Increased thrombophilic tendency in pediatric cystic fibrosis patients.

Thrombophilia has recently been reported to be increased in patients with cystic fibrosis (CF). We wanted to determine whether this was applicable to our population with CF and how our patients compared to the previously reported groups. Seventy one pediatric CF patients were assessed for a thrombophilic tendency, using a lupus anticoagulant screen, protein C, protein S, antithrombin assay, and activated protein C resistance (APCR) screen. The incidence of activate protein C resistance (4.2%) was within expected limits for the general population as was the incidence of antithrombin deficiency. However there was a marked increase in the incidence of lupus anticoagulants (18%) and 14% and 19.7% of the patients showed a reduced protein C and protein S, respectively, far in excess of the general population. This increased incidence of thrombophilia was not related to any specific CF phenotype and while perturbed liver function cannot be entirely ruled out, it appeared unlikely to be responsible for all the abnormal coagulation findings. Despite the apparent thrombophilic tendency, no clinically evident thrombotic episodes were noted during the study period. Thrombophilia is of concern because of the increasingly frequent placement of indwelling catheters in CF patients. The precise cause for the thrombophilic tendency in CF patients is unknown at this stage.