Pulmonary function abnormalities after infusion of antihemophilic factor (AHF) concentrates

Antihemophilic factor (AHF) concentrates contain debris which passes freely through the 170 μ filter routinely used for patient infusion. We have previously shown that this material is composed in part of IgG, fibrinoprotein and cold-insoluble globulin and that it is retained by a screen filter of 40 μ pore size. The purpose of this study was to investigate pulmonary effects of this particulate material in hemophiliac patients receiving frequent AHF infusions. Pulmonary function studies were performed before and after the infusion of a standard dose of AHF concentrate calculated to raise the in vivo factor VIII level to 50 per cent of normal. Using a standard 170 μ filter, five of six patients showed a significant decrease (p < 0.01) in the single breath carbon monoxide diffusing capacity (D_LCO_SB) 30 minutes and 6 hours after the infusion, with values returning to preinfusion levels by 48 hours. Slow vital capacity, forced vital capacity, maximum voluntary ventilation and a helium dilution residual lung volume remained normal in all patients. Two patients who were restudied using a 40 μ filter showed no significant change in the D_LCO_SB after the infusion. We conclude that lodging of particulate material in the pulmonary capillary bed was most likely responsible for the reduced D_lCO_sb. Since the defect was prevented by microfiltration, the use of a finer mesh filter than is currently recommended may be desirable for hemophiliac patients receiving large amounts of AHF concentrate at frequent intervals.