The risk of developing more severe COVID-19 infection and a poor prognosis for patients with sickle cell disease (SCD) is increased with having a history of acute chest syndrome (ACS), lack of hydroxyurea usage before the infection, and homozygous genotype (HbSS), according to a new study published in the Journal of Investigative Medicine.

Researchers retrospectively obtained data from 30 patients with SCD infected with COVID-19 between February 2020 and February 2021 in the University of Texas Health System. The information included medical history, disease progression, treatments, and outcomes. They divided the patients into 2 groups—those with mild/moderate COVID-19 infection and those with severe COVID-19 infection requiring hospitalization.

Twenty patients (67%) developed mild COVID-19 who did not require hospitalization. Three (14%) patients in the mild group had a history of ACS whereas 5 (50%) of patients in the severe group had a history of ACS. ACS correlates with chronic lung disease development, posing a higher risk of more severe COVID-19 infection.

Read more about SCD comorbidities

In the mild group, 17 patients (85%) took the disease-modifying treatment, hydroxyurea, to manage SCD while only 6 patients (60%) in the severe group took hydroxyurea. Prior to COVID-19 infection, patients taking hydroxyurea in the mild group demonstrated higher hemoglobin and hemoglobin F levels than patients on hydroxyurea in the severe COVID-19 group (9.3% and 13.9% vs 8.6% and 10.9%).

Patients with the HbSS genotype stayed in the hospital longer than patients with the HbSC genotype (9.14 days vs 2.67 days). The standard treatment for hospitalized patients with SCD and COVID-19 involved intravenous fluids, pain control, and packed red blood cell transfusions. No hospitalized patients died, required intubation, or experienced a red cell aplastic crisis.

“By creating systems to better interpret what makes a patient with SCD at high risk for poor prognosis, practitioners are better equipped to make data-supported recommendations for prevention, risk, and treatment,” the authors concluded.

“These recommendations should include beginning or maintaining hydroxyurea usage in all qualifying patients with SCD, advising patients with a history of ACS to take extra precautions to prevent initial COVID-19 infection, and initiating close monitoring in the hospital for patients with HbSS and a history of ACS.”


Cai J, Chen-Goodspeed A, Idowu M. Risk and protective factors for severe COVID-19 infection in a cohort of patients with sickle cell disease. J Investig Med. Published online March 8, 2022. doi:10.1136/jim-2021-002196