Zeitschrift für Hämatologie und thromboembolische Erkrankungen

Zeitschrift für Hämatologie und thromboembolische Erkrankungen
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ISSN: 2329-8790


FLAER Based Paroxysmal Nocturnal Hemoglobinuria Clone Detection in Patients of Aplastic Anemia: Single Centre Experience from a Developing Country

Zohra Farooq1*, Ghassan Umair Shamshad1, Mehreen Ali Khan1 , Muhammad Yousaf1 , Sobia Umar1,2

Background: Paroxysmal Nocturnal Hemoglobinuria (PNH) is a rare acquired genetic hematopoietic stem cell disorder due to a somatic mutation of the X-linked Phosphatidyl-Inositol Glycan (PIG-A) gene. It is closely related to aplastic anemia with a significant number of aplasia patients having a PNH clone.

Methodology: A total of 115 aplastic anemia patients were enrolled in the study. PNH testing was done by multiparameter flow cytometry analysis specifically using Fluorescein-Labeled Proaerolysin (FLAER) to increase the sensitivity of the procedure. The antibody panel for neutrophils and monocytes consisted of CD45, CD15, CD157 and CD64 along with FLAER. Whereas, CD235a was used for gating the true RBCs population on which the co expression of CD59 was observed. This population was differentiated into RBCs with complete and partial deficiency based on CD59 expression.

Results: A total of 70 (60.9%) out of 115 enrolled patients were detected to have PNH clone. There were 80 (69.6%) male and 35 (30.4%) female. Mean age of the patients was 33.63 Â ± 16.78 years. Out of these patients 65 (56.5%) patients had Non Severe Aplastic Anemia, while 36 (31.3%) and 14 (12.2%) were classified as Severe Aplastic Anemia and Very Severe Aplastic Anemia respectively. The mean bone marrow cellularity was 13.19% Â ± 7.89%. A very small PNH clone was found in 23 (20.0%) patients while 35 (30.4%) had a small PNH clone size and 12 (10.4%) patients had a large PNH clone size.

Conclusion: Aplastic anemia patients have a relatively high frequency of PNH Clone of varying size when assessed with sensitive technique like MPFC using FLAER.