A new bleeding tendency due to hereditary hyper alpha 2-macroglobulinemia.
Mots clés
Abstrait
A heritable elevation in alpha 2-macroglobulin (alpha 2M) was identified in a 9-year-old girl with a severe bleeding tendency and activated partial thromboplastin time (APTT) prolonged to 49.1 sec (normal 27-38) as well as recalcification time prolonged to 438 sec (less than 180). The addition of her plasma to normal plasma made APTT prolong from 26.8 to 38.3 sec. The plasma alpha 2M levels in her relatives were checked, i.e., proband, her sister, mother, maternal grandmother, father, and paternal grandmother: Their levels were 406, 380, 352, 339, 166 and 236 mg/100 ml (140-285), respectively. Thus the patient's condition was thought to be an autosomal dominant disease, though her other relatives displayed no apparent clinical symptoms. Of significance was that a possible causal association between her elevated alpha 2M and her prolonged APTT was indicated. The activity of the alpha 2M, determined as trypsin-protein esterase, was 351 mg/100 ml (197%). The alpha 2M also demonstrated normal horizontal mobility to anti-alpha 2M plasma with a high precipitin arc (showing the difference of the protein concentration) by crossed immunoelectrophoresis, and a normal horizontal mobility of immunofixation electrophoresis. In addition, after analysis of testing done by SDS-polyacrylamide-gel-electrophoresis, we found no qualitative abnormality in the alpha 2M of the patient.