[Estimation of expression of glycosylphosphatidylinositol-anchored protein in B lymphocytes for diagnosis of paroxysmal nocturnal hemoglobinuria].
OBJECTIVE
To estimate whether the expression of glycosylphosphatidylinositol (GPI)-anchored protein in B lymphocytes could be an indicator for detecting paroxysmal nocturnal hemoglobinuria (PNH).


METHODS
Flow cytometry and two-color McAbs were used to detect CD59 expression in B lymphocytes and granulocytes of 92 clinical samples. The feasibility of the indicators for diagnosis of PNH was assessed.


RESULTS
B lymphocytes from healthy individuals mainly showed a single population of cells strongly positive for CD59, as the percentage of CD59 expression was (96.3 +/- 1.2)%. In PNH patients, B lymphocytes showed decreased expression of CD59, as well as negative cells and partly-positive cells were observed, as the percentage of CD59 expression was 10.5%-92.3%. In 26 of 28 non-PNH anemia patients, CD59 expression in B lymphocyte was normal, and in the other 2 patients, CD59 expression were decreased (< 95%), but no negative cell peak was observed. The precision CV of CD59 in B lymphocyte assay is less than 4.4%, stained samples could be kept stable for 24 h, the CD59 in B lymphocyte assay was 100% in accordance with routine assay (CD59 in granulocyte assay). The sensitivity of the indicators (CD59 in B lymphocytes and granulocytes) was 100%, the specificity was 97.4%, misdiagnosis rate was 2.6%, the rate of failing to diagnosis was 0%, the rate of positive forecast was 87.5%, the rate of negative forecast was 100%, the accuracy was 97.8%.


CONCLUSIONS
The test of CD59 expression in B lymphocytes by flow cytometry was simple, accurate and reproduceable. It could be a good marker for diagnosis of PNH because of high sensitivity and specificity.
Cui
Wei
W
Department of Clinical Laboratory, PUMC Hospital, CAMS and PUMC, Beijing 100730, China. cuiwei@pumch.ac.cn
He
Ying
Y
D001402:B-Lymphocytes / Q000378:metabolism*; D015415:Biomarkers; D018957:CD59 Antigens / Q000097:blood; D005260:Female; D005434:Flow Cytometry; D017261:Glycosylphosphatidylinositols / Q000096:biosynthesis*; D006098:Granulocytes / Q000378:metabolism; D006457:Hemoglobinuria, Paroxysmal / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D012680:Sensitivity and Specificity
D015415:Biomarkers; D018957:CD59 Antigens; D017261:Glycosylphosphatidylinositols; D008565:Membrane Proteins