Clinical Research Directory

Inclusion Criteria: 1. Patients with RRMS who are being treated with alemtuzumab at Barts Health NHS Trust will be approached to participate in the study. 2. Patients must be willing and able to undergo blood tests. Exclusion Criteria: 1. Ineligible for alemtuzumab under NHS England prescribing guidelines. 2. Those unable to comply with study requirements, including frequency of visits. Abnormal baseline investigations (WBC\<3 x 10\*9/l, lymphocytes \<1.0 x 10\*9/l, neutrophil count \<1.5 x 10\*9/l, platelet count \<100 x 10\*9/l, haemoglobin \<110 g/l, LFT \>/3x upper limit of normal of site reference ranges, potassium \<2.8 mmol/l or \>5.5 mmol/l, sodium /,125 mmol/l, creatinine \>130 umol/l).