RESUMO
BackgroundPatients with end stage kidney disease (ESKD) receiving in-centre haemodialysis (ICHD) have had high rates of SARS-CoV-2 infection. Following infection, ICHD patients frequently develop serological evidence of infection, even with asymptomatic disease. The aim of this study is to investigate the durability and functionality of immune responses to SARS-CoV-2 infection in ICHD patients. MethodsThree hundred and fifty-six ICHD patients were longitudinally screened for SARS-CoV-2 antibodies and underwent routine PCR-testing for symptomatic and asymptomatic infection. Patients were screened for nucleocapsid protein (anti-NP) and receptor binding domain (anti-RBD) antibodies. Patients who became seronegative at 6 months were investigated for SARS-CoV-2 specific T-cell responses. ResultsOne hundred and twenty-nine (36.2%) patients had detectable antibody to anti-NP at Time 0, of which 127 (98.4%) also had detectable anti-RBD. At 6 months, of 111 patients tested, 71(64.0%) and 97 (87.4%) remained anti-NP and anti-RBD seropositive respectively, p<0.001. For patients who retained antibody, both anti-NP and anti-RBD levels reduced significantly after 6 months. Ten patients who were anti-NP and anti-RBD seropositive at Time 0, had no detectable antibody at 6 months; of which 8 were found to have SARS-CoV-2 antigen specific T cell responses. Independent of antibody status at 6 months, patients with baseline positive SARS-CoV-2 serology were significantly less likely to have PCR confirmed infection over the following 6 months. ConclusionsICHD patients mount durable immune responses 6 months post SARS-CoV-2 infection, with <3% of patients showing no evidence of humoral or cellular immunity. These immune responses are associated with a reduced risk of subsequent reinfection. SIGNIFICANCE STATEMENTFollowing infection with SARS-CoV-2, patients with end stage kidney disease (ESKD) frequently develop serological evidence of infection, even with asymptomatic disease. Patients with ESKD receiving in-centre haemodialysis (ICHD) have had high rates of SARS-CoV-2 infection. What is not known is how durable the serological responses in ESKD patients are or whether evidence of prior immune responses protect patients from reinfection. In this study of 356 ICHD patients, at 6 months following the detection of SARS-CoV-2 antibodies, fewer than 3% of patients lacked evidence of either humoral or cellular immunity. Furthermore, patients with serological evidence of infection had a significantly lower risk of being diagnosed with subsequent infection or reinfection, suggesting functional immune protection.
RESUMO
BackgroundUnderstanding of the true asymptomatic rate of infection of SARS-CoV-2 is currently limited, as is understanding of the population-based seroprevalence after the first wave of COVID-19 within the UK. The majority of data thus far come from hospitalised patients, with little focus on general population cases, or their symptoms. MethodsWe undertook enzyme linked immunosorbent assay characterisation of IgM and IgG responses against SARS-CoV-2 spike glycoprotein and nucleocapsid protein of 431 unselected general-population participants of the TwinsUK cohort from South-East England, aged 19-86 (median age 48; 85% female). 382 participants completed prospective logging of 14 COVID-19 related symptoms via the COVID Symptom Study App, allowing consideration of serology alongside individual symptoms, and a predictive algorithm for estimated COVID-19 previously modelled on PCR positive individuals from a dataset of over 2 million. FindingsWe demonstrated a seroprevalence of 12% (51participants of 431). Of 48 seropositive individuals with full symptom data, nine (19%) were fully asymptomatic, and 16 (27%) were asymptomatic for core COVID-19 symptoms: fever, cough or anosmia. Specificity of anosmia for seropositivity was 95%, compared to 88% for fever cough and anosmia combined. 34 individuals in the cohort were predicted to be Covid-19 positive using the App algorithm, and of those, 18 (52%) were seropositive. InterpretationSeroprevalence amongst adults from London and South-East England was 12%, and 19% of seropositive individuals with prospective symptom logging were fully asymptomatic throughout the study. Anosmia demonstrated the highest symptom specificity for SARS-CoV-2 antibody response. FundingNIHR BRC, CDRF, ZOE global LTD, RST-UKRI/MRC
