1. Idiosyncratic reactions: Individual factors leading to response (adverse reactions for instance) upon exposure to a xenobiotic Xenobiotic response Individual factors Pharmaco- or toxicological

2. Xenobiotics = small M.W. foreign compounds - drugs, - atmospheric and alimentary compounds, - pollutants as well as natural products Exposure unavoidable

3. Xenobiotic Metabolites A Metabolites B Elimination Influence of metabolism on xenobiotic response XME Target pharmaco toxico XME expression may vary according to - genetic - environmental factors

4. Xenobiotic Metabolites Elimination Target: interactions with proteins (receptors enzymes…), ADN, lipids, small molecules Pharmacological or Toxicological response Defense system, immune system No response Exposure metabolism target Reaction (cell, organ, organism) Response

5. Gene Medications Response linked to polymorphism Metabolism CYP2C9Tolbutamide, warfarin, phenytoin, Anticoagulant effect of warfarin nonsteroidal anti-inflammatories CYP2D6Beta blockers, antidepressants, antipsychotics,Tardive dyskinesia from antipsychotics codeine, debrisoquin, dextromethorphan,narcotic side effects, efficacy, and encainide, flecainide, guanoxan,requirement; beta-blocker effect methoxyamphetamine, N-propylajmaline, perhexiline, phenacetin, phenformin, propafenone, sparteinedependence; imipramine dose Dihydropyrimidine dehydrogenase FluorouracilFluorouracil neurotoxicity Thiopurine methyltransferaseMercaptopurine, thioguanine, azathioprineThiopurine toxicity and efficacy; risk of second cancers Transport mdr1digoxin, anti HIVplasma concentration, effect Target ACE Enalapril, lisinopril, captoprilRenoprotective effects, cardiac indices, blood pressure, immunoglobulin A nephropathy Potassium channels HERGQuinidine Drug-induced long QT syndrome CisaprideDrug-induced torsade de pointe KvLQTTerfenadine, disopyramide, meflaquineDrug-induced long QT syndrome hKCNE2ClarithromycinDrug-induced arrhythmia

6. THIOPURINE METHYL-TRANSFERASE (TPMT) AZATHIOPRINE METABOLISM AZATHIOPRINE 6-MERCAPTOPURINE TPMTHGPRT, … XO 6-MMP 6-THIOGUANINE Ntides 6-TGN THIOURIC ACID ACTIVE TOXIC GSTs

7. Xenobiotic Metabolites B Elimination Interaction with cell, receptor Target: interactions with proteins (receptors enzymes…), ADN, lipids, small molecules Pharmacological or Toxicological response Defense system, immune system No response Exposure metabolism target Reaction (cell, organ, organism) Response

8. 68% of the patients have an altered p53 in the tumor. 87% of non responders and 57% of the responders (p<0,003) have an alteration of p53. Response to chemotherapy in head and neck cancer

9. Logistic regression Cabelguenne et coll. Response to chemotherapy in head and neck cancer

10. Xenobiotic Metabolites B Elimination Interaction with cell, receptor Target: interactions with proteins (receptors enzymes…), ADN, lipids, small molecules Pharmacological or Toxicological response Defense system, immune system No response Exposure metabolism target Reaction (cell, organ, organism) Response

11. Hepatitis Tienilic acidquinolones Dihydralazineanti-HIV carbamazepine anticonvulsants Diclofenac Halothane Iproniazid Agranulocytosis sulfamidesClozapine Blood dyscrasias Procainamideanti-HIV aminopyrine clozapine carbamazepine propylthiouracile hydralazine Systemic lupus erythromatosus hydralazine sulfamides Toxidermias sulfamidesquinolones anticonvulsantsNSAIDs penicillinsanti-HIV Examples of drugs inducing adverse immune reactions

12. * These diseases are life-threatening * They cannot be predicted * which individuals? * which drugs? * Mechanisms? -----> prediction * metabolism * individual reaction

13. Xenobiotic: X Reactive Metabolite: RM* P-RM* EMR* Neoantigen Presentation to the immune system Immune response depends on many factors variable 2 nd exposure control exposure Metabolism Toxic response

14. N O NHSO 2 H 3 C NH 2 N O NHSO 2 H 3 C NHOH N O NHSO 2 H 3 C NO NAT2 UGT GSH from Park et al. 1998 Detoxication CYP 2C9

15. Lyell syndrome, TEN: very severe toxidermia to sulfamides 13/14 NAT2 -

16. Toxidermias in AIDS patients treated with sulfamides NGSTM1 - / NAT2 - (%) Patients with Tx 4146 (OR=2.5) Patients withoutTx 7925 Total13032 Wolkenstein et al. 2000

17. Genotype/Phenotype discrepency in AIDS patients 64 Patients slowrapid phenotype559 Genotype3034 25 discrepencies genotype fast/phenotype slow checked by sequence Disease may modify the phenotype

18. Response is also dependent on immune response * In the same study: CD8+ above median --> OR 5,7 p<0,0005), Wolkenstein et al. * HLA A30B13Cw6 more frequent than in control population ( Oszkaya-Bayazit, J. AM. Acad. Dermatol. 2001) Response is dependent on target cells GST P1 genotype: GST P1*B are protected against toxidermias (OR~9.5 p< 0,005 Wolkenstein et al.

19. Toxicity of sulfamides linked to -Metabolism ± (NAT2/GST…) - Organism response + (GSTP1…) - Immune response ++ (CD8, HLA…) - multistep - each factor has influence

20. Xenobiotic: X Reactive Metabolite: RM* P-RM*EMR*Neoantigen Presentation to the immune system Immune response depends on many factors variable 2 nd exposure control exposure Metabolism Toxic response

21. Autoantibodies against xenobiotic metabolizing enzymes diseasexenobioticautoantibodies hepatitistienilic acidCYP2C9, LKM2 dihydralazineCYP1A2, LM anticonvulsantsCYP? halothaneCYP2E1 iproniazideMAO B ?CYP2D6, LKM1 ?UGT, LKM3 ?GST agranulocytosisclozapineMPO Addison or PGS? CYP 17, 21, Scc CYP 1A2 CYP 2A6

22. DRUG Immune response autoantibodies Reactive metabolite: R* R*-P neoantigen R*-E Enzyme: E P 1 2 3 4 4 4

23. CYP 2C9 Neoantigen: AT-CYP 2C9 tiénilic acid Hépatitis anti LKM2 Immune response autoantibodies 1 2 4 3 H2OH2O S C O Cl OCH 2 COOH Cl Ar S C O S C O O S C O HO

24. Covalent Binding with human liver microsomes and yeasts expressing a single human P450 Tienilic acid pmol/min/nmolP450 Human liver microsomes 98 control yeasts0 1A177 1A241 2C88-10 2C9340-380 2C1845-42 2C1941 2D66 3A40-0

25. SPECIFICITY of the COVALENT BINDING of TIENILIC ACID on HUMAN LIVER MICROSOMES. 50403020100 0 1000 2000 P 450 2C cpm/band protein migration protein migration # bands with NADPH without NADPH

26. R* enzyme xenobiotic enzyme xenobioticR* enzyme R* enzyme + Covalent binding

27. Links between the formation of a protein-adduct and an abnormal immune reponse

28. In most cases a reactive metabolite was produced; it was able bind to protein(s) (covalent binding). Tienilic acid Halothane CHFC Dihydralazine Diclofenac Carbamazepine Sulfamide procainamide Clozapine Phenytoin Iproniazide......

29. Hypothesis: the quantity of reactive metabolite is important - high production of reactive metabolite - concentration of RM on one target - dose adverse drug reaction - RM * adverse drug reaction

30. Hypothesis: the quantity of reactive metabolite is important - high production of reactive metabolite - concentration of RM on one target - dose adverse drug reaction - RM * adverse drug reaction

31. Captoril: lower doses -------> lower incidence Halothane: high variability in the covalent binding Isoflurane and enflurane: lower covalent binding lower incidence hepatitis CHFC: ???? clozapine / olenzapine: highest covalent binding = highest incidence agranulocytosis anticonvulsants, sulfamides: higher sensitivity in patients with higher production of RM*

32. Xenobiotic: X Reactive Metabolite: RM* P-RM*EMR*Neoantigen Presentation to the immune system Immune response depends on many factors variable 2 nd exposure control exposure Metabolism Toxic response

33. Animals models - difficult: many factors to control - metabolism - generation of hapten - variable immune response * genetic *non genetic

34. * Lewis, Th1: Dihydralazine p.o. : liver disease, inflammation, no autoantibodies Dihydralazine, hapten s.c.: liver disease, inflammation no autoantibodies * BN (HgCl2), Th2: Dihydralazine, hapten s.c.: no liver disease, no inflammation autoantibodies Tienilic acid, hapten s.c.: no liver disease, no inflammation no autoantibodies

35. Animal model Conclusions * No complete disease was observed * Partial response Th1: inflammation, liver disease Th2: autoantibodies * Autoantibodies: not pathogenic * Control of immune system * unknown factors such as infection

36. Xenobiotic: X Reactive Metabolite: RM* P-RM*EMR*Neoantigen Presentation to the immune system Immune response depends on many factors variable 2 nd exposure control exposure Metabolism Toxic response

37. Xenobiotic Protein: P* Molecular mimicry: P Reactive metabolite M* Enzyme: P NEOANTIGEN P* or P-M* Immune response: presentation, processing, HLA B cells, autoantibodies, epitopes T cells, Th1/Th2 Tolerance Rare diseases not very well understood not predictable (xenobiotic, individuals) Auto-Ab Ab Auto-Ab Scheme 2

38. Anti-HIV treatments lead to: - high prevalence of adverse reactions (Fellay et al. Lancer 2001) - hyperlipidémia (SREBP1c, ABC Cassette) - numerous drug interactions (metabolism) - variation in response (metabolism and transport) Abacavir (Mellal et al. Lancet 2002) - 4 to 9% ADR - linked to HLA57

39. Xenobiotic Metabolites B Elimination Interaction with cell, receptor Target: interactions with proteins (receptors enzymes…), ADN, lipids, small molecules Pharmacological or Toxicological response Defense system, immune system No response Exposure metabolism target Reaction (cell, organ, organism) Response Conclusions

40. Becquemont, Pharmacogenomics 2010 HLA-B*5701 HLA-B*5801 HLA-B*1502 HLA-A*3101 HLA-B*3802 HLA-B*7301 HLA-DRB5*0201 HLA-B*1502 HLA-DRB1*1501 Abacavir hypersensitivity Flucloxacillin DILI cholestasis Allopurinol SJS Carbamazepine SJS (Asian) Phenytoin SJS (Asian) Carbamazepine SJS (european) Sulfomethoxazole SJS oxicams SJS Clozapine neutropenia Co-amoxiclav SJS

43. D D-->R*-->R*P= Apoptosis Necrosis APC no signal 2 APC signal 2 danger signal Tolerance Helper T cell Helper T cell B and T cell mediated toxicity Mphages NK cells  cells

44. Autoreactive B-cell T-cell Autoantibodies production