Paroxysmal nocturnal hemoglobinuria clones are not present in HIV positive patients

Abstract

The existence of paroxysmal nocturnal hemoglobinuria (PNH) clones in aplastic anemia and myelodysplastic syndrome is well established (Dunn et al., Ann Intern Med 1999;131:401–408; Kaiafa et al., Ann Hematol 2008;87:257–262). Although decreased expression of CD55 and CD59 on lymphocytes has been described in human immunodeficiency virus (HIV) positive patients, to our knowledge, PNH clones have not been characterized in HIV. However, a recent study from Greece (Terpos et al., Med Sci Monit 2008;14:CR276–CR280) found a significant loss of glycophosphotidylinositol (GPI)-linked antigens CD55 and CD59 on red blood cells from HIV positive patients. Blood samples from patients with confirmed HIV infection were submitted to our flow cytometry laboratory for absolute CD4 count analysis. When a blood sample demonstrated an absolute CD4 count of less than 400, the excess blood sample was then tested for the expression level of the GPI-linked cell surface antigens on red blood cells (CD55 and CD59) and white blood cells (CD14 and CD24). In addition, we used fluorescent areolysin (FLAER) to evaluate the presence or absence of the GPI anchor directly on white blood cells. Samples from 73 HIV positive patients were evaluated for expression levels of CD14, CD24, CD55, CD59, and FLAER. No patient sample demonstrated a loss of CD55, or CD59 on the red blood cells, or a loss of CD14, CD24, or FLAER on the granulocytes and monocytes. While PNH clones have been described in other hematologic diseases, we did not find evidence of PNH clones in our examined HIV positive patient samples. © 2010 International Clinical Cytometry Society