mercaptopurine and Inflammation

The incidence and prevalence of inflammatory bowel disease (IBD) are increasing. Although the etiology of IBD is unknown, it is thought that genetically susceptible individuals display an inappropriate inflammatory response to commensal microbes, resulting in intestinal tissue damage. Key proteins involved in regulating the immune response, and thus in inflammation, are the small triphosphate-binding protein Rac and its regulatory network. Recent data suggest these proteins to be involved in (dys)regulation of the characteristic inflammatory processes in IBD. Moreover, Rac-gene variants have been identified as susceptibility risk factors for IBD, and Rac1 GTPase signaling has been shown to be strongly suppressed in non-inflamed mucosa compared with inflamed colonic mucosa in IBD. In addition, first-line immunosuppressive treatment for IBD includes thiopurine therapy, and its immunosuppressive effect is primarily ascribed to Rac1 suppression. In this review, we focus on Rac modification and its potential role in the development of IBD, Rac as the molecular therapeutic target in current thiopurine therapy, and the modulation of the Rac signal transduction pathway as a promising novel therapeutic strategy.

Topics: Genetic Markers; Genetic Predisposition to Disease; Humans; Immunosuppressive Agents; Inflammation; Inflammatory Bowel Diseases; Mercaptopurine; NADPH Oxidases; Polymorphism, Single Nucleotide; rac1 GTP-Binding Protein; Signal Transduction

The evidence for testing thiopurine S-methyltransferase (TPMT) enzymatic activity or genotype before starting therapy with thiopurine-based drugs is unclear.. To examine the sensitivity and specificity of TPMT genotyping for TPMT enzymatic activity, reducing harm from thiopurine by pretesting, and the association of thiopurine toxicity with TPMT status in adults and children with chronic inflammatory diseases.. MEDLINE, EMBASE, the Cochrane Library, and Ovid HealthSTAR (from inception to December 2010) and BIOSIS and Genetics Abstracts (to May 2009).. Two reviewers screened records and identified relevant studies in English.. Data on patient characteristics, outcomes, and risk for bias were extracted by one reviewer and independently identified by another.. 54 observational studies and 1 randomized, controlled trial were included. Insufficient evidence addressed the effectiveness of pretesting. Genotyping sensitivity to identify patients with low and intermediate TPMT enzymatic activity ranged from 70.33% to 86.15% (lower-bound 95% CI, 54.52% to 70.88%; upper-bound CI, 78.50% to 96.33%). Sparse data precluded estimation of genotype sensitivity to identify patients with low to absent enzymatic activity. Genotyping specificity approached 100%. Compared with noncarriers, heterozygous and homozygous genotypes were both associated with leukopenia (odds ratios, 4.29 [CI, 2.67 to 6.89] and 20.84 [CI, 3.42 to 126.89], respectively). Compared with intermediate or normal activity, low TPMT enzymatic activity was significantly associated with myelotoxicity and leukopenia.. Available evidence was not rigorous and was underpowered to detect a difference in outcomes.. Insufficient evidence addresses the effectiveness of TPMT pretesting in patients with chronic inflammatory diseases. Estimates of the sensitivity of genotyping are imprecise. Evidence confirms the known associations of leukopenia or myelotoxicity with reduced TPMT activity or variant genotype.. Agency for Healthcare Research and Quality.

Topics: Chronic Disease; Genetic Testing; Genotype; Humans; Inflammation; Mercaptopurine; Methyltransferases; Purines; Sensitivity and Specificity

The thiopurines, azathioprine and 6 MP are potent inhibitors of both experimental and clinical immune responses. The primary pharmacological activities are mediated by competitive inhibition of enzymes concerned with de novo purine base synthesis; Immunosuppressive activities appear to result from cytotoxic activities directed against antigen-responsive lymphocytes; this inhibition is maximal when the treatment course coincides with the proliferative expansion phase of the response. By contrast, thiopurines are comparatively ineffective if used during an effector phase of an immune response. Furthermore, administration prior to antigenic challenge does not lead to immune inhibition; in fact, it may lead to augmentation of selected immune responses. Treatment with thiopurines does not result in acute lymphopenia; prolonged courses will cause a moderate decrease in circulating lymphocytes. The drug does not selectively deplete peripheral T or B cells but can acutely reduce K (killer) cells, which are effectors in ADCC responses. In addition, short-lived thymocytes and marrow lymphocytes are rapidly depleted by these anti-metabolites. Many in vitro functions of lymphocytes, from treated animals remain normal. Recent studies indicate that, in vitro, azathioprine is specifically able to bind murine T lymphocytes; this can be shown by their ability to inhibit their capacity to rosette with sheep erythrocytes. Azathioprine is also a potent inhibitor of mixed lymphocyte culture responses and can readily suppress the in vitro generation of cytotoxic T cells. These observations suggest that drugs exert preferential toxicities for murine T cells. B lymphocytes for mice appear to vary in their susceptibility for thiopurines. By contrast, the activity of human B cells can be readily suppressed with this drug whereas T helper function is comparatively resistant. In addition to immunosuppressive properties, thiopurines are capable of exerting anti-inflammatory activities, primarily by inhibiting the replication of hematopoietic precursors.

Topics: Animals; Azathioprine; Humans; Immunity; Immunosuppressive Agents; Inflammation; Lymphocytes; Mercaptopurine

Topics: Animals; Anti-Inflammatory Agents; Bone Marrow; Bone Marrow Cells; Cell Division; Culture Techniques; DNA; Encephalomyelitis, Autoimmune, Experimental; Glucocorticoids; Histocytochemistry; Hypersensitivity, Delayed; Inflammation; Leukocyte Count; Listeria monocytogenes; Listeriosis; Liver; Lung; Macrophages; Mercaptopurine; Mice; Monocytes; Neuroglia; Parabiosis; Peritoneum; Phagocytosis; Rabbits; Radiation Chimera; Synovial Membrane; Thymidine; Tritium

Topics: Alopecia; Antibody Formation; Bone Marrow; Bone Marrow Cells; Child; Child, Preschool; Chromosome Aberrations; Daunorubicin; Drug Hypersensitivity; Heart; Humans; Immunosuppressive Agents; Inflammation; Intestinal Mucosa; Leukemia; Leukocytes; Leukopenia; Lymphocyte Activation; Mercaptopurine

Increasing evidences indicate that the enteric nervous system (ENS) and enteric glial cells (EGC) play important regulatory roles in intestinal inflammation. Mercaptopurine (6-MP) is a cytostatic compound clinically used for the treatment of inflammatory bowel diseases (IBD), such as ulcerative colitis and Crohn's disease. However, potential impacts of 6-MP on ENS response to inflammation have not been evaluated yet. In this study, we aimed to gain deeper insights into the profile of inflammatory mediators expressed by the ENS and on the potential anti-inflammatory impact of 6-MP in this context. Genome-wide expression analyses were performed on ENS primary cultures exposed to lipopolysaccharide (LPS) and 6-MP alone or in combination. Differential expression of main hits was validated by quantitative real-time PCR (qPCR) using a cell line for EGC. ENS cells expressed a broad spectrum of cytokines and chemokines of the C-X-C motif ligand (CXCL) family under inflammatory stress. Induction of Cxcl5 and Cxcl10 by inflammatory stimuli was confirmed in EGC. Inflammation-induced protein secretion of TNF-α and Cxcl5 was partly inhibited by 6-MP in ENS primary cultures but not in EGC. Further work is required to identify the cellular mechanisms involved in this regulation. These findings extend our knowledge of the anti-inflammatory properties of 6-MP related to the ENS and in particular of the EGC-response to inflammatory stimuli.

Topics: Animals; Anti-Inflammatory Agents; Cells, Cultured; Enteric Nervous System; Gene Expression; Inflammation; Interleukin-1beta; Lipopolysaccharides; Mercaptopurine; Mice; Neurons; Rats; Tumor Necrosis Factor-alpha

Oral steroids are recommended for the treatment of nasal polyps (NPs), but prolonged use is avoided because of side effects. Topical steroids can also control NPs without significant complications; however, the response to this is partially successful, and additional therapies are needed to treat glucocorticoid-resistant NPs. Azathioprine (AZA) and its first metabolite 6-mercaptopurine (6-MP) are important immunosuppressants used for the therapy of various diseases. The aim of this study was to investigate the effects of AZA and 6-MP on inflammatory cytokines in organ-cultured NPs.. NP explants were cultured using an air-liquid interface method. Cultures were maintained in the absence and presence of steroid, AZA, and 6-MP for 72 hours. Elaboration of cytokines tumor necrosis factor alpha (TNF-α), interleukin (IL)-2, IL-4, IL-5, and IL-13 into the supernatant was quantitated using the enzyme-linked immunosorbent assay (ELISA). The messenger RNA (mRNA) expression levels of TNF-α, IL-2, IL-4, IL-5, and IL-13 in cultured mucosa were measured using real-time polymerase chain reaction. Hematoxylin and eosin staining of cultured mucosa was performed to observe inflammatory cells. Immunohistochemistry was done to evaluate the distribution pattern of inflammatory cytokines in NP explants.. On histologic examination, less inflammatory cell infiltration was found in NPs treated by steroid, AZA, and 6-MP than in control, but there was no statistical significance (p = 0.218). On immunohistochemistry, IL-13 showed a steady falling tendency in submucosal glands by steroid, AZA, and 6-MP. Expression of TNF-α, IL-2, IL-4, IL-5, and IL-13 mRNA in the NPs treated by steroid, AZA, and 6-MP were significantly lower than those of the control (p < 0.001 for all). By ELISA, IL-2 and IL-13 were significantly lower with topical steroid, AZA, and 6-MP treatment (p = 0.012 and p < 0.001).. Topical AZT decreases inflammatory cytokines on human NP explants and this could have future therapeutic implications for NPs.

Topics: Adolescent; Adult; Azathioprine; Cytokines; Female; Humans; Immunosuppressive Agents; Inflammation; Male; Mercaptopurine; Middle Aged; Nasal Mucosa; Nasal Polyps; Organ Culture Techniques; Young Adult

Pulmonary arterial hypertension (PAH) is a progressive fatal disease characterised by abnormal remodelling of pulmonary vessels, leading to increased vascular resistance and right ventricle failure. This abnormal vascular remodelling is associated with endothelial cell dysfunction, increased proliferation of smooth muscle cells, inflammation and impaired bone morphogenetic protein (BMP) signalling. Orphan nuclear receptor Nur77 is a key regulator of proliferation and inflammation in vascular cells, but its role in impaired BMP signalling and vascular remodelling in PAH is unknown.We hypothesised that activation of Nur77 by 6-mercaptopurine (6-MP) would improve PAH by inhibiting endothelial cell dysfunction and vascular remodelling.Nur77 expression is decreased in cultured pulmonary microvascular endothelial cells (MVECs) and lungs of PAH patients. Nur77 significantly increased BMP signalling and strongly decreased proliferation and inflammation in MVECs. In addition, conditioned medium from PAH MVECs overexpressing Nur77 inhibited the growth of healthy smooth muscle cells. Pharmacological activation of Nur77 by 6-MP markedly restored MVEC function by normalising proliferation, inflammation and BMP signalling. Finally, 6-MP prevented and reversed abnormal vascular remodelling and right ventricle hypertrophy in the Sugen/hypoxia rat model of severe angioproliferative PAH.Our data demonstrate that Nur77 is a critical modulator in PAH by inhibiting vascular remodelling and increasing BMP signalling, and activation of Nur77 could be a promising option for the treatment of PAH.

Topics: Animals; Bone Morphogenetic Proteins; Cell Proliferation; Culture Media, Conditioned; Disease Models, Animal; Disease Progression; Endothelial Cells; HEK293 Cells; Humans; Hypertension, Pulmonary; Inflammation; Lung; Male; Mercaptopurine; Microcirculation; Nuclear Receptor Subfamily 4, Group A, Member 1; Rats; Rats, Sprague-Dawley; Signal Transduction; Vascular Remodeling

The pathogenesis of several neurodegenerative diseases often involves the microglial activation and associated inflammatory processes. Activated microglia release pro-inflammatory factors that may be neurotoxic. 6-Mercaptopurine (6-MP) is a well-established immunosuppressive drug. Common understanding of their immunosuppressive properties is largely limited to peripheral immune cells. However, the effect of 6-MP in the central nervous system, especially in microglia in the context of neuroinflammation is, as yet, unclear. Tumor necrosis factor-α (TNF-α) is a key cytokine of the immune system that initiates and promotes neuroinflammation. The present study aimed to investigate the effect of 6-MP on TNF-α production by microglia to discern the molecular mechanisms of this modulation.. Lipopolysaccharide (LPS) was used to induce an inflammatory response in cultured primary microglia or murine BV-2 microglial cells. Released TNF-α was measured by enzyme-linked immunosorbent assay (ELISA). Gene expression was determined by real-time reverse transcription polymerase chain reaction (RT-PCR). Signaling molecules were analyzed by western blotting, and activation of NF-κB was measured by ELISA-based DNA binding analysis and luciferase reporter assay. Chromatin immunoprecipitation (ChIP) analysis was performed to examine NF-κB p65 and coactivator p300 enrichments and histone modifications at the endogenous TNF-α promoter.. Treatment of LPS-activated microglia with 6-MP significantly attenuated TNF-α production. In 6-MP pretreated microglia, LPS-induced MAPK signaling, IκB-α degradation, NF-κB p65 nuclear translocation, and in vitro p65 DNA binding activity were not impaired. However, 6-MP suppressed transactivation activity of NF-κB and TNF-α promoter by inhibiting phosphorylation and acetylation of p65 on Ser276 and Lys310, respectively. ChIP analyses revealed that 6-MP dampened LPS-induced histone H3 acetylation of chromatin surrounding the TNF-α promoter, ultimately leading to a decrease in p65/coactivator-mediated transcription of TNF-α gene. Furthermore, 6-MP enhanced orphan nuclear receptor Nur77 expression. Using RNA interference approach, we further demonstrated that Nur77 upregulation contribute to 6-MP-mediated inhibitory effect on TNF-α production. Additionally, 6-MP also impeded TNF-α mRNA translation through prevention of LPS-activated PI3K/Akt/mTOR signaling cascades.. These results suggest that 6-MP might have a therapeutic potential in neuroinflammation-related neurodegenerative disorders through downregulation of microglia-mediated inflammatory processes.

Topics: Animals; Blotting, Western; Chromatin Immunoprecipitation; Enzyme-Linked Immunosorbent Assay; Gene Expression Regulation; Immunosuppressive Agents; Inflammation; Lipopolysaccharides; Mercaptopurine; Mice; Microglia; Nuclear Receptor Subfamily 4, Group A, Member 1; Phosphatidylinositol 3-Kinases; Polymerase Chain Reaction; Proto-Oncogene Proteins c-akt; RNA, Small Interfering; Signal Transduction; TOR Serine-Threonine Kinases; Transfection; Tumor Necrosis Factor-alpha

Drug-eluting stents (DES) have dramatically reduced restenosis rates compared to bare metal stents and are widely used in coronary artery angioplasty. The anti-proliferative nature of the drugs reduces smooth muscle cell (SMC) proliferation effectively, but unfortunately also negatively affects endothelialization of stent struts, necessitating prolonged dual anti-platelet therapy. Cell-type specific therapy may prevent this complication, giving rise to safer stents that do not require additional medication. 6-Mercaptopurine (6-MP) is a drug with demonstrated cell-type specific effects on vascular cells both in vitro and in vivo, inhibiting proliferation of SMCs while promoting survival of endothelial cells. In rabbits, we demonstrated that DES locally releasing 6-MP during 4 weeks reduced in-stent stenosis by inhibiting SMC proliferation and reducing inflammation, without negatively affecting endothelialization of the stent surface. The aim of the present study was to investigate whether 6-MP-eluting stents are similarly effective in preventing stenosis in porcine coronary arteries after 3 months, in order to assess the eligibility for human application.. 6-MP-eluting and polymer-only control stents (both n = 7) were implanted in porcine coronary arteries after local balloon injury to assess the effect of 6-MP on vascular lesion formation. Three months after implantation, stented coronary arteries were harvested and analyzed.. Morphometric analyses revealed that stents were implanted reproducibly and with limited injury to the vessel wall. Unexpectedly, both in-stent stenosis (6-MP: 41.1 ± 10.3 %; control: 29.6 ± 5.9 %) and inflammation (6-MP: 2.14 ± 0.51; control: 1.43 ± 0.45) were similar between the groups after 3 months.. In conclusion, although 6-MP was previously found to potently inhibit SMC proliferation, reduce inflammation and promote endothelial cell survival, thereby effectively reducing in-stent restenosis in rabbits, stents containing 300 μg 6-MP did not reduce stenosis and inflammation in porcine coronary arteries.

Topics: Animals; Blood Vessel Prosthesis Implantation; Coronary Vessels; Drug-Eluting Stents; Female; Inflammation; Mercaptopurine; Sus scrofa; Time Factors

The introduction of drug-eluting stents (DES) has dramatically reduced restenosis rates compared with bare metal stents, but in-stent thrombosis remains a safety concern, necessitating prolonged dual anti-platelet therapy. The drug 6-Mercaptopurine (6-MP) has been shown to have beneficial effects in a cell-specific fashion on smooth muscle cells (SMC), endothelial cells and macrophages. We generated and analyzed a novel bioresorbable polymer coated DES, releasing 6-MP into the vessel wall, to reduce restenosis by inhibiting SMC proliferation and decreasing inflammation, without negatively affecting endothelialization of the stent surface.. Stents spray-coated with a bioresorbable polymer containing 0, 30 or 300 μg 6-MP were implanted in the iliac arteries of 17 male New Zealand White rabbits. Animals were euthanized for stent harvest 1 week after implantation for evaluation of cellular stent coverage and after 4 weeks for morphometric analyses of the lesions.. Four weeks after implantation, the high dose of 6-MP attenuated restenosis with 16% compared to controls. Reduced neointima formation could at least partly be explained by an almost 2-fold induction of the cell cycle inhibiting kinase p27Kip1. Additionally, inflammation score, the quantification of RAM11-positive cells in the vessel wall, was significantly reduced in the high dose group with 23% compared to the control group. Evaluation with scanning electron microscopy showed 6-MP did not inhibit strut coverage 1 week after implantation.. We demonstrate that novel stents coated with a bioresorbable polymer coating eluting 6-MP inhibit restenosis and attenuate inflammation, while stimulating endothelial coverage. The 6-MP-eluting stents demonstrate that inhibition of restenosis without leaving uncovered metal is feasible, bringing stents without risk of late thrombosis one step closer to the patient.

Topics: Animals; Coated Materials, Biocompatible; Drug-Eluting Stents; Iliac Artery; Immunosuppressive Agents; Inflammation; Male; Mercaptopurine; Neointima; Polymers; Rabbits

This protocol describes microsphere-based protease assays for use in flow cytometry and high-throughput screening. This platform measures a loss of fluorescence from the surface of a microsphere due to the cleavage of an attached fluorescent protease substrate by a suitable protease enzyme. The assay format can be adapted to any site or protein-specific protease of interest and results can be measured in both real time and as endpoint fluorescence assays on a flow cytometer. Endpoint assays are easily adapted to microplate format for flow cytometry high-throughput analysis and inhibitor screening.

Topics: Animals; Biotinylation; Flow Cytometry; Fluorescence Resonance Energy Transfer; Green Fluorescent Proteins; High-Throughput Screening Assays; Humans; Inflammation; Kinetics; Microspheres; Peptide Hydrolases; Peptides; Reproducibility of Results; Temperature

Topics: Cell Line, Tumor; Coagulants; Gene Expression Regulation, Neoplastic; Hep G2 Cells; Humans; Inflammation; Jurkat Cells; Lymphoma, Large B-Cell, Diffuse; Mercaptopurine; Stem Cell Transplantation; Thioguanine; Treatment Outcome

The aim of the study was to evaluate the incidence of abnormality of liver tests (LTs) or hepatotoxicity in a large group of inflammatory bowel disease (IBD) patients and, specifically, to assess the incidence of azathioprine (AZA)/mercaptopurine (MP)-induced liver injury in a long-term follow-up study.. All consecutive IBD patients followed for at least 5 years were included in this retrospective study. LTs including alanine transaminase, aspartate transaminase, alkaline phosphatase, gamma-glutamyl transferase, and bilirubin were periodically monitored. "Abnormality-of-LTs" was defined as LTs between N (upper limit of the normal range) and 2 N, and "liver injury/hepatotoxicity" as LTs>2 N.. A total of 786 patients were included, and 138 received AZA/MP; 120 patients (15%) and 39 (5%) presented abnormality of LTs or hepatotoxicity, respectively, during follow-up. The most frequent explanations were AZA/MP treatment and fatty liver disease. Among AZA/MP-treated patients (690 patient-years follow-up) the incidence of abnormal LTs and hepatotoxicity was, respectively, 7.1% and 2.6% per patient-year. Most patients spontaneously normalized LTs despite maintaining AZA/MP. These drugs were withdrawn due to hepatotoxicity (LTs>5 N and lack of decrease despite 50% dose reduction) in 3.6% of the patients and all of them normalized LTs.. In IBD patients, AZA or MP treatment induces abnormality of LTs in a relatively high proportion of the cases, but the development of true hepatotoxicity/liver injury is exceptional. Moreover, most of the cases of thiopurine-induced hepatotoxicity in IBD patients are mild, and the abnormalities in LTs spontaneously return to normal values despite AZA/MP being maintained, therapy withdrawal being necessary in only approximately 4% of the patients.

Topics: Adult; Algorithms; Azathioprine; Chemical and Drug Induced Liver Injury; Colitis, Ulcerative; Female; Follow-Up Studies; Humans; Immunosuppressive Agents; Inflammation; Inflammatory Bowel Diseases; Liver; Male; Mercaptopurine; Middle Aged; Time Factors

Azathioprine and 6-mercaptopurine are antimetabolite thiopurine drugs that play important roles in the treatment of leukemia and in the management of conditions requiring immunosuppression, such as inflammatory bowel disease. The biochemical pharmacology of these drugs suggests that inhibition of purine nucleotide formation through the 6-thioguanine nucleotide metabolites is their key molecular mechanism. However, it is unclear how these metabolites suppress immunity. We hypothesized that azathioprine produces a selective inhibitory effect on activated but not quiescent T lymphocytes. We first established a model system of T lymphocyte culture with azathioprine that produced pharmacologically relevant concentrations of 6-thioguanine nucleotides. Using genome-wide expression profiling, we identified a group of azathioprine-regulated genes in quiescent and activated T lymphocytes. Several genes involved in immunity and inflammation were selectively down-regulated by azathioprine in stimulated but not quiescent cells. Quantitative reverse transcription-polymerase chain reaction for three of these genes, tumor necrosis factor-related apoptosis-inducing ligand, tumor necrosis factor receptor superfamily member 7, and alpha4-integrin, confirmed down-regulated expression of transcript levels. Tumor necrosis factor-related apoptosis-inducing ligand protein expression was further studied and found to be inhibited by azathioprine, 6-mercaptopurine, and 6-thioguanine, implying that the inhibitory effects of azathioprine on expression are mediated by 6-thioguanine nucleotides. These results therefore provide a previously unrecognized molecular mechanism for the immunosuppressive properties of thiopurine antimetabolite drugs.

Topics: Annexin A5; Apoptosis Regulatory Proteins; Azathioprine; Cells, Cultured; Coloring Agents; Dose-Response Relationship, Drug; Enzyme Inhibitors; Enzyme-Linked Immunosorbent Assay; Gene Expression; Gene Expression Profiling; Humans; Immunity; Immunosuppressive Agents; Inflammation; Interleukin-2; Lymphocyte Activation; Membrane Glycoproteins; Mercaptopurine; Oligonucleotide Array Sequence Analysis; Propidium; Reverse Transcriptase Polymerase Chain Reaction; T-Lymphocytes; TNF-Related Apoptosis-Inducing Ligand; Tumor Necrosis Factor-alpha; Up-Regulation

Inflammatory bowel disease (IBD) is characterized by periods of relapse and remission. Treatment is aimed at reducing symptoms during relapse and prolonging the duration of remissions. 6-Mercaptopurine (6-MP) and its prodrug azathioprine (AZA) are commonly used to prolong clinical remissions. The erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are two widely used laboratory markers of inflammation. The authors observed an unexplained discordance between ESR and CRP in children with asymptomatic IBD who were being treated with AZA or 6-MP.. To characterize children with IBD in remission treated with 6-MP or AZA who have persistently elevated ESR but normal CRP.. All patients seen in Pediatric Gastroenterology Clinic between January 1, 1995, and December 31, 2002, with Crohn disease or ulcerative colitis who received AZA or 6-MP continuously for at least 6 months were identified and their medical records reviewed.. One hundred twenty patients met the eligibility criteria. Twelve had an ESR >18 mm/hour on at least three occasions during at least 12 consecutive months with a simultaneous CRP <0.8 mg/dL. Eleven of these 12 had no signs or symptoms of active disease and had Pediatric Crohn Disease Activity Index scores <10 for at least 12 consecutive months while the ESR was elevated. Disease duration was similar in the 11 children with asymptomatic disease and with discordant ESR and CRP and in 108 children with concordant ESR and CRP (69.2 + 22.5 months v 54.3 +/- 40.1 months, P = 0.0709). Duration of AZA or 6-MP therapy was greater in the 11 children with asymptomatic disease and discordant ESR and CRP than in those with or without symptoms and with concordant ESR and CRP (58.1 +/- 16.4 months v 36.6 +/- 24.1 months, P = 0.0043). There were no differences between the groups with respect to diagnosis, location of disease, or age at onset of symptoms. The mean corpuscular volume (MCV) was somewhat larger in the children with discordant ESR and CRP than in the children with concordant ESR and CRP (91.4 +/- 6.97 fL v 87.0 +/-7.07 fL, respectively, P = 0.0373); however, in both groups, the MCV was in the normal range. There were no significant differences in hematocrit, white blood cell count, serum albumin, total serum protein, or estimated serum globulin between the groups.. The results suggest that among children treated with AZA or 6-MP, CRP may be a more reliable indirect indicator of inflammation than ESR. This report alerts clinicians that some children taking AZA or 6-MP may have persistent elevation of the ESR with a normal CRP and have no clinical evidence of active disease.

Topics: Adolescent; Azathioprine; Biomarkers; Blood Sedimentation; C-Reactive Protein; Child; Female; Humans; Immunosuppressive Agents; Inflammation; Inflammatory Bowel Diseases; Male; Mercaptopurine; Predictive Value of Tests

Topics: Advisory Committees; Azathioprine; Child; Drug Labeling; Drug Utilization; Genetic Testing; Humans; Inflammation; Mercaptopurine; Methyltransferases; Pharmacogenetics; Precursor Cell Lymphoblastic Leukemia-Lymphoma; United States; United States Food and Drug Administration

Following the injection of turpentine and carrageenan into rats, laboratory models for counter irritation were assessed by measuring changes in paw thicknesses and serum acute phase alpha 2-macroglobulin concentrations. Both indices of inflammation were also examined in groups of rats dosed with 6-mercaptopurine, the best inhibitor found so far of elevated levels of alpha 2-macroglobulin in rat serum. Results showed that there is no relationship between the degree of irritant-induced inhibition of inflammation and the serum concentration of the acute phase protein. Hence, at least in the models for counter irritation used in this study, alpha 2-macroglobulin cannot be viewed as an endogenous anti-inflammatory protein.

Topics: alpha-Macroglobulins; Animals; Arthritis, Experimental; Carrageenan; Inflammation; Irritants; Male; Mercaptopurine; Rats; Time Factors; Turpentine

With the use of a previously described electroimmunoassay, 4 more compounds were found to depress acute phase alpha 2-macroglobulin levels in rat serum following the injection of turpentine. The compounds, meclofenamic acid, dextropropoxyphene, 5,8,11,14-eicosatetraynoic acid and 6-mercaptopurine are thus grouped with a variety of anti-inflammatory agents, cyclo-oxygenase inhibitors, hypolipidaemics and colchicine, all of which share the property of reducing the concentration of alpha 2-macroglobulin in rat serum. Compounds with immunosuppressant properties, namely amethopterin, azathioprine, cyclophosphamide and 5-fluorouracil, the steroids, betamethasone and dexamethasone, the lipoxygenase inhibitor, nordihydroguaiaretic acid, and MK477, a compound said to stimulate prostaglandin synthesis, did not reduce serum levels of the acute phase protein. 6-Mercaptopurine, a compound known to show anti-inflammatory properties in some systems, proved to be the strongest inhibitor found so far. The rat acute phase protein electroimmunoassay may thus be an effective screen for detecting a new class of anti-inflammatory agents. Knowledge of the mechanisms of action of drugs that depress rat serum alpha 2-macroglobulin concentrations may promote understanding of the control of acute phase protein production by the liver.

Topics: 5,8,11,14-Eicosatetraynoic Acid; alpha-Macroglobulins; Animals; Clofibrate; Cyclooxygenase Inhibitors; Dextropropoxyphene; Inflammation; Lipoxygenase Inhibitors; Male; Meclofenamic Acid; Mercaptopurine; Rats

Tilorone (5-35 mg/kg/day) suppressed the development of adjuvant-induced arthritis and the concurrent development of cell-mediated immune response to a secondary immunogen(EL4 cells) in a dose-related manner. Its influence on the development of the humoral immune response tp EL4 cells was found to be dependent on dosage: stimulatory at low doses (7.5 and 11.0 mg/kg/day), but inhibitory at high doses (24.0 and 35.0 mg/kg/day). Single doses of tilorone (30-300 mg/kg), administered at 24 hours or 1 hour before the injection of carrageenan, suppressed the development of acute inflammation in the rat. Evidence is presented that neither the anti-inflammatory effect of tilorone, nor its influence on the immune response could account for its antiarthritic effect. It appears plausible that the compound may act via interferon induction.

Topics: Animals; Arthritis; Arthritis, Experimental; Cell Line; Fluorenes; Immunity; Immunity, Cellular; Inflammation; Male; Mercaptopurine; Neoplasms, Experimental; Phenylbutazone; Rats; Rats, Inbred Strains; Tilorone

The present communication concerns the effect of azathioprine on the mitotic activity of promonocytes and the production of monocytes. In vitro and in vivo labeling with [3H]thymidine showed that during azathioprine treatment the promonocytes synthesize DNA and that, contrary to expectation, the labeling index increases. Cytospectrophotometric determination of the Feulgen-DNA content of the promonocytes during azathioprine treatment showed an increase in the percentage of tetraploid promonocytes, and determination of the various phases of the cell cycle showed significantly increased DNA synthesis and cell cycle times as compared with the normal steady state. On the basis of these results it can be concluded that azathioprine arrests the cell cycle of the promonocytes late in the DNA synthesis phase or in the postsynthesis (G2) phase and mitosis does not occur. This timing of the effect of azathioprine had not been previously observed. The diminished mitotic activity of the promonocytes during azathioprine treatment depressed monocyte production. During treatment with 3 mg/kg azathioprine the cell cycle time of the promonocytes was on the average 5.5 h longer than in the normal steady state and the rate of monocyte production was reduced by 70%. During an acute inflammatory reaction too, monocyte production is affected by azathioprine. In animals not treated with azathioprine but with an acute inflammation the cell cycle time becomes shorter and the monocyte production increases, but animals treated with (3 mg/kg) azathioprine do not show this effect. The kinetics of the monocyte also changes under the low dosage of azathioprine. As consequence of the diminished production of monocytes, far fewer (about 50%) monocytes enter and leave the circulation than during the normal steady state. During an acute inflammatory reaction the numbers in transit through the circulation are slightly augmented but remain considerably lower than in nonazathioprine-trehat of animals not treated with azathioprine.

Topics: Acute Disease; Animals; Azathioprine; Bone Marrow; Bone Marrow Cells; Cell Count; Cell Division; Cell Nucleus; DNA; Inflammation; Kinetics; Male; Mercaptopurine; Mice; Mitosis; Monocytes; Spectrophotometry; Thymidine; Time Factors; Tritium

The effect of azathioprine on the kinetics of peripheral blood monocytes and peritoneal macrophages was studied in normal mice and in mice in which an inflammatory reaction was provoked. Two dosage levels were used: a high dose of 200mg/kg which is the maximum tolerated daily dose in mice, and low dose of 3 mg/kg which is about equivalent to a nontoxic, immunosuppressive, anti-inflammatory dose in man. The number of peripheral blood monocytes decreases gradually during azathioprine treatment of normal mice, the extent and duration being dependent on the dose and duration of administered over a period of 9 days gives an almost complete reduction, and a low dose (3 mg/kg) given for the same period results in a reduction of about 50%. This effect seems to be reversible, because when treatment is stopped the number of monocytes starts to increase 24-48 hr later. The number of peritoneal macrophages is only affected when a high dose (200 mg/kg) is given over a long period; a low dose has virtually no effect. In mice in which an inflammatory reaction was prevoked in the peritoneal cavity, the normally occurring increase in the numbers of both peripheral blood monocytes and peritoneal macrophages was suppressed, the extent being dependent on the dose of azathioprine administered. Labeling studies with 3H-thymidine indicated that the reduction of peripheral blood monocytes and peritoneal macrophages in the inflammatory exudate is due to a diminished monocyte production.

Topics: Animals; Autoradiography; Azathioprine; Cells, Cultured; Germ-Free Life; Inflammation; Kinetics; Leukocyte Count; Lymphocytes; Macrophages; Male; Mercaptopurine; Mice; Monocytes; Peritoneum; Thymidine; Tritium

Topics: Aminopyrine; Animals; Anti-Inflammatory Agents; Arthritis, Rheumatoid; Azathioprine; Biological Assay; Cyclophosphamide; Dexamethasone; Disease Models, Animal; Drug Evaluation, Preclinical; Freund's Adjuvant; Hexobarbital; Humans; Hydroxylation; Inflammation; Irritants; Male; Mercaptopurine; Microsomes, Liver; Rats; Rats, Inbred Lew; Sleep; Time Factors

Topics: Animals; Antineoplastic Agents; Arthritis; Chickens; Columbidae; Cyclophosphamide; Cytarabine; Dactinomycin; Hybridization, Genetic; Inflammation; Male; Mercaptopurine; Nitrosourea Compounds; Procarbazine; Uric Acid; Vinblastine; Vincristine

Topics: Animals; Azathioprine; Busulfan; Carrageenan; Chlorambucil; Cyclophosphamide; Edema; Immunosuppressive Agents; Inflammation; Leukocyte Count; Male; Mercaptopurine; Methotrexate; Rats; Time Factors

Topics: Animals; Antineoplastic Agents; Aspergillosis; Aspergillus fumigatus; Brain; Chlortetracycline; Cyclophosphamide; Dexamethasone; Fluorouracil; Hydrocortisone; Inflammation; Kidney; Liver; Lung; Mercaptopurine; Methotrexate; Mice; Myocardium; Penicillin V; Spleen; Streptomycin

Topics: Animals; Anti-Inflammatory Agents; Antibiotics, Antineoplastic; Arthritis; Aspirin; Azathioprine; Chloramphenicol; Cyclophosphamide; Dexamethasone; Drug Antagonism; Edema; Hydrocortisone; Immunosuppressive Agents; Indomethacin; Inflammation; Male; Mefenamic Acid; Mercaptopurine; Nystatin; Phenylacetates; Phenylbutazone; Prednisolone; Rats; Rifampin; Triamcinolone

Topics: Animals; Antilymphocyte Serum; Cicatrix; Dogs; Electrodes, Implanted; Female; Fibroblasts; Heart; Humans; Immunosuppressive Agents; Inflammation; Male; Mercaptopurine; Myocardium; Necrosis; Pacemaker, Artificial; Prednisone; Rats; Tissue Survival

Topics: Aminopyrine; Analgesics; Anaphylaxis; Animals; Anti-Inflammatory Agents; Aspirin; Bradykinin; Capillary Permeability; Carrageenan; Croton Oil; Depression, Chemical; Edema; Exudates and Transudates; Female; Guinea Pigs; Indomethacin; Inflammation; Male; Mefenamic Acid; Mercaptopurine; Mice; Phenylbutazone; Phenytoin; Pregnanes; Protein Denaturation; Rabbits; Radiation-Protective Agents; Rats; Sulfones; Yeast, Dried

Topics: Animals; Anti-Inflammatory Agents; Antilymphocyte Serum; Burns; Capillary Permeability; Immune Sera; Immunosuppressive Agents; Inflammation; Lectins; Leukocyte Count; Lymph Nodes; Mercaptopurine; Methotrexate; Pleurisy; Rats; Turpentine

Topics: Absorption; Animals; Chromium Isotopes; Cortisone; Erythrocytes; Eye Diseases; Hemoglobins; Hemorrhage; Hypersensitivity; Infections; Inflammation; Injections; Iron; Mercaptopurine; Prednisolone; Rabbits; Uveitis; Vitreous Body

Topics: Animals; Conjunctiva; Female; Inflammation; Male; Mercaptopurine; Necrosis; Rabbits; Transplantation Immunology; Transplantation, Homologous

Topics: Anaphylaxis; Animals; Chloramphenicol; Dactinomycin; Dextrans; Edema; Emetine; Female; Ileum; Inflammation; Mannomustine; Mercaptopurine; Muscle Contraction; p-Methoxy-N-methylphenethylamine; Rats; Serotonin; Uterus

Topics: Acid Phosphatase; Animals; Exudates and Transudates; Female; Glucuronidase; Inflammation; Leukocytes; Lysosomes; Male; Mercaptopurine; Methods; Rabbits; Ribonucleases

Topics: Animals; Connective Tissue; Foreign Bodies; Granuloma; Granuloma, Giant Cell; Guinea Pigs; Hydroxyproline; Inflammation; Injections, Intraperitoneal; Leukocyte Count; Mercaptopurine; Pentoses; Pharmaceutical Vehicles; Phospholipids; Polyvinyls; Proteins

Topics: Antimetabolites; Humans; Inflammation; Leukemia; Mercaptopurine; Methotrexate; Neoplasms; Uveitis

Topics: Agranulocytosis; Aminopterin; Animals; Azaguanine; Biopsy; Chloramphenicol; Connective Tissue; Cyclophosphamide; Dactinomycin; Fluorouracil; Glycosaminoglycans; Histocytochemistry; Inflammation; Leukopenia; Lymphocytes; Mercaptopurine; Mice; Neutrophils; Photomicrography; Puromycin; Rabbits; Research

Topics: Busulfan; Hodgkin Disease; Inflammation; Leukemia; Leukemia, Lymphoid; Leukemia, Myeloid; Leukocyte Count; Lymphoma; Lymphoma, Non-Hodgkin; Mercaptopurine; Nitrogen Mustard Compounds; Skin Tests; Skin Window Technique

Topics: Inflammation; Mercaptopurine