The COVID-19 pandemic, arguably the most significant disruptor of medical norms and practices in a century, has brought about a subsection of medical literature exploring the course of various diseases during the viral outbreak. 

There are a few key issues that have been examined. The first is whether treatment regimens can readily switch to home-based approaches, given that visiting a healthcare facility drastically increases the risk of catching the virus . The second is whether certain diseases are exacerbated by COVID-19 infection and whether this leads to a poorer prognosis in the long term. 

The body of medical literature exploring the diagnosis and management of conditions during the pandemic gives us insight into what we can expect, and what we must preemptively change, should another pandemic occur in the future. 

In this article, we will be looking at some of the literature on patients with sickle cell disease (SCD) and how the COVID-19 pandemic has affected them. 

A Greater Risk of Serious Infection

The COVID-19 pandemic is not the first pandemic in recent years to have been discussed in the context of SCD. During the H1N1 pandemic, a number of studies investigated the susceptibility of patients with SCD to infection and death. The consensus that emerged was that the H1N1 pandemic heightened the occurrence of vaso-occlusive events and acute coronary syndrome (ACS) in these patients, often leading to the need for intensive care. 

Based on the medical literature on H1N1 and SCD, Minniti and colleagues wrote, “We hypothesized that patients with SCD have an increased risk for morbidity and mortality from COVID-19 infection.” This increased risk makes sense, considering that SCD is a chronic condition that is always present in the background, even when acute crises are absent. 

Read more about SCD epidemiology

Sayad and colleagues outlined in more detail why patients with SCD are considered to be at greater risk of serious illness if infected with COVID-19 compared to the general population. These patients, they wrote:

  • Have underlying pathophysiology of chronic inflammation, with a higher risk of thrombosis 
  • Have an immunocompromised status due to auto-infarction of the spleen, making makes them particularly susceptible to infectious diseases and ACS 
  • Tend to have significant comorbidities and secondary organ dysfunction. 

In the midst of the COVID-19 pandemic, we have observed the sometimes blasé attitude of healthy young people who think that their health and young age make them immune to serious infection (and hence give them an excuse not to follow public health guidelines). This luxury, however, is not afforded to people with SCD, who often know from multiple hospital visits that they are especially vulnerable to any type of infection.

A Lower Median Age of Death

 In order to test their hypothesis that people with SCD are at a higher risk of morbidity and mortality from COVID-19 infection, Minniti et al conducted a study at 5 academic centers in the US that serve around 3500 patients (both pediatric and adult) with SCD. To study the impact of COVID-19 on SCD, patients who tested positive for the virus by polymerase chain reaction between February 2020 and May 2020 were included. Participants were followed up for up to 3 months after diagnosis. 

The research team collected demographic information, medical and medication history, and vital signs of the participants upon presentation. If the participants were hospitalized, their hospital data were collected. Conditions such as ACS, stroke, and congestive heart failure were abstracted from the participants’ electronic medical reports. The treatment regimens prescribed to the participants were also recorded. 

Their findings included: 

  • There was a wide spectrum of disease severity among patients with SCD who were infected with COVID-19.
  • Generally, younger patients had a less severe course of disease. 
  • The mortality rate in the cohort was 10.6%, which is higher than other published studies to date studying mortality among patients with SCD and COVID-19. 
  • Factors that increased the risk of death included older age and the presence of end-organ disease. 
  • Chronic hydroxyurea therapy was protective of death. 
  • The median age of death for patients with SCD from COVID-19 was 53 years, while the median age of death for the US non-SCD population was 78 years. 

The results of this study demonstrate just how vulnerable SCD patients are when infected with COVID-19. Since the data was collected prior to the availability of a vaccine, it can be assumed that all these patients experienced infection without the benefit of having been vaccinated. 

Mitigating Factors 

The findings reported by Minniti et al correlate with findings by Sayad and colleagues, who conducted a literature review of published papers and an international SCD registry to understand the clinical course of COVID-19 in patients with SCD. 

That team discovered that morbidity and mortality were lower in children with SCD than in adults with the disease. In addition, they found that about 51.3% of children and 36.5% of adults with SCD and COVID-19 required simple/exchange transfusions when hospitalized. They wrote, “Benefit of early simple/exchange transfusion in the patients with ACS was indicated with rapid clinical improvement of tachypnea/dyspnea and oxygen saturation, and it affected the clinical course of disease in patients who required respiratory support in the ICU.”

Read more about SCD treatment 

Similar to Minniti and colleagues, Sayad et al also found hydroxyurea therapy to be safe, cost-effective, and efficient in reducing the frequency and intensity of painful events in SCD patients. Hydroxyurea therapy was successful in reducing transfusion requirements, the rate of ACS events, and hospitalization. 

The body of medical literature reporting on the conditions of SCD patients when infected with COVID-19 clearly demonstrates that they are more vulnerable to severe disease compared to the general population, but that there are ways to mitigate this risk. The question is: what can we now do to improve patient resilience before the next global pandemic arrives? 

References

Minniti CP, Zaidi AU, Nouraie M, et al. Clinical predictors of poor outcomes in patients with sickle cell disease and COVID-19 infectionBlood Adv. 2021;5(1):207-215. doi:10.1182/bloodadvances.2020003456

Sayad B, Karimi M, Rahimi Z. Sickle cell disease and COVID-19: susceptibility and severityPediatr Blood Cancer. 2021;68(8):e29075. doi:10.1002/pbc.29075