A new case of 'type II' inherited protein S deficiency.
Protein S inherited deficiency is associated with high risk of recurrent venous thrombotic disease (Broekmans et al, 1985a, b). Protein S exists as two forms in plasma, either free and functionally active or complexed with C4b-binding protein (C4b BP) and inactive (Dahlbäck & Stenflo, 1981). We report here the case of a 26-year-old woman and her brother, 28 years old, both suffering from recurrent venous thrombosis since the age of 20, diagnosed as severe protein S deficiency according to the following data: free protein S: 2.5-3% by ELISA, undetectable by electroimmunodiffusion (EID); total protein S: 13-16% by ELISA, 21-18% by EID, C4b BP: normal levels. Crossed immunoelectrophoresis using anti-protein S antibodies revealed only traces of protein S associated with C4b BP and no free protein S. All these assays were performed in the absence of any anticoagulant therapy. Among the investigated relatives, less severe protein S deficiency was observed in three children of the propositus: total protein S levels ranging from 41% to 50% (EID), 40-53% (ELISA); free protein S levels ranging from 16% to 18% (EID), 10-12% (ELISA); normal C4b BP levels. Crossed immunoelectrophoresis revealed traces of free protein S but a significant amount of protein S associated with C4b BP. From these results, we consider, according to Comp's classification (Comp et al, 1986a), that the propositus and her brother are the second case of protein S deficiency type II to be reported in the literature while her children belong to the type I category.
Chafa
O
O
C.T.S., C.H.U. Mustapha, Alger, Algérie.
Fischer
A M
AM
Meriane
F
F
Chellali
F
F
Rahal
S
S
Sternberg
C
C
Benabadji
M
M
D000328:Adult; D002352:Carrier Proteins / Q000097:blood; D003181:Complement C4; D003169:Complement Inactivator Proteins; D005260:Female; D006023:Glycoproteins / Q000172:deficiency*; D006489:Hemostatic Techniques; D006801:Humans; D007123:Immunoelectrophoresis, Two-Dimensional; D010375:Pedigree; D018455:Protein S Deficiency; D011951:Receptors, Complement / Q000032:analysis; D013924:Thrombophlebitis / Q000235:genetics*
D002352:Carrier Proteins; D003181:Complement C4; D003169:Complement Inactivator Proteins; D006023:Glycoproteins; D011951:Receptors, Complement