The presence of CD55- and/or CD59-deficient erythrocytic populations in patients with rheumatic diseases reflects an immune-mediated bone-marrow derived phenomenon.

BACKGROUND: Complement has the potential to provoke severe impairment to host tissues, as shown in autoimmune diseases where complement activation has been associated with diminished CD55 and/or CD59 expression on peripheral blood cell membranes. The aim of this study was to evaluate the presence of CD55- and/or CD59-deficient erythrocytic populations in patients with different rheumatic diseases and to investigate possible correlations with clinical or laboratory parameters. MATERIAL AND METHODS: CD55 and CD59 expression was evaluated in erythrocytes of 113 patients with rheumatic diseases, 121 normal individuals, and 10 patients with paroxysmal nocturnal hemoglobinuria (PNH) using the Sephacryl gel microtyping system. Ham and sucrose tests were also performed. RESULTS: Interestingly, the majority of patients (104/113, 92%) demonstrated CD55- and/or CD59-deficient erythrocytes: 47 (41.6%) with concomitant deficiency of CD55 and CD59, 50 (44.2%) with isolated deficiency of CD55, and 6 (6.2%) with isolated deficiency of CD59. In normal individuals, only 2 (1%) had concomitant CD55/CD59 negativity and 3 (2%) had isolated CD55 or CD59 deficiency. All PNH patients exhibited simultaneous CD55/CD59 deficiency. Positive Ham and sucrose tests were found only in PNH patients. There was no association between the CD55- and/or CD59-deficient erythrocytes and hemocytopenias or undergoing treatment. However, CD55 expression significantly influenced hemoglobin values (F=6.092, p=0.015). CONCLUSIONS: This study provides evidence supporting the presence of erythrocytes with CD55 and/or CD59 deficiency in patients with rheumatic diseases. Moreover, CD55 deficiency on red cells influences hemoglobin concentration. Further studies using molecular techniques will clarify the exact pathophysiological mechanisms of this deficiency.

Risk factors for the in­hospital and 1­year mortality of elderly patients hospitalized due to COVID­19­related pneumonia.

Coronavirus disease 2019 (COVID-19) is characterized by poor outcomes and a high mortality rate, particularly among elderly patients. Since the beginning of the pandemic, an older age has been recognized as a critical risk factor for disease severity, with increasing mortality rates in each decade of life. This phenomenon may be a consequence of a poor previous health status, with a higher prevalence of pre-existing comorbidities and a higher degree of frailty. The majority of studies on the outcomes and risk factors of elderly patients refer to the first waves of the pandemic and the predictors of in-hospital mortality in these patients. The aim of the present study was to provide a detailed description of the clinical characteristics and management of a cohort of elderly patients (≥65 years of age) who were hospitalized with COVID-19-related pneumonia in all phases of the pandemic, presenting their outcomes, and investigating predictors of in-hospital and out-of-hospital mortality over a period of 1 year in this particularly vulnerable population. A total of 1,124 elderly patients (603 males, 53.7%) with a mean age of 78.51±7.42 years and a median Charlson comorbidity index (CCI) of 5 were included in the study. Of these patients, 104 (9.3%) were hospitalized during the period of prevalence of the original strain Wuhan, 385 (34.3%) were hospitalized during the period of prevalence of the Alpha variant, 221 (19.7%) were hospitalized during the period of prevalence of the Delta variant, and 414 (36.8%) were hospitalized during the period of prevalence of the Omicron variant. Overall, the in-hospital mortality rate was 33.4% (375 patients), and the 1-year mortality rate was 44.7% (502 patients). The majority of patients had not been vaccinated or had not completed full vaccination against severe acute respiratory syndrome coronavirus-2 (843 patients, 75%), given the period of infection. Age, immature granulocytes, lactate dehydrogenase (LDH) levels, ferritin levels, chest X-ray score, as well as the absence of full vaccination, cough and fatigue, were statistically significantly and independently associated with in-hospital mortality, while age, LDH levels, ferritin levels, alanine aminotransferase levels, CCI, chest X-ray score, the absence of cough and fatigue, and a history of dementia were statistically significantly and independently associated with 1-year mortality. On the whole, the present study demonstrates that both the in-hospital mortality and 1-year mortality rates of elderly patients hospitalized due to COVID-19-related pneumonia are high.

Factors predicting poor outcomes of patients treated with tocilizumab for COVID­19­associated pneumonia: A retrospective study.

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic is a significant global issue that has major implications for the healthcare system. The mortality rates associated with SARS-CoV-2 infection vary according to the geographical region and are associated with age, comorbidities and vaccination status. Organ damage is caused by the cytokine release syndrome, which plays a crucial role in the course of coronavirus disease 2019 (COVID-19) infection. Innate and adaptive immune system stimulation in patients with COVID-19 results in inappropriate cytokine release. The anti-IL-6 receptor antagonist, tocilizumab, is used in the treatment of connective tissue diseases. The present single-center retrospective study on patients with COVID-19 admitted to hospital between September, 2020 and April, 2022 aimed to identify predictors of mortality and other unfavorable outcomes in patients treated with tocilizumab for COVID-19-associated pneumonia. Demographics, vaccination status against SARS-CoV-2, the Charlson comorbidity index (CCI), laboratory data and chest X-ray scores were recorded upon admission. In total, 174 subjects (121 males; mean age, 62.43±13.47 years) fulfilling the inclusion criteria were included. Among the 174 participants, 58 (33.3%) were intubated. The mortality rate was 35.1%. The non-survivors were older, mostly females, and had a higher CCI score. At the evaluation upon admission, the survivors presented with higher levels of alanine transferase and gamma glutamyl-transferase and with a greater number of platelets (PLTs), while patients that were intubated were also older, mostly females, and had a higher CCI score (P<0.05). Age was identified as the only independent factor predicting mortality in the Cox proportional hazards multivariate regression analysis. By performing a sub-analysis regarding sex, it was revealed that the value of PLTs was an independent factor predicting intubation and 90-day mortality in male patients, and the lymphocyte count was the only factor associated with intubation in female patients. On the whole, the data of the present study may be used to identify patient subpopulations responding to treatment with tocilizumab in prospective clinical trials.

Does Route of Full Feeding Affect Outcome among Ventilated Critically Ill COVID-19 Patients: A Prospective Observational Study.

The outbreak of the new coronavirus strain SARS-CoV-2 (COVID-19) highlighted the need for appropriate feeding practices among critically ill patients admitted to the intensive care unit (ICU). This study aimed to describe feeding practices of intubated COVID-19 patients during their second week of hospitalization in the First Department of Critical Care Medicine, Evaggelismos General Hospital, and evaluate potential associations with all cause 30-day mortality, length of hospital stay, and duration of mechanical ventilation. We enrolled adult intubated COVID-19 patients admitted to the ICU between September 2020 and July 2021 and prospectively monitored until their hospital discharge. Of the 162 patients analyzed (52.8% men, 51.6% overweight/obese, mean age 63.2 ± 11.9 years), 27.2% of patients used parenteral nutrition, while the rest were fed enterally. By 30 days, 34.2% of the patients in the parenteral group had died compared to 32.7% of the patients in the enteral group (relative risk (RR) for the group receiving enteral nutrition = 0.97, 95% confidence interval = 0.88-1.06, p = 0.120). Those in the enteral group demonstrated a lower duration of hospital stay (RR = 0.91, 95% CI = 0.85-0.97, p = 0.036) as well as mechanical ventilation support (RR = 0.94, 95% CI = 0.89-0.99, p = 0.043). Enteral feeding during second week of ICU hospitalization may be associated with a shorter duration of hospitalization and stay in mechanical ventilation support among critically ill intubated patients with COVID-19.

The role of gut microbiota in Clostridium difficile infection.

Clostridium difficile infection has emerged as a major health problem. Because it is a spore-forming microorganism, C. difficile is difficult to eradicate and recurrences of the infection are frequent. The strong association of CDI with prior use of antibiotics led to the recognition that disturbances in the gut microbiota apparently plays a central role in CDI. Except for antibiotics, several other risk factors for CDI have been recognised, such as advanced age and use of proton pump inhibitors. The common characteristic of these factors is that they are associated with changes in the composition of gut microbiota. Data from human studies have shown that the presence of C. difficile, either as a colonizer or as a pathogen, is associated with reduced microbiota diversity. C. difficile infection per se seems to be associated with changes in the representation of specific microbial populations (e.g. taxa) which either may act protectively against C. difficile colonization of the gut or may increase susceptibility for C. difficile infection. Therapeutic gut microbiota manipulation can be achieved by faecal microbiota transplantation, which is highly effective for the treatment of CDI.