CVID participants had higher absolute counts of T cells and CD8+ T cells compared to healthy donors and pulmonary complications groups (p < 0.05) as well as a lower relative frequency of NK cells compared to these groups, with 5% (IQR: 3–7%) vs. 14% (IQR: 10–17%) and 16% (IQR: 9–20%), respectively, of the total lymphocytes’ frequency. Here, CD8A is linked to common variable immunodeficiency.