GVH 022P: Study Using Anti Tumor Necrosis Factor Antibody (Infliximab) for Treatment of Acute Graft Versus Host Disease

Inclusion Criteria: * Patients must have received corticosteroids at \>= 2 mg/kg/day for a minimum of 72 hours prior to study entry. * Overall clinical grade II-IV acute GVHD (aGVHD) with intestinal involvement with biopsy of at least one site "consistent with" aGVHD. Acute GVHD is defined in this study as occurring within 100 days after transplant. * Men and women of childbearing potential must use adequate birth control measures (e.g., abstinence, oral contraceptives, intrauterine device, barrier method with spermicide, or surgical sterilization) for the duration of the study and should continue such precautions for 6 months after receiving the study drug infusion. * Parent(s)/legal guardian must give informed consent Exclusion Criteria: * Patients with uncontrolled infection(s), i.e. documented bacterial, viral or fungal infection within 72 hours prior to study entry. Neither continuation of antibiotics for a controlled infection nor prophylactic/empiric antibiotics warrant exclusion. * Patients with any one of the following opportunistic infections documented within 8 weeks prior to study entry are excluded: cytomegalovirus disease, pneumocystis carinii, aspergillosis, histoplasmosis, atypical mycobacterium infection or other pathogenic molds/fungi. * Serum creatinine \> 1.5 mg/dl at study entry. * Women who are pregnant, nursing, or planning pregnancy within 6 months following study drug infusion. * Use of any investigational drug for the treatment of acute GVHD within 14 days prior to study entry. An investigational drug is defined as one that is being given on study, requiring informed consent. * Use of ATG or similar product within 14 days prior to study entry requires study chair approval. Judgment will be based on ATG dosing and timing. * Previous administration of infliximab. * Any allergy to murine products. * Documented HIV infection. * Patients with grade IV renal, hepatic, pulmonary, or neurologic toxicity by National Cancer Institute (NCI) Common Toxicity Criteria (CTC). * Patients with any history of congestive heart failure, defined as cardiac dysfunction requiring inotropic support other than dopamine at \<= 5 mcg/kg/minute. * Peripheral neuropathy or any demyelinating disease, greater than CTC grade 1. * Presence of a transplanted solid organ (with the exception of a corneal transplant \> 3 months prior to screening). * Any prior history of tuberculosis (TB). Patients with a recent close contact with an individual with active TB are excluded. Patients with a household member who has a history of pulmonary TB should have a thorough evaluation for TB prior to study enrolment as recommended by a local infectious disease specialist or by guidelines on TB screening published by the United States (US) Federal Centers for Disease Control and Prevention (CDC).