LONGITUDINAL FOLLOW-UP of HUMORAL RESPONSE AGAINST SARS-COV-2 and VIRAL PERSISTENCE in 96 DMARDS-TREATED PATIENTS with PREVIOUS COVID-19 INFECTION

ABSTRACT

Background: Although it prevents severe forms of the disease, vaccination does not completely protect against the occurrence of COVID19 disease. If, DMARDs used have been associated with variable humoral response to SARS-CoV-2 vaccination, the impact of their use after SARS-CoV-2 natural infection have been poorly studied. Objectives: To characterize humoral response after SARS-CoV-2 infection and viral persistence in the nasopharyngeal sphere (NP), stools and blood of patients with rheumatic disease under DMARDs, and compared to healthy controls. Methods: Prospective monocentric longitudinal study including patients with rheumatoid arthritis or spondyloarthritis under DMARDs and with a confrmed SARS-CoV-2 infection (positive NP PCR and/or positive serology and/or pathognomonic thoracic tomography (CT)) during the frst or second wave of the COVID pandemic. Patients were followed up until one year after infection and humoral response was assessed before vaccination. Serum IgG and IgA antibodies against spike (S) and nucleocapsid (N) proteins were measured at every visit. Viral persistence was assessed at the early visit in the NP and stools using conventional RT-PCR and in the blood using a high sensitive technique (droplet digital PCR). Results: Between June 2020 and July 2021, we include 96 patients (50 SpA and 46 RA) with a mean age of 53 +/-14 years and 20 healthy controls (mean age 49 ± 16 years) corresponding to relatives of patients (spouses, children) living together and infected at the same time. The immune responses were analyzed according to 6 treatment groups methotrexate (MTX)/salazopyrine (SLZ) monotherapy (n=17/2);anti-TNF monotherapy (n=24), anti-TNF + MTX (n=23);rituximab (RTX) (n=11);anti-IL17 or-23 (n=8);others (n=11). Visits were made at 1 month (29 ±13 days;n=18), 3 months (110 ±23 days;n=67), 6 months (231 ±35 days;n=48) and 12 months (368 ± 19 days;n=19) after infection. The anti-S and anti-N IgG Ab titers were not signifcantly different in the 6 treatment groups and the control population at 3 months. A signifcant decrease in anti-S IgA Ab titers was noted in the group treated with RTX (p=0.007) and with molecules targeting the IL17/23 pathway (p=0.007). A similar but non-signifcant trend was observed in these same treatment groups for anti-N IgA Ab (p=0.07). The titers of anti-SARS-CoV-2 antibodies at M3, was not associated with a severe COVID disease. Detection of SARS-Cov-2 RNA in stools and serum was negative for all samples taken at 1 month or 3 months. 4 patients (2 RA treated with abatacept/RTX and 2 SpA treated with anti-TNF/secukinumab) had a positive RT-PCR NP with low to very low viral load at the 1-month visit (mean Ct 36). None of these 4 patients had had a severe form of COVID19 infection. Conclusion: DMARDs-treated patients with previous proven COVID-19 did not seem to alter IgG Ab response but RTX and anti-IL17/-IL-23 might alter IgA humoral response. This lower immune response was not associated with a more severe disease. In these patients, new infection may not be considered as a full boost for the immune system. DMARDs did not induce viral persistence in the serum, the NP or in the stool.