MO906: Antibody Response to COVID-19 Vaccination in Patients Under Dialysis

BACKGROUND AND AIMS

Patients (pts) with end-stage kidney disease (ESRD) may be more vulnerable to infections and may have a suboptimal response to vaccination. Dialysis patient (pt) began to be vaccinated against COVID-19 in February 2021. However, there were many doubts about whether immunization would be effective for them, as these pts have an impaired immune system, and it seems that this population responds poorly to vaccinations. Serum neutralizing antibodies (AbN) rapidly appear after the SARS-CoV-2 infection and the vaccination and are maintained for several months. The emergence of SARS-CoV-2 variants has raised concerns about the breadth of the neutralizing antibody responses.

METHOD

Serum samples were obtained from 181 patients receiving dialysis. Levels of circulating SARS-CoV-2 anti-spike IgG(S) and anti-nucleocapsid IgG (N) antibodies were quantified using the Abbott Diagnostics SARS-CoV-2 IgG chemiluminescent microparticle immunoassay (Abbott Diagnostics, Abbott Park, IL, USA) on an Abbott Diagnostics Architect i2000 SR and an Alinity analyzer, according to the manufacturer's instructions. Serum neutralizing antibodies (AbN) by commercially available assays (cPass SARS-CoV-2 Neutralization Antibody Detection Kit), at the first and the third months after the vaccination, were identified.

RESULTS

The IgG-spike Abs had a statistically significant decrease at 3 months after the vaccination in relation to the measurements 1 month after that.

AbN had a statistically significant decline at 3 months after the vaccination in relation to the measurements 1 month after. Pts with cardiovascular disease (CD) had significantly lower levels of antibodies than those who did not have CD. Additionally, CD was an aggravating factor in combination with the other comorbidities for the development of antibodies. Pts with a history of malignancy had significantly lower levels of antibodies in relation to those who did not. Those under therapy with antihistamines in the 1st month after the vaccination presented a statistically lower level of the AbNs, but this difference did not exist in the measurements 3 months after vaccination. There was a correlation between the AbNs and the age, also between the time these patients underwent dialysis. Those who had COVID-19 infection presented higher levels of the antibodies AbN/IgG-spiked Ab at 3 months.

CONCLUSION

It is presented that the IgG-spike Abs and the AbN had a statistically significant decrease at 3 months after the vaccination, which shows the importance of completing vaccination with the third dose after 3 months. Also, it is presented that CD is a risk factor for lower levels of Abs. Randomized clinical trials for COVID-19 vaccines included a few patients with kidney disease; therefore, the vaccine immunogenicity is uncertain in this population.

Homocysteine as a risk factor of restenosis after carotid endarterectomy

AIM

Homocysteine (Hcy) has been identified as a potential risk factor for vascular disease. This study investigates the role of serum Hcy as clinical risk factor for restenosis after carotid endarterectomy (CEA).

METHODS

In a prospective design, we studied patients who underwent carotid endarterectomy with venous patch closure technique with respect to alterations of Hcy levels pre and postoperatively. The patients studied were subjected to reevaluation for possible restenosis at time-points 3, 6, 9, 12, 18 and 24 months postoperatively.

RESULTS

Fifty-three symptomatic and 37 asymptomatic patients with stenosis of internal carotid artery >70% were studied. Restenosis appeared in 7.25% of the patients within 24 months postoperatively. Hcy was the only parameter that correlated significantly with the presence of restenosis (P=0.010) and the presence of type VI (complicated) atheromatous plaque (P=0.005) within 24 months postoperatively.

CONCLUSION

Hcy levels were found to be statistically significantly correlated with both the presence of complicated atheromatous plaque and the degree of internal carotid artery restenosis after CEA.