RESUMEN
The thiopurine drugs-azathioprine and mercaptopurine-are purine antimetabolites used for the treatment of autoimmune hepatitis. These drugs undergo metabolism through genetically determined pathways, which influences their effectiveness and toxicity. There is scarce information regarding the clinical effects of measuring drug metabolites in these patients. The goal of the study is to test the clinical significance of measuring thiopurine metabolites in patients unsuccessfully treated with thiopurines. Clinical and laboratory data collected for patients who were treated for autoimmune hepatitis between 2015 and 2018, and did not achieve full remission under thiopurine therapy and had thiopurine metabolite levels measured due to lack of response and suspicious side effects were chosen. We compared clinical and laboratory data before and after the therapy change. The study included 25 tests of thiopurine metabolites in 21 patients. Six tests had therapeutic levels. Three tests showed high levels leading to lowering the drug dose. In 11 cases, levels of 6-thioguanine nucleotide were low; the dose was not changed in 3 of these, and the dose was increased in the remaining 8. Shunting was observed in 5 cases, 2 of which were mild and the dose was not changed. In the remaining 3, the dose was decreased, and allopurinol was added. Significant improvements in liver enzymes were observed following dose adjustments. We showed that, in cases of suboptimal response to thiopurine treatment, measuring thiopurine metabolites had an important role in optimizing therapy. In most patients, changing the dose led to a significant improvement with no need to switch to secondline therapies.
Asunto(s)
Azatioprina , Hepatitis Autoinmune , Inmunosupresores , Mercaptopurina , Humanos , Hepatitis Autoinmune/tratamiento farmacológico , Hepatitis Autoinmune/metabolismo , Hepatitis Autoinmune/sangre , Femenino , Masculino , Mercaptopurina/análogos & derivados , Mercaptopurina/uso terapéutico , Mercaptopurina/metabolismo , Mercaptopurina/sangre , Persona de Mediana Edad , Azatioprina/uso terapéutico , Adulto , Inmunosupresores/uso terapéutico , Anciano , Resultado del Tratamiento , Nucleótidos de Guanina/sangre , Estudios Retrospectivos , Monitoreo de Drogas/métodos , Tionucleótidos/sangreRESUMEN
Aims: This study aimed to investigate the impact of genetic polymorphisms of thiopurine methyltransferase (TPMT) and NUDT15 on pharmacokinetics profile of mercaptopurine in healthy adults in China. Methods: Blood samples were obtained from 45 healthy adult volunteers who were administered azathioprine. Genomic DNA was extracted and sequenced for TPMT and NUDT15. The plasma concentrations of 6-mercaptopurine (6-MP) were determined by ultra-performance liquid chromatography-tandem mass spectrometry. Finally, pharmacokinetic parameters were calculated based on the time-concentration curve. Results: Among the 45 healthy adult volunteers enrolled in the study, two TPMT allelic variants and three NUDT15 allelic variants were detected. In total, six genotypes were identified, including TPMT*1/*1&NUDT15*1/*1, TPMT*1/*1&NUDT15*1/*2, TPMT*1/*1&NUDT15*1/*9, TPMT*1/*1&NUDT15*2/*5, TPMT*1/*6&NUDT15*1/*2, and TPMT*1/*3&NUDT15*1/*2. The results indicated that Area Under Curve (AUC) of 6-MP in volunteers with TPMT*1/*3&NUDT15*1/*2 and TPMT*1/*6&NUDT15*1/*2 were 1.57-1.62-fold higher than in individuals carrying the wild type (TPMT*1/*1&NUDT15*1/*1). Compared with wild type, the half-life (T1/2) of TPMT*1/*6&NUDT15*1/*2 was extended by 1.98 times, whereas T1/2 of TPMT*1/*3&NUDT15*1/*2 decreased by 67%. The maximum concentration (Cmax) of TPMT*1/*3&NUDT15*1/*2 increased significantly by 2.15-fold, whereas the corresponding clearance (CL/F) decreased significantly by 58.75%. Conclusion: The findings of this study corroborate the notion that various genotypes of TPMT and NUDT15 can impact the pharmacokinetics of mercaptopurine, potentially offering foundational insights for personalized mercaptopurine therapy.
Asunto(s)
Genotipo , Voluntarios Sanos , Mercaptopurina , Metiltransferasas , Pirofosfatasas , Humanos , Metiltransferasas/genética , Metiltransferasas/metabolismo , Adulto , Pirofosfatasas/genética , Pirofosfatasas/metabolismo , Masculino , Mercaptopurina/farmacocinética , Mercaptopurina/metabolismo , Femenino , Alelos , Polimorfismo Genético/genética , China , Polimorfismo de Nucleótido Simple/genética , Pueblo Asiatico/genética , Adulto Joven , Persona de Mediana Edad , Azatioprina/farmacocinética , Azatioprina/metabolismo , Hidrolasas NudixRESUMEN
The interaction between the gut microbiota and mercaptopurine (6-MP), a crucial drug used in pediatric acute lymphoblastic leukemia (ALL) treatment, has not been extensively studied. Here we reveal the significant perturbation of gut microbiota after 2-week 6-MP treatment in beagles and mice followed by the functional prediction that showed impairment of SCFAs production and altered amino acid synthesis. And the targeted metabolomics in plasma also showed changes in amino acids. Additionally, targeted metabolomics analysis of feces showed changes in amino acids and SCFAs. Furthermore, ablating the intestinal microbiota by broad-spectrum antibiotics exacerbated the imbalance of amino acids, particularly leading to a significant decrease in the concentration of S-adenosylmethionine (SAM). Importantly, the depletion of gut microbiota worsened the damage of small intestine caused by 6-MP, resulting in increased intestinal permeability. Considering the relationship between toxicity and 6-MP metabolites, we conducted a pharmacokinetic study in pseudo germ-free rats to confirm that gut microbiota depletion altered the methylation metabolites of 6-MP. Specifically, the concentration of MeTINs, a secondary methylation metabolite, showed a negative correlation with SAM, the pivotal methyl donor. Additionally, we observed a strong correlation between Alistipes and SAM levels in both feces and plasma. In conclusion, our study demonstrates that 6-MP disrupts the gut microbiota, and depleting the gut microbiota exacerbates 6-MP-induced intestinal toxicity. Moreover, SAM derived from microbiota plays a crucial role in influencing plasma SAM and the methylation of 6-MP. These findings underscore the importance of comprehending the role of the gut microbiota in 6-MP metabolism and toxicity.
Asunto(s)
Microbioma Gastrointestinal , Mercaptopurina , Animales , Microbioma Gastrointestinal/efectos de los fármacos , Mercaptopurina/farmacocinética , Mercaptopurina/metabolismo , Perros , Ratones , Masculino , S-Adenosilmetionina/metabolismo , Heces/microbiología , Heces/química , Ratas , Metabolómica , Mucosa Intestinal/metabolismo , Mucosa Intestinal/efectos de los fármacos , Aminoácidos/metabolismo , Antimetabolitos Antineoplásicos/farmacocinética , Antimetabolitos Antineoplásicos/efectos adversos , Antimetabolitos Antineoplásicos/toxicidad , Antibacterianos/farmacocinética , Antibacterianos/farmacología , Antibacterianos/efectos adversos , Ratones Endogámicos C57BLRESUMEN
INTRODUCTION: Mercaptopurine, a thiopurine, is used in various disorders of immune regulation, such as autoimmune hepatitis. Thiopurine metabolism is complex with risk for overdosing, especially when metabolism is impaired by liver dysfunction. Hepatotoxicity may be due to mercaptopurine overdose and is often reversible after prompt cessation of the drug. CASE PRESENTATION: Treatment of thiopurine toxicity is mainly supportive and literature on enhanced elimination by renal replacement therapy is ambiguous. CONCLUSION: In this case of thiopurine toxicity, a patient with autoimmune hepatitis presents with abdominal pain, nausea, vomiting, and diarrhea. We show in this case report that renal replacement therapy had no effect on total body clearance of mercaptopurine.
Asunto(s)
Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Hepatitis Autoinmune , Enfermedades Inflamatorias del Intestino , Humanos , Mercaptopurina/efectos adversos , Mercaptopurina/metabolismo , Hepatitis Autoinmune/tratamiento farmacológico , Purinas/uso terapéutico , Terapia de Reemplazo Renal , Azatioprina/metabolismo , Azatioprina/uso terapéutico , Enfermedades Inflamatorias del Intestino/tratamiento farmacológico , Metiltransferasas/metabolismo , Metiltransferasas/uso terapéuticoRESUMEN
Thiopurine S-methyltransferase (TPMT) is an important enzyme involved in the deactivation of thiopurines and represents a major determinant of thiopurine-related toxicities. Despite its well-known importance in thiopurine metabolism, the understanding of its endogenous role is lacking. In the present study, we aimed to gain insight into the molecular processes involving TPMT by applying a data fusion approach to analyze whole-genome expression data. The RNA profiling was done on whole blood samples from 1017 adult male and female donors to the Estonian biobank using Illumina HTv3 arrays. Our results suggest that TPMT is closely related to genes involved in oxidoreductive processes. The in vitro experiments on different cell models confirmed that TPMT influences redox capacity of the cell by altering S-adenosylmethionine (SAM) consumption and consequently glutathione (GSH) synthesis. Furthermore, by comparing gene networks of subgroups of individuals, we identified genes, which could have a role in regulating TPMT activity. The biological relevance of identified genes and pathways will have to be further evaluated in molecular studies.
Asunto(s)
Metiltransferasas , Purinas , Adulto , Femenino , Humanos , Masculino , Perfilación de la Expresión Génica , Mercaptopurina/metabolismo , Metiltransferasas/genética , Metiltransferasas/metabolismo , Oxidación-Reducción , S-Adenosilmetionina/metabolismoRESUMEN
The role of ABCC4, an ATP-binding cassette transporter, in the process of platelet formation, megakaryopoiesis, is unknown. Here, we show that ABCC4 is highly expressed in megakaryocytes (MKs). Mining of public genomic data (ATAC-seq and genome wide chromatin interactions, Hi-C) revealed that key megakaryopoiesis transcription factors (TFs) interacted with ABCC4 regulatory elements and likely accounted for high ABCC4 expression in MKs. Importantly these genomic interactions for ABCC4 ranked higher than for genes with known roles in megakaryopoiesis suggesting a role for ABCC4 in megakaryopoiesis. We then demonstrate that ABCC4 is required for optimal platelet formation as in vitro differentiation of fetal liver derived MKs from Abcc4-/- mice exhibited impaired proplatelet formation and polyploidization, features required for optimal megakaryopoiesis. Likewise, a human megakaryoblastic cell line, MEG-01 showed that acute ABCC4 inhibition markedly suppressed key processes in megakaryopoiesis and that these effects were related to reduced cAMP export and enhanced dissociation of a negative regulator of megakaryopoiesis, protein kinase A (PKA) from ABCC4. PKA activity concomitantly increased after ABCC4 inhibition which was coupled with significantly reduced GATA-1 expression, a TF needed for optimal megakaryopoiesis. Further, ABCC4 protected MKs from 6-mercaptopurine (6-MP) as Abcc4-/- mice show a profound reduction in MKs after 6-MP treatment. In total, our studies show that ABCC4 not only protects the MKs but is also required for maximal platelet production from MKs, suggesting modulation of ABCC4 function might be a potential therapeutic strategy to regulate platelet production.
Asunto(s)
Plaquetas , Megacariocitos , Animales , Humanos , Ratones , Transportadoras de Casetes de Unión a ATP/metabolismo , Plaquetas/metabolismo , Diferenciación Celular , Megacariocitos/metabolismo , Mercaptopurina/farmacología , Mercaptopurina/metabolismo , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/genética , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/metabolismoRESUMEN
Thiopurine drugs are immunomodulatory antimetabolites relevant for pediatric patients characterized by dose-dependent adverse effects such as myelosuppression and hepatotoxicity, often related to inter-individual differences, involving the activity of important enzymes at the basis of their biotransformation, such as thiopurine S-methyltransferase (TPMT). Surface Enhanced Raman Scattering (SERS) spectroscopy is emerging as a bioanalytical tool and represents a valid alternative in terms of affordable costs, shorter analysis time and easier sample preparation in comparison to the most employed methods for pharmacokinetic analysis of drugs. The aim of this study is to investigate mercaptopurine and thioguanine pharmacokinetics by SERS in cell lysates of a B-lymphoblastoid cell line (NALM-6), that did (TPMT*1) or did not (MOCK) overexpress the wild-type form of TPMT as an in vitro cellular lymphocyte model to discriminate between cells with different levels of TPMT activity on the base of the amount of thioguanosine nucleotides (TGN) metabolites formed. SERS analysis of the cell lysates was carried out using SERS substrates constituted by Ag nanoparticles deposited on paper and parallel samples were used for quantification of thiopurine nucleotides with liquid chromatography-tandem mass spectrometry (LC-MS/MS). A direct SERS detection method has been set up that could be a tool to study thiopurine drug pharmacokinetics in in vitro cellular models to qualitatively discriminate between cells that do and do not overexpress the TPMT enzyme, as an alternative to other more laborious techniques. Results underlined decreased levels of TGN and increased levels of methylated metabolites when TPMT was overexpressed, both after mercaptopurine and thioguanine treatments. A strong positive correlation (Spearman's rank correlation coefficient rho = 0.96) exists between absolute quantification of TGMP (pmol/1 x 106 cells), obtained by LC-MS/MS, and SERS signal (intensity of TGN at 915 cm-1). In future studies, we aim to apply this method to investigate TPMT activity in pediatric patients' leukocytes.
Asunto(s)
Leucemia , Nanopartículas del Metal , Humanos , Niño , Mercaptopurina/metabolismo , Tioguanina/metabolismo , Cromatografía Liquida , Plata , Espectrometría de Masas en Tándem , Metiltransferasas , Nucleótidos , Análisis EspectralRESUMEN
OBJECTIVE: Combination therapy with infliximab and a thiopurine has been shown to be more effective than monotherapy in patients with inflammatory bowel disease (IBD). The therapeutic efficacy of thiopurines is correlated with 6-thioguanine (6-TGN) levels between 235 and 450 pmol/8×108 erythrocytes. The primary aim of the study was to investigate the association between 6-TGN levels and inhibition prevention of the production of antibodies to infliximab (ATI). DESIGN: We performed a retrospective review of the medical records of patients being treated with infliximab for IBD at University Hospitals Bristol NHS Foundation Trust. Demographic and biochemical data were extracted, alongside thiopurine metabolite levels, trough levels of infliximab and the presence of ATI. χ2 tests were used to investigate the association between 6-TGN levels and prevention of ATI. Logistic regression was used to compare the odds of prevented ATI between those with a 6-TGN level between 235 and 450 pmol/8×108 erythrocytes, those with a 6-TGN level outside of this range, and the baseline group who were on infliximab monotherapy. RESULTS: Data were extracted for 100 patients. Six of 32 patients with a 6-TGN level between 235 and 450 pmol/8×108 erythrocytes developed ATI (18.8%) compared with 14 out of 22 (63.6%) patients with a 6-TGN outside of this range and 32 out of 46 (69.6%) patients on monotherapy (p=0.001). The OR (95% CI) for prevented ATI in those with a 6-TGN between 235 and 450 pmol/8×108 erythrocytes compared with a 6-TGN outside of this range was 7.6 (2.2, 26.3) (p=0.001) and compared with monotherapy was 9.9 (3.3, 29.4) (p=0.001). CONCLUSION: 6-TGN levels between 235 and 450 pmol/8×108 erythrocytes prevented production of ATI. This supports therapeutic drug monitoring to help guide treatment and maximise the beneficial effects of combination therapy for patients with IBD.
Asunto(s)
Azatioprina , Enfermedades Inflamatorias del Intestino , Humanos , Infliximab/uso terapéutico , Azatioprina/metabolismo , Azatioprina/uso terapéutico , Mercaptopurina/metabolismo , Mercaptopurina/uso terapéutico , Inmunosupresores/metabolismo , Inmunosupresores/uso terapéutico , Enfermedades Inflamatorias del Intestino/tratamiento farmacológicoRESUMEN
Haemophilus influenzae is a human-adapted bacterial pathogen that causes airway infections. Bacterial and host elements associated with the fitness of H. influenzae within the host lung are not well understood. Here, we exploited the strength of in vivo-omic analyses to study host-microbe interactions during infection. We used in vivo transcriptome sequencing (RNA-seq) for genome-wide profiling of both host and bacterial gene expression during mouse lung infection. Profiling of murine lung gene expression upon infection showed upregulation of lung inflammatory response and ribosomal organization genes, and downregulation of cell adhesion and cytoskeleton genes. Transcriptomic analysis of bacteria recovered from bronchoalveolar lavage fluid samples from infected mice showed a significant metabolic rewiring during infection, which was highly different from that obtained upon bacterial in vitro growth in an artificial sputum medium suitable for H. influenzae. In vivo RNA-seq revealed upregulation of bacterial de novo purine biosynthesis, genes involved in non-aromatic amino acid biosynthesis, and part of the natural competence machinery. In contrast, the expression of genes involved in fatty acid and cell wall synthesis and lipooligosaccharide decoration was downregulated. Correlations between upregulated gene expression and mutant attenuation in vivo were established, as observed upon purH gene inactivation leading to purine auxotrophy. Likewise, the purine analogs 6-thioguanine and 6-mercaptopurine reduced H. influenzae viability in a dose-dependent manner. These data expand our understanding of H. influenzae requirements during infection. In particular, H. influenzae exploits purine nucleotide synthesis as a fitness determinant, raising the possibility of purine synthesis as an anti-H. influenzae target. IMPORTANCE In vivo-omic strategies offer great opportunities for increased understanding of host-pathogen interplay and for identification of therapeutic targets. Here, using transcriptome sequencing, we profiled host and pathogen gene expression during H. influenzae infection within the murine airways. Lung pro-inflammatory gene expression reprogramming was observed. Moreover, we uncovered bacterial metabolic requirements during infection. In particular, we identified purine synthesis as a key player, highlighting that H. influenzae may face restrictions in purine nucleotide availability within the host airways. Therefore, blocking this biosynthetic process may have therapeutic potential, as supported by the observed inhibitory effect of 6-thioguanine and 6-mercaptopurine on H. influenzae growth. Together, we present key outcomes and challenges for implementing in vivo-omics in bacterial airway pathogenesis. Our findings provide metabolic insights into H. influenzae infection biology, raising the possibility of purine synthesis as an anti-H. influenzae target and of purine analog repurposing as an antimicrobial strategy against this pathogen.
Asunto(s)
Infecciones por Haemophilus , Haemophilus influenzae , Ratones , Humanos , Animales , Haemophilus influenzae/genética , Mercaptopurina/metabolismo , Mercaptopurina/uso terapéutico , Tioguanina , Pulmón/patología , Perfilación de la Expresión Génica , Infecciones por Haemophilus/tratamiento farmacológico , Nucleótidos de Purina/metabolismo , Nucleótidos de Purina/uso terapéuticoRESUMEN
Mercaptopurine is a crucial component in the treatment of acute lymphoblastic leukemia. It is associated with toxicities that can delay treatment. Mercaptopurine is metabolized into 6-thioguanine nucleotides and 6-methylomercaptopurine nucleotides (6MMPN). Accumulation of 6MMPN has previously been associated with hepatotoxicity, pancreatitis, and hypoglycemia. However, skin toxicity has rarely been reported. We report 5 cases of elevated 6MMPN levels associated with cutaneous manifestations.
Asunto(s)
Leucemia-Linfoma Linfoblástico de Células Precursoras , Enfermedades de la Piel , Niño , Humanos , Mercaptopurina/metabolismo , Antimetabolitos Antineoplásicos/efectos adversos , Antimetabolitos Antineoplásicos/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Tioguanina/efectos adversosRESUMEN
Skin is the biggest organ of the human body, which easily gets irritated by exposure to the sun. Skin photoaging and acute photodamage are caused by intense UV-B radiation. Therefore, it is imperative to find new compounds to prevent skin damage and aging. Mercaptopurine is an immunologic agent commonly used for treating Acute lymphoblastic leukemia and inflammatory bowel disease. The beneficial effects of mercaptopurine on the skin have not been reported, and its intrinsic mechanism of action is unclear. Therefore, this study was to explore mercaptopurine when exposed to UV-B radiation in HacaT cells and C57BL6 mice aging and damage effects. The model of in vivo UV-B-induced skin damage and skin photoaging was established, and the impact of mercaptopurine on cell and animal skin was studied. The study found that mercaptopurine, on the one hand, inhibits cellular and animal senescence. On the other, it inhibits the expression of mitogen-activated protein kinase (MAPK) and the nuclear factor κB (NF-κB), which are important signaling molecules in the early UV-B reaction signaling pathway. In addition, mercaptopurine downregulates matrix metalloproteinase expression, increases collagen fiber content, and facilitates collagen synthesis. Treatment with mercaptopurine also inhibits the expression of inflammatory factors and reduces inflammatory cell infiltration of the skin. In conclusion, our study elucidates mercaptopurine's anti-photoaging and anti-inflammatory activity in cellular and animal models.
Asunto(s)
Mercaptopurina , Envejecimiento de la Piel , Animales , Humanos , Ratones , Mercaptopurina/farmacología , Mercaptopurina/metabolismo , Ratones Endogámicos C57BL , Piel/metabolismo , Antiinflamatorios/farmacología , Antiinflamatorios/metabolismo , Envejecimiento , Colágeno/metabolismo , Rayos Ultravioleta , FibroblastosRESUMEN
Stricture formation is a common complication of Crohn's disease (CD), driven by enhanced deposition of extracellular matrix (ECM) and expansion of the intestinal smooth muscle layers. Nuclear receptor subfamily 4 group A member 1 (NR4A1) is an orphan nuclear receptor that exhibits anti-proliferative effects in smooth muscle cells (SMCs). We hypothesized that NR4A1 regulates intestinal SMC proliferation and muscle thickening in the context of inflammation. Intestinal SMCs isolated from Nr4a1+/+ and Nr4a1-/- littermates were subjected to shotgun proteomic analysis, proliferation, and bioenergetic assays. Proliferation was assessed in the presence and absence of NR4A1 agonists, cytosporone-B (Csn-B) and 6-mercaptopurine (6-MP). In vivo, we compared colonic smooth muscle thickening in Nr4a1+/+ and Nr4a1-/- mice using the chronic dextran sulfate sodium (DSS) model of colitis. Second, SAMP1/YitFc mice (a model of spontaneous ileitis) were treated with Csn-B and small intestinal smooth muscle thickening was assessed. SMCs isolated from Nr4a1-/- mice exhibited increased abundance of proteins related to cell proliferation, metabolism, and ECM production, whereas Nr4a1+/+ SMCs highly expressed proteins related to the regulation of the actin cytoskeleton and contractile processes. SMCs isolated from Nr4a1-/- mice exhibited increased proliferation and alterations in cellular metabolism, whereas activation of NR4A1 attenuated proliferation. In vivo, Nr4a1-/- mice exhibited increased colonic smooth muscle thickness following repeated cycles of DSS. Activating NR4A1 with Csn-B, in the context of established inflammation, reduced ileal smooth muscle thickening in SAMP1/YitFc mice. Targeting NR4A1 may provide a novel approach to regulate intestinal SMC phenotype, limiting excessive proliferation that contributes to stricture development in CD.
Asunto(s)
Enfermedad de Crohn , Mercaptopurina , Animales , Células Cultivadas , Constricción Patológica/complicaciones , Constricción Patológica/metabolismo , Enfermedad de Crohn/metabolismo , Sulfato de Dextran , Inflamación/metabolismo , Mercaptopurina/metabolismo , Ratones , Músculo Liso , Miocitos del Músculo Liso/metabolismo , Miembro 1 del Grupo A de la Subfamilia 4 de Receptores Nucleares/genética , Miembro 1 del Grupo A de la Subfamilia 4 de Receptores Nucleares/metabolismo , Receptores Nucleares Huérfanos/metabolismo , Fenotipo , Fenilacetatos , ProteómicaRESUMEN
6-Mercaptopurine (6-MP) is commonly used for treatment of acute lymphoblastic leukemia (ALL). The incidence of hematotoxicity caused by this drug is quite high in Asians even using a standard low dosage regimen. The present study was aimed to elucidate the impact of thiopurine S-methyltransferase (TPMT), a nucleoside diphosphate-linked moiety X-type motif 15 (NUDT15), inosine triphosphatase (ITPA) and ATP Binding Cassette Subfamily C Member 4 (ABCC4) polymorphisms on hematotoxicity in pediatric patients who received a standard low starting dose of 6-MP. One hundred and sixty-nine pediatric patients were enrolled and their genotypes were determined. Patients who carried NUDT15∗3 and NUDT15∗2 genotypes were at a 10-15 fold higher risk of severe neutropenia than those of the wild-type during the early months of the maintenance phase. Risk of neutropenia was not significantly increased in patients with other NUDT15 variants as well as in patients with TPMT, ITPA or ABCC4 variants. These results suggest that NUDT15 polymorphisms particularly, NUDT15∗3 and NUDT15∗2, play major roles in 6-MP-induced severe hematotoxicity even when using a standard low dosage of 6-MP and genotyping of these variants is necessary in order to obtain precise tolerance doses and avoid severe hematotoxicity in pediatric patients.
Asunto(s)
Mercaptopurina , Leucemia-Linfoma Linfoblástico de Células Precursoras , Pueblo Asiatico , Niño , Genotipo , Humanos , Mercaptopurina/efectos adversos , Mercaptopurina/metabolismo , Metiltransferasas/genética , Polimorfismo Genético/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/inducido químicamente , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genéticaRESUMEN
Persistently elevated absolute neutrophil counts during maintenance for acute lymphoblastic leukemia is a risk factor for relapse and may be related to wild-type thiopurine methyltransferase activity and overly efficient shunting of 6-mercaptopurine to hepatotoxic metabolites (6-methylmercaptopurine nucleotides), leading to low 6-thioguanine nucleotides. 6-mercaptopurine is also metabolized by xanthine oxidase, and therefore allopurinol, an inhibitor of xanthine oxidase, allows for increased 6-thioguanine nucleotides and decreased 6-methylmercaptopurine nucleotide. Here, we report our experience with allopurinol for persistently elevated absolute neutrophil count or hepatotoxicity and suggest an algorithmic approach for checking thiopurine metabolites and initiating allopurinol in acute lymphoblastic leukemia maintenance.
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Alopurinol , Leucemia-Linfoma Linfoblástico de Células Precursoras , Alopurinol/uso terapéutico , Niño , Humanos , Mercaptopurina/metabolismo , Nucleótidos , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Tioguanina/metabolismo , Xantina OxidasaRESUMEN
Background: Prevalence and impact of thiopurine S-methyltransferase (TPMT) and Nudix hydrolase (NUDT15) minor allele frequencies in South Asian population is unclear.Methods: We searched PubMed and Embase with keywords-TPMT and NUDT15 combined with South Asian countries. We included studies reporting frequency of TPMT and NUDT15 polymorphisms. We estimated the pooled prevalence of TPMT and NUDT15 polymorphisms and their impact on pooled odds ratio of adverse events with thiopurines.Results: We included 26 studies in our analysis. The pooled prevalence of NUDT15 and TPMT polymorphisms was 16.5% (95% CI: 13.09-20.58) and 4.57% (95% CI: 3.66-5.68), respectively. In patients with adverse effects, the pooled prevalence of NUDT15 and TPMT polymorphism was 49.51% (95% C.I. 21.69-77.64) and 9.47% (95% C.I. 5.39-16.11), respectively. The odds ratio (OR) of adverse events with presence of TPMT polymorphisms was 3.65 (95% C.I., 1.43-9.28). The pooled OR for adverse events in presence of NUDT15 polymorphism was 12.63 (95% C.I., 3.68-43.26).Conclusion: NUDT15 were reported more frequently than the TPMT polymorphisms in South Asian population and were more frequently associated with adverse events. These findings may have implications for preemptive testing amongst South Asian population and immigrants prior to starting thiopurines.
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Metiltransferasas/genética , Pirofosfatasas/genética , Alelos , Pueblo Asiatico/genética , Azatioprina/administración & dosificación , Azatioprina/efectos adversos , Azatioprina/metabolismo , Humanos , Inmunosupresores/metabolismo , Mercaptopurina/administración & dosificación , Mercaptopurina/efectos adversos , Mercaptopurina/metabolismo , Metiltransferasas/metabolismo , Polimorfismo Genético , Pirofosfatasas/metabolismoRESUMEN
Skewed drug metabolism of 6-mercaptopurine (6-MP) can jeopardize antileukemic effects and result in toxicities during the treatment of acute lymphoblastic leukemia and lymphoblastic lymphoma. Allopurinol can alter 6-MP metabolism to maximize therapeutic effects while reducing toxicities. Over 75% of our patients with acute lymphoblastic leukemia or lymphoblastic lymphoma experienced a 6-MP-related toxicity. Review of metabolite date a showed 6-methylmercaptopurine nucleotide levels were >10,000 in 55% of the cohort, suggesting 6-MP shunting. Allopurinol was initiated in 12 of 23 shunters with resolution of toxicities. We propose an algorithm to incorporate allopurinol into chemotherapy regimens for patients with inappropriate 6-MP metabolism.
Asunto(s)
Algoritmos , Alopurinol/farmacología , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/prevención & control , Linfoma no Hodgkin/tratamiento farmacológico , Mercaptopurina/administración & dosificación , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Adolescente , Adulto , Antimetabolitos , Antimetabolitos Antineoplásicos/administración & dosificación , Antimetabolitos Antineoplásicos/efectos adversos , Antimetabolitos Antineoplásicos/metabolismo , Niño , Preescolar , Quimioterapia Combinada , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/etiología , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/metabolismo , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/patología , Femenino , Estudios de Seguimiento , Humanos , Lactante , Recién Nacido , Linfoma no Hodgkin/metabolismo , Linfoma no Hodgkin/patología , Masculino , Mercaptopurina/efectos adversos , Mercaptopurina/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Pronóstico , Estudios Retrospectivos , Adulto JovenRESUMEN
BACKGROUND: Several genetic variants of thiopurine metabolic pathway are associated with 6-thiopurine-mediated leucopenia. A population-based evaluation of these variants lays the foundation for Pharmacogenetic-guided thiopurine therapy. METHODS: A total of 2000 subjects were screened for the pharmacogenetic determinants using the infinium global screening array (GSA). The functional relevance of these variants was deduced using SNAP2, SIFT, Provean, Mutalyzer, Mutation Taster, Phyre2, SwissDock, AGGRESCAN, and CUPSAT. RESULTS: The minor allele frequencies of NUDT15*3, NUDT15*5, TPMT*3C, TPMT*3B variant alleles were 6.78%, 0.11%, 1.98% and 0.69%, respectively. TPMT*3A genotype was observed in 0.35% subjects. No gender-based differences were observed in the incidence of these variants. Data from studies of the Indian population showed that 92.86% subjects heterozygous for NUDT15*3 and 60% subjects heterozygous for TPMT*3C exhibit thiopurine-mediated hematological toxicity. NUDT15 variants have no impact on the binding of 'dGTP' to the NUDT protein. NUDT15*3 variant increases aggregation 'hot spot' region and induces unfavourable torsion in the protein. NUDT15*5 destabilizes the protein and impairs Mg/Mn binding. TPMT*3A, TPMT*3B and TPMT*3C variants lower binding affinity to 6-mercaptopurine compared to the wild protein. TPMT*3C variant destabilizes the TPMT protein in the thermal experiment. Compared to the data of European and African/African American populations, NUDT15*3 frequency is higher and TPMT*3C frequency is lower in our population. CONCLUSIONS: TPMT variants were less frequent in Indian population, while NUDT15*3 is more frequent compared to European and African/African American populations. NUDT15*3 increases aggregation 'hot spot' and induces unfavourable torsion in the protein. NUDT15*5 and TPMT*3C destabilize the respective proteins. TPMT*3A, TPMT*3B and TPMT*3C are associated with a lower binding affinity towards 6-mercaptopurine.
Asunto(s)
Antimetabolitos Antineoplásicos/efectos adversos , Antimetabolitos Antineoplásicos/metabolismo , Leucopenia/inducido químicamente , Leucopenia/genética , Mercaptopurina/efectos adversos , Mercaptopurina/metabolismo , Farmacogenética , Pueblo Asiatico , Población Negra , Estudios de Cohortes , Biología Computacional , Femenino , Frecuencia de los Genes , Genotipo , Humanos , Incidencia , India/epidemiología , Leucopenia/epidemiología , Masculino , Redes y Vías Metabólicas , Metiltransferasas/genética , Estructura Molecular , Pirofosfatasas/genética , Población BlancaRESUMEN
BACKGROUND: Inadequate myelosuppression during maintenance therapy for acute lymphoblastic leukemia (ALL) is associated with an increased risk of relapse. One mechanism is skewed metabolism of 6-mercaptopurine (6MP), a major component of maintenance therapy, which results in preferential formation of the hepatotoxic metabolite (6-methyl mercaptopurine [6MMP]) with low levels of the antileukemic metabolite, 6-thioguanine nucleotides (6TGN). Allopurinol can modify 6MP metabolism to favor 6TGN production and reduce 6MMP. METHODS: Patients in maintenance were considered for allopurinol treatment who had the following features: (a) Grade ≥3 hepatotoxicity; (b) Grade ≥2 nonhepatic gastrointestinal (GI) toxicity; or (c) persistently elevated absolute neutrophil count (ANC) despite >150% protocol dosing of oral chemotherapy. RESULTS: From 2013 to 2017, 13 ALL patients received allopurinol: nine for hepatotoxicity, five for inadequate myelosuppression, and three for nonhepatic GI toxicity (four met multiple criteria). Allopurinol was well tolerated, without significant adverse events. Allopurinol resulted in a significant decrease in the average 6MMP/6TGN ratio (mean reduction 89.1, P = .0001), with a significant increase in 6TGN (mean 550.4, P = .0008) and a significant decrease in 6MMP (mean 13 755, P = .0013). Patients with hepatotoxicity had a significant decrease in transaminase elevation after starting allopurinol (alanine transaminase [ALT] mean decrease 22.1%, P = .02), and all with nonhepatic GI toxicity had improved symptoms. Those with inadequate myelosuppression had a significant increase in the time with ANC in goal (mean increase 26.4%, P = .0004). CONCLUSIONS: Allopurinol during ALL maintenance chemotherapy is a safe, feasible, and effective intervention for those who have altered metabolism of 6MP causing toxicity or inadequate myelosuppression.
Asunto(s)
Alopurinol/uso terapéutico , Antimetabolitos/uso terapéutico , Enfermedades de la Médula Ósea/tratamiento farmacológico , Enfermedades Gastrointestinales/tratamiento farmacológico , Mercaptopurina/metabolismo , Recurrencia Local de Neoplasia/prevención & control , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Enfermedades de la Médula Ósea/etiología , Enfermedades de la Médula Ósea/metabolismo , Enfermedades de la Médula Ósea/patología , Niño , Preescolar , Femenino , Estudios de Seguimiento , Enfermedades Gastrointestinales/etiología , Enfermedades Gastrointestinales/metabolismo , Enfermedades Gastrointestinales/patología , Humanos , Lactante , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Pronóstico , Estudios Retrospectivos , Tasa de SupervivenciaRESUMEN
Aim: To investigate the current state of TPMT testing at a single-academic medical center. Methods: Single-center, retrospective chart review for patients newly prescribed a thiopurine. Data collection and evaluation included the prevalence and timing of TPMT testing, correct dosage adjustment if applicable, and incidence of myelosuppression. Results: 121 patients (71%) received TPMT testing. Out of the tested patients, 110 (90.9%) were designated as wild-type with normal metabolism. Dosing modification was appropriate in applicable patients. In unadjusted analysis, there was a lower incidence of myelosuppression among patients who were tested versus those who were not (16.5 vs 36.7%). Conclusion: Based on the study results, TPMT testing opportunities exist for nearly 30% of patients. Testing may reduce the incidence of myelosuppression.
Asunto(s)
Atención a la Salud/métodos , Metiltransferasas/genética , Pruebas de Farmacogenómica/métodos , Adulto , Anciano , Azatioprina/administración & dosificación , Azatioprina/metabolismo , Atención a la Salud/tendencias , Femenino , Humanos , Masculino , Mercaptopurina/administración & dosificación , Mercaptopurina/metabolismo , Persona de Mediana Edad , North Carolina/epidemiología , Farmacogenética/métodos , Farmacogenética/tendencias , Pruebas de Farmacogenómica/tendencias , Estudios RetrospectivosRESUMEN
BACKGROUND: Thiopurine and allopurinol in combination are associated with clinical remission in inflammatory bowel diseases but their influence on subsequent outcomes is unclear. We compared outcomes during exposure to both thiopurines and allopurinol versus thiopurines alone. METHODS: We established a nationwide cohort of patients with inflammatory bowel diseases exposed to thiopurines ± allopurinol during 1999-2014, using registry data. Patients were followed until hospitalization, surgery, anti-TNFα, or death (as a primary composite outcome). We used Poisson regression analyses to calculate incidence rate ratios overall and stratified by calendar period (assuming the combined exposure was unintended before 2009). RESULTS: A total of 10,367 patients with inflammatory bowel diseases (Crohn's disease, n = 5484; ulcerative colitis, n = 4883) received thiopurines. Of these, 217 (2.1%) also received allopurinol. During 24,714 person years of follow-up, we observed 40 outcomes among thiopurine-allopurinol-exposed patients, and 4745 outcomes among those who were thiopurine exposed; incidence rate ratio, 1.26 (95% confidence interval, 0.92-1.73). The incidence rate ratios decreased over time: 4.88 (95% confidence interval 2.53-9.45) for 1999-2003, 2.19 (95% confidence interval, 1.17-4.09) for 2004-2008 and 0.80 (95% confidence interval, 0.52-1.23) for 2009-2014. CONCLUSION: Our nationwide inflammatory bowel disease cohort study shows that concomitant thiopurine-allopurinol is as safe to use as thiopurines alone, with a tendency towards a positive effect on clinical outcomes in recent calendar periods when combined use was intended.