Butters C, et al. - In a systematic review of 17 studies that involved 6,022 unique patients with primary invasive pneumococcal disease, researchers analyzed the literature, in children younger than 18 years manifesting with invasive pneumococcal disease (IPD) with no another predisposing state, on the prevalence of primary immunodeficiency (PID) and notified guidelines for immunologic assessment following the first episode of IPD on the basis of the published evidence. Of all children, five of 393 to 17 of 162 and of those older than 2 years, 14 of 53 had an identified PID. In children with recurrent IPD, greater rates of PID, up to 10 of 15, were discovered. The most prevalent immunodeficiency was antibody deficiency, followed by complement deficiency, asplenia, and rarer defects in T-cell signaling. In children with meningitis or complicated pneumonia, a chief indicator for the risk of underlying PID was the site of infection with the highest risk of PID. Hence, results of this study imply that in children without other risk factors, invasive pneumococcal disease, and especially recurrent IPD, is a significant marker of underlying PID. Furthermore, the findings also infer that for an immune assessment, children older than 2 years with pneumococcal meningitis or complicated pneumonia and all children with recurrent IPD should be referred.