Investigating the utility of COVID-19 antibody testing in end-stage renal disease patients receiving haemodialysis: a cohort study in the United Kingdom

Table 2 Trend of antibody status in the 32 positive patients

Variable	First antibody	Second antibody	Third antibody	Fourth antibody	Fifth antibody	Sixth Antibody
Number of patients with IgG antibody level available	32	21	18	20	17	22
Number of patients with IgG antibody level positive	31 (96.9%)	19 (90.5%)	17 (94.4%)	18 (90%)	15 (88.2%)	22 (100%)
Median time between Covid-19 PCR and antibody, days	22 (16–36)	120 (109–124)	152 (142–158)	185 (174–189)	215 (210–220)	242 (233–250)

Categorical variables are expressed as number (%). Continuous variables are expressed as median (interquartile range). The first antibody testing was performed via a CE marked chemiluminescent immunoassay (SNIBE, Shenzhen, China) and the analysis was performed by Medical Diagnostics Ltd. in conjunction with Affinity Biomarker Labs. All subsequent antibody testing was performed by Siemens’ immunoassay using acridinium ester chemiluminescent technology which was a Public Health England approved hospital assay)

ISSN: 1471-2369