Lymphocyte Populations and Autoantibodies, in a Cohort of Patients with Rheumatoid Arthritis: A Long-Term Study of Covid-19 Cases and Non-Covid-19 Controls

Objectives: To assess the immunological [Lymphocyte populations (LP) and Autoantibodies (Ab)] and clinical profile of rheumatoid arthritis (RA) patients who suffered from COVID-19 compared with non-COVID-19 RA patients. Method(s): A nested case-control study of RA patients treated under a strict follow-up model. RA patients and confirmed COVID-19 infection (last 24 months) and RA patients without the infection were included. Subgroups of cases: Long COVID (LC): symptoms after infection for >=4 weeks;Post COVID syndrome (PCS): symptoms for >=12 weeks;and patients with symptoms alpha4 weeks. Sociodemographic, clinical, and paraclinical variables of RA and COVID-19 infection (in cases) were captured. Antinuclear antibodies (ANA), anticardiolipin antibodies, lymphocyte populations (BD FACSDuetTM-BDFACSLyricTMmultiparameter flow cytometry) T cells, B cells, and NK were evaluated. Univariate and bivariate analyzes (STATA 17) were done. Result(s): 300 patients were included (148 cases/152 controls;87.3% women). Median age 59 years (IQR 11). 71.86% were in low disease activity. There were no significant differences in sociodemographic and clinical characteristics between cases and controls. Cases had a time since infection of 18.5 months (IQR 7). Of the total cases, 69%presented LC and 63%PCS.No significant differences were found between cases and controls in the lymphocyte population nor in the antibodies evaluated. There were no differences in the immune profile when comparing patients with LC and PCS with those with symptoms alpha4 weeks after COVID-19 infection. Conclusion(s): No differences were found in the behavior of the immunological profile (independent of symptoms of LC and PCS) in RA patients under strict follow up, evaluated long-term after infection with those who did not have COVID-19. This suggest that patients returned to their baseline homeostatic state, something that has not yet been reported up to now. These results should be replicated in populations with different RA characteristics.

Rituximab in multiple sclerosis: A tertiary hospital experience

Background and aims: B-lymphocytes play an important role in the pathophysiology of MS. As with other anti- CD20-antibodies, there is evidence that Rituximab may be effective and safe in this disease. Methods: Retrospective study in MS patients treated with Rituximab between 2017-2021. Demographic, clinical, radiologic and laboratory variables were analyzed. Results: 45 patients were included (60% males, mean age 48.3±8;84.4% presented SPMS;median baseline EDSS 6.0, IQR 4-6.5;mean follow-up 22.69±8.75 months). After one year of treatment, there was a significant reduction of relapses (ARR 0.51 vs 0.1, p=0.002), new/enlarged T2 lesion (60% vs 10%, p<0.001) or gadolinium-enhancing lesions (40% vs 0%, p<0.001) on MRI. EDSS, T25FWT, 9HPT or SDMT did not significally change. 33.3% presented confirmed disability progression (CDP). 56.4% achieved NEDA-3. Retreatment was guided by B-lymphocytes count. Mean B-cells count was 285.7, 1.553, 4.456, 54.35, 10.47 at baseline, 3, 6, 9 and 12 months, respectively. Mean time to retreatment was 9.05±3.14 months. Lipidospecific IgM-OCB were associated with CDP (adjusted OR 6.33, p=0.047). At first dose, 31.1% presented an infusion reaction, with fewer cases with retreatment. 28.8% presented infections of any kind, including three cases of Covid19 (only one case of severe infection was reported). No cases of hypogammaglobulinemia were reported. Conclusion: B-lymphocytes count guiding retreatment with Rituximab among patients with MS may favor a good safety profile, while being effective in reducing inflammatory activity. CDP was associated with lipidospecific IgM-OCB.

Acute-onset smell and taste disorders in the context of COVID-19: a pilot multicentre polymerase chain reaction based case-control study.

BACKGROUND AND PURPOSE: Specific respiratory tract infections, including COVID-19, may cause smell and/or taste disorders (STDs) with increased frequency. The aim was to determine whether new-onset STDs are more frequent amongst COVID-19 patients than influenza patients. METHOD: This was a case-control study including hospitalized patients of two tertiary care centres. Consecutive patients positive for COVID-19 polymerase chain reaction (cases) and patients positive for influenza polymerase chain reaction (historical control sample) were assessed during specific periods, employing a self-reported STD questionnaire. RESULTS: Seventy-nine cases and 40 controls were included. No significant differences were found in basal features between the two groups. New-onset STDs were significantly more frequent amongst cases (31, 39.2%) than in the control group (5, 12.5 %) [adjusted odds ratio 21.4 (2.77-165.4, P = 0.003)]. COVID-19 patients with new-onset STDs were significantly younger than COVID-19 patients without STDs (52.6 ± 17.2 vs. 67.4 ± 15.1, P < 0.001). Amongst COVID-19 patients who presented STDs, 22 (70.9%) recalled an acute onset and it was an initial manifestation in 11 (35.5%). Twenty-five (80.6%) presented smell disorders (mostly anosmia, 14, 45.2%) and 28 (90.3%) taste disorders (mostly ageusia, 14, 45.2%). Only four (12.9 %) reported concomitant nasal obstruction. The mean duration of STD was 7.5 ± 3.2 days and 12 patients (40%) manifested complete recovery after 7.4 ± 2.3 days of onset. CONCLUSION: New-onset STDs were significantly more frequent amongst COVID-19 patients than influenza patients; they usually had an acute onset and were commonly an initial manifestation. The use of STD assessment in anamnesis as a hint for COVID-19 and to support individuals' self-isolation in the current epidemic context is suggested.

Impact of the COVID-19 pandemic on the Colombian population according to mitigation measures Preliminary data from epidemiological models for the period March 18 to April 18, 2020

Introduction First case of COVID-19 in Colombia was diagnosed on March 6th. Two weeks later, cases have rapidly increased, leading the government to establish some mitigation measures. Objectives The first objective is to estimate and model the number of cases, use of hospital resources and mortality by using different R0 scenarios in a 1-month scenario (from March 18 to April 18, 2020), based on the different isolation measures applied. This work also aims to model, without establishing a time horizon, the same outcomes given the assumption that eventually 70% of the population will be infected. Materials and Methods Data on the number of confirmed cases in the country as of March 18, 2020 (n=93) were taken as the basis for the achievement of the first objective. An initial transmission rate of R0= 2.5 and a factor of 27 for undetected infections per each confirmed case were taken as assumptions for the model. The proportion of patients who may need intensive care or other in-hospital care was based on data from the Imperial College of London. On the other hand, an age-specific mortality rate provided by the Instituto Superiore di Sanità in Italy was used for the second objective. Results Based on the 93 cases reported as of March 18, if no mitigation measures were applied, by April 18, the country would have 613 037 cases. Mitigation measures that reduce R0 by 10% generate a 50% reduction in the number of cases. However, despite halving the number of cases, there would still be a shortfall in the number of beds required and only one in two patients would have access to this resource. Conclusion This model found that the mitigation measures implemented to date by the Colombian government and analyzed in this article are based on sufficient evidence and will help to slow the spread of SARS-CoV-2 in Colombia. Although a time horizon of one month was used for this model, it is plausible to believe that, if the current measures are sustained, the mitigation effect will also be sustained over time. © 2020, Universidad Nacional de Colombia. All rights reserved.