Cellular and humoral responses after second and third SARS-CoV-2 vaccinations in patients with autoimmune diseases treated with rituximab: specific T cell immunity remains longer and plays a protective role against SARS-CoV-2 reinfections.

Background: Humoral and cellular immune responses are known to be crucial for patients to recover from COVID-19 and to protect them against SARS-CoV-2 reinfection once infected or vaccinated. Objectives: This study aimed to investigate humoral and T cell responses to SARS-CoV-2 vaccination in patients with autoimmune diseases after the second and third vaccine doses while on rituximab and their potential protective role against reinfection. Methods: Ten COVID-19-naïve patients were included. Three time points were used for monitoring cellular and humoral responses: pre-vaccine to exclude virus exposure (time point 1) and post-second and post-third vaccine (time points 2 and 3). Specific IgG antibodies were monitored by Luminex and T cells against SARS-CoV-2 spike-protein by ELISpot and CoVITEST. All episodes of symptomatic COVID-19 were recorded. Results: Nine patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis and one with an undifferentiated autoimmune disease were included. Nine patients received mRNA vaccines. The last rituximab infusion was administered for a mean (SD) of 15 (10) weeks before the first vaccine and six patients were CD19-B cell-depleted. After a mean (SD) of 19 (10) and 16 (2) days from the second and third vaccine dose, IgG anti-SARS-CoV-2 antibodies were detected in six (60%) and eight (80%) patients, respectively. All patients developed specific T cell responses by ELISpot and CoVITEST in time points 2 and 3. Previous B cell depletion correlated with anti-SARS-CoV-2 IgG levels. Nine (90%) patients developed mild COVID-19 after a median of 7 months of the third dose. Conclusion: Rituximab in patients with autoimmune diseases reduces humoral responses but does not avoid the development of T cell responses to SARS-CoV-2 vaccination, which remain present after a booster dose. A steady cellular immunity appears to be protective against subsequent reinfections.

FRAGILE-COLCOVID19: A Clinical Trial Based on Early Administration of an Oral Combination of Colchicine and Prednisone in Elderly Patients with COVID-19 in Geriatric Facilities.

BACKGROUND: Unprotected and fragile elderly people in nursing homes experienced the highest mortality rates during the initial coronavirus disease 2019 (COVID-19) pandemic. OBJECTIVE: Our aim was to study the role of two oral anti-inflammatory drugs, colchicine and prednisone, in elderly patients with COVID-19 in geriatric centers. METHODS: A phase II/III, randomized, controlled, multicenter clinical trial was performed in a geriatric population comparing the efficacy and safety of an oral combination of prednisone (60 mg/day for 3 days) and colchicine (at loading doses of 1-1.5 mg/day for 3 days, followed by 0.5 mg/day for 11 days) with the standard treatment, based on intravenous dexamethasone. Primary endpoints assessed the efficacy in reducing death or the modified endpoint death/therapeutic failure to the study drugs over a 28-day period, while secondary endpoints included safety, laboratory changes, and additional therapies used. RESULTS: Fifty-four patients (35 female/19 male) were enrolled, 25 (46.3%) of whom were allocated to the experimental arm and 29 (53.7%) to the control arm. At day 28, no differences in deaths were observed. The combination of mortality or therapeutic failure occurred in 12 (45.13%) patients receiving dexamethasone and 6 (28.13%) patients receiving colchicine/prednisone, resulting in a reduction of risk difference (RD) of - 17% (p = 0.17), with an average reduction of 39% (risk ratio [RR] 0.61) in patients receiving colchicine/prednisone (p = 0.25). Control patients received higher amounts of additional glucocorticoids (p = 0.0095) over a longer time frame (p = 0.0003). Colchicine/prednisone significantly reduced ferritin levels at day 14, as well as D-dimer and lactate dehydrogenase (LDH) levels at day 28. Adverse events were similar in both groups. CONCLUSIONS: The combination colchicine/prednisone compared with intravenous dexamethasone has shown a remarkable trend to increase disease survival over a 28-day period in elderly patients requiring oxygen therapy in geriatric centers, without safety issues. CLINICAL TRIAL REGISTRY: Clinical Trials Registration Number: NCT04492358.