Department of Histopathology & Cytopathology , Hammersmith Hospital

1. 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). Imperial College London Hazem AH Ibrahim, Michael J Neat, MufaddalMoonim, Amen Furrat, LiaMenasce, 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

2. Background

3. Post-transplant lymphoproliferative disorders (PTLD) • Early lesions • Polymorphic PTLD • Monomorphic PTLD • Classical Hodgkin lymphoma-type PTLD

4. Monomorphic PTLD • B-cell neoplasms DLBCL Burkitt lymphoma Plasmacytoma / plasma cell myeloma Plasmacytoma-like Others • T-cell neoplasms (~15%) Peripheral T-cell lymphoma, NOS Hepatosplenic T-cell lymphoma Others

5. 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.

6. Aetiology • Viruses: 1) EBV 2) HHV-8 • Genetic changes (translocation, Mutation,......) • Antigen stimulation

7. 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-MYConcogene. • Very few reports investigated chromosomal translocations among PTLDs

8. Question ?

9. Do common lymphoma-associated gene rearrangements differ among B-PTLDs, B-cell HIV-lymphomas and iDLBCL?

10. Materials & Methods

11. Tissue microarray Cases collected • 64 B-PTLD • 41 HIV-BCL • 139 iDLBCL TMA Serial sections IHC ISH H&E FISH Genes investigated • BCL2, BCL3, BCL6, c-MYC, PAX5, MALT1 and IGH

12. Results

13. Percentage involvement of rearrangements of different genes among DLBCLs in different settings iDLBCL (139 cases) HIV-DLBCL(39cases) PTLD-DLBCL(24 cases)

14. 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.

15. 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.

16. Rearrangements of different genes among iDLBCL subsets

17. EBV association • 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.

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

19. EBER Dual-colour break-apart probes C-MYC IGH Monomorphic PTLD, plasmablastic lymphoma

20. Summary and Conclusion

21. 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.

22. 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.

23. References 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 posttransplantlymphoproliferations 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. HematolOncol 23:61-67, 2005

24. Acknowledgements Prof. KikkeriNaresh Prof. Gordon Stamp. Dr Roberto Dina MahrokhNohdani. Donna Homcastle, PriteshTrivedi, Tyler Lloyd & Kay Elderfield. William Mathieson John Brennan and David Peston. Prof. LetiziaForoni, Alistair Raid, and JamshidSorouri. The Egyptian Government All members of the Department of Histopathology, of Hammersmith Hospital.

25. Thank you