Introduction: Streptococcus pneumoniae is one of the most common infectious pathogens in common variable immunodeficiency (CVID). Both innate and adaptive immune response appears to play a role in defense against S. pneumoniae. In mice, it has been established that TLR2 and macrophages-derived cytokines (IL-6, TNF-alpha) play a crucial role in defense against S. pneumoniae. In humans, monocyte/macrophage-derived cytokines in response to S. pneumoniae have not been studied. Patients with CVID respond poorly to Pneumovax-23 (containing all capsular polysaccharides) vaccination.
Findings: In this study, we show that Pneumovax-23, in a concentration and time-dependent manner, induced secretion of IL-6, IL-10, and TNF-alpha by monocytes and not by B cells or T cells from healthy controls. Furthermore, Pneumovax-23-induced secretion of IL-6 and TNF-alpha was significantly less in patients with CVID as compared with controls. In addition, Pneumovax-23-induced upregulation of TLR2 in all four subsets of monocytes; however, differences between control and CVID were not significant.
Conclusion: Pneumovax-23-induced monocytes-derived cytokine production is impaired in CVID, which may play an important role in increased susceptibility of CVID patients to S. pneumoniae infection.