Inclusion Criteria:

          -  Patients who are planned to receive chimeric antigen receptor T-cell therapy as per
             the United States Food and Drug Agency (USFDA) approved indications for Diffuse large
             B-cell lymphoma (DLBCL), Mantle cell lymphoma (MCL), Follicular lymphoma (FL), Primary
             mediastinal large B-cell lymphoma (PMBCL), High grade B-cell lymphoma, DLBCL arising
             from follicular lymphoma, Multiple myeloma and B-cell precursor acute lymphoblastic
             leukemia

          -  Patients with hepatitis C virus (HCV) can be included if they have completed therapy
             for hepatitis C with undetectable HCV RNA viral load.

          -  Patients with Hepatitis B can be included if they are on suppressive therapy for
             hepatitis B infection and with no detectable viral load.

          -  Adequate organ function as defined below unless attributed to disease
             involvement.Acceptable window for assessing adequate organ function is 7 days to 30
             days before planned CAR T-cell infusion with day 0 as the planned day of CAR T-cell
             infusion.Adequate liver function (bilirubin < 2mg/dL, aspartate aminotransferase (AST)
             and/or alanine aminotransferase (ALT) <3 x ULN), adequate kidney function (crcl >
             30ml/min using Cockcroft-Gault, based on actual weight) and adequate hematological
             parameters (Absolute neutrophil count ≥ 1,000/µL, Hemoglobin > 8, Platelet Count ≥
             50,000/ µL)

          -  Patients able to tolerate washout periods for therapies prior to CAR T-cell infusion.
             Systemic therapy: Washout period is 2 weeks prior to CAR T-cell infusion. Radiation
             therapy: Washout period is 1 week prior to CAR T-cell infusion. Corticosteroids: The
             washout period is 5 days prior to CAR T-cell infusion.

          -  A negative urine pregnancy test is required within 1 week for all women of
             childbearing potential prior to enrolling on this trial.

          -  For females of reproductive potential: use of highly effective contraception for at
             least 1 month prior to screening and agreement to use such a method during study
             participation and for an additional 4 months after infusion of siltuximab.

          -  For males of reproductive potential: use of condoms or other methods to ensure
             effective contraception with partner

          -  Willing and able to participate in all required evaluations and procedures in this
             study protocol including receiving intravenous administration of the investigational
             product and being admitted, when required, for at least 24 hours during
             investigational product administration.

        Exclusion Criteria:

          -  Subjects requiring ongoing daily corticosteroid therapy at a dose of > 10 mg of
             prednisone per day (or equivalent). Pulsed corticosteroid use for disease control is
             acceptable.

          -  Active autoimmune disease requiring immunosuppressive therapy is excluded unless
             discussed with the principal investigator (PI)

          -  Pregnant women are excluded from this study.

          -  Evidence of ongoing systemic bacterial, or fungal or viral infection, except localized
             fungal infection of skin or nails.

          -  Patients with ongoing or past HIV infection.