Sickle Cell Disease Tied to Worse COVID-19 Outcomes

Patients with sickle cell disease (SCD) may be at higher risk for some COVID-19 complications and COVID-19-related death, researchers reported.

African-American patients with SCD and COVID-19 may be more at risk for hospitalization, pneumonia, and pain than Black patients with COVID-19 but without SCD, reported Ashima Singh, PhD, of the Medical College of Wisconsin in Milwaukee, at the American Society of Hematology (ASH) virtual meeting.

While there was no increased risk for mortality in their study, according to Singh and colleagues, a separate study indicated that individuals with SCD faced 6.2 times the risk for COVID-19-related mortality versus the general Black population, according to Lana Mucalo, MD, also at the Milwaukee institution.

“In our study, we matched patients on age, gender and other preexisting comorbidities and compared outcomes; so, the comparison group is not exactly the general population and has higher prevalence of comorbidities than the general population,” Singh explained to Healio. “Whereas, Dr. Mucalo’s study compared the mortality rate for patients with sickle cell disease with the general population and does not adjust for other preexisting comorbidities.” Singh, Mucalo, and co-authors participated in both studies.

Additional Risks with COVID-19

Singh’s group analyzed data from electronic health records to look at three cohorts:

• 214 patients with COVID-19 and SCD (mean age 31.9; 63% women)
• 260 patients with COVID-19 and sickle cell trait (mean age 40.1; 81% women)
• 29,992 Black patients with COVID-19 but no SCD or trait (mean age 45.8; 60% women)

The COVID-19 patients with SCD were significantly younger, with a higher proportion having asthma, type 1 diabetes (T1D), and preexisting liver conditions versus Blacks without SCD or trait, according to the authors. Also, COVID-19 patients with sickle cell trait were significantly younger, more likely to be female, overweight/obese, and also more likely to have asthma or T1D versus Blacks without SCD or trait.

Singh reported that among the COVID-19 patients with SCD, nearly half required hospitalization, 43% experienced pain, and 31% developed pneumonia. Among Black patients without SCD or trait, 23% required hospitalization, 13% experienced pain, and 20% developed pneumonia.

She and her colleagues also found that the risk of hospitalization for patients with SCD or trait and COVID-19 was 2.6 times than the rate in Blacks without SCD (P<0.001), as was the risk of being diagnosed with pneumonia for patients with SCD or trait and COVID-19 versus Blacks without SCD (P=0.002). And the risk of experiencing pain among the former patients was 2.8 times versus the latter patients (P<0.001).

“In our study, people with sickle cell disease had a higher risk of hospitalization, pain, and pneumonia within 2 weeks of COVID-19 diagnosis as compared to a general population of Black people matched with regard to age, gender, and other comorbidities,” Singh said. “This speaks to a need for health equity for patients with SCD, as they are at risk of significantly more severe expression of COVID-19.”

“The case fatality rates were not significantly different between those with sickle cell disease compared to Blacks,” the authors wrote. “These data provide evidence that sickle cell disease imposes additional risk of severe COVID-19 illness and hospitalization, after balancing for age, gender and other preexisting conditions.”

Higher Death Rate

“People with SCD are definitely a high-risk group,” Mucalo explained. “In particular, young adults and children with SCD are at higher risk for severe COVID-19 infection and hospitalization than the general population. That means they should be following recommended precautions, such as mask-wearing, and their healthcare providers should be aware that they are at increased risk of severe illness.”

Mucalo and colleagues accessed data from SECURE-SCD, an international, voluntary registry that collects information about COVID-19 infections in individuals living with SCD, including details on hospitalization, severity, management strategies, and complications.

The researchers compared hospitalization rates in the registry data to hospitalization rates among Black individuals in COVID-NET, a national surveillance system that covers about 10% of the U.S. population. They compared case fatality rates in the registry with rates among Black individuals in data from the California Department of Public Health.

The analysis included 152 children (mean age 10.9 years; 46.7% female) and 214 adults (mean age 34; 58.1% women) with SCD and COVID-19.

Mucalo’s group found hospitalization rates of 46.1% among children and 66.8% among adults, along with mortality rates of 0.7% among children and 7% among adults.

The COVID-19 case fatality rate was higher among those with SCD than among Blacks in the general California population for all age groups:

• 0-17 years: 0.8% vs 0%
• 18-34: 2.6% vs 0.4%
• 35-49: 11.9% vs 1%
• 50-64: 17.6% vs 3.8%
• 65-79: 20% vs 15%

The case fatality rate was highest in the general population among those ages 80 or older (34.3%) but there were no patients in the SCD cohort in this age group for comparison, according to the authors.

Mucalo’s group also found that age was the only risk factor that met significance among adults, but that SCD genotype and use of hydroxyurea did seem to be tied to COVID-19 severity or hospitalization.

‘Advocate for Themselves’

ASH press conference moderator Chancellor Donald, MD, of Tulane University School of Medicine in New Orleans, told MedPage Today that “SCD is a disease that predominantly affects African Americans in [the U.S.], and COVID-19 has had a disproportionate burden on the African-American communities as far as outcomes of morbidity and death.”

Donald said both studies “shine a light on a given disease that affects mostly African Americans, and there has not been a lot of advance in treating modalities of SCD, and there hasn’t been a lot of additional research.”

In addition, “COVID 19 is known to affect older people, and those with underlying medical conditions the worst. We have teased out that those underlying medical conditions to be cardiovascular disease, diabetes, chronic lung disease, hypertension, and so forth. It is important to be able to fit in another disease state, such as SCD, where persons who have that disease can understand their personal risk and advocate for themselves.”

Results from the studies “may empower a person with SCD to understand he or she has a higher risk from COVID-19, and that person would know how to advocate for themselves and take those precautions,” Donald stated.

Donald also advised clinicians take a closer look at at patients with SCD who present with COVID-19-like symptoms and increase their suspicion of risk. “Knowledge allows us to treat people more precisely,” he said.