# Presentation: 026993

## Introduction to BMT What every pediatric heme/onc fellow should know

- Allen R. Chen

## Introduction 

- Introduction

- Decisions
- Indications, donors, stem cell sources, preparative regimens, immunologic manipulations
- Management of complications
- Regimen-related toxicities, opportunistic infections, graft failure, graft-vs.-host disease, relapse

**Notes:**
Translational research
Active evolution
High intensity therapy
Relatively little experience with decision-making during residency, lots in fellowship

## Overview 

- Evaluation
- Transplant
- Outcome

## Decisions

- Indications
- Donors
- Graft
- Preparative regimen
- Immunologic regimen

## Indications

- Severe marrow dysfunction
- Immune deficiency
- Hematologic disease
- Metabolic disease
- Facilitate giving a lethal dose of chemoradiotherapy
- Diseases incurable by conventional therapy
- Poor prognosis malignancies
- Relapsed/refractory disease
- Immunotherapy of malignancy
- Break tolerance
- Allogeneic effect
- Immunotherapy of severe auto-immune disease

## Why BMT works for malignanciesAlkylator dose-response 

- Frei & Canellos, 1980

## Why BMT works for malignanciesAllogeneic effect

- Gale, 1994

## Why BMT works for malignanciesGraft-vs.-leukemia

- Marks, 1992

## Why BMT works for malignanciesEfficacy of donor lymphocytes after relapse

- Kolb, 1995

## Decisions

- Indications
- Donors
- Graft
- Preparative regimen
- Immunologic regimen

## Donor selection

- Autologous = Patient’s stored cells
- Syngeneic = Identical twin
- Allogeneic = Another person
- Genotypically HLA identical
- Phenotypically HLA matched
- Haploidentical +/- phenotypic matching

## HistocompatibilityWhy are HLA antigens the major histocompatibility antigens?

| Function |
| --- |
| Processing |
| Density on APCs |
| Context |
| CTLp frequency |
| Serologic responses |

- Antigen presentation
- Not required
- High
- Heterogeneous
- 10-2 to 10-3 vs 10-5
- Positive

## Histocompatibility:  HLA

- Function
- Structure
- Genetics
- Sequence 1999 224 loci, 128 expressed
- 479 HLA-A, 805 B, 257 C, 460 DRB1, 34 DQA1, 73 DQB1, 23 DPA1, 125 DPB1 alleles (as of 7/06)

**Notes:**
Polymorphism
Linkage

MIC-A and MIC-B:  ligands for activating NK and CD8 immunoreceptor, NK G2D, expressed on epithelial cells, class I homolog but independent of beta2microglobulin

TAP-1 and TAP-2: transporter for antigen presentation

LMP 2/7:  large multifunctional proteasome

## Importance of type of donor match

## What’s the best typing for

- A patient with no siblings?
- A patient with all siblings and both parents available?

- DNA
- Serologic – but when is DNA typing necessary?
- When parents appear to share antigens or appear homozygous

## Decisions

- Indications
- Donors
- Graft
- Preparative regimen
- Immunologic regimen

## Choice of allogeneic graft

| Vs. BM | Pro | Con |
| --- | --- | --- |
| TCD BM | Less GVHD, mismatch more feasible | More relapse, infection, graft failure |
| PBSC | Faster engraftment, less infection, less relapse | More CGVHD, G-CSF for normal donor |
| Cord | Less GVHD, mismatch more feasible, fast searches | Slower engraftment, more early mortality |

## Decisions

- Indications
- Donors
- Graft
- Preparative regimen
- Immunologic regimen

## Preparative regimen goals

- Overcome immunologic barrier to engraftment
- Destroy malignant cells
- Provide competitive advantage for normal cells

## Preparative regimen:Immunologic considerations

- How mismatched is the graft?
- Is the patient immune deficient?
- Has the patient been alloimmunized?
- Will the graft contain immune cells?

## Preparative regimen:Immunologic considerations

- Cy
- TBI
- Bu
- ATG, alemtuzumab
- Fludarabine, cladribine, pentostatin

## Preparative regimen:Malignancy desiderata

- Steep dose response
- DLT is marrow suppression
- Major increase in dose before the next DLT
- No cross-resistance with prior therapy

## Preparative regimen:Malignancy considerations

- TBI
- Targeted radiation
- 131I-MIBG, 153Samarium EDTMP, mAb anti-CD33
- Alkylating agents
- Cyclophosphamide, busulfan, melphalan, thioTEPA, nitrosureas
- Carboplatin
- Topoisomerase inhibitors?
- Etoposide, topotecan

## Non-myeloablative BMT

- Improve post-transplant immune suppression, reduce preparative regimen intensity
- Use graft immune cells to eliminate residual host immunity

## When to use a non-myeloablative preparative regimen

- High risk of RRT
- Low benefit of ablative rx

- Uncontrolled infection
- Debilitated host
- GVL > dose-response
- Non-malignant disorder
- Loss of function
- Normal cells have survival advantage

## Decisions

- Indications
- Donors
- Graft
- Preparative regimen
- Immunologic regimen

## Immunologic regimen

- GVHD prophylaxis
- T cell depletion
- Immune suppression
- Specific tolerance
- Immunotherapy for malignancy
- Alloreactive CTL
- NK
- Vaccine

## 18 y/o, AML, CR1

- Good response to intensively timed DCTER
- H/O presumed fungal pneumonia, BOOP
- Matched sibling...
- Bu-Cy
- T cell replete BM, CSA/MTX
- Alternative: Bu-Cy/Cy

## 12 y/o AML, CR2

- Relapsed 11 mo after matched sibling BMT in first remission, Bu-Cy prep, CSA/MTX GVHD prophylaxis, no GVHD
- H/O cardiomyopathy, resolved...
- Cy-TBI, T cell replete PBSC, no GVHD prophylaxis
- Alternatives: chemo/DLI, phase I, palliative care

## 10 y/o, ALL, CR2

- BM relapse 6 months off therapy
- Matched sibling...
- Cy-TBI, BM +/- TCD

## 9 y/o, ALL, CR2

- Relapse 3 years off therapy
- Matched unrelated donor...
- No transplant, salvage chemotherapy

## 6 y/o, ALL, CR2

- CNS relapse 17 months from diagnosis
- Matched sibling cord blood...
- Modified craniospinal XRT, Cy-TBI, ATG, CSA

## 16 y/o with AA

- Previously healthy
- Matched sibling...
- High Cy, T cell replete BM, CSA/MTX

## 9 y/o with AA

- Severe AA, never treated before
- No matched sibling, 4 potential URD...
- High-dose Cy without BMT
- Standard: Cy/TBI; URD BMT; CSA/MTX
- Alternative: Flu/mel/campath; URD BMT; CSA/MMF

## 1 y/o, neuroblastoma 2nd relapse

- Initially stage I, gross total resection, favorable biology
- 2nd metastatic relapse, responding to salvage chemotherapy...
- ThioTEPA/topotecan/carboplatin auto PBSCT; mAb study; cis-retinoic acid

## 18 y/o, beta thalassemia

- Chronic hepatitis C, poor chelation, hepatic fibrosis
- HLA-identical sibling, ABO match...
- Non-myeloablative fludarabine/cy/TBI, T cell replete BM, Cy/tacro/MMF

## Infant with immune deficiency

- Absent CD8, reduced CD4, intact B cells
- Multiple bacterial sepsis, candidiasis, disseminated mycobacterial infection
- Matched sibling...
- Non-myeloablative fludarabine/TBI, T cell replete BM, tacrolimus/MMF

## Complications

- Regimen-related toxicities
- Opportunistic infections
- Graft failure
- Graft-vs.-host disease
- Relapse

## Regimen-related toxicitiesImmediate

- Busulfan - seizures, N+V, D, rash
- Cyclophosphamide - cardiomyopathy, hemorrhagic cystitis, N+V
- TBI - fatigue, sialitis, burn, N+V, D, scrotal inflammation
- Carboplatin - N+V, tubular & glomerular nephropathy, tinnitus, transaminase elevation
- Etoposide - N+V, extremity pain, allergic reactions

## Regimen-related toxicitiesDelayed

- Mucositis (day 0, peaks day 7 - 15)
- Diarrhea (non-infectious before day 15)
- Veno-occlusive disease of the liver (onset day 0 to 21)
- Alopecia (onset day 7-14)
- Pneumonitis (non-infectious before day 30)
- Hemolytic-Uremic Syndrome (day 100+)

## Regimen-related toxicitiesDelayed

- Mucositis (day 0, peaks day 7 - 15)
- Diarrhea (non-infectious before day 15)
- Veno-occlusive disease of the liver (onset day 0 to 21)
- Alopecia (onset day 7-14)
- Pneumonitis (non-infectious before day 30)
- Hemolytic-Uremic Syndrome (day 100+)

## VOD: Diagnostic criteria

- Seattle:  At least 2
- Hyperbilirubinemia > 2.5 mg/dl
- Hepatomegaly or RUQ pain
- Unexplained weight gain > 2% or ascites

- Baltimore: Jaundice & at least 2
- Painful hepatomegaly
- Ascites
- Weight gain > 5%

**Notes:**
The features of the clinical syndrome are the same, with more stringent criteria in the East, so some cases will be missed, and less stringent criteria in the West, so some other entities will be included.  There is a trade-off between sensitivity and specificity, and the optimal cutoff point depends on the prevalence of the condition in the population one is treating and the relative costs of a false positive and a false negative.

## Differential diagnosis

- Sepsis with cholangitis lenta
- CHF / tamponade / constrictive pericarditis plus hemolysis
- GVHD
- Hepatic infiltration (fungus, tumor)
- Pancreatitis, peritonitis, cholecystitis
- Other patterns of hepatotoxicity

## Confirmatory tests

- Direct hyperbilirubinemia; ↑ALT/AST later
- Lipase; paracentesis if febrile
- CBC, coags: platelet consumption
- FENa < 1% without volume contraction
- Elevated PAI-1

## Ultrasonography

- Doppler
- High hepatic artery resistive index
- Monophasic hepatic venous flow
- Slowing / reversal of portal flow

- Gray-scale
- Hepatomegaly
- Splenomegaly
- Gall bladder wall thickening > 6 mm
- Ascites

- Specific   Sensitive

**Notes:**
Much is made of the ultrasound criteria, but these are certainly insensitive, with reversal of portal flow not universally present, particularly early in the course.  Nevertheless, useful for showing what is not present, e.g. pancreatitis, cholecystitis, tumor mass, fungal abscesses, and reversal of portal flow has prognostic importance.

## Transvenous manometry & biopsy

- Hepatic venous pressure gradient:
- Wedge pressure - free pressure ≥ 10 mm Hg
- PPV 80%
- < 10 mm Hg:  NPV 80%

## Etiology

- Herbal tea: pyrrolizidine alkaloids
- Crotalaria, heliotropium, comfrey
- Transplant prep regimens: Bu, Cy, TBI
- Immune suppression
- Azathioprine
- Standard-dose chemotherapy
- Actinomycin D, gemtuzumab ozogamycin (Mylotarg), cytosine arabinoside, dacarbazine, 6-thioguanine

**Notes:**
Cy metabolism: variable acrolein (toxic) and phophoramide mustard (desired alkylator)
Bu depletes glutathione.  Strong relationship between PK and toxicity.  Particularly high risk of VOD with prior liver irradiation, 2nd transplant.
Clear relationship between TBI dose, dose rate, & VOD.

## Histology

- Early: edematous subendothelial zone; hepatocyte necrosis around central vein

- Late: Stellate cell proliferation; fibrous matrix deposition in sinusoids

- DeLeve, Shulman, & McDonald, Seminars in Liver Disease 2002

**Notes:**
Early:  Venule is narrowed by subendothelial widening with edema, RBC fragments & debris.  The area around portal triads (zone 1) is richly oxygenated and relatively spared.  Hemorrhagic necrosis of hepatocytes begins in zone 3 (around central veins that become hepatic veins, hence “centrizonal necrosis”).

Late:  Immunostain against smooth muscle shows proliferation of stellate cells in the sinusoids, and deposition of collagen in the sinusoids and venules.

## Pathogenesis

- Plasma abnormalities
- Clotting cascade
- ↑PAI-1; ↓protein C, AT-III, platelets
- Inflammatory cascade
- ↑TNF-, TGF-, IL-1, -2, -6, -8, sIL-2R

**Notes:**
Portal hypertension before parenchymal damage because disruption of microcirculation is the cause of parenchymal disease.
Sinusoidal obstruction precedes hepatic venular obstrucion, which correlates with ascites
Clotting cascade activated (plasma factors) but no clot histologically.

## Histology

- Early: edematous subendothelial zone; hepatocyte necrosis around central vein

- Late: Stellate cell proliferation; fibrous matrix deposition in sinusoids

- DeLeve, Shulman, & McDonald, Seminars in Liver Disease 2002

## Pathogenesis

- Animal model
- Glutathione depletion from endothelial cells
- Vasoconstriction
- ↑Endothelin-1, ↓NO
- Endothelial cells round up
- ↑MMP-9 activity required
- Sinusoidal lining dissects / embolizes
- ↑Hyaluronic acid, VWF, PAI-1, tPA

- What the etiologic agents have in common:
- Glutathione depletion
- Greater toxicity against sinus endothelial cells than hepatocytes

**Notes:**
Portal hypertension before parenchymal damage because disruption of microcirculation is the cause of parenchymal disease.
Sinusoidal obstruction precedes hepatic venular obstrucion, which correlates with ascites
Clotting cascade activated (plasma factors) but no clot histologically.

## How do you treat VOD?

## Clinical course

- Variable severity
- Mild: self-limited
- Moderate: symptomatic therapy
- Severe: multiple organ failure, death from renal / cardiopulmonary failure

## Supportive care

- Maintain renal perfusion with minimum fluid retention
- Limit Na intake
- Support intravascular volume with cells & colloid
- Use diuretics with extreme caution
- Monitor weight, postural BP, BUN / creatinine, FENa
- Consider hemofiltration

## Specific therapy: fibrinolytic

- Rationale: Hypercoagulable plasma
- t-PA response rate < 1/3
- Effective only before day 15
- Thrombocytopenic, 20% severe hemorrhage

## Markers of severity

- Bearman criteria
- Rapid ↑bilirubin & weight in first 2 weeks
- MOF
- Creatinine 2 x baseline; O2 requirement
- PAI-1, IL-8, collagen peptide levels
- High wedged pressure gradient, ALT

## New agent: Defibrotide

- ssDNA, specific binding sites on endothelium
- Anti-thrombotic, anti-ischemic, fibrinolytic
- Emergency use: 35 – 55% complete resolution
- Younger age, autologous SCT, reversal of portal flow favorable for survival
- Flushing, low BP; exacerbation of bleeding
- Phase II trial showed lower dose preferable
- Pivotal trial starting up

**Notes:**
Specific binding sites on vascular endothelium
Increases PGI2, PGE2, TM, tPA in vitro and in vivo
Decreases thrombin generation, TF expression, PAI-1 release, endothelin activity.
Fibrinolytic activity is selective for small vessels, with no effects on systemic coagulation

## Prevention

- Dose reduction
- Heparin (2+, 4-)
- Ursodiol (2+, 1-)
- Glutathione?
- N-acetyl cysteine?
- Defibrotide??

**Notes:**
AT-III infusions don’t prevent VOD.
Pentoxifylline (TNF-a release) doesn’t work
Ursodiol: 2 small RCTs showed benefit with very high control rates of VOD; larger RCT showed no benefit for VOD, but less GVHD (reduced inflammatory cytokine release from blood monocytes)

## Regimen-related toxicitiesLate

- Leukoencephalopathy
- Endocrinopathy
- Growth impairment
- Cataracts
- Infertility
- 2nd malignancy

## Regimen-related toxicitiesImmune suppression

- ATG
- Anaphylaxis, fever, chills, serum sickness
- Cyclosporine, tacrolimus
- Nephropathy, peripheral neuropathy, CNS, hepatic, HTN
- Methotrexate
- Delayed engraftment, mucositis, VOD
- Mycophenolate mofetil
- BM, HA/tremor/insomnia, GI
- Rapamycin
- TG, chl, BM, HTN, edema, GI, arthralgia

## BM infusion reactions

- Volume - especially in renal insufficiency
- Emboli - inspect for clumps
- Hemolysis - ABO incompatibility, RBC contamination of cryopreserved BM
- DMSO
- N+V, odor, cardiac, nephrotoxicity, CNS
- Foreign proteins
- Antibodies, complement, enzymes used in processing
- Cytokines from platelets and WBC

## Complications

- Regimen-related toxicities
- Opportunistic infections
- Graft failure
- Graft-vs.-host disease
- Relapse

## Infections - Bacterial

- During pancytopenia
- Pseudomonas, other GNR
- S. epidermidis, S. aureus
- Enterococcus sp.
- Subacute
- Atypical mycobacteria, e.g. fortuitum
- CGVHD: functional asplenia

## Infections - mycotic

- Yeast
- Prolonged WBC << 100
- C. albicans
- Other
- Aspergillus
- Aplastic anemia, GVHD
- A. fumigatus from airways
- A. flavus nosocomial outbreaks
- Zygomycetes, Fusarium, Scedosporium

## Infections - viral

- HSV day 0-28 - stomatitis
- BK day 0-100 - hemorrhagic cystitis
- Adenovirus - hemorrhagic cystitis, hepatitis, nephritis
- CMV day 30-60, CGVHD
- Pneumonitis, encephalitis, enteritis, hepatitis, retinitis
- Mortality 50% despite ganciclovir & CMV-Ig
- Reactivation in 25% of allogeneic recipients, esp. mismatched

## Infections - viral

- HVZ day 45+ - may disseminate
- RSV day 0 - 60 - pneumonitis
- Parvovirus
- HHV6
- EBV - lymphoproliferative syndrome

## Infections – Pneumocystis jiroveci, formerly PCP

- Day 30+ if intensive prophylaxis given during preparative regimen
- 7% incidence without prophylaxis
- Prophylaxis
- Bactrim
- Dapsone
- Pentamidine
- Atovaquone

## Complications

- Regimen-related toxicities
- Opportunistic infections
- Graft failure
- Graft-vs.-host disease
- Relapse

## Graft failure mechanisms

- Immune rejection
- Non-specific stem cell consumption
- Inadequate stem cell dose or function
- Marrow stromal dysfunction
- Competition from abnormal endogenous cells
- Toxic exposures

## Graft rejection risk

- Mismatch
- T-cell depletion
- Non-malignant disease
- Alloimmunization, e.g. transfused aplastic anemia

## Graft rejection risk

| 								 | HLA-Genotype Non-identical
N = 269 | HLA-Genotype Identical 
N = 930 |
| --- | --- | --- |
| Primary graft failure | 23 (8.6%) | 15 (1.6%)
 |
| Late graft failure
 | 10 (3.7%)
 | 4 (0.4%)
 |
| All failures	 | 33 (12.3%)	 | 19 (2.0%)
 |

## Graft failure risk: T cell depletion

| Small lymphocyte dose / kg IBW | 1.0E+06 | 5.0E+05 |
| --- | --- | --- |
| n | 40 | 45 |
| AGVHD II - IV | 21% | 11% |
| CGVHD | 56% | 6% |
| Graft failure early | 5% | 14% |
| Mixed chimerism	 |  | 32% |
| WBC recovery | 18 d | 22 d |
| Platelet recovery | 29 d | 44 d |

## Complications

- Regimen-related toxicities
- Opportunistic infections
- Graft failure
- Graft-vs.-host disease
- Relapse

## Pathophysiology of Acute GVHD 

## Acute GVHD manifestations

- Skin
- Pruritic erythematous maculopapular rash accentuated on ears, face, palms, soles, trunk
- May progress to total body erythema, blistering, like full-thickness burn, requiring grafting
- GI
- Foul green slimy diarrhea
- May progress to voluminous diarrhea, cramping, tissue sloughing
- Liver
- Cholestatic + hepatocellular inflammatory process
- Least likely to respond to medication

## Staging for Acute GVHD Keystone Criteria

- Staging for Acute GVHD *Keystone Criteria*

|  | Stage 1 | Stage 2 | Stage 3 | Stage 4 |
| --- | --- | --- | --- | --- |
| Skin
(Rash) | <25% of skin | 25%-50% of skin
 | >50% of skin | Erythroderma with bullous formation |
| Liver
(Bilirubin) | 2-3 mg/dL | 3-6 mg/dL | 6 -15 mg/dL | >15 mg/dL |
| Gut
(Diarrhea) | >500 mL/day | >1000 mL/day | >1500 mL/day | Abdominal pain and/or ileus |

**Notes:**
The stage of GVHD is determined by a system that quantifies the extent of rash, serum bilirubin level, and the extent of the diarrhea.[Przepiorka 1995] 

## Grading for Acute GVHD Keystone Criteria

- Grading for Acute GVHD *Keystone Criteria*

|  | I | II | III | IV |
| --- | --- | --- | --- | --- |
| Skin | Stage 1/2 | Stage 3 or | - | Stage 4 |
| Liver | None | Stage 1 or | Stage 2/3 or | Stage 4 |
| Gut | None | Stage 1 | Stage 2-4 | - |

## Survival after Allogeneic BMT by acute GVHD grade

## Treatment of Acute GVHD

- Corticosteroids are first line of therapy for acute GVHD
- 40%-60% of patients have a sustained response to corticosteroid therapy
- Patients with steroid-resistant acute GVHD have an unfavorable prognosis

- Champlin. *Cancer Medicine.* 2003:1019.

## ATG for steroid-refractory acute GVHD

- Arai, 2002 BBMT

## ATG for steroid-refractory acute GVHD

- Arai, 2002 BBMT

- Grade II

- Grade III

- Grade IV

## GVHD: Chronic

- Mimics scleroderma
- Impedes immunologic recovery, so predisposes to opportunistic infection

## Complications

- Regimen-related toxicities
- Opportunistic infections
- Graft failure
- Graft-vs.-host disease
- Relapse

## Management of relapse

- Palliative care
- Donor lymphocyte infusion
- Chemotherapy
- Cytokines
- 2nd BMT

## Summary

- Decisions
- Indications, donors, stem cell sources, preparative regimens, immunologic manipulations
- Management of complications
- Regimen-related toxicities, opportunistic infections, graft failure, graft-vs.-host disease, relapse

**Notes:**
Apply training to management on inpt service
Evaluation during outpt rotations
BMT interest group