Clinical features and outcome of maintenance hemodialysis patients with COVID-19 from a tertiary nephrology care center in Romania

Background There is limited information about the clinical characteristics, treatment and outcome of maintenance hemodialysis patients with COVID-19. Moreover, regional differences are also conceivable since the extend and severity of outbreaks varied among countries.Methods In this retrospective, observational, single-center study, we analyzed the clinical course and outcomes of 37 maintenance hemodialysis patients (median age 64 years, 51% men) hospitalized with COVID-19 from 24 March to 22 May 2020 as confirmed by real-time PCR.Results The most common symptoms at admission were fatigue (51%), fever (43%), dyspnea (38%) and cough (35%). There were 59% mild/moderate patients and 41% severe/critical patients. Patients in the severe/critical group had a significantly higher atherosclerotic burden since diabetic kidney disease and vascular nephropathies were the most common primary kidney diseases and eighty percent of them had coronary heart disease. Also, Charlson comorbidity score was higher in this group. At admission chest X-ray, 46% had ground-glass abnormalities. Overall, 60% patients received hydroxychloroquine, 22% lopinavir–ritonavir, 11% tocilizumab, 24% systemic glucocorticoids, and 54% received prophylactic anticoagulation. Seven (19%) patients died during hospitalization and 30 were discharged. The main causes of death were cardiovascular (5 patients) and respiratory distress syndrome (2 patients). In Cox regression analysis, lower oxygen saturation, anemia and hypoalbuminemia at admission were associated with increased mortality.Conclusions In conclusion, we observed a high mortality rate among maintenance hemodialysis patients hospitalized for COVID-19. Anemia, lower serum albumin and lower basal oxygen saturation at admission were factors associated with poor prognosis.     

Increased postoperative myeloperoxidase concentration associated with low baseline antioxidant capacity as the risk factor of delirium after cardiac surgery

BackgroundThough risk factors of postoperative delirium are well described, its pathophysiology is still undiscovered. The primary objective of the current study is to assess whether increased pre- and postoperative myeloperoxidase (MPO) levels are associated with postoperative delirium in the population of cardiac surgery patients. The secondary objective is to evaluate the correlation between MPO levels and serum antioxidant capacity (AC).MethodsThe patients’ cognitive status was assessed one day preoperatively with the use of the Mini-Mental State Examination Test and the Clock Drawing Test. A diagnosis of major depressive disorder and anxiety disorders was established based on DSM-5 criteria. Blood samples for MPO and AC levels were collected both pre- and postoperatively. The Confusion Assessment Method for the Intensive Care Unit was used to screen for a diagnosis of delirium.ResultsDelirium occurred in 34% (61 of 177) of patients. Multivariable logistic regression analysis revealed that increased postoperative MPO concentration was independently associated with postoperative delirium development, and negatively correlated with lower baseline serum AC.ConclusionsCardiac surgery patients with less efficient antioxidative mechanisms experience a higher postoperative peak of serum MPO, which in turn may predispose to postoperative delirium development.

KEY MESSAGES

• MPO is a lysosomal enzyme with strong pro-oxidative and pro-inflammatory properties.
• Cardiac surgery patients who have increased concentration of postoperative MPO are at significantly higher risk of postoperative delirium development.
• This higher level of postoperative MPO is negatively correlated with baseline antioxidant capacity (AC).
• It can be hypothesized that individuals with decreased baseline AC experience a higher peak of MPO post-surgery due to less efficient antioxidative mechanisms, which in turn contributes to postoperative delirium development.

     

The effect of antibiotics on the function of the phagocytic system

The present paper reviews the effect of various antibiotics (ATB) on the cells of the phagocytic system. The first part deals with an indirect mechanism of action of ATB, i.e. with changes induced in the bacterial cell which in turn renders these bacteria susceptible to phagocytosis. In the second part, the direct effect of ATB on phagocytic cells is discussed: binding of ATB to phagocytes, penetration into the cell, change in chemotactic (migratory) activity, effects on ingestion of particles, intracellular killing of bacteria and on phagocytosis-associated metabolic changes (e.g. chemiluminescence).     

Comparative phagocytosis of cadmium microcrystals by peripheral blood glass-adherent cells of newborn and healthy adults

Microcrystals of cadmium, saturated with human serum albumin, were employed as a microassay for phagocytosis by glass-adherent blood cells. Using this assay, it was found that leukocytes of newborns possess significantly higher phagocytic activity and that a higher proportion of active phagocytic cells is present in newborns than in adults. In contrast, adult sera contain higher level of opsonins for cadmium microcrystals than cord sera. Heat inactivation and zymosan absorption of both adult and cord sera decreased significantly the opsonic power of sera, thus suggesting the participation of complement in opsonization of these particles.     

Effects of bilirubin on murine peritoneal and spleen cells

The effect of bilirubin on murine peritoneal and spleen cells was investigated. Bilirubin was found to have a strong and rapid effect on the expression of various kinds of Fc receptors on peritoneal macrophages. Significant changes were observed 30 min after the infection of bilirubin. The return to normal values was not observed earlier than after 24 h. The effect of bilirubin on Fc receptor expression of splenic macrophages was less pronounced. Expression of Ia antigen on macrophages was not influenced by bilirubin. The changes in percentage of sIg+ and Thy 1.2+ lymphocytes reflect a change in the ratio of T to B cells in the peritoneal cavity, as bilirubin caused 40% increase in numbers of B cells and a similar decrease in numbers of T cells. The percentage of splenic B lymphocytes was not influenced by bilirubin injection; but the ratio of T helper to suppressor cells was altered.