ABSTRACT
Background: The COVID-19 PCR swab test has low sensitivity and some infected people are asymptomatic, which makes it possible for inadvertent spread of the virus to occur. We reviewed laboratory data in haemodialysis (HD) patients to investigate the utility of routine blood tests as surrogate markers of COVID-19 infection. Methods: Retrospective cohort study of data in prevalent patients on HD from 1st March 2020. Blood test results from June 2018 to May 2020 were analysed. Results: There were 708 patients. 473 were on HD since June 2018. 150 had ≥1 PCR test for COVID-19: 69 were positive. 268 (37.9%) were female and 282 (39.8%) were of non-white race. Median age was 69 years (IQR 56-78). Lymphocytes Mean lymphocyte count at baseline was 1.5 (SD 4.3). Prior to March 2020, the mean monthly prevalence of lymphopaenia was stable at 32 %, but rose to 67 % in COVID +ve patients and 36 % in COVID -ve patients (p<0.001) during the peak of the COVID crisis in April. Ferritin Mean monthly ferritin at baseline was 395μg/L. Prior to March 2020, only 3% of patients each month had a ferritin of >;1000μg/L. In April, 68 % of COVID +ve individuals had a ferritin of >;1000μg/L compared to 18 % of COVID -ve patients (p<0.001). No significant differences were noted in platelet count, neutrophils and CRP over the study period. Conclusions: Our data show a high prevalence of lymphopaenia which was more pronounced in COVID +ve patients. There was no similar rise over the previous 2 winter periods, so we feel this was a COVID specific, rather than just a viral phenomenon. A low lymphocyte count has recently been associated with adverse prognosis in our patients with COVID-19. Our data support reports which suggest that ferritin could aid screening for COVID-19 in HD patients. The degree of elevation of ferritin during the 'COVID months' in our COVID +ve group suggests that the disease was contributing to this. This may be due to a cytokine storm and multi-organ involvement and ferritin may prove to be a prognostic factor for COVID-19.
ABSTRACT
Background: Dialysis patients, with frequent co-morbidities, advanced age and frailty, visiting treatment facilities frequently are perhaps more prone to SARS-Cov-2 infection and related death - the risk-factors and dynamics of which are unknown. The aim of this study was to investigate the hospital outcomes in SARS-CoV-2 infected dialysis patients. Methods: This prospective, observational, multi-centre study collected data on SARS-CoV-2 infected HD patients between 29/02/2020 and 15/05/2020. Data was collected on demographics, comorbidities, WHO performance status, clinical symptoms, laboratory parameters, hospital management and outcomes. Treatment was predominantly supportive, unless patients were part of an approved clinical trial. The study was approved by NHS Research Ethics Committee 20/SW/0077 and Heath Research Authority IRAS 283130. Results: Of 1737 HD patients at the 3 renal centres, 224 (13%) were COVID-19 positive over the study period. The characteristics of the COVID-19 HD patients were: mean age 65.8;59% male;38% Caucasian;81% hypertension;54% diabetes;25% chronic lung disease;29% ischaemic heart disease and 22% cerebrovascular disease. The most common symptoms at presentation were fever (62%) and cough (53%). About 143 (64%) patients were managed as an inpatient and 81 (36%) as an outpatient. Of 9 patients that required mechanical ventilation: 6 died, 1 patient was discharged and 2 are still under clinical care. Overall 51 patients died (23%), 154 (69%) were discharged alive and 19 (8%) were still under clinical care as of 15/05/2020. Preliminary analyses suggested that those that died were significantly older (p=0.0028), more likely to have ischaemic heart disease (p=0.003), cerebrovascular disease (p=0.019), smoking history (p=0.006), WHO performance status 3-4 (p=0.004), higher neutrophil: lymphocyte ratio at presentation (p=0.0001) and higher CRP at presentation (p=0.0021). Conclusions: This large cohort of COVID-19 positive haemodialysis demonstrates a high case fatality ratio, which increased significantly with age, cardiovascular disease, smoking history, frailty and markers of inflammation.