RESUMEN
BACKGROUND: Refractory coeliac disease type II (RCDII) frequently transforms into an enteropathy-associated T-cell lymphoma (EATL) and therefore requires intensive treatment. Current evaluated treatment strategies for RCDII include cladribine (2-CdA) and autologous stem cell transplantation (auSCT). OBJECTIVE: The purpose of this study was to evaluate long-term survival and define clear prognostic criteria for EATL development comparing two treatment strategies. METHODS: A total of 45 patients were retrospectively analysed. All patients received 2-CdA, after which they were either closely monitored (monotherapy, n = 30) or a step-up approach was used including auSCT (step-up therapy, n = 15). RESULTS: Ten patients (22%) ultimately developed EATL; nine of these had received monotherapy. Absence of histological remission after monotherapy was associated with EATL development (p = 0.010). Overall, 20 patients (44%) died with a median survival of 84 months. Overall survival (OS) within the monotherapy group was significantly worse in those without histological remission compared to those with complete histological remission(p = 0.030). The monotherapy group who achieved complete histological remission showed comparable EATL occurrence and OS as compared to the step-up therapy group (p = 0.80 and p = 0.14 respectively). CONCLUSION: Histological response is an accurate parameter to evaluate the effect of 2-CdA therapy and this parameter should be leading in the decisions whether or not to perform a step-up treatment approach in RCDII.
RESUMEN
BACKGROUND AND PURPOSE: Although 6-mercaptopurine and azathioprine are effective treatments in inflammatory bowel disease (IBD), many patients discontinue treatment because of side effects. 6-Thioguanine (6-TG) may be an alternative rescue therapy in these intolerant patients but the pharmacokinetics of 6-TG are not fully described. Here we have measured the pharmacokinetics of the biotransformation of 6-TG into the pharmacologically active metabolites, 6-thioguanine nucleotides (6-TGN), in IBD patients. EXPERIMENTAL APPROACH: In 12 patients with IBD, levels of 6-TGN and activities of thiopurine S-methyltransferase, xanthine oxidase and hypoxanthine guanine-phosphoribosyl-transferase were measured in a two-stage (i.v. and p.o. administration of 0.3 mg·kg(-1) 6-TG), prospective study. Median exposure of 6-TGN in red blood cells (RBC) was expressed as the ratio of the area under the curve (AUC) per mg 6-TG after i.v. dosing and that after p.o. dosing. KEY RESULTS: The median AUC per mg 6-TG was 1068 (p.o.) and 7184 (i.v.) pmol·h (8 × 10(8) RBC)(-1) . Median exposure of 6-TGN in RBC was 15% (9-28). Hypoxanthine guanine-phosphoribosyl-transferase activity correlated with peak 6-TGN and with AUC per mg (r= 0.7, P= 0.02 and r= 0.6, P= 0.03 respectively). Thiopurine S-methyltransferase activity was inversely related to AUC per mg (r=-0.8, P= 0.001), whereas that of xanthine oxidase was correlated with a lower peak 6-TGN (r=-0.7, P= 0.02). CONCLUSIONS AND IMPLICATIONS: The great variability of the AUC per mg for 6-TG observed after p.o. and i.v. administration of 6-TG, was partly explained by variability in activities of metabolizing enzymes. Exposure of 6-TGN was low in all patients.
