18. Presence of serious gastrointestinal, renal, hepatic, pulmonary, cardiovascular, neurological disease or other known systemic disease (like leukemia, tuberculosis, immune mediated diseases, multiple sclerosis, Acquired Immuno Deficiency Syndrome, Human Immunodeficiency Virus-infections or other chronic virus-infections) that might interfere with the outcome of the study or the patient's ability to comply with study requirements.