Genetski dejavniki učinkovitosti in varnosti zdravljenja juvenilnega idiopatskega artritisa z metotreksatom in zaviralci tumor nekrotizirajočega faktorja alfa

Zajc Avramovič, Mojca (author), Avčin, Tadej (mentor)

UVOD Juvenilni idiopatski artritis (JIA) spada med pogostejše kronične bolezni otrok. Med zdravili, ki spreminjajo potek bolezni (angl. disease modifying antirheumatic drugs; DMARD), je zdravilo prve izbire metotreksat (MTX). Kadar je zdravljenje z MTX neučinkovito ali pride do hujših neželenih učinkov (NU), je potrebno nadaljevati zdravljenje z biološkimi zdravili. Biološka zdravila, ki jih uporabljamo pri zdravljenju JIA, so najpogosteje zaviralci tumor nekrotizirajočega faktorja alfa (TNF alfa). Zaenkrat ne poznamo napovednih dejavnikov, kako uspešno in varno bo določeno zdravljenje pri posameznem bolniku. Genetski polimorfizmi v poteh presnove, prenosa in delovanja zdravil so se v preteklih raziskavah izkazali kot pomemben vzrok razlik v odgovoru na zdravljenje in razvoju NU med posameznimi bolniki. NAMEN DELA Namen dela je bil določiti genetske dejavnike za oceno učinkovitosti in varnosti zdravljenja JIA z MTX in zaviralci TNF alfa ter na osnovi naših rezultatov izdelati napovedni model zdravljenja s temi zdravili pri bolnikih z JIA. Dodatno smo želeli opredeliti klinične značilnosti otrok z JIA, ki se zdravijo z MTX ali zaviralci TNF alfa na Pediatrični kliniki v Ljubljani, in sicer spol, starost bolnikov, razporeditev po podtipih, opredeliti učinkovitost in pojav NU ob zdravljenju z omenjenimi zdravili. METODE V raziskavo smo vključili 119 zaporednih bolnikov, zdravljenih z MTX, in 61 bolnikov, zdravljenih z zaviralci TNF alfa na Pediatrični kliniki Univerzitetnega kliničnega centra Ljubljana od septembra 2011 do oktobra 2014. Aktivnost bolezni smo ocenjevali z novim merilom aktivnosti bolezni (angl. juvenile arthritis disease activity score; JADAS) JADAS 71. Bolnike, pri katerih v 6 mesecih od začetka zdravljenja ni prišlo do vsaj 30 % izboljšanja ocene JADAS 71, smo definirali kot skupino, neodzivno na zdravljenje. Na zdravljenje neodzivni so bili tudi bolniki, pri katerih je bilo zdravljenje ukinjeno prej kot v 6 mesecih. Zabeležili smo vse neželene učinke. Opravili smo genotipizacijo genetskih polimorfizmov z metodo pomnoževanja nukleinskih kislin v realnem času (PCR). Rezultate smo obdelali z univariantno in multivariantno penalizirano logistično regresijo in Coxovo penalizirano regresijo. REZULTATI Po 6 mesecih zdravljenja je bilo na zdravljenje neodzivnih 25,8 % bolnikov, zdravljenih z MTX, in 14,7 % bolnikov, zdravljenih z zaviralci TNF alfa. Ob zdravljenju z MTX je 54,5 % bolnikov poročalo o NU v skupno 405 bolnikovih letih zdravljenja, 32,8 % bolnikov je imelo NU v GIT, 23,5 % pa porast jetrnih transaminaz. Deset bolnikov (8,4 %) je prekinilo zdravljenje z MTX zaradi NU. Ob zdravljenju z zaviralci TNF alfa je 70,5 % je poročalo o vsaj enem NU, pri več kot tretjini je šlo za blage kožne reakcije, pri 9,8 % bolnikih pa se je pojavila resna alergijska reakcija na infundirano zdravilo. ABCC2 rs2804402 je bil povezan z neodzivnostjo na zdravljenje z MTX po 6 mesecih (p = 0,048). MTHFR rs1801133 (HR 1,41), MTRR rs1801394 (HR 1,18) in ABCC2 rs2273697 (HR 1,05) so bili povezani s časom do uvedbe biološkega zdravljenja. AMPD1 rs17602729 in MTHFD1 rs2236225 (HR 1,61 in 1,55) sta bila povezana z razvojem NU v GIT. Enajst polimorfizmov je bilo povezanih s porastom jetrnih transaminaz: MTRR rs1801394 (HR 2,60), MTHFD1 rs2236225 (HR 1,64 za divji tip), MTHFR rs1801133 (HR 1,12), MTR rs1805087 (HR 1,24 za divji tip), TS*2/*3 (HR 1,01), ATIC rs2372536 (HR 1,24), ABCB1 rs1045642 (HR 1,28), ABCG2 rs2231137 (HR 1,54 za divji tip), SLC19A1 rs1051266 (HR 1,10), ABCC2 rs717620 (HR 1,29) in ABCC2 rs2804402 (HR 1,05). Vsi bolniki, ki so zdravljenje z MTX prekinili zaradi NU, so imeli vsaj en polimorfen alel v MTHFR rs1801131, v primerjavi z le 52,7 % bolniki, ki so MTX dobro prenašali. Noben bolnik, ki je prekinil zdravljenje z MTX zaradi NU, ni imel polimorfnih alelov v MTR rs1805087, ABCG2 rs2231137 in ABCC2 rs2273697 v primerjavi z 31,8 %, 71,8 % in 40,8 % bolnikov, ki so zdravljenje prenašali. Polimorfizmi niso bili povezani z odgovorom na zdravljenje ali z razvojem NU ob zdravljenju z zaviralci TNF alfa. ZAKLJUČEK Z raziskavo smo dobro opredelili klinične značilnosti bolnikov z JIA v Sloveniji, ki se zdravijo z MTX in zaviralci TNF alfa. Genetska raznolikost je bila v naši raziskavi boljši kazalec za razvoj NU kot za napoved učinkovitosti zdravljenja. AMPD1 rs17602729 in MTHFD1 rs223622 sta bila povezana z NU v GIT, drugi je bil skupaj z MTRR rs1801394 tudi najmočneje povezan s hepatotoksičnostjo. MTHFR rs1801131, MTR rs1805087, ABCG2 rs2231137 in ABCC2 rs2273697 so potencialni označevalci za bolnike, ki zdravljenje z MTX prekinejo zaradi NU. MTHFR rs1801133, MTRR rs1801394 in ABCC2 rs2273697 so bili povezani z uvedbo biološkega zdravljenja zaradi neučinkovitosti MTX ali NU. Analizirani polimorfizmi v naši skupini niso vplivali na odgovor na zdravljenje ali na razvoj neželenih učinkov ob zdravljenju z zaviralci TNF alfa. Napovednega modela zdravljenja zaradi šibkih povezav ni bilo mogoče sestaviti.

• Language: Slovenian
• Keywords: Juvenilni idiopatski artritis, metotreksat, zaviralci tumor nekrotizirajočega faktorja alfa, biološko zdravljenje, genetski polimorfizmi, farmakogenetika
• Work type: Doctoral dissertation
• Organization: MF - Faculty of Medicine
• Year: 2018
• PID: 20.500.12556/RUL-101982
• COBISS.SI-ID: 3914516
• Publication date in RUL: 18.07.2018

Secondary language

• Language: English
• Title: Genetic Determinants Of Juvenile Idiopathic Arthritis Treatment With Methotrexate And Tumor Necrosis Factor Αlpha Blockers

Abstract

BACKGROUND Juvenile idiopathic arthritis (JIA) is one of the most common chronic diseases in childhood. Methotrexate (MTX) is recommended as an initial disease modifying anti-rheumatic drug (DMARD). When MTX is not effective or when intolerable adverse events (AEs) occur, biologic drugs are used. TNF alfa inhibitors are most commonly used biologic drugs in JIA. Early predictors are needed to identify patients who will not respond to a particular therapy or develop AEs. There is growing evidence that single nucleotide polymorphisms (SNPs) within the pathway genes are significant contributors to inter-individual differences in response to drugs. AIMS The aims of our study were to identify pharmacogenetic determinants of efficacy and toxicity of methotrexate (MTX) and TNF alfa inhibitors in juvenile idiopathic arthritis (JIA) over time as well as to construct a pharmacogenetic model. Additionally, we wanted to describe clinical characteristics of patients with JIA treated with MTX and TNF alpha inhibitors at the University Children's Hospital Ljubljana, namely sex, age, disease subtypes, we wanted to evaluate efficacy and AEs of treatment with MTX and TNF alpha inhibitors in our patient cohort. METHODS A cohort of 119 consecutive patients with JIA treated with MTX and 61 treated with TNF alpha inhibitors was reviewed. JADAS 71 score was used to measure disease activity. Non-responders were patients that did not reach a minimum of 30 % improvement after 6 months of treatment or were switched to biologic drugs in the first 6 months due to inefficacy. All AEs were noted. Genotyping of SNPs in the genes coding for MTX transporters, folate pathway and adenosine pathway, and polymorphisms in the promotor of TNF alpha gene was performed using real time PCR methods. Univariate and multivariable penalized logistic and Cox regression were used to analyse data. RESULTS After 6 months 25.8 % of patients treated with MTX and 14.7 % of patients treated with TNF alpha inhibitors were defined as non-responders. During treatment with MTX 54.5 % of patients reported AEs in a total of 405 patient years, 32.8 % of patients reported GIT AEs and 23.5 % hepatotoxicity. Ten patients (8.4 %) discontinued MTX because of AEs. During treatment with TNF alpha inhibitors 70.5 % of patients reported at least one AE, around one third of them being mild skin reactions, whereas 9.8 % of patients suffered severe allergic reaction. ABCC2 rs2804402 was associated to non-response to MTX (p = 0.048). MTHFR rs1801133 (HR 1.41), MTRR rs1801394 (HR 1.18) and ABCC2 rs2273697 (HR 1.05) were associated to switching to biologics. AMPD1 rs17602729 and MTHFD1 rs2236225 (HR 1.61 and 1.55) demonstrated associations with developing GIT AEs. Eleven SNP were associated with hepatotoxicity: MTRR rs1801394 (HR 2.76), MTHFD1 rs2236225 (HR 1.64 for wild type), MTHFR rs1801133 (HR 1.12), MTR rs1805087 (HR 1.24 for wild type) TS*2/*3 (HR 1.01), ATIC rs2372536 (HR 1.24), ABCB1 rs1045642 (HR 1.28), ABCG2 rs2231137 (HR 1.54 for wild type), SLC19A1 rs1051266 (HR 1.10), ABCC2 rs717620 (HR 1.29) and ABCC2 rs2804402 (HR 1.05). All patients who discontinued MTX because of AEs had at least one polymorphic MTHFR rs1801131 allele, in comparison to only 52,7 % of patients who tolerated MTX. Patients that discontinued MTX because of AEs did not have any polymorphic MTR rs1805087, ABCG2 rs2231137 and ABCC2 rs2273697 alleles in comparison to 31,8 %, 71,8 % and 40,8 % of carriers among patients that tolerated MTX. None of the investigated SNPs influenced treatment outcome or AEs in patients treated with TNF alfa inhibitors. CONCLUSION Our study was based on a well-described patient cohort representative of the whole JIA population treated with MTX and TNF alpha inhibitors followed at the tertiary care pediatric rheumatology center. In our cohort genetic variability was a better marker for toxicity than efficacy. AMPD1 rs17602729 and MTHFD1 rs223622 were associated with GIT AEs while the latter together with MTRR rs1801394 also demonstrated the strongest association with developing hepatoxicity. MTHFR rs1801131, MTR rs1805087, ABCG2 rs2231137 and ABCC2 rs2273697 were identified as potential markers for discontinuing MTX treatment because of AEs. MTHFR rs1801133, MTRR rs1801394 and ABCC2 rs2273697 were associated with switching to biologics due to inefficacy or toxicity. Because of weak associations we were not able to construct a pharmacogenetic model.

• Keywords: Juvenile idiopathic arthritis, methotrexate, tumur necrosis factor alpha blockers, biologic treatment, single nucleotide polymorphisms, pharmacogenetics