Reduced cardiovascular reserve and exercise intolerance are common in patients with CKD and are associated with adverse outcomes. Summary: The gold standard for identifying exercise limitation is cardiopulmonary exercise testing (CPET). CPET provides an integrative evaluation of cardiovascular, pulmonary, hematopoietic, neuropsychological, and metabolic function during maximal or submaximal exercise. It is useful in clinical setting for differentiation of the causes of exercise intolerance, risk stratification, and assessment of response to relevant treatments. A number of recent studies have used CPET in patients with pre-dialysis CKD, aiming to assess the cardiovascular reserve of these individuals, as well as the effect of interventions such as exercise training programs on their functional capacity. This review provides an in-depth description of CPET methodology and an overview of studies that utilized CPET technology to assess cardiovascular reserve in patients with pre-dialysis CKD. Key Messages: CPET can delineate multisystem changes and offer comprehensive phenotyping of factors determining overall cardiovascular risk. Potential clinical applications of CPET in CKD patients range from objective diagnosis of exercise intolerance to preoperative and long-term risk stratification and providing intermediate endpoints for clinical trials. Future studies should delineate the association of CPET indexes, with cardiovascular and respiratory alterations and hard outcomes in CKD patients, to enhance its diagnostic and prognostic utility in this population.

HFpEF represents a heterogeneous syndrome with complex pathophysiological substrates and multiple clinical manifestations. Recently, much attention has been focused on cardiac rehabilitation programs for HFpEF patients, and several studies have examined the effects of exercise training on this specific population. This systematic review and meta-analysis included studies on adult patients with HFpEF and evaluated the impact of exercise on the cardiorespiratory fitness variables measured during CPET. The primary outcome was the difference in the change in the peak oxygen uptake (Δpeak VO₂) between the groups. Literature search involved PubMed/MEDLINE, Cochrane/CENTRAL and Scopus databases. From an initial 5,143 literature records, we identified 18 studies fulfilling the inclusion criteria; 11 studies with 515 patients were finally included in the primary outcome analysis. Δpeak VO₂ between baseline and study end was significantly higher in the groups of exercise training versus control (WMD 2.25 ml/kg/min, 95% CI 1.81-2.70). Exercise training resulted in greater change in the 6-minute walking test (6MWT) distance (WMD 2.25 m, 95% CI 1.81-2.70). Health-related quality of life (HRQoL) (WMD: -3.36, 95% CI -9.42 to 2.70, I² = 14%, p = 0.33) and echocardiographic indices of diastolic function showed no differences between exercise and control groups at study end. In the subgroup analysis, no difference between resistance versus aerobic exercise was noted in Δpeak VO₂, but high-intensity interval training showed a greater increase in peak VO₂ versus aerobic exercise (WMD 1.62 ml/kg/min, 95% CI 0.96-2.29, I² = 0%, p = 0.82). Exercise training in HFpEF results in significant improvements in peak VO₂ and 6MWT distance as compared to those for controls. High-intensity interval training may offer greater enhancement of the exercise capacity of these patients than standard aerobic exercise.