Omicron-COVID-19 Manifestations in Sickle Cell Disease: A Brief Report

Background: Sickle cell disease (SCD) is an inherited red blood cell (RBC) disorder that is secondary to a single amino acid change in the beta-chain of the human hemoglobin protein. Patients with SCD suffer from a chronic hemolytic anemia, which can lead to recurrent vascular occlusion with pain crises, organ disfunction, early mortality, and increased risk of infection due to functional asplenia. The Omicron (B.1.1.529) variant, first described in South Africa in November 2021, was identified as a variant of concern due to more than 30 changes in the spike protein of the virus, as well as a sharp rise in the number of cases seen in South Africa. Previous data suggested that children with SCD were less likely to experience COVID-19 related severe illness and death compared to adults with SCD and adults without SCD.

Methods: We present a retrospective cohort analysis of 20 patients aged 3-20 years old with SCD admitted due to SARS-CoV-2 infection in a single center institution in the Bronx, New York between December 19, 2021 and January 10, 2022 aligned with the Omicron spike in New York City. Bivariate analyses were performed using Stata software, version 17, to compare differences between SCD patients diagnosed with acute chest syndrome (ACS) and those without.

Results: In SCD patients admitted due to risk of complications, there were no statistically significant differences between HbSS patients diagnosed with ACS and those without. Average CT values did demonstrate a borderline statistically significant difference with those with ACS having a higher burden of disease with a lower CT value (p=0.07) with those without, with HbSC patients having overall higher CT values and lower burden of disease. Rates of COVID-19 vaccination did not statistically significantly differ between groups but only 25% of HbSS patients diagnosed with ACS and 36% of those without ACS were vaccinated. A higher proportion of HbSC patients were vaccinated (67%). COVID-19 vaccination was offered to all patients who were not vaccinated. No patients developed thromboses of any kind, as had been common during previous surges.

Conclusions: Our results demonstrate that the Omicron variant affected patients with SCD in different ways than seen previously. More patients required hospitalization for COVID-modifying therapy due to unvaccinated status than seen previously, confirming the need for continued vigilance for vaccination efforts.

Table 1. Comparison of baseline characteristics and markers of COVID-19 disease severity in HbSS and HbSC patients with and without ACS in a single center cohort analysis (n=20).

No relevant conflicts of interest to declare.