Objective: To study the effect of either ion-exchange (high purity, HPC) or affinity chromatograhpy purified (ultra-high purity, UPC), plasma-derived factor VIII concentrates on the circulating lymphocyte subsets in hemophilia A patients.

Methods: Multicenter, follow-up, study. Thirty-seven patients from 4 Spanish Hemophilia Units, previously treated with intermediate- purity concentrates, were given either HPC or UPC. Lymphocyte subsets and basic analytical profile were performed every 4 months, and clinical and epidemiological data were recorded through the following 3 years. 17 patients had been treated with HPC and 20 with UPC. Ages ranged from 5 to 16 years(median, 11.5), and no differences were found between groups at start in any of the parameters studied. Lymphocyte subsets including CD4+, CD8+, natural killer (NK), cytotoxic and activated cells have been analyzed by double direct immunofluorescence in the flow cytometer. Variations of the different subsets were analyzed by the Kaplan-Meier estimates, and curves compared by the log rank test, Peto-Prentice and Gehan-Breslow methods.

Results: Median follow-up was 2.96 yr. Decrease higher than 30% in CD4+ cells was found in 7 patients (18.9%), and comparisons between HPC and UPC actuarial curves demonstrated no statistically significant differences in any of the subsets studied.

Conclusions: Treatment with chromatography purified, plasma-derived factor VIII concentrates do not have deleterious effects on the CD4+ and CD8+ lymphocyte subsets, neither in NK cells and cytotoxic and activated T lymphocytes, after 3 years of treatment. In addition, no differences between HPC and UPC have been observed in the evolution of these lymphocyte subpopulations.

Acknowledgements: This study has been supported by grants of the Real Fundación Victoria Eugenia and the GEHT, Spain.