Abstract
Enzyme replacement therapy for a severely affected premature boy (birthweight: 2380 g, GA:36 weeks) with hypophosphatasia was attempted by infusions of purified human hepatic alkaline phosphatase(AP). Treatment started at age of two weeks and was repeated in weekly intervals until death (10 weeks). Samples of AP were diluted with 10 ml of physiological saline and infused over a time span of 30 minutes via an umbilical arterial catheter. No toxic or allergic side effects were observed. Serum-AP increased from 3 mU/ml before treatment to a maximum level of 195 mU/ml with a half-life time between 37 and 62 hours. Urinary excretion of phosphoethanolamine (PEA) decreased under therapy from a maximal value of 9.5 to 5.5 μmol/mg creatinine (normal: < 0.4). Calcium, phosphorus, parathormone and 1-25 dihydroxyvitamin D levels were within the normal range during therapy. Sequential radiographic studies showed no improvement of bone mineralization under therapy. Bone morphology was studied by light and electron microscopy before treatment and post mortem. In contrast to previous studies an unusually woven bundle bone structure was found with abrupt mineralization fronts without osteoblast-like cells. We conclude that this enzyme, substituted for the first time, altered PEA concentrations but failed to influence the iniiial abnormal bone structure of this infant.
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Weninger, M., Stinson, R., Plenk, H. et al. 91: BIOCHEMICAL VERSUS MORPHOLOGICAL EFFECTS OF HUMAN HEPATIC ALKALINE PHOSPHATASE IN A NEONATE WITH HYPOPHOSPHATASIA. Pediatr Res 24, 276 (1988). https://doi.org/10.1203/00006450-198808000-00117
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DOI: https://doi.org/10.1203/00006450-198808000-00117