A comparison of the frequency of common lymphoma-associated gene rearrangements among B-Post transplant

lymphoproliferative disorders (B-PTLD), B-cell HIV-lymphomas and diffuse large B-cell lymphoma in immune

competent patients (iDLBCL).

Hazem AH Ibrahim, Michael J Neat, Mufaddal Moonim, Amen Furrat, Lia Menasce, Sabine Pomplun, Margaret Burke, Donald Macdonald, Ed Kanfer, Mark Bower, Paul Fields, Nicola Foot, Alistair Reid and Kikkeri N Naresh.

Department of Histopathology & Cytopathology,Hammersmith Hospital

Imperial College London

Background

Post-transplant lymphoproliferative disorders (PTLD)

• Early lesions

• Polymorphic PTLD

• Monomorphic PTLD

• Classical Hodgkin lymphoma-type PTLD

Monomorphic PTLD

• B-cell neoplasmsDLBCL

Burkitt lymphomaPlasmacytoma / plasma cell

myeloma Plasmacytoma-likeOthers

• T-cell neoplasms (~15%)Peripheral T-cell lymphoma,

NOS Hepatosplenic T-cell lymphoma Others

HIV-LPDs

• Burkitt lymphoma.• Diffuse large B-cell lymphoma (DLBCL). • Primary effusion lymphoma (PEL).• Plasmablastic lymphoma.• HHV-8-associated LPDs in patients of MCD.• Polymorphic lymphoid proliferations resembling

PTLDs.

Aetiology

• Viruses: 1) EBV

2) HHV-8

• Genetic changes (translocation, Mutation,......)

• Antigen stimulation

20-40% of iDLBCL and HIV-related DLBCLs harbour BCL6 rearrangement that are very rarely seen in PTLDs.

Post-transplant Burkitt lymphomas (PT-BL), similar to HIV-BL and iBL, display chromosomal breaks at 8q24 involving the c-MYC oncogene.

Very few reports investigated chromosomal translocations among PTLDs

Question ?

Do common lymphoma-associated gene rearrangements differ among B-PTLDs, B-cell HIV-

lymphomas and iDLBCL?

Materials & Methods

H&EISH

Serial sections

TMA

FISH

IHC

Tissue microarray

• 64 B-PTLD

• 41 HIV-BCL

• 139 iDLBCL

Cases collected

BCL2, BCL3, BCL6, c-MYC, PAX5, MALT1 and IGH

Genes investigated

Results

c-MYC 8%

None 92%

c-MYCNone

c-MYC 30%

double hits 8%

None 62%

c-MYC double hitsNone

BCL6 23%

BCL2 11%

c-MYC 4%

BCL3 2%

IGH only 2%

Double hit 5%

None 53%

BCL6BCL2c-MYCBCL3IGH onlyDouble hitNone

Percentage involvement of rearrangements of different genes among DLBCLs in different settings

HIV-DLBCL(39cases)PTLD-DLBCL(24 cases)

iDLBCL (139 cases)

• BCL2 and BCL6 rearrangements were predominantly restricted to GC and AGC/non-GC subtypes respectively.

• 8% PT-DLBCLs and 30% HIV-DLBCLs showed c-MYC rearrangement.

• PT-DLBCLs and HIV-DLBCLs lacked BCL2 and BCL6 rearrangements.

• Seven iDLBCLs (5%) and 2 HIV-DLBCLs (8%) had rearrangements of two oncogenes.

• Among Burkitt lymphoma (BL), 2/2 PT-BL and 12/13 (92%) HIV-BL had c-MYC rearrangement.

• Among plasmablastic lymphoma (PL), 2/6 (33%) PT-PL and 1/2 HIV-PL had c-MYC rearrangement.

BCL2

BCL2

BCL6

BCL6

BCL3

BCL3

c-MYC

c-MYC

Double hit

Double hit

IGH only

IGH only

Negative

Negative

0% 10% 20% 30% 40% 50% 60%

GC (MUM-neg)

AGC/non GC (MUM1-pos)

Rearrangements of different genes among iDLBCL subsets

• EBV-association was noted in 6%, 67% and 54% of iDLBCLs, PT-DLBCLs and HIV-DLBCLs respectively.

• 100% PT-BL and 63% HIV-BL had EBV-association.

• 83% PT-PL and 100% HIV-PL had EBV-association.

EBV association

• None of the cases with either BCL2 or BCL6 rearrangement showed EBV-association (p=0.031 & p<0.001 respectively).

• No significant correlation between EBV-association and c-MYC or IGH rearrangement.

Correlation of rearrangements of c-MYC, BCL2 and BCL6 genes among the EBV-positive cases

Dual-colour break-apart probes

EBER

IGH C-MYC

Monomorphic PTLD, plasmablastic lymphoma

Summary and Conclusion

1- Gene rearrangements

• Gene rearrangement, apart from c-MYC-IGH (characteristically seen in BL and PL), appear to be very rare among both HIV-BCL and B-PTLD.

• HIV-DLBCL is more frequently associated with c-MYC rearrangement than iDLBCL.

• BCL6 rearrangement is frequently seen in iDLBCL of AGC and non-GC subtypes.

• None of the cases with either BCL2 or BCL6 rearrangement showed EBV-association.

2- Alternate pathogenetic pathways in immune deficiency LPDs

• Other (cyto)genetic abnormalities that are that are not conventionally associated primary abnormalities in lymphomas

• Aberrant somatic hypermutation of critical genes.

• Aberrant hypermethylation of critical genes.

1. Jaffe ES, Harris NL, Stein H et al: World Health Organization Classification of Tumour: Pathology and Genetics, Tumours of Haematopoietic and Lymphoid Tissues. IARC Press: Lyon, 2008.

2. Vega F, Medeiros LJ: Chromosomal translocations involved in non-Hodgkin lymphomas. Arch Pathol Lab Med 127:1148-1160, 2003.

3. Tibiletti MG, Martin V, Bernasconi B et al: BCL2, BCL6, MYC, MALT 1, and BCL10 rearrangements in nodal diffuse large B-cell lymphomas: a multicenter evaluation of a new set of fluorescent in situ hybridization probes and correlation with clinical outcome. Hum Pathol 40:645-652, 2009.

4. Vakiani E, Nandula SV, Subramaniyam S et al: Cytogenetic analysis of B-cell posttransplant lymphoproliferations validates the World Health Organization classification and suggests inclusion of florid follicular hyperplasia as a precursor lesion. Hum Pathol 38:315-325, 2007.

5. Gaidano G, Lo CF, Ye BH et al: Rearrangements of the BCL-6 gene in acquired immunodeficiency syndrome-associated non-Hodgkin's lymphoma: association with diffuse large-cell subtype. Blood 84:397-402, 1994

6. Windebank K, Walwyn T, Kirk R et al: Post cardiac transplantation lymphoproliferative disorder presenting as t(8;14) Burkitt leukaemia/lymphoma treated with low intensity chemotherapy and rituximab. Pediatr Blood Cancer 53:392-396, 2009.

7. Capello D, Rossi D, Gaidano G: Post-transplant lymphoproliferative disorders: molecular basis of disease histogenesis and pathogenesis. Hematol Oncol 23:61-67, 2005

References

Acknowledgements

• Prof. Kikkeri Naresh• Prof. Gordon Stamp.• Dr Roberto Dina• Mahrokh Nohdani.• Donna Homcastle, Pritesh Trivedi, Tyler Lloyd & Kay

Elderfield.• William Mathieson• John Brennan and David Peston.• Prof. Letizia Foroni, Alistair Raid, and Jamshid Sorouri.

The Egyptian Government

All members of the Department of Histopathology, of Hammersmith Hospital.

Thank you