583. SARS-CoV-2 Spike Protein S1/S2 Antibodies after Vaccination with Sinopharm in Peruvian Physicians

Background

Peru started its national vaccination campaign in February 2021 using Sinopharm vaccine, targeting healthcare personnel on its initial phase. Although the immunogenicity of this vaccine was tested in clinical trials, there are no studies that evaluated the humoral response post vaccination in Peru.

Methods

We conducted a cross sectional study, which objective was to evaluate the humoral immunogenicity triggered by the Sinopharm vaccine in Peruvian physicians. We collected demographic and epidemiologic data via an electronic. The SARS-CoV-2 spike protein S1/S2 antibodies were measured by chemiluminescense (Liaison®). A positive test was defined as >15 U/ml, which has correlation of 95% with neutralizing antibodies measured by plaque reduction neutralizing test.

Results

92 participants were enrolled in the study. The epidemiologic characteristics are described in table 1. The mean level of antibodies measured at least 2 weeks from the second vaccine dose was 67.5 ± 70.5 U/ml. 85.7% of the study cohort had positive S1/S2 antibodies. In the univariate analysis, an imperfect negative correlation was found between the level of antibodies and participants’ age (r= -0.24; regression F test 5.25; p = 0.0242). A weak negative correlation was observed between the antibody titer and the time elapsed from the second vaccine dose and the day of antibody measurement (r= -0.17). A higher antibody level post vaccine was found in individuals who worked in COVID units (105.5 U / mL vs 58.2 U / mL; p = 0.0125), and in participants with history of COVID (216.5 U / mL vs 81.2 U / mL; p = < 0.0000). Hypertension was associated with lower antibody titers (36.9 U / mL vs. 74.6; p = 0.0464). In the multivariate analysis, working in COVID units, having previous COVID infection and shorter time from second vaccine dose and day of antibody measurement were associated with higher antibody levels post vaccine (table 2).

Conclusion

Our study showed that the time elapsed from the second vaccine dose and the day of antibody measurement, having previous COVID-19 infection and working in COVID -19 units may help to predict higher antibody titers post vaccine. Larger studies to evaluate the humoral response post Sinopharm vaccine and its clinical implications are still needed in Peru.

Disclosures

All Authors: No reported disclosures

P1438IMPACT OF HOSPITALIZATION ON BODY COMPOSITION OF DIALYSIS PATIENTS

Background and Aims

Patients with CKD are at higher risk of hospitalization (hosp) and this event is a known marker of prognosis. In this study we aim to describe hospitalizations in LatinAmerica and the impact on body composition as measured by multifrequency bioimpedance.

Method

All hospitalizations from Fresenius Medical Care clinical database (EuCliD®) registered in dialysis patients from Argentina, Brasil, Chile, Colombia, Ecuador and Perú during calendar year 2018 were included into the analysis. For each hospitalization we reviewed main reason (ICD10 code), duration and outcome (discharge or death). Body composition was measured using multifrequency bioimpedance (BMC®). On patients with BCM data available in the 30 days prior to hospitalization and before 15 days after discharge values pre and post hospitalization were recorded (BCM data, lab data, treatment data). Pre and post data were compared using Student t test for paired samples. All values expressed as mean ± standard deviation (SD).

Results

During all calendar year 2018, a total of 23,347 hospitalizations from 44,228 patients were recorded.  Mean age was 61.4 ± 16.1 / Male 56.4% / diabetes 38.7%. Accounting for time at risk, hosp rate was 0.74 hosp/pt-year at risk. Mean stay at hospital was 10.9 ± 14.4 days (7.6 days/pt-yr). 35.24% of patients suffer at least one hosp during the year.

Reasons for hospitalization are indicated in table 1:

Conclusion:

Hospitalization in dialysis patients is a frequent event. It has a significant impact on Hb, Ca, P and Albumin levels. Although net patient's weight is significantly reduced, real decrease in muscular and fat mass may be masked by increase in excess water (overhydration) as shown in our results. An early BCM measurement and dry weight adjustment after discharge may be a helpful tool for patient management optimization.

Optical coherence tomography characteristics of full-thickness traumatic macular holes

PURPOSE

The objective of this paper is to describe the optical coherence tomography (OCT) characteristics of patients with full-thickness traumatic macular hole (TMH) and to correlate them with biomicroscopy findings.

METHODS

Twelve eyes of ten consecutive patients with full-thickness TMH participated in this observational retrospective multicentre study. Patients underwent biomicroscopic fundus examination, colour fundus photography, and OCT.

RESULTS

Traumatic macular hole was documented with OCT in five women and five men. Mean (range) time between trauma and macular hole (MH) diagnosis was 8.1 (1-24) months. The shape of TMHs was round in 11 (91.7%) eyes. The posterior vitreous was completely detached in six (50%) eyes, and with an operculum in one (8.3%) eye. The common findings seen on OCT were: (1) full-thickness loss of retinal tissue through the hole with sharp edges, perpendicular to the retinal pigment epithelium in five (41.7%) eyes; (2) TMH with an operculum totally detached from the hole's edge in two (16.7%) eyes; (3) presence of epiretinal membrane around of the hole in three (25%) eyes; and (4) presence of abnormalities of the surrounding retina in all (100%) eyes. The OCT characteristics correlated well with biomicroscopic findings, and these characteristics may be predictive for final visual acuity (VA) in TMHs. Only one of the TMHs closed spontaneously in our series.

CONCLUSION

Optical coherence tomography complements biomicroscopy in the evaluation of full-thickness TMHs.