CLONAL HEMATOPOIESIS AND ACQUIRED THALASSEMIA IN COMMON VARIABLE IMMUNODEFICIENCY

Background: Common variable immunodeficiency (CVID) is defined by hypo gammaglobulinemia and increased susceptibility to infections. The gene defect responsible for CVID remains unknown. Methods: During the cour se of their CVID disease, a female and three male patients developed m icrocytic anemia. The investigation of this anemia forms the basis for this report. Results: Reticulocyte globin chain synthesis studies rev ealed the abnormal alpha/beta ratios that are pathognomonic of thalass emia. Through transcriptional analysis of the glucose-6-phosphate-dehy drogenase (G6PD) locus of the active X-chromosome in blood cells, we d etermined that the female patient has clonal reticulocytes, platelets, granulocytes, and B and T lymphocytes. Conclusions: The simultaneous presence of globin synthesis abnormalities and panhypogammaglobulinemi a suggests that a common insult at the stem cell level could contribut e to the development of CVID and acquired thalassemia.