March 31, 2024
Potential PD-1 inhibitor immune dysregulation as a risk factor for Listeria monocytogenes bacteremia and meningitis
- Cherry Au, MD
- Case Reports
As immune checkpoint inhibitor (ICI) therapy becomes increasingly popular for the treatment of cancer, there is a growing body of literature on opportunistic infections associated with ICI therapy. Pembrolizumab binds specifically to the PD-1 receptor on T cells, preventing PD-1’s interaction with PD-L1 and PD-L2. This blockade interrupts the inhibitory signal and restores a T cell’s ability to recognize and attack tumor cells. We present a case of invasive Listeria infection associated with ICI therapy. The case also suggests treating patients undergoing active ICI therapy as potential immunocompromised hosts due to possible immune dysregulation related to ICI therapy.
Predictors of Disease Severity in Patients Hospitalized with COVID-19 during the Omicron Surge of January 2022
- Jonathan K. Pinsky, MD
- Original Article
Abstract: Background: The surge of COVID-19 hospitalizations in January 2022, at the onset of the Omicron period and before widespread population immunity, was a window in which to study the impact of vaccination status and other factors on disease severity in Omicron infections. Methods: This was a case-control study of adults hospitalized with COVID-19 during January 2022 that evaluated risk factors for severe disease. Cases were patients with severe COVID-19, defined in three ways: (1) requiring supplemental oxygen > 24 hours if not on home oxygen, (2) requiring high-level oxygen: either high flow of > 15 L/min, noninvasive ventilation, or mechanical ventilation (MV), and (3) the composite of MV or hospital death. Controls were patients hospitalized with COVID-19 who did not meet the respective case definition. Results: Among the 379 patients not on home oxygen before admission, 133 required supplemental oxygen. Among all 393 patients meeting the study criteria, 58 required high-level oxygen, 22 required MV, and 28 died. Factors associated with all case definitions were (1) absence of full vaccination compared to booster vaccination: requiring oxygen, odds ratio [OR], 7.86 [95% CI, 3.78-16.4]; high-level oxygen, OR, 5.17 [95% CI, 2.01-13.3]; MV or hospital death, OR, 5.21 [ 95% CI, 1.63-16.6]; (2) immunocompromised status: requiring oxygen, OR, 2.79 [95% CI, 1.38-5.63]; high-level oxygen, OR, 3.79 [95% CI 1.66-8.67]; MV or hospital death, OR 4.63 [95% CI 1.72-12.5], and (3) age > 75 years compared to 50 to 64 years: requiring oxygen, OR 2.85, [95% CI 1.43-6.07]; high-level oxygen, OR 4.02 [95% CI 1.47-11.0]; MV or hospital death, OR 5.68 [95% CI 1.49-21.7]. Other factors associated with requiring oxygen were obesity: body mass index (BMI) 35.0-39.9 kg/m2, OR, 2.4 [95% CI 1.09-5.26]; BMI > 40.0 kg/m2, OR, 3.29 [95% CI 1.34-8.10] compared to BMI 65 years, and body mass index > 35 kg/m2, but not the absence of a booster if fully vaccinated. This is further evidence that immune memory mitigates disease severity in Omicron infections.
