EDITORIALS & PERSPECTIVES Dendritic cell, monocyte, B and NK lymphoid deficiency defines the lost lineages of a new GATA-2 dependent myelodysplastic syndrome Venetia Bigley and Matthew Collin Institute of Cellular Medicine, Newcastle University, UK. E-mail:
[email protected] doi:10.3324/haematol.2011.048355 (Related Original Article on page 1221) novel immunodeficiency syndrome has recently been International Prognostic Scoring System (IPSS). defined in young adults. Known variously as dendritic It is worth emphasizing at this point that DCML deficiency cell, monocyte, B and NK lymphoid (DCML deficien - patients may have significant risk to their health before addi - A1 2 2 cy), ‘autosomal dominant and sporadic monocytopenia’ or tional cytopenias evolve. Disseminated mycobacterial infec - ‘MonoMAC’ (monocytopenia with Mycobacterium avium com - tion, PAP and carcinoma in situ may all occur prior to the onset plex), 3 it is characterized by a composite mononuclear cell defi - of an obvious myelodysplastic syndrome, underscoring the ciency, atypical mycobacterial and viral infection, and progres - fact that immunodeficiency is a cardinal feature of the disor - sion to myelodysplasia and leukemia. Strikingly, a number of der. In the series of 4 subjects described in 2011, one had mild patients also develop pulmonary alveolar proteinosis (PAP). anemia (10.3 g/dL) and one mild thrombocytopenia Patients typically present in their 3 rd or 4 th decade, although his - (123 ¥10 9/L), yet 2 required hematopoietic stem cell transplan - torical blood counts may show pre-existing monocytopenia tation (one for refractory mycobacterial infection, one for PAP) for ten years or more. A substantial number of patients devel - and a third died of influenza H1N1 prior to transplantation.