The aims of this study were to explore (1) whether the serum levels of neurotensin, pannexin-1 and sestrin-2 change in the patients with CID; (2) whether altered serum levels of these neuron-related markers correlated with poor sleep quality; and (3) the relationship between these serum biomarkers and cognitive function in the patients with CID. Here, SESN2 is linked to combined immunodeficiency.