Megakaryocyte progenitors in paroxysmal nocturnal haemoglobinuria are sensitive to complement.
We have investigated growth in vitro of bone marrow megakaryocytic progenitors (CFU-Mk) in 7 patients with paroxysmal nocturnal haemoglobinuria (PNH) to determine the sensitivity of CFU-Mk to complement. Bone marrow light density mononuclear cells were exposed to fresh or heat-inactivated AB human serum in the presence of medium or isotonic sucrose solution. We found that the proliferative activity of bone marrow CFU-Mk in PNH patients was significantly lower than in controls. In addition, the number of CFU-Mk in PNH bone marrow cells exposed to isotonic sucrose and complement was reduced to 25% of that in PNH cells exposed to isotonic sucrose without complement. In conclusion, our finding showed an increased sensitivity of CFU-Mk in PNH bone marrow cells to complement, supporting the hypothesis that the PNH defect is present at the level of CFU-Mk.
Institute of Haematology, Clinical Center of Serbia, Belgrade, Yugoslavia.
N
N
Basara
P
P
Antunovic
D
D
Sefer
N
N
Radosevic
M
M
Gotic
D003165:Complement System Proteins / Q000494:pharmacology*; D006457:Hemoglobinuria, Paroxysmal / Q000097:blood* / Q000473:pathology; D006801:Humans; D008533:Megakaryocytes / Q000166:cytology*; D013234:Stem Cells / Q000187:drug effects / Q000276:immunology*; D013395:Sucrose / Q000494:pharmacology
D013395:Sucrose; D003165:Complement System Proteins