ISSN 2997-1036
International Journal of Hematology | Vol. 1, No. 8, August 2010 | pp. 57–64
DOI: 10.46882/2010/IJH/000008
Short Communication
Title: Flow cytometric evaluation of CD55 and CD59 deficiency in paroxysmal nocturnal hemoglobinuria: A regional diagnostic audit
Names of Authors: H. I. Kolo¹, I. J. Mohammed²
Authors’ Affiliations: ¹Department of Haematology and Blood Transfusion, Ahmadu Bello University Teaching Hospital, Zaria, Nigeria; ²Department of Immunology, Bayero University, Kano, Nigeria
Abstract: Paroxysmal nocturnal hemoglobinuria is an acquired clonal hematopoietic stem cell disorder requiring sensitive diagnostic tools. This audit evaluated flow cytometric detection of glycosylphosphatidylinositol-anchored protein deficiencies (CD55 and CD59) on peripheral blood erythrocytes and neutrophils across 28 suspected clinical cases over a 1-year period. Dual-color flow cytometry utilizing fluorescently labeled monoclonal antibodies demonstrated distinct deficient cell populations in 9 out of 28 referred patients (32.1% positivity rate). Mean deficiency expression for CD55 on granulocytes was 88.4% within positive clones, while CD59 absence on erythrocytes averaged 76.5%. The assay successfully identified small clones (< 10%) previously missed by older Ham test methodologies. Clinical correlates in confirmed cohorts included hemolytic crises, dark urine, and unprovoked venous thromboses. The implementation of standardized high-resolution flow cytometry dramatically improves diagnostic accuracy and timely initiation of terminal complement inhibitor therapies in sub-Saharan cohorts.
Keywords: Paroxysmal nocturnal hemoglobinuria, flow cytometry, CD55, CD59, glycosylphosphatidylinositol
Manuscript Timeline: Received: May 15, 2010; Revised: June 22, 2010; Accepted: July 12, 2010; Published: August 18, 2010