A bleeding syndrome in infants: acquired prothrombin complex deficiency of unknown aetiology.

A total of 240 cases of a bleeding syndrome in infants due to prothrombin complex deficiency of unknown aetiology were reviewed. The majority of patients were breast fed, aged 1-2 months and the syndrome was more prevalent in males. Clinical manifestations consisted of bleeding, pallor and mild hepatomegaly in the majority of cases. Mild fever, diarrhoea, jaundice, and upper respiratory tract infection were associated in a few patients. Acute onset, short course and a high rate of intracranial bleeding (65%), particularly subdural and subarachnoid, were observed. The haemostatic defects appeared to be a marked reduction in factor II, VII, IX, and X. Complete blood counts remained relatively normal, with the exception of some changes (anaemia, leukocytosis), in response to the acute bleeding. Liver chemistry was normal or slightly impaired. No specific pathological changes were noted at autopsy, there were mild changes of liver cells, such as rare focal necrosis of liver cells, the proliferation of Kupffer cells, extramedullary haemopoeisis and mild cholestasis. Clinical improvement and correction of hemostatic defects were noted after vitamin K therapy alone or with fresh blood transfusion. Mortality rates were high in infants with intracranial bleeding (40-55%), while the overall mortality rate was 25%. The pathogenesis and the possibility of prevention of the syndrome were discussed.