The overall objectives of this study are to evaluate feasibility and safety of thoracic duct sampling, including "in-and-out" cannulation and "indwelling" catheterization in early MS and to compare cellular and signaling markers in thoracic duct lymph compared to measures in the blood, within and across populations of MS patients before and after ofatumumab and compared to healthy controls. The study is designed to evaluate the safety and feasibility of collection of lymphoid fluid via thoracic duct cannulation in healthy people and people with MS, and to assess the impact of ofatumumab treatment in patients with MS on biological measures in the thoracic duct fluid and in the blood.

You may be eligible for this study if you meet the following criteria:

• Conditions: Medical Research
• Age: Between 18 Years - 55 Years
• Gender: All