Stability and sterility of a recombinant factor VIII concentrate prepared for continuous infusion administration.

Minipumps may facilitate cost-effective and convenient continuous infusion (CI) therapy for severe hemophilia A. This study evaluated the in vitro sterility, ability to support bacterial growth, and specific activity stability of a recombinant factor VIII (FVIII; Bioclate, Centeon) delivered by simulated CI at a variety of temperatures and after the addition of heparin or antibiotic. Closed system CIs of Bioclate (89.5 IU/ml) with and without heparin were sampled and cultured over a 6 day period. Bioclate (53.7 IU/ml) with and without heparin or vancomycin was inoculated with 102-105 CFU/ml of S. aureus, S. epidermidis, Escherichia coli, E. cloacae, or Y. enterocolitica and assessed by quantitative culture after 1 and 3 days. The stability of Bioclate (50, 100, and 250 IU/ml) at three temperatures (21 degrees C, 37 degrees C, and 39 degrees C) with and without heparin or vancomycin was tested over a period of 28 days. FVIII activity was measured in triplicate by a chromogenic assay (Coamatic Factor VIII, Chromogenix) and purity evaluated by Western blot. No bacterial growth was detected during CI of FVIII for up to 6 days. Following bacterial inoculation, there was rapid growth (>3 log increase) of all tested bacterial species except S. aureus which only displayed a 1 log expansion at 3 days. The addition of heparin containing 9.45 microg/U benzyl alcohol had no effect on bacterial growth. The addition of vancomycin caused a modest suppression of S. aureus growth but not of E. coli. Diluent alone did not support bacterial growth. Neither concentration, increased temperature, nor the addition of heparin or vancomycin had a significant effect on FVIII activity stability. Samples retained >75% baseline activity for between 3 and 7 days, except the infusion of Bioclate 50 IU/ml plus heparin maintained at 21 degrees C which remained stable for 28 days. Western blot analysis supported the activity assay findings. Standard and concentrated preparations of Bioclate are suitable for CI when delivered by the MiniMed 404-SP minipump. Because of the observed nutritive capability of this FVIII concentrate for sustaining bacterial growth, any contamination could result in systemic infection.

Blindness in children with neuroblastoma.

BACKGROUND: Neuroblastoma is the most common extracranial solid tumor among pediatric patients, and orbital metastatic disease is not uncommon in these children. Physical signs as a consequence of orbital metastases, such as proptosis and periorbital ecchymosis, frequently are encountered. However, subsequent blindness is rare. METHODS: A retrospective study was conducted to determine the incidence, related physical findings, treatment, and outcome of children who developed visual loss during treatment for neuroblastoma. Medical records for a 24-year period (1971-1994) were reviewed to identify these patients. The charts, diagnostic imaging studies, and autopsy material of these patients were reviewed. RESULTS: Of the 450 patients treated for neuroblastoma at the study institution during this period, 47 presented with abnormalities in physical examination of the eye. Eight of these 47 patients and 7 others developed visual loss in at least 1 eye during the first week after diagnosis (n = 5), during primary therapy (n = 6), at recurrence (n 2), or after completion of therapy (n = 2). In ten patients the visual loss was a direct consequence of the primary disease process, whereas a direct relationship between loss of vision and neuroblastoma could not be identified in the remaining five patients. Proptosis and periorbital ecchymosis were the most common associated physical findings. Although ten patients received steroids and eight received radiation, visual loss could not be prevented or reversed in these patients. CONCLUSIONS: Early initiation of effective, multiagent chemotherapy remains the primary approach for the treatment of neuroblastoma and its ophthalmologic complications. Radiation therapy and steroids may have benefit but failed to show good effect in this series. The prevention and treatment of blindness is probably most relevant in infants and children age < 2 years because they have the best chance for cure.