Influence of NaCl 0.9% Infusion during Plasmapheresis on IgG Content in Plasma

BACKGROUND: The aim of this study was to evaluate the influence of an infusion of NaCl 0.9% 500 ml during preparatory plasmapheresis or apheresis on the immunoglobulin G (IgG) content in separated plasma. METHODS: 32 donors of plasma were studied in a crossover design after informed consent on one day without NaCl 0.9% 500 ml during apheresis and on another day with infusion of NaCl 0.9% 500 ml during apheresis. Infusion of NaCl 0.9% 500 ml was given step by step in divided doses after each cycle through the harness set of the Haemonetics® plasma collecting system 2 (PCS2). Concentrations of IgG in serum and in plasma were measured by an immunoturbidimetric assay. Percentages of IgG concentrations in plasma were calculated by dividing the IgG concentration in plasma by the mean serum IgG concentrations (x 100). RESULTS: Without infusion of NaCl 0.9% 500 ml, the mean percentage of IgG in separated plasma was 85.5 ± 2.3% while it was 80.5 ± 3.4% when NaCl 0.9% 500 ml was given. The difference between the two samples was statistically highly significant (p < 0.001). CONCLUSIONS: We conclude that the gradual infusion of NaCl 0.9% 500 ml during apheresis causes a statistically highly significant difference of IgG content in separated plasma.