[Paroxysmal nocturnal hemoglobinuria. Diagnosis aided by a monoclonal antibody directed against the decay accelerating factor glycoprotein].

The laboratory diagnosis of paroxysmal nocturnal haemoglobinuria (also called Marchiafava-Micheli disease) is based on the sensitivity of the patient's red cells to complement-induced lysis. In view of the clonal expression of the disease, haemolysis tests are difficult to interpret when the abnormal red cell population is small. The sensitivity of abnormal red cells to haemolysis is due to the absence of proteins attached to the cell membrane by a phosphatidyl-inositol link, which intervene in the regulation of the complement-induced lysis mechanism.

[Characterization of murine monoclonal antibodies against fetal erythrocytes].

Balb/c mice were immunized against papain-treated fetal erythrocytes and splenocytes were fused with Sp2/0-Ag-14 myeloma cells. Several hybrids secreting antibodies directed against antigenic determinants predominantly exposed on fetal and cord cells were selected and cloned twice. Antibodies NaM61-1A2 and NaM61-768 (IgM class) were shown to be specific for an endo-beta-galactosidase-sensitive oligosaccharide chain.

Cytotoxicity and hemolysis by an extract of the sponge Pachymatisma johnstonii.

In vitro cytotoxicity on human rhinopharynx KB cells, as well as hemolytic activity on human erythrocytes, was produced by an aqueous extract of the sponge Pachymatisma johnstonii. Optimum temperature and pH were the same for both activities (37 degrees C, pH 5). Moreover, after partial purification, the compounds involved were found in the same chromatographic fraction.