Long-term follow up of patients treated with intermediate FVIII concentrate BPL 8Y.

Long-term surveillance studies of clotting factor concentrates are important to detect infrequent or delayed complications and to provide data against which newer products can be compared. We have assessed the long-term use of BPL 8Y factor VIII (FVIII) concentrate (Bio Products Limited, Elstree, UK) in a cohort of 33 patients. These patients have been treated for a median of 96 months. They have received between one batch (in total) and 10 batches per year and between 1020 units (in total) and 116,700 units per year of BPL 8Y concentrate. No patient has developed a clinically significant FVIII inhibitor. There has been no evidence of transmission of hepatitis C, hepatitis B or HIV 1 or 2. Parvovirus B19 IgG antibody was present in 100% of the patients screened. Analysis of CD4 and CD8 lymphocyte subsets, using age-related normal ranges, showed persistently depressed values in five patients, one of whom had a consistently low CD4/CD8 ratio.