COVID-19 has had a profound impact on the world since it was first discovered in Wuhan, China. As COVID-19 research continues, questions including how this virus impacts certain populations remain unanswered. Due to the nature of the disease, immunodeficient patients would seemingly be at a greater risk for higher infection rates and worse outcomes than the general population. A recent review article compiled data from 14 publications describing COVID-19 infections in patients with CVID. [3] Of the 68 total cases of COVID-19 in CVID patients reviewed, 39 patients (57%) had a mild infection, defined as not hospitalized and/or no oxygen supplementation. 20 patients (29%) were categorized as having moderate to severe infection defined as hospitalization required with oxygen supplementation, but no intubation. Seven (10%) patients had critical infection requiring hospitalization and intubation. Lastly, nine (13%) patients died. Cohen et al. described a cohort of ten CVID patients infected with COVID-19 in New York City [2]. Seven of the patients were on IVIG at the time of COVID-19 diagnosis and three patients had comorbidities for severe COVID-19. Nine of the patients had mild-to-moderate symptoms and were managed outpatient. The only patient hospitalized had multiple known risk factors for severe COVID-19. None of these patients were diagnosed with pneumonia or required mechanical ventilation, and all patients recovered. This cohort of CVID patients in NYC showed a low risk of severe COVID-19 disease. Results from our cohort of patients with primary humoral immunodeficiency diagnosed with COVID-19 show that 33% had a more severe infection, and 7% had fatal outcome. Comparing our results with the approximate general population mortality rate of 1.4%, we suggest that our cohort of humoral immunodeficient patients had a higher risk of severe disease [5].
Several reasons can be postulated to explain the increased severity of infections in our patients. First, consistent with literature, patients with comorbidities and risk factors, which include: advanced age, male gender, preexisting heart condition, HTN, chronic kidney disease, increased BMI, COPD, and diabetes are at a higher risk for worse outcomes [1]. In our cohort, 100% of the 5 patients with severe COVID-19 infection had at least 1 comorbidity. Comparatively, of the 10 patients with milder COVID-19 infection only 30% had at least 1 comorbidity. The only patient with a fatal outcome in our cohort had 2 comorbidities including HTN and COPD. Severe COVID-19 infections have also been associated with autoantibodies against type 1 interferon (IFN). [6] Although genetic testing was not analyzed, searching for inborn errors of type 1 IFN in our cohort could lead to another explanation for the severe COVID-19 infections seen.
Factors intrinsic to the virus itself can also contribute to the increased severity in our cohort. Over the course of the pandemic, there have been waves of increased infections and reports of virus mutations. The majority of our cohort of patients presented during end of 2020. Variations seen in the severity of infections could possibly be due to the time the individual was infected, whether it was during the initial wave of infections in Spring of 2020 or a later wave. Variability of viral load in patients can also account for the difference in severity of COVID-19 infections.
COVID-19 is a serious disease that continues to have global ramifications. Those living with primary immunodeficiencies are at an increased risk of contracting infections and may be more susceptible to COVID-19. Prior studies on patients with CVID have shown varied outcomes among those that have contracted COVID-19. Our study indicates a higher rate (33%) of severe COVID-19 infections in those with primary humoral immunodeficiency with a mortality rate of 7%. These results may differ from previous reports showing milder COVID-19 infections due to the existence of comorbidities, variability in viral load, and presentation during different infection waves. Future studies with larger cohorts are necessary to further assess COVID-19 outcomes in immunocompromised patients.