Clinical disease caused by Klebsiella in 2 unrelated patients with interleukin 12 receptor beta1 deficiency.

Patients with interleukin 12 (IL-12)p40 or IL-12 receptor β1 (IL12Rβ1) 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 IL12Rβ1 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 IL12Rβ1 deficiency. Conversely, IL12Rβ1 deficiency should be considered in patients with unexplained klebsiellosis.