Varma, SVarma, NReddy, V VNaseem, SBose, PMalhotra, P2012-10-172012-10-172012-04Varma S, Varma N, Reddy V V, Naseem S, Bose P, Malhotra P. Detection of paroxysmal nocturnal hemoglobinuria-phenotype in patients with chronic lymphocytic leukemia and multiple myeloma. Indian Journal of Pathology & Microbiology. 2012 Apr-Jun 55(2): 206-210.http://imsear.searo.who.int/handle/123456789/142223Background : Paroxysmal nocturnal hemoglobinuria (PNH) results due to decrease or absence of glycosylphosphatidylinositol-anchored (GPI) molecules, such as CD55 and CD59, from the surface of the affected cells. PNH-phenotype has been described in various hematological disorders, mainly aplastic anemia and myelodysplastic syndromes; recently it has been reported in patients with lymphoproliferative syndromes and multiple myeloma (MM). Materials and Methods : We evaluated the presence of CD55 negative and/or CD59 negative red blood cell (RBC) populations in newly diagnosed treatment naive-54 chronic lymphocytic leukemia (CLL) and 29 MM patients by flow cytometry. Results : PNH-phenotype was not reported in any patient; however, RBC populations deficient in CD55 were detected in 16.66% (9/54) CLL and 6.89% (2/29) MM patients. Clinical presentation or the hematological parameters did not show any relationship with the presence of CD55 deficient RBC population. Conclusion : Our study showed absence of PNH-phenotype in patients with CLL and MM; however, isolated CD55 deficient RBC were identified in both CLL and MM. Larger prospective studies by other centers, including simultaneous analysis of granulocytes for the presence of PNH-phenotype, are needed to corroborate these findings and to work out the mechanisms and the significance of the existence of this phenotype in these patients.enChronic lymphocytic leukemiaflow cytometrymultiple myelomaparoxsymal nocturnal hemoglobinuriaAdultAgedAged, 80 and overAntigens, CD55 --analysisErythrocytes --chemistryFemaleHemoglobinuria, Paroxysmal --diagnosisHumansLeukemia, Lymphocytic, Chronic, B-Cell --complicationsMaleMiddle AgedMultiple Myeloma --complicationsArticle