Antiphospholipid antibodies and coagulation regulatory protein abnormalities in children with pulmonary emboli

To evaluate the demographics, presentation, family history, and laboratory findings in children with clinically recognized pulmonary emboli.

Data were collected about children with clinically recognized pulmonary emboli from 1987 to 1994 at two pediatric hematology referral centers.

Sixteen children, mean age 11.8 years (standard deviation 4.69 years) including 11 boys were affected. Lower extremity thromboses were present in 7/14 children evaluated. Eight of the 16 children were apparently well before development of pulmonary emboli; seven were found to have antiphospholipid antibodies. None of the 15 children tested were antithrombin III deficient. One of 14 children tested was protein C deficient. Three of 13 children tested were protein S deficient or had a free protein S antigen at the fifth percentile. One of 10 children tested had an acquired dysfibrinogenemia. Two of nine children tested had the Factor V Leiden mutation.

Our limited data suggest at least 70% of children with pulmonary emboli referred for hematology evaluation have antiphospholipid antibodies and coagulation regulatory protein abnormalities.