Rapid Decline of Anti-SARS-COV-2 Antibodies in Patients on Hemodialysis. The COVID-FRIAT Study

Alcázar-Arroyo, Roberto; Portolés, José; López-Sánchez, Paula; Zalamea, Felipe; Furaz, Karina; Méndez, Ángel; Nieto, Luis; Sánchez-Hernández, Rosa; Pizarro, Soledad; García, Alicia; Pereira, Mónica; Gallego-Valcárcel, Eduardo; Llópez-Carratala, María Rosario; Gironés, Ignacio Gadea; Martín, Roberto; Miranda, Blanca

BACKGROUND: COVID-19 patients on hemodialysis (HD) have high mortality. We investigated the value of RT-PCR and the dynamic changes of antibodies (ELISA IgM+IgA and IgG) in a large HD cohort. METHODS: Prospective observational study in ten Madrid HD centers. Infection rate, anti- SARS-CoV-2 body dynamics and the incidence of asymptomatic SARS-CoV-2 infection (defined by positive RT-PCR, IgM-IgA or IgG) were assessed. RESULTS: From March 1 to April 15, 2020, 136 (16.8%) of 808 HD patients were diagnosed of symptomatic COVID-19 by nasopharyngeal RT-PCR and 42/136 (31%) died. In the second fortnight of April, RT-PCR and anti-SARS-CoV-2 antibodies were assessed on 763 of the surviving patients. At this point, 69/91 (75,8%) symptomatic COVID-19 patients had anti-SARS-CoV-2 antibodies. Four weeks later, 15.4% (10/65) of initially antibody positive patients had become negative. Among patients without prior symptomatic COVID-19, 9/672 (1.3%) were RT-PCR positive and 101/672 patients (15.0%) were antibody positive. Four weeks later, 6224/86 (72.1%) of initially antibody positive patients had become negative. Considering only IgG tittles, serology remained positive after four weeks in 90% (54/60) of patients with symptomatic COVID-19 and in 52.5% (21/40) of asymptomatic patients. The probability of an adequate serologic response (defined as the development of anti-SARS-CoV2 antibodies that persisted at 4 weeks) was higher in patients who had symptomatic COVID-19 than in asymptomatic SARS-CoV2 infection (OR 4.04 [2.04-7.99] corrected for age, Charlson score and time on HD. Living in a nursing home (5.9 [2.3-15.1]) was the main risk factors for SARS-CoV2 infection CONCLUSION: The anti-SARS-CoV-2 antibody immune response in HD patients depends on clinical presentation and the antibody titers decay earlier than previously reported for the general population. This inadequate immune response raises questions about the efficacy of future vaccines.