Study: Children With Primary Immunodeficiency Disease May Have Higher Mortality from COVID-19

Children with certain immunodeficiency diseases have a higher mortality rate due to COVID-19, suggests new research out of the Karolinska Institutet published in the Journal of Allergy and Clinical Immunology.

Most children infected with COVID-19 are asymptomatic or have mild symptoms, but those with certain immunodeficiency diseases—also called inborn errors of immunity (IEI)—may have mutated genes that affect the immune system, preventing it from protecting itself against infections. This could lead to severe, or deadly, complications.

“Mortalityis much higher among children with primary immunodeficiency diseases infected with SARS-CoV-2. Our results indicate that basic immunological examination and genetic analysis should be conducted in children with severe COVID-19 or multi-inflammatory syndrome (MIS-C). The clinicians will then be able to help these children with more precise therapies based on their genetic changes,” said study leader Qiang Pan-Hammarström, professor at the Department of Biosciences and Nutrition, Karolinska Institutet, in a press release.

Among children with primary immunodeficiency diseases (examples include hereditary and congenital diseases of the immune system), certain individuals have mild or no symptoms after contracting infection from COVID-19, whereas others experience severe symptoms. There is controversial evidence explaining why the range of symptoms differs greatly, according to the authors of the current study.

Researchers at Karolinska Institutet set out to understand whether genetics play a role in the severity of some COVID-19 cases among children with primary immunodeficiency diseases. Between August 2020 and September 2020, researchers identified 31 unvaccinated children in Iran who had the same primary immunodeficiency disease. The participants, aged 5 months to 19 years, suffered from a severe or critical COVID-19 infection.

After performing genetic and immunological analyses, researchers found that 11 children died from SARS-CoV-2 complications. Among participants, 5 (16%) children were diagnosed with MIS-C.

The research suggests that patients with MIS-C differ from those without MIS-C because they cannot produce their own antiviral antibodies. Consequently they, “would not have the full benefit of vaccination,” said lead author Hassan Abolhassani, assistant professor at the Department of Biosciences and Nutrition, Karolinska Institutet, in the press release.

Further, the genetic analyses showed that more than 90% of children with primary immunodeficiency diseases had a mutation that affected proteins (interferons) that regulate the immune system during a viral infection. These mutated genes could explain why their immune defenses were not functioning properly.

The researchers performed an additional literature review of global reports that studied this population. The team identified the mortality rate from COVID-19 to be 8% among children with an IEI.

The study was limited to researching patients with severe COVID-19 cases, those infected with the original strain, and non-vaccinated children.

“Our results clarify the molecular mechanism of these immune diseases, which opens up the possibility of developing a more targeted therapy. The knowledge acquired from the study also allows us to develop better strategies for the treatment and prevention of severe COVID-19 disease in these patients,” Pan-Hammarström said in the press release.

Reference

Karolinska Institutet. Higher risk of serious COVID-19 complications in children with primary immunodeficiency. EurekAlert! September 16, 2022. Accessed on September 19, 2022. https://www.eurekalert.org/news-releases/964997