Low-affinity immunoglobulin gamma Fc region receptor III-B (Fc gamma RIIIB, CD16B) deficiency in patients with blood and immune system disorders

Low-affinity immunoglobulin gamma Fc region receptor III-B (Fc gamma RIIIB) deficiency is present in similar to 0.05% of the general population. Among our patients, Fc gamma RIIIB deficiency was less frequent in those with immune-system disorders (one of 1815 patients, 0.05%) than in those with blood disorders (nine of 2147 patients, 0.42%, P = 0.023): mainly primary immune thrombocytopenia (4.34%), therapy related myeloid neoplasms (1.16%) and myelodysplastic syndrome with excess blasts (1.28%). Four of the nine (44.4%) patients with blood disorders were diagnosed with or quickly evolved to acute myeloid leukaemia (AML), suggesting that Fc gamma RIIIB deficiency could be an adverse prognostic factor for progression to AML that should be confirmed in large multicentre studies.