Table 3.

CSF and Serum Rituximab Levels (n=8)

Patient	Pre* (ng/ml)	Post (ng/ml)	CSF (ng/ml)	CSF/Post (%)
15	--	410,000	343	0.084
21	36,400	375,000	498	0.133
22	47,500	367,000	351	0.096
25	< 500	334,000	276	0.083
26	--	373,000	440	0.118
27	31,400	394,000	< 250**	not calculated+
28	--	649,000	272	0.042
30	36,900	349,000	1310	0.375

^*Levels detected in “Pre” serum samples likely from previous treatment with rituximab

^**Level was less than minimum detectable limit

⁺Not calculated given that CSF level was less than detectable limit