Distinct anti-NP, anti-RBD and anti-Spike antibody profiles discriminate death from survival in COVID-19
Authors: Servian Carolina do Prado , Spadafora-Ferreira Mônica , Anjos Déborah Carolina Carvalho dos , Guilarde Adriana Oliveira , Gomes-Junior Antonio Roberto , Borges Moara Alves Santa Bárbara , Masson Letícia Carrijo , Silva João Marcos Maia , de Lima Matheus Henrique Assis , Moraes Brenda Grazielli Nogueira , Souza Sueli Meira , Xavier Luiz Eterno , de Oliveira Denise Cristina André , Batalha-Carvalho João Victor , Moro Ana Maria , Bocca Anamélia Lorenzetti , Pfrimer Irmtraut Araci Hoffmann , Costa Nádia Lago , Feres Valéria Christina de Rezende , Fiaccadori Fabiola Souza , Souza Menira , Gardinassi Luiz Gustavo , Durigon Edison Luiz , Romão Pedro Roosevelt Torres , Jorge Soraia Attie Calil , Coelho Verônica , Botosso Viviane Fongaro , Fonseca Simone Gonçalves 
Published: October 2023

Introduction

Infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces rapid production of IgM, IgA, and IgG antibodies directed to multiple viral antigens that may have impact diverse clinical outcomes.

Methods

We evaluated IgM, IgA, and IgG antibodies directed to the nucleocapsid (NP), IgA and IgG to the Spike protein and to the receptor-binding domain (RBD), and the presence of neutralizing antibodies (nAb), in a cohort of unvaccinated SARS-CoV-2 infected individuals, in the first 30 days of post-symptom onset (PSO) (T1).

Results

This study included 193 coronavirus disease 2019 (COVID-19) participants classified as mild, moderate, severe, critical, and fatal and 27 uninfected controls. In T1, we identified differential antibody profiles associated with distinct clinical presentation. The mild group presented lower levels of anti-NP IgG, and IgA (vs moderate and severe), anti-NP IgM (vs severe, critical and fatal), anti-Spike IgA (vs severe and fatal), and anti-RBD IgG (vs severe). The moderate group presented higher levels of anti-RBD IgA, comparing with severe group. The severe group presented higher levels of anti-NP IgA (vs mild and fatal) and anti-RBD IgG (vs mild and moderate). The fatal group presented higher levels of anti-NP IgM and anti-Spike IgA (vs mild), but lower levels of anti-NP IgA (vs severe). The levels of nAb was lower just in mild group compared to severe, critical, and fatal groups, moreover, no difference was observed among the more severe groups. In addition, we studied 82 convalescent individuals, between 31 days to 6 months (T2) or more than 6 months (T3), PSO, those: 12 mild, 26 moderate, and 46 severe plus critical. The longitudinal analyzes, for the severe plus critical group showed lower levels of anti-NP IgG, IgA and IgM, anti-Spike IgA in relation T3. The follow-up in the fatal group, reveals that the levels of anti-spike IgG increased, while anti-NP IgM levels was decreased along the time in severe/critical and fatal as well as anti-NP IgG and IgA in several/critical groups.

Discussion

In summary, the anti-NP IgA and IgG lower levels and the higher levels of anti-RBD and anti-Spike IgA in fatal compared to survival group of individuals admitted to the intensive care unit (ICU). Collectively, our data discriminate death from survival, suggesting that anti-RBD IgA and anti-Spike IgA may play some deleterious effect, in contrast with the potentially protective effect of anti-NP IgA and IgG in the survival group.