Kinetics of Rituximab Excretion into Urine and Peritoneal Fluid in Two Patients with Nephrotic Syndrome

Figure 2

CD20 expressing Daudi cells (a1) were incubated with urine for 20 min to enable suspected Rituximab to bind the CD20 antigen (a2). After three washes in PBS/BSA, cells were incubated with a PE-labeled anti-human IgG antibody and incubated for 20 min (a3). After three washes in PBS/BSA, cells were subjected to flow cytometry analysis. Controls were identically performed but by using Octagam solution instead of urine. Flow cytometric analysis of Daudi cells. Daudi cells were gated according to their FSC/SSC properties (b1). Histograms of Daudi after incubation with PBS (b2), Octagam (b3), urine of the first patient (b4), and peritoneal dialysate fluid of the second patient (b5) are shown. Cell numbers are shown on -axis and relative fluorescence intensity of the secondary (anti-human IgG) antibody on -axis.