Objective: To study the feasibility of diagnosing paroxysmal nocturnal hemoglobinuria (PNH) with hec toxin (secreted by Aeromonus hydrophila) test.
Methods: The crude hec toxin was extracted from the culture medium of Aeromonus hydrophila by precipitating with saturated (NH(4))(2)SO(4) and then purified through DEAE52. This crude hec toxin was used to act on red blood cells (RBCs) from patients with PNH, non-PNH anemias, and normal persons. Absorbance at 630nm was measured to quantitate the extent of hemolysis. Hec treated and untreated RBCs were both stained with anti CD(59) monoclonal antibody and FITC labelled goat-anti-mouse IgG. The percentage of CD(59)(+) cells was detected by flow cytometry.
Results: After hec toxin treatment, RBCs from PNH patients showed resistance to the toxin hemolysis, which was negatively related to the CD(59)(+) cells percentage, while RBCs from non-PNH were lysed totally.
Conclusion: RBCs from PNH have obvious resistance to the hemolytic effect of hec toxin, and the percentage of remained unhemolytic cells reflect the severity of PNH. Resistance detection of RBCs to hec toxin can be used for the diagnosis of PNH.