RESUMEN
Patients with interleukin 12 (IL-12)p40 or IL-12 receptor ß1 (IL12Rß1) deficiencies are prone to develop infections caused by mycobacteria and salmonella; other infections have only been rarely observed. In this report we describe 2 unrelated patients with complete autosomal recessive IL12Rß1 deficiency who suffered from sepsis attributable to Klebsiella pneumoniae. A Mexican boy suffered from disseminated bacille Calmette-Guérin disease and infections caused by K pneumoniae and Candida albicans and had a fatal outcome. A Turkish girl living in France suffered from disseminated Nocardia nova infection and K pneumoniae sepsis. Therefore, Klebsiella infections should be considered in patients with IL12Rß1 deficiency. Conversely, IL12Rß1 deficiency should be considered in patients with unexplained klebsiellosis.