New Antibody in Severe Rhesus Incompatible Pregnancies: IgG‐Kappa Antiplacental Alkaline Phosphatase

Abstract

As already found in other various diseases, a macromolecular alkaline phosphatase complex (HMW-AP) was also found in sera of two severe Rhesus-incompatible pregnancies complicated by ascites and fetal hydrops at delivery. This atypical complex was detected and isolated by agarose gel electrophoresis. Immunoelectrophoresis and heat inactivation of this HMW-AP complex revealed that it consisted of IgG of the kappa type and placental AP isoenzyme. The transitory presence of this immuncomplex is discussed. However, in all women with Rh-immunized complicated pregnancies, significant variations of neutrophil and serum AP activities were observed. A fall in AP activity and the presence of an antiplacental AP antibody in serum of women with complicated Rh immunization should be of value in assessing the prognosis of the disease.

About the Presence of a Circulating Anti-Alkaline Phosphatase Antibody in a Trisomy 21 Patient’s Serum

“…These abnormal data prompted us to investigate the possible existence of an anti-AP antibody. In the same way, a similar result recently led us to detect antiplacental AP antibodies occurring in some cases of complicated Rhesus incom patible pregnancies [2].…”

“…In a first step a circu lating slow-moving macromolecular AP complex was detected by means of agarose gel electrophoresis and Although the diagnostic or pathophysiologi cal significance is still obscure, a relationship between the simultaneous presence in serum of increased AP activity and AP macromolecular complex to altered skeletal growth, frequenly observed in Down's syndrome, cannot be ruled out. specific staining [2]. This complex, localized in the y-globulin zone, was isolated, eluted and concentrated by centrifugation (Centrisart tubes).…”

“…This complex, localized in the y-globulin zone, was isolated, eluted and concentrated by centrifugation (Centrisart tubes). It was then tested by immunoelectrophoresis according to the pre viously described protocol [2],…”