Vaccination against SARS-CoV-2 in Haemodialysis Patients: Spike's Ab Response and the Influence of BMI and Age.

Patients with chronic kidney disease (CKD-5D) in dialysis have been associated with higher rates of SARS-CoV-2 infection. Objective: To identify the CKD-5D patients' immune system behavior regarding the Pfizer-BioNTech (BNT162b2 mRNA) vaccine (Comirnaty©). This was a multicenter study carried out in 38 dialysis units in NephroCare Portugal. Eligible patients from two cohorts-one composed of completely vaccinated patients with Comirnaty© (vaccinated group) against a second cohort of patients who recovered from SARS-CoV-2 infection (control group)-were selected through representative sampling for each cohort. Humoral response was assessed at 3 (t0) and 6 months (t1) after complete vaccination and, in the control group, 6 months after COVID-19 recovery. In the vaccinated group, at t0, the median anti-Spike IgG level was 1120 AU/mL and, at t1, all participants' antibody level decreased to a median of 455 AU/mL. In the control group, the median serum SARS-CoV-2 antibodies level was 1836 AU/mL. In the vaccinated group, at t0, patients < 70 years presented a significantly (p = 0.002) higher level of anti-Spike IgG titres. In contrast, older patients from the control group presented a significantly (p = 0.038) higher IgG. No correlation was found between age and anti-Spike IgG antibodies level in any of the studied groups. Patients with a higher body mass index showed a greater immune response in both the vaccinated and control group, although without significance. We concluded that, in the vaccinated group, elderly patients developed a lower immune response than younger patients and the levels of anti-Spike IgG antibodies declined faster between t0 and t1, while in the control group, the oldest and overweight patients developed the best humoral response.

[Vaccination Against COVID-19 in a Network of Hemodialysis Units in Portugal: A Promising Experience].

INTRODUCTION: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) responsible for coronavirus disease 2019 (COVID-19) seriously affected Portugal, particularly in the elderly population with a high number of comorbidities, including patients with chronic kidney disease in stage 5 (CKD-5D) undergoing a regular dialysis program. The aims of this study were to identify the impact of vaccination on the incidence of new daily cases and mortality in the CKD-5D population. MATERIAL AND METHODS: Prospective, observational study, involving patients with CKD-5D from 38 NephroCare clinics, Portugal. Daily SARS-CoV-2 infections and mortality among these patients was compared with the incidence in the general population. Three periods were analysed: before vaccination, during the vaccination process, and a third period after complete vaccination with the Pfizer-BioNTech' Comirnaty® vaccine. The primary outcome was infection by the SARS-CoV-2 virus and the secondary outcome was death associated with the infection. RESULTS: A total of 4617 patients (average of 69.37 years of age) were analysed. During the first period, there was a significantly higher COVID-19 incidence of 14.9% in patients with CKD-5D compared with the general population (7.9%; p < 0.001). During the fifteen days after the complete vaccination, results reverted to a significant decrease in COVID-19 cases was observed (p < 0.001). The mortality rate among CKD-5D was significantly higher than in the general population (p < 0.001). DISCUSSION: A high incidence rate of infection was observed in CKD-5D patients, probably due to several factors such as advanced age, number of comorbidities, inability to remain in confinement, among others. After vaccination there was a significant reduction of new cases. CONCLUSION: Vaccination significantly reduced SARS-CoV-2 infection in patients with CKD-5D.

Introdução: Portugal foi atingido severamente pela síndrome respiratória aguda grave (SARS-CoV-2), responsável pela doença por coronavírus 2019 (COVID-19). A população idosa e com comorbilidades, na qual estão incluídas as pessoas com doença renal crónica em estádio 5 em programa regular de hemodiálise (CKD-5D), foi particularmente afetada. Definimos como objetivos deste estudo a identificação do impacto da vacinação no surgimento de novos casos diários e a sua influência na mortalidade na população CKD-5D.Material e Métodos: Estudo observacional, prospetivo, envolvendo doentes com CKD-5D de 38 clínicas da NephroCare, Portugal. A infeção e a mortalidade diárias por SARS-CoV-2 destes doentes foi comparada com a taxa de incidência na população em geral. Foram analisados três períodos: antes da vacinação, durante, e um terceiro período após a vacinação completa pela vacina Comirnaty ®, da Pfizer-BioNTech. Foi considerado desfecho primário a infeção pelo vírus SARS-CoV-2 e como desfecho secundário, a morte associada à infeção.Resultados: Foram analisados 4617 doentes com uma média de 69,37 anos. Durante o primeiro período, verificou-se uma taxa de incidência de COVID 19 de 14,9%, significativamente maior nos doentes CKD-5D quando comparado com a taxa de incidência de 7,9% da população em geral (p < 0,001). Durante os quinze dias após a vacinação completa observámos uma reversão, com diminuição significativa de casos de COVID-19 (p < 0,001). A mortalidade atribuível a COVID-19 no grupo CKD-5D foi significativamente superior ao da população em geral (p < 0,001).Discussão: Observámos uma elevada taxa de incidência de infeção nos doentes CKD-5D, presumivelmente correlacionada com vários fatores como a idade avançada, as comorbilidades, a impossibilidade de confinar, entre outros. Após a vacinação verificou-se uma redução significativa de novos casos.Conclusão: A vacinação reduziu significativamente a infeção por SARS-CoV-2 nos doentes CKD-5D.

Contamination inside CT gantry in the SARS-CoV-2 era.

We investigated whether the internal gantry components of our computed tomography (CT) scanner contain severe acute respiratory syndrome 2 (SARS-CoV-2) ribonucleic acid (RNA), bacterial or fungal agents. From 1 to 27 March 2020, we performed 180 examinations of patients with confirmed SARS-CoV-2 infection using a dedicated CT scanner. On 27 March 2020, this CT gantry was opened and sampled in each of the following components: (a) gantry case; (b) inward airflow filter; (c) gantry motor; (d) x-ray tube; (e) outflow fan; (f) fan grid; (g) detectors; and (h) x-ray tube filter. To detect SARS-CoV-2 RNA, samples were analysed using reverse transcriptase-polymerase chain reaction (RT-PCR). To detect bacterial or fungal agents, samples have been collected using "replicate organism detection and counting" contact plates of 24 cm2, containing tryptic soy agar, and subsequently cultured. RT-PCR detected SARS-CoV-2 RNA in the inward airflow filter sample. RT-PCR of remaining gantry samples did not reveal the presence of SARS-CoV-2 RNA. Neither bacterial nor fungal agents grew in the agar-based growth medium after the incubation period. Our data showed that SARS-Cov-2 RNA can be found inside the CT gantry only in the inward airflow filter. All remaining CT gantry components were devoid of SARS-CoV-2 RNA.

Evaluation of novel coronavirus disease (COVID-19) using quantitative lung CT and clinical data: prediction of short-term outcome.

BACKGROUND: Computed tomography (CT) enables quantification of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, helping in outcome prediction. METHODS: From 1 to 22 March 2020, patients with pneumonia symptoms, positive lung CT scan, and confirmed SARS-CoV-2 on reverse transcription-polymerase chain reaction (RT-PCR) were consecutively enrolled. Clinical data was collected. Outcome was defined as favourable or adverse (i.e., need for mechanical ventilation or death) and registered over a period of 10 days following CT. Volume of disease (VoD) on CT was calculated semi-automatically. Multiple linear regression was used to predict VoD by clinical/laboratory data. To predict outcome, important features were selected using a priori analysis and subsequently used to train 4 different models. RESULTS: A total of 106 consecutive patients were enrolled (median age 63.5 years, range 26-95 years; 41/106 women, 38.7%). Median duration of symptoms and C-reactive protein (CRP) was 5 days (range 1-30) and 4.94 mg/L (range 0.1-28.3), respectively. Median VoD was 249.5 cm3 (range 9.9-1505) and was predicted by lymphocyte percentage (p = 0.008) and CRP (p < 0.001). Important variables for outcome prediction included CRP (area under the curve [AUC] 0.77), VoD (AUC 0.75), age (AUC 0.72), lymphocyte percentage (AUC 0.70), coronary calcification (AUC 0.68), and presence of comorbidities (AUC 0.66). Support vector machine had the best performance in outcome prediction, yielding an AUC of 0.92. CONCLUSIONS: Measuring the VoD using a simple CT post-processing tool estimates SARS-CoV-2 burden. CT and clinical data together enable accurate prediction of short-term clinical outcome.