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Journal of Clinical Rheumatology ; 29(4 Supplement 1):S8, 2023.
Article in English | EMBASE | ID: covidwho-2322533


Objectives: To evaluate the humoral immune response to the third dose (booster) of vaccine against SARS-CoV-2 in patients with autoimmune rheumatic diseases who were seronegative after a two-dose regimen. Method(s): Observational study. Patients with autoimmune rheumatic diseases who had not achieved seroconversion after a two-dose vaccine schedule against SARS-CoV-2 were included. To assess the humoral immune response, anti-RBD IgG (S protein receptor binding domain) neutralizing antibody titers were determined by ELISA (cutoff titer 200). The determination was made between 30 to 45 days after the third dose. Result(s): From 66 patients who received SARS-CoV-2 vaccination, 18 patients (29.5%) were seronegative after a two-dose schedule. 61% had SLE, 77% had comorbidities (61% with hypertension, p = 0.03). Patients were on treatment: 10 with prednisone (8 with doses greater than 10 mg/d, p = 0.01), 10 with hydroxychloroquine, one with methotrexate, one with leflunomide, four with azathioprine, five with my cophenolatemofetil and five with rituximab (they are the total number of non-responders on biological treatment, p = 0.03). Regarding the primary vaccination regimen, 11 received BBIBP-CorV (p = 0.01), 5 AZD1222, 1 Gam-COVID-Vac and 1 mRNA1273/Gam-COVID-Vac heterologous scheme. Of these 18 non-responders, 14 received a third dose;nine patients (62%) presented anti-RBD IgG detectable. Of the five patients who did not respond to the booster vaccination, three had received BBIBP-CorV as the initial schedule and the vaccines applied as a third dose were Ad5-nCoV (1), BNT162b2 (1), AZD 1222 (2) and Gam-COVID-Vac (1). They were being treated with: rituximab (2), azathioprine (2) and mycophenolate mofetil (1). Treatment with higher doses of prednisone was the only factor associated with non-seroconversion to the third dose (8 +/- 4.5;p 0.02). Conclusion(s): The third dose of SARS-CoV-2 vaccine allowed to improve the serological response to vaccination, achieving a seroconversion of 62% in this group of patients.

Annals of the Rheumatic Diseases ; 81:1689, 2022.
Article in English | EMBASE | ID: covidwho-2009070


Background: Several trials have reported lower seroconversion rates in patients with autoimmune rheumatic diseases than in healthy patients. In Argentina, the vaccines that were available during the development of this study were: Sputnik V (Gam-COVID-Vac), AstraZeneca (ChAdOx1 nCov-19), Sinopharm (BBIBP-CorV) and Moderna (mRNA-1273). Limited information is available about vaccines against SARS-CoV2 with inactivated virus or viral vector in autoimmune patients. Objectives: To evaluate the humoral immune response to vaccines against SARS-CoV2 in patients with autoimmune rheumatic diseases;to compare the humoral response among patients with Systemic Lupus Erythematosus (SLE) and other autoimmune diseases and to analyse the variables associated. Methods: We included patients with autoimmune rheumatic diseases (Rheumatology Unit of Padilla Hospital, Tucumán, Argentina), who received vaccination against SARS-CoV2 from June 2021. Sociodemographic, comorbidities, related to rheumatic disease, vaccination and SARS-CoV2 infection were the variables recorded. To evaluate the humoral immune response, the neutralizing anti-S-RBD IgG antibody titres were determined by ELISA 'In House' test with a cut-off titre of 200 (IMMCA). The times established for the serological determinations were: T0 or baseline: 1st vaccine dose, T1: 14 ± 2 days after the 1st dose, T2: 2nd dose, T3: 21-45 days after the 2nd dose, T4: 30 days after the 3rd dose, T5: 6 months and T6: 12 months after the 3rd dose. Results: 66 patients were included, 91% women and 92.4% Amerindians. The mean age was 40.7 ± 11.4 years;53% with SLE, 15.2% Rheumatoid Arthritis, 7.6% Systemic Sclerosis, 7.6% Juvenile Idiopathic Arthritis, 7.6% Systemic Vasculitis and 9% other diagnoses;mean disease duration was 12.05 ± 7. 5 years;63.6% had at least one comorbidity (57% HBP, 31% overweight or obesity). At baseline, the treatments received were: corticoster-oids (37.9%, prednisone mean dose 4.12 ± 8 mg/day), cDMARDs (75.7%), bDMARDs (18.2%): Rituximab (58.3%) and anti TNF (25%). Sixteen patients (24.2%) had previous COVID19 (75% mild symptoms). The vaccines applied were: AstraZeneca 38.2%, Sinopharm 31.7%, Sputnik V 19%, and combined schedule Sputnik V/Moderna in 11%. At baseline, 28.8% had detectable anti-S-RBD IgG antibodies. This frequency increased to 48.4% at 1st dose and 70.2% at 2nd dose. The variables that were associated with lower sero-conversion rates and lower antibody titre were vaccination with Sinopharm (p 0.028) and treatment with bDMARDs (p 0.02), none of the 5 patients with Rituximab showed seroconversion. There were no significant differences in the levels of anti-S-RBD IgG antibodies between patients with SLE and the other rheumatic diseases. Patients who had SARS-CoV2 infection prior to vaccination had higher antibody titres in both T1 (p 0.006) and T2 (p 0.002) but after the two doses this difference was not significant (p 0.67). In the regression analysis, the variables that were independently associated with seroconversion were the type of vaccine applied at the 1st dose and the hypertensive disease. The chance of responding to vaccination was 13 and 9 times higher for those who received Sputnik V (OR 12.78;95% CI 1.46-315.9) or AstraZeneca (OR 8.61;95% CI 1.63-72.5) respectively, than Sinopharm in the 1st dose. The chance of being a responder was 88% lower for hypertensive patients (OR 0.12;95% CI 0.02-0.58). Conclusion: In this preliminary analysis, a seroconversion rate of 70.2% was associated with two-dose vaccination for SARS-CoV2 in patients with autoimmune rheumatic diseases. There were no differences in the serological response between patients with SLE and other rheumatic diseases. The humoral immune response was lower in patients with bDMARDs and null in those who received Rituximab. Seroconversion and antibody titres levels were associated with the type of vaccine applied, being Sinopharm who presented the lowest response. The follow-up will provide more knowledge about the behaviour of the humoral response in our patients.

Biocell ; 46:12, 2022.
Article in English | EMBASE | ID: covidwho-2003440


Despite worldwide efforts to develop different treatments for SARS-CoV-2 COVID-19, the situation remains critical, requiring rapid and effective strategies. In this regard, antibodies (Ab) have demonstrated clinical potential. Among them, camelid nanoAb (VHH) arise as a possible alternative, as they recognize epitopes which are inaccessible to conventional Ab. Further advantages of VHH are their small size, high solubility, high stability, and resistance to low pH. The aim of this work is to describe a purification scheme of different isotypes of anti-SARS-CoV-2 immunoglobulin G (IgG) produced after immunizing two llamas (Lama glama). To achieve this, plasma was injected into an affinity chromatographic column (Protein G), and the resulting fractions were analyzed by SDS-PAGE under non-reducing conditions. The anti-RBD titers were determined by an “in house” ELISA, reaching titers of 52000 and 13000 for IgG1 and IgG3 fractions, respectively. Subsequently, an affinity column (HiTrap NHS-activated) was prepared to separate monospecific anti-RBD polyclonal Ab. RBD produced in our laboratory was covalently coupled to this column, achieving a coupling efficiency of 97%. Different isotypes of monospecific anti-RBD Ab (IgG1: 140 kDa and IgG3: 95 kDa) were obtained. IgG3 represent the starting point for obtaining VHH and/or evaluating their potential use as a therapeutic or preventive alternative, which represents a notable regional contribution in the fight against COVID-19.