Efficacy Study of Granulocytapheresis Plus Steroids vs Steroids Alone in Active Steroid Dependant Ulcerative Colitis

Inclusion Criteria: * 18 - 75 years old * Active ulcerative colitis with documented clinical symptoms and endoscopic findings * Active disease defined as DAI (Mayo score) ≥ 4 and ≤10 with at least 1 point in flexible sigmoidoscopy * Steroid dependency as defined by: A. Inability to withdraw corticosteroids within three months of starting treatment, without recurrent active disease B. appearance of relapse within 3 months after withdrawal of corticosteroids * Colonic involvement with ulcerative colitis beyond 15cm of the anal verge * Stable doses:A. Aminosalicylates for the last 4 weeks B. Prednisolone or equivalent dose ≤ 20 mg/day for the last 2 weeks C. Azathioprine or 6-mercaptopurine at stable dose for the last 12 weeks * Signed informed consent form * Agree to participate in the required follow-up visits * Able to complete the diary Exclusion Criteria: * Febrile (\> 38ºC) * Evidence of toxic megacolon * Anticipated need for surgery within 24 weeks * Known obstructive diseases of the gastrointestinal system * Proctocolectomy, total colectomy, ileostomy, stoma or ileal pouch-anal anastomosis * A history of allergic reaction to heparin or heparin-induced thrombocytopenia * A history of hypersensitivity reaction associated with an apheresis procedure or intolerance of apheresis procedures * Requires a central venous access catheter for the apheresis treatments * Known infection with enteric pathogens, pathogenic ova or parasites, C. difficile toxin or CMV * Hypotension (systolic blood pressure \<80 mmHg and/or diastolic blood pressure \<50 mmHg) at screening visit only * Uncontrolled hypertension (systolic blood pressure \>180 mmHg or diastolic blood pressure \>120 mmHg) despite medical therapy * A history of myocardial infarction or unstable angina within the past 6 months * A history of coronary artery bypass grafting surgery or angioplasty within the past 6 months * Prosthetic heart valve, pacemaker or other permanent implant * Severe cardiovascular or peripheral vascular disease, severe renal disease * Liver disease defined as levels of SGOT \[AST\], SGPT \[ALT\] or alkaline phosphatase \>2.5x the upper limit of the normal range for the laboratory performing test * History of cirrhosis * Known bleeding disorder (PT or PTT\>1.5x the upper limit of the normal range for the laboratory performing the test), or concomitant anticoagulant therapy for purposes other than apheresis treatment * Prior history suggestive of a hypercoagulable disorder, including 1 or more episodes of pulmonary embolism or deep vein thrombosis * Known infection with Hepatitis B or C, or HIV * Abnormal hematology parameters defined as severe anemia with hemoglobin \<8.5g/dL, white blood cell count of \<3,500/μl and a granulocyte count \< 2,000/μl * Fibrinogen level \>700mg/dL * Major surgery within the past 6 months * Infection:Active infections less than 4 weeks from successful completion of antibiotic treatment for routine bacterial infectionFebrile viral infection within 4 weeks of entry into the clinical investigationLess than 12 weeks from conclusion of therapy for systemic fungal infections * Malignancy within the past 2 years other than surgically cured skin carcinoma or cervical dysplasia (CIN I-II) * History of dysplasia or carcinoma of the colon or lack of a complete colonoscopy in the last 12 months in patients with longstanding UC (\> 10 años) * Current drug or alcohol abuse * Pregnant, lactating or planning to become pregnant during the course of the clinical investigation * Used within the last 30 days an investigational drug, biologic or device or 5 half-lifes, if known, for any investigational drug or biologic * Received cyclosporine or tacrolimus within the last 8 weeks * Received infliximab within the last 8 weeks * Fulminant ulcerative colitis