NFKB1 and Splenomegaly: Apart from having recurrent and severe infections (including viral disease) for which these patients had been given a diagnosis of PID in the first place, autoimmunity and unexplained splenomegaly are very common manifestations in our patient cohort similar to the other heterozygous NFKB1 cases described.6, 7, 8, 9, 10, 11 Although autoimmunity has been subject to variable percentages per cohort study,3, 48, 49 it seems that these complications occur more frequently in NFKB1-haploinsufficient patients compared with unselected CVID cohorts.