COVID-19 mortality risk greater among patients with primary immunodeficiency

Patients with primary immunodeficiencies demonstrated higher COVID-19 mortality rates than the general population, according to a study conducted in Turkey and published in Journal of Clinical Immunology.

To contribute more data on the course of COVID-19 among patients with primary immunodeficiencies, Saliha Esenboga, MD, clinician in the department of pediatric immunology at Hacettepe University in Ankara, Turkey, and colleagues retrospectively analyzed 26 patients (male, n = 14; median age, 20.5 years; interquartile range [IQR], 9.41-39) with primary immunodeficiency who also tested positive for COVID-19 via polymerase chain reaction testing.

Of the patients, eight had combined immunodeficiency (CID), five had common variable immunodeficiency (CVID), four had immunodeficiencies with immune dysregulation, four had agammaglobulinemia, four had other antibody deficiencies, and one had congenital neutropenia.

House contact transmission appeared responsible for 16 (61.5%) COVID-19 infections. COVID-19 symptoms at presentation included fever (n = 21), cough (n = 7) and headache (n = 6).

Clinicians treated 16 of the patients as outpatients, whereas eight patients were hospitalized and two received intensive care, for an overall 38.4% hospitalization rate.

Patients with CID had the highest hospitalization rate, at 62.5%.

Median time to recovery was 8 (IQR: 7-16) days, with one patient diagnosed with X-linked agammaglobulinemia (XLA) experiencing a 60-day recovery.

Two patients died, both of whom had a potential of uncontrolled immune response due to CID and immunodeficiency with immune dysregulation.

“In the case of combined immunodeficiency, disease severity will be increased due to the impaired cellular immunity and viral control,” the researchers wrote. “In the case of immune dysregulation, uncontrolled inflammatory responses may also make the patients more susceptible to the COVID-19.”

The 7.69% mortality rate observed in this study was eight times higher than the 0.97% infection mortality rate of Turkey’s general population, according to the researchers.

The researchers noted the range of COVID-19 mortality rates calculated among other populations with primary immunodeficiency. For instance, a study in the United Kingdom showed a 20% mortality rate, whereas an international study found a 9.57% mortality rate, and an Iran group showed a 42.1% mortality rate.

These differences may be due to the heterogeneous nature of primary immunodeficiencies and the varied severities of related comorbidities, according to the researchers, who also noted that their study included 11 children, and none of its patients were aged older than 50 years, which may have impacted the mortality rate.

Still, the researchers wrote, the mortality rates of patients with primary immunodeficiency appeared higher than those of the general population across all studies. They also said that further studies or metanalysis would help clinicians better understand the clinical course of COVID-19 in this population.