Patients with hematologic disease have a high risk of morbidity and mortality after infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. It is currently unknown whether the Omicron variant leads to a reduction in the severity of the disease in these individuals.
Study: Early report on the severity of COVID-19 in haematological patients infected with the omicron SARS-CoV2 variant. Image credit: Naeblys / Shutterstock
A new study published in the European Journal of Hematology has addressed this gap in our understanding by studying the clinical outcome and spectrum in 61 patients infected with the Omicron SARS-CoV-2 variant.
Fund
Since the outbreak of coronavirus disease 2019 (COVID-19) in 2019, non-pharmaceutical interventions (NPI) along with the morbidity and mortality of COVID-19 have continued to disrupt daily life.
The disease has now been shown to affect several systems, including the cardiovascular system, the nervous system, and the gastrointestinal tract.
Hematological patients are exposed to immunosuppressive treatments and have severe immune deficiency. This makes these patients more vulnerable to fatal outcomes after SARS-CoV-2 infection. Hemoglobinopathies, for example, sickle cell disease (SCD) and transfusion-dependent beta-thalassemia (DTT), are associated with a high risk of death.
Although aspects of morbidity and mortality are well documented in hematologic patients, the clinical course of the disease in patients with non-malignant hematologic disease is less studied. It has been observed that these patients also respond poorly to vaccination. A significant fraction of patients showed low antibody responses even after receiving three doses of an mRNA vaccine.
The Omicron variant is currently the dominant circulating strain of SARS-CoV-2 and its clinical presentation differs markedly from previous variants. Although the mortality rate has decreased, Omicron has a reduced susceptibility to be neutralized with monoclonal antibody treatment or vaccination. Because data on hematologic patients with COVID-19 are rare, in the current study, scientists analyzed the characteristics of the disease in this extremely vulnerable population.
Key findings
Early data showed an attenuation of disease severity with the Omicron variant, but morbidity and mortality among hematology patients remained high, compared to the general population. The authors state that this study is the first to describe the severity of Omicron SARS-CoV-2 variant disease in both outpatient and inpatient settings.
The sample size was small with 61 individuals. During the study period, 10 patients remained asymptomatic, a percentage that was observed to be similar to pre-Omicron-era statistics and prevaccination. Most patients had mild to moderate disease, and overall, 50 patients had common symptoms of COVID-19. More specifically, 60.66% of patients reported fatigue, 52.46% cough and 39.34 fever. Seven patients required oxygen therapy, while 10 patients reported dyspnea. Anosmia and ageusia were observed in less than 10% of patients. No significant hemolysis was observed in patients suffering from inherited hemolytic anemia.
The severity of the disease could be studied in 60 patients and during the study period, 5 cases required admission to the ICU, due to the critical illness. The mortality rate was 9.84 in this cohort of patients, but there were heterogeneities in the cause of death. The mortality rate among patients with non-malignant blood disease was 6.25%. The increased prevalence of pulmonary and cardiovascular comorbidities could have made these individuals more susceptible to severe clinical outcomes. It should also be noted that one patient who died was not vaccinated and five more were exposed to B-cell therapy prior to infection. As mentioned above, most hematologic patients, however, remained asymptomatic or presented with mild symptoms.
During the course of the pandemic, several treatment options also emerged. Molnupiravir and Sorovimab were approved to treat outpatients in the risk category. In this study, 4 patients were treated with the first, while 17 patients were treated with the second. After treatment, only one individual was admitted to the ICU, which hints at the excellent overall tolerance of both drugs. The researchers noted the urgent need to further evaluate specific virus treatments in hematologic patients infected with SARS-CoV-2.
Concluding remarks
The results as a whole suggest milder symptoms of Omicron infection in haematological patients, compared with previous SARS-CoV-2 variants. The scientists, however, mentioned that it was not possible to infer whether these results were motivated by preexisting host immunity or altered viral pathogenicity, and this problem should be considered in broader studies in the future.