Immunosuppression in Bone Marrow Transplant Nwogoh Benedict Department of Haematology/Blood Transfusion, Federal Medical Centre, Owerri BBMT Conference, Benin, July , 2013

Objectives  Summarize the principles for use of immunosuppression in allogeneic stem cell transplant (SCT)  Compare and contrast commonly used medications used for immunosuppression  Describe monitoring parameters and common adverse effects associated with immunosuppression

Introduction  HSCT is a process of reconstituting the haemopoietic and immunological system of a recipient using previously harvested stem cells from same individual or a donor HSC.  Allogeneic HSCT involves a complex immunological interplay between donor and recipient immune systems with potentials of both beneficial and serious life threatening complications

Introduction  Appropriate manipulation of this complexity is necessary for a successful transplant.  Immunosuppresion is a important modality of moderating this immunological interaction to ensure a successful HSCT.

Immune System  Innate Immunity Physical Barriers Secretions with microbiocidal activity Phagocytes  Adaptive/Specific Immunity Humoral Cellular: B, T and Plasma cells

Cells of the Immune System

Antigen  Major HLA Ags Class I HLA A, B, C Class II HLA DP, DQ, DR Class III  Minor HLA Ags  Non HLA Ags

Use of Immunosuppression  Immunosuppression is used in allogeneic stem cell transplant to: Prevention of rejection Prophylaxis for graft versus host disease (GVHD) Treatment of GVHD

Prevention of rejection  Rejection is a consequence of host versus graft reaction.  Immunosuppresants are incuperated into the conditioning regimen to prevent rejection.  Eradicates host T-cells to allow acceptance of donor cells  Commonly used agents include ATG, Alemtuzimab and Cyclophosphamide.

Prophylaxis for graft versus host disease (GVHD)  Pre- & post-transplant medications  Suppresses donor T-cells to minimize recognition of host cells as foreign  Post transplant could be Ex-vivo manipulation of the graft to deplete it of T cells (TCD) In-vivo

Treatment of GVHD  The first line agent is usually steroids (methylprednisolone 1-2mg/kg)  A calcineurine inhibitor (Cyclosporine) may be used in combination.  Second line agent may be indicated when first line fails.  First line agent is adjudged to have failed when : Features are progressive after 3 days of steroid therapy Failure to respond after 14 days of therapy

Pathophysiology of GVHD Ferrara, et al. Lancet 2009;373:

Medications used for immunosuppression ClassDrug Immune globulinAntithymocyte globulin (ATG) - Equine ATG: Atgam  - Rabbit ATG: Thymoglobulin  Monoclonal antibodyAlemtuzumab - Campath  Calcineurin InhibitorsTacrolimus - Prograf  Cyclosporine - Non-modified: SandIMMUNE  - Modified: Gengraf  or Neoral  Antifolate antimetaboliteMethotrexate ImmunosuppressantMycophenolate mofetil - CellCept  CorticosteroidsMethylprednisolone Prednisone mTOR inhibitorSirolimus - Rapamune 

Alemtuzumab  Anti CD52 monoclonal antibody  CD52 expressed on: B and T lymphocytes Monocytes Macrophages NK cells Dendritic cells

Alemtuzumab Adverse Effects  Infusion related reactions Chills, dyspnea, fevers, hypotension, rigors  May be fatal Premedicate with acetaminophen, diphenhydramine, ± corticosteroid  Hypersensitivity reactions  Cytokine release syndrome  Opportunistic infections Requires anti-infective prophylaxis

Antithymocyte Globulin (ATG) Mohty. Leukemia.2007, 21:

Antithymocyte Globulin  Polyclonal antibodies active against T cells  Administration Infuse over at least 6 hours Premedicate with acetaminophen, corticosteroids, and an antihistamine Rabbit ATG (Thymoglobulin®) and equine ATG (Atgam ®) are NOT interchangeable

Antithymocyte Globulin  Adverse effects Infusion-related reactions  Fever, chills, headache Hypersensitivity reactions Cytokine release syndrome Increased risk of infections Serum sickness

Calcineurin inhibitors

Calcineurin Inhibitors  Inhibit T cell activation by suppressing production of IL-2  IV Administration Non-PVC tubing Continuous infusion over 24 hours  IV:PO conversion = ~1:3  Therapeutic Drug Monitoring (TDM) PO: trough levels (30 min prior to dose)

Calcineurin Inhibitors: Adverse Effects  Nephrotoxicity  Hypertension  Hyperglycemia  Hypercholesterolemia  Hypomagnesemia  Hyperkalemia  HUS/TTP  CNS toxicity Tremor Posterior reversible encephalopathy syndrome (PRES)

Calcineurin Inhibitors: Drug Interactions  Many others CYP3A4 inducers and inhibitors Anti- fungals AntibioticsGI AgentsAnti- convulsants Others FluconazoleMetronidazoleMetoclopramidePhenytoinProtease inhibitors VoriconazoleErythromycinCimetidinePhenobarbitalSirolimus PosaconazoleClarithromycinLansoprazoleCarbamazepineSt. John’s wort KetoconazoleRifampinGrapefruit juice

Calcineurin Inhibitors: Cyclosporine  Dosing 3 mg/kg CIVI over 24 hours (initial) 5-6 mg/kg PO every 12 hours (initial) Modified ≠ non-modified May mix oral solution with orange juice  TDM ng/ml  Adverse effects Hirsutism/hypertrichosis Gingival hyperplasia

Methotrexate  Mechanism of action Induces apoptosis of activated lymphocytes Blocks dihydrofolate reductase to inhibit purine synthesis  Dosing 5-15 mg/m2 IVP on D+1, 3, 6, 11 +/- leucovorin rescue  Adverse effects Mucositis Myelosuppression Hepatotoxicity

Mycophenolate mofetil  Mechanism of action Inhibits lymphocyte proliferation by blocking purine synthesis  Dosing 1000 mg PO/IV every 12 hours  Drug interactions Calcium & magnesium  Adverse effects Nausea, vomiting, diarrhea Myelosuppression

Corticosteroids  Mechanism of action Affect number & function of B-cells & T-cells  Dosing Systemic  Methylprednisolone or prednisone mg/kg IV/PO daily  Taper when applicable Topical  Budesonide-SR 3 mg PO every 8-12 hours (gut GVHD)  Triamcinolone cream 0.1% to body +/- hydrocortisone 1% to face (skin GVHD)

Corticosteroid Adverse Effects  Short term Hyperglycemia Mood disturbance, psychosis Insomnia Hypertension Fluid retention Skin atrophy Gastric ulcers  Long term Adrenal suppression Moon facies Weight gain Osteoporosis Buffalo hump Cataracts Myopathy Infections

Sirolimus  Mechanism of action Inhibits proliferation of lymphocytes by blocking m-TOR  Dosing 12 mg PO x 1 then 4 mg PO once daily  Therapeutic Drug Monitoring (TDM) 3-12 ng/ml Trough levels (30 min prior to dose)

Sirolimus  Drug interactions Similar to calcineurin inhibitors (CYP 3A4)  Adverse effects Hyperlipidemia Myelosuppression Pneumonitis Thrombotic microangiopathy

Additional Immunosuppressants: Treatment for GVHD  TNF α blockers Etanercept, infliximab  Pentostatin  Alefacept  Many drugs under investigation for treatment of acute and chronic GVHD

Infection Prevention  Use appropriate anti-infective prophylaxis throughout immunosuppressive therapy Pneumocystis carinii pneumonia Fungal infections Viral infections

Summary  Immunosuppression is utilized in allogeneic SCT to prevent rejection and GVHD, and for the treatment of GVHD  Infectious complications are common, making appropriate anti-infective prophylaxis important

Date Conditioning Doses Route Immunsuppr. 10mg/kg Isolation Heparin CsA 200mg/d MMF i.v mg/ m2 Acyclor 1500 mg/ m2 Gut decontamination Tue Catheter -7Wed Thu Fludarabine40 mg/m 2 IV.ATGAM 500mg -5Fri Fludarabine Busulphan 40 mg/m 2 4mg/kg/d IV PO ATGAM 500mg -4Sat Fludarabine Busulphan 40 mg/m 2 4mg/kg/d IV PO ATGAM 500 mg -3Sun Fludarabine Busulphan 40 mg/m 2 4mg/kg/d IV PO -2Mon Fludarabine Busulphan 20 mg/m 2 4mg/kg/d IV PO Tue Rest day 0Wed BMT +1Thu Fri Sat Stem Cell Unit, Dept of Haematology, Blood Transfusion and Stem Cell Transplantation. Physician:Bazuaye G. N Patient: Matthew Ebenezer, DOB: Diagnosis: Sickle Cell Anaemia Donor: Matthew Naomi (MSD), Genotype: AA Conditioning: Flu 180 mg/m 2, Bu 16mg/kg, ATG (ATGAM) 1500mg total dose over 3days, CSA 5mg/kg/day. (analog EBMT 2005 Sykora und Sauer et al.) Weight. 48 kg, Height 175 cm, BSA 1.53 m 2 PROTOCOL

References  Ashley Newland. Notes on Immunosuppression in Bone Marrow Transplant.  Eliane Gluckman. Choice of the donor according toHLA typing and stem cell source. In EBMT HSCT handbook 6th Edition  Jane Appley. Graft versus host disease. In EBMT HSCT handbook 6th Edition

Thank You!