Conditions: Rheumatoid Arthritis Psoriatic Arthritis Psoriasis Crohn's Disease
Allocation: NA | Intervention model: SINGLE_GROUP
Enrollment: 31
Healthy volunteers: yes

Brief summary:
Specific Aim 1. To determine the transcriptome of peripheral blood mononuclear cells isolated monocytes and target tissues in IMIDs.

Specific Aim 2. To analyze the change in gene expression profiles in patients with Crohn's disease, psoriatic and rheumatoid arthritis before and after infliximab therapy.

Detailed description:
Our hypothesis is that hematopoietic stem cells are very sensitive to elevated levels of TNFa, which potentiates their differentiation into myeloid effector cells. During their migration from the bone marrow to the end organ, these cells express a unique set of genes that function to prime these cells to respond to critical differentiation signals. Elucidation of this transcriptome through microarray analysis will provide insight into novel drug targets and a formal understanding of the biochemical and molecular genetic events linking IMIDs. To test our hypothesis, will determine the transcriptome in peripheral blood mononuclear cells and isolated monocytes from 20 normal healthy donors, 10 patients with psoriatic arthritis, 10 patients with psoriasis, 10 patients with Crohn's disease and 10 patients with rheumatoid arthritis. The transcriptome will also be examined in inflamed intestinal tissue from patients with Crohn's disease, psoriatic skin and synovial tissue from patients with rheumatoid and psoriatic arthritis.

Arms:

Interventions: intervention 1: Infliximab
Intervention descriptions: intervention 1: Subjects will be on a stable dose of methotrexate 12.5 to 20 mg per week and will be started on infliximab 5 mg/kg.

Protocol document: