Arginine-178 is an essential residue for ITPA function.

The inosine triphosphate pyrophosphatase (ITPA) enzyme plays a critical cellular role by removing noncanonical nucleoside triphosphates from nucleotide pools. One of the first pathological ITPA mutants identified is R178C (rs746930990), which causes a fatal infantile encephalopathy, termed developmental and epileptic encephalopathy 35 (DEE 35). The accumulation of noncanonical nucleotides such as inosine triphosphate (ITP), is suspected to affect RNA and/or interfere with normal nucleotide function, leading to development of DEE 35. Molecular dynamics simulations have shown that the very rare R178C mutation does not significantly perturb the overall structure of the protein, but results in a high level of structural flexibility and disrupts active-site hydrogen bond networks, while preliminary biochemical data indicate that ITP hydrolyzing activity is significantly reduced for the R178C mutant. Here we report Michaelis-Menten enzyme kinetics data for the R178C ITPA mutant and three other position 178 ITPA mutants. These data confirm that position 178 is essential for ITPA activity and even conservative mutation at this site (R178K) results in significantly reduced enzyme activity. Our data support that disruption of the active-site hydrogen bond network is a major cause of diminished ITP hydrolyzing activity for the R178C mutation. These results suggest an avenue for developing therapies to address DEE 35.

Inosine triphosphate pyrophosphatase: A guardian of the cellular nucleotide pool and potential mediator of RNA function.

Inosine triphosphate pyrophosphatase (ITPase), encoded by the ITPA gene in humans, is an important enzyme that preserves the integrity of cellular nucleotide pools by hydrolyzing the noncanonical purine nucleotides (deoxy)inosine and (deoxy)xanthosine triphosphate into monophosphates and pyrophosphate. Variants in the ITPA gene can cause partial or complete ITPase deficiency. Partial ITPase deficiency is benign but clinically relevant as it is linked to altered drug responses. Complete ITPase deficiency causes a severe multisystem disorder characterized by seizures and encephalopathy that is frequently associated with fatal infantile dilated cardiomyopathy. In the absence of ITPase activity, its substrate noncanonical nucleotides have the potential to accumulate and become aberrantly incorporated into DNA and RNA. Hence, the pathophysiology of ITPase deficiency could arise from metabolic imbalance, altered DNA or RNA regulation, or from a combination of these factors. Here, we review the known functions of ITPase and highlight recent work aimed at determining the molecular basis for ITPA-associated pathogenesis which provides evidence for RNA dysfunction. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA in Disease and Development > RNA in Development.

An inosine triphosphate pyrophosphatase safeguards plant nucleic acids from aberrant purine nucleotides.

In plants, inosine is enzymatically introduced in some tRNAs, but not in other RNAs or DNA. Nonetheless, our data show that RNA and DNA from Arabidopsis thaliana contain (deoxy)inosine, probably derived from nonenzymatic adenosine deamination in nucleic acids and usage of (deoxy)inosine triphosphate (dITP and ITP) during nucleic acid synthesis. We combined biochemical approaches, LC-MS, as well as RNA-Seq to characterize a plant INOSINE TRIPHOSPHATE PYROPHOSPHATASE (ITPA) from A. thaliana, which is conserved in many organisms, and investigated the sources of deaminated purine nucleotides in plants. Inosine triphosphate pyrophosphatase dephosphorylates deaminated nucleoside di- and triphosphates to the respective monophosphates. ITPA loss-of-function causes inosine di- and triphosphate accumulation in vivo and an elevated inosine and deoxyinosine content in RNA and DNA, respectively, as well as salicylic acid (SA) accumulation, early senescence, and upregulation of transcripts associated with immunity and senescence. Cadmium-induced oxidative stress and biochemical inhibition of the INOSINE MONOPHOSPHATE DEHYDROGENASE leads to more IDP and ITP in the wild-type (WT), and this effect is enhanced in itpa mutants, suggesting that ITP originates from ATP deamination and IMP phosphorylation. Inosine triphosphate pyrophosphatase is part of a molecular protection system in plants, preventing the accumulation of (d)ITP and its usage for nucleic acid synthesis.

Disease-associated inosine misincorporation into RNA hinders translation.

Failure to prevent accumulation of the non-canonical nucleotide inosine triphosphate (ITP) by inosine triphosphate pyrophosphatase (ITPase) during nucleotide synthesis results in misincorporation of inosine into RNA and can cause severe and fatal developmental anomalies in humans. While the biochemical activity of ITPase is well understood, the pathogenic basis of ITPase deficiency and the molecular and cellular consequences of ITP misincorporation into RNA remain cryptic. Here, we demonstrate that excess ITP in the nucleotide pool during in vitro transcription results in T7 polymerase-mediated inosine misincorporation in luciferase RNA. In vitro translation of inosine-containing luciferase RNA reduces resulting luciferase activity, which is only partly explained by reduced abundance of the luciferase protein produced. Using Oxford Nanopore Direct RNA sequencing, we reveal inosine misincorporation to be stochastic but biased largely towards misincorporation in place of guanosine, with evidence for misincorporation also in place of cytidine, adenosine and uridine. Inosine misincorporation into RNA is also detected in Itpa-null mouse embryonic heart tissue as an increase in relative variants compared with the wild type using Illumina RNA sequencing. By generating CRISPR/Cas9 rat H9c2 Itpa-null cardiomyoblast cells, we validate a translation defect in cells that accumulate inosine within endogenous RNA. Furthermore, we observe hindered cellular translation of transfected luciferase RNA containing misincorporated inosine in both wild-type and Itpa-null cells. We therefore conclude that inosine misincorporation into RNA perturbs translation, thus providing mechanistic insight linking ITPase deficiency, inosine accumulation and pathogenesis.

The GTP responsiveness of PI5P4Kß evolved from a compromised trade-off between activity and specificity.

Unlike most kinases, phosphatidylinositol 5-phosphate 4-kinase ß (PI5P4Kß) utilizes GTP as a physiological phosphate donor and regulates cell growth under stress (i.e., GTP-dependent stress resilience). However, the genesis and evolution of its GTP responsiveness remain unknown. Here, we reveal that PI5P4Kß has acquired GTP preference by generating a short dual-nucleotide-recognizing motif called the guanine efficient association (GEA) motif. Comparison of nucleobase recognition with 660 kinases and 128 G proteins has uncovered that most kinases and PI5P4Kß use their main-chain atoms for adenine recognition, while the side-chain atoms are required for guanine recognition. Mutational analysis of the GEA motif revealed that the acquisition of GTP reactivity is accompanied by an extended activity toward inosine triphosphate (ITP) and xanthosine triphosphate (XTP). Along with the evolutionary analysis data that point to strong negative selection of the GEA motif, these results suggest that the GTP responsiveness of PI5P4Kß has evolved from a compromised trade-off between activity and specificity, underpinning the development of the GTP-dependent stress resilience.

Inosine triphosphate pyrophosphatase from Trypanosoma brucei cleanses cytosolic pools from deaminated nucleotides.

Inosine triphosphate pyrophosphatases (ITPases) are ubiquitous house-cleaning enzymes that specifically recognize deaminated purine nucleotides and catalyze their hydrolytic cleavage. In this work, we have characterized the Trypanosoma brucei ITPase ortholog (TbITPA). Recombinant TbITPA efficiently hydrolyzes (deoxy)ITP and XTP nucleotides into their respective monophosphate form. Immunolocalization analysis performed in bloodstream forms suggests that the primary role of TbITPA is the exclusion of deaminated purines from the cytosolic nucleoside triphosphate pools. Even though ITPA-knockout bloodstream parasites are viable, they are more sensitive to inhibition of IMP dehydrogenase with mycophenolic acid, likely due to an expansion of IMP, the ITP precursor. On the other hand, TbITPA can also hydrolyze the activated form of the antiviral ribavirin although in this case, the absence of ITPase activity in the cell confers protection against this nucleoside analog. This unexpected phenotype is dependant on purine availability and can be explained by the fact that ribavirin monophosphate, the reaction product generated by TbITPA, is a potent inhibitor of trypanosomal IMP dehydrogenase and GMP reductase. In summary, the present study constitutes the first report on a protozoan inosine triphosphate pyrophosphatase involved in the removal of harmful deaminated nucleotides from the cytosolic pool.

Inosine Triphosphate Pyrophosphatase (ITPase): Functions, Mutations, Polymorphisms and Its Impact on Cancer Therapies.

Inosine triphosphate pyrophosphatase (ITPase) is an enzyme encoded by the ITPA gene and functions to prevent the incorporation of noncanonical purine nucleotides into DNA and RNA. Specifically, the ITPase catalyzed the hydrolysis of (deoxy) nucleoside triphosphates ((d) NTPs) into the corresponding nucleoside monophosphate with the concomitant release of pyrophosphate. Recently, thiopurine drug metabolites such as azathioprine have been included in the lists of ITPase substrates. Interestingly, inosine or xanthosine triphosphate (ITP/XTP) and their deoxy analogs, deoxy inosine or xanthosine triphosphate (dITP/dXTP), are products of important biological reactions such as deamination that take place within the cellular compartments. However, the incorporation of ITP/XTP, dITP/dXTP, or the genetic deficiency or polymorphism of the ITPA gene have been implicated in many human diseases, including infantile epileptic encephalopathy, early onset of tuberculosis, and the responsiveness of patients to cancer therapy. This review provides an up-to-date report on the ITPase enzyme, including information regarding its discovery, analysis, and cellular localization, its implication in human diseases including cancer, and its therapeutic potential, amongst others.

Clinico-radiological features, molecular spectrum, and identification of prognostic factors in developmental and epileptic encephalopathy due to inosine triphosphate pyrophosphatase (ITPase) deficiency.

Developmental and epileptic encephalopathy 35 (DEE 35) is a severe neurological condition caused by biallelic variants in ITPA, encoding inosine triphosphate pyrophosphatase, an essential enzyme in purine metabolism. We delineate the genotypic and phenotypic spectrum of DEE 35, analyzing possible predictors for adverse clinical outcomes. We investigated a cohort of 28 new patients and reviewed previously described cases, providing a comprehensive characterization of 40 subjects. Exome sequencing was performed to identify underlying ITPA pathogenic variants. Brain MRI (magnetic resonance imaging) scans were systematically analyzed to delineate the neuroradiological spectrum. Survival curves according to the Kaplan-Meier method and log-rank test were used to investigate outcome predictors in different subgroups of patients. We identified 18 distinct ITPA pathogenic variants, including 14 novel variants, and two deletions. All subjects showed profound developmental delay, microcephaly, and refractory epilepsy followed by neurodevelopmental regression. Brain MRI revision revealed a recurrent pattern of delayed myelination and restricted diffusion of early myelinating structures. Congenital microcephaly and cardiac involvement were statistically significant novel clinical predictors of adverse outcomes. We refined the molecular, clinical, and neuroradiological characterization of ITPase deficiency, and identified new clinical predictors which may have a potentially important impact on diagnosis, counseling, and follow-up of affected individuals.

Investigation of the Association Between the ITPA Gene 94C>A Gene Sequence Variant and Liver Transplant Rejection in Iranian Liver Transplant Recipients.

OBJECTIVES: Inosine triphosphate pyrophosphatase is an enzyme encoded by the ITPA gene and functions to prevent the incorporation of thiopurine nucleotides into DNA and RNA. Thiopurine drug metabolites such as azathioprine and 6-mercaptopurine have been included in the lists of inosine triphosphate pyrophosphatase substrates. Inosine triphosphatase gene alterations are other pharmacogenetic sequence variants possibly involved in thiopurine metabolism. This study aimed to evaluate the possible association between ITPA 94C>A gene sequence variant (C-to-A substitution at nucleotide 94) in liver transplant recipients. MATERIALS AND METHODS: The genotyping of ITPA 94C>A was evaluated by the polymerase chain reaction- restriction fragment length polymorphism method in 200 liver transplant recipients as well as 100 controls. Data were analyzed with SPSS statistical software. RESULTS: This study showed statistically significant associations between the CA genotype of the ITPA 94C>A sequence variant and liver transplant in the rejection and nonrejection groups. Moreover, the results reported in this study showed no significant differences between sex, age, and blood group in patients with liver transplant (with or without transplant rejection). CONCLUSIONS: Our results indicated that there were statistically significant associations of the CA genotype of ITPA 94C>A sequence variant with liver transplant in the rejection and nonrejection groups. Further studies are recommended.

Finding Ways to Relax: A Revisionistic Analysis of the Chemistry of E. coli GTP Cyclohydrolase II.

Guanosine triphosphate (GTP) cyclohydrolase II (RibA) is one of three enzymes that hydrolytically cleave the C8-N9 bond of the GTP guanine. RibA also catalyzes a subsequent hydrolytic attack at the base liberating formate and in addition cleaves the α-ß phosphodiester bond of the triphosphate to form pyrophosphate (PPi). These hydrolytic reactions are promoted by tandem active-site metal ions, zinc and magnesium, that respectively function at the GTP guanine and triphosphate moieties. The RibA reaction is part of riboflavin biosynthesis and forms 2,5-diamino-6-ß-pyrimidinone 5'-phosphate, an exocyclic pyrimidine nucleotide that ultimately forms the pyrimidine ring of the isoalloxazine of riboflavin. The stoichiometry of the RibA reaction was defined in the study that first identified this activity in Escherichia coli (Foor, F., Brown, G. M. J. Biol. Chem., 1975, 250, 9, 3545-3551) and has not been quantitatively evaluated in subsequent works. Using primarily transient state approaches we examined the interaction of RibA from E. coli with the GTP, inosine triphosphate, and PPi. Our data indicate that PPi is a slow substrate for RibA that is cleaved to form two phosphate ions (Pi). A combination of real-time enzymatically coupled Pi reporter assays and end-point 31P NMR revealed that Pi is formed at a catalytically relevant rate in the native reaction of RibA with GTP, redefining the reaction stoichiometry. Furthermore, our data indicate that both PPi and GTP stimulate conformational changes prior to hydrolytic chemistry, and we conclude that the cleavage of PPi bound as a substrate or an intermediate state results in conformational relaxation.

Incidencia del perímetro abdominal en la resistencia a esfuerzos intermitentes de universitarios físicamente activos / Incidence of abdominal perimeter in endurance to intermittent efforts by physically active university students

Introducción: El perímetro abdominal y la resistencia a esfuerzos intermitentes, reflejada en el VO2máx, son dos grandes indicadores; el primero del riesgo cardiovascular y el segundo de la capacidad aeróbica máxima. Este estudio permitirá determinar si las mediciones del perímetro abdominal tienen relación con la capacidad del sujeto de responder a esfuerzos intermitentes. Objetivo: Determinar la asociación entre el perímetro de cintura y la resistencia a esfuerzos intermitentes reflejada en el VO2máx. Métodos: Los participantes fueron 91 hombres y 22 mujeres estudiantes de la Licenciatura en Educación Física, Recreación y Deportes de la Universidad de Pamplona. Para la valoración de la resistencia intermitente se empleó el test de fitness intermitente 30-15 (30-15 ITF) con el cual se determinó el VO2máx. Se realizó la toma del perímetro de cintura teniendo en cuenta los criterios de la Federación Internacional de Diabetes. La tabulación y análisis de datos se llevó a cabo en el paquete estadístico PSPP, con la prueba de normalidad de Kolmogorov - Smirnov para hombres y Shapiro - Wilk para mujeres, y el coeficiente correlacional de Spearman (p < 0,05) (valor p de 0,05). Resultados: Se encontró una asociación negativa entre las variables perímetro abdominal e indicador de resistencia a esfuerzos intermitentes VO2máx, en hombres (r = -0,17) y en mujeres (r = 0,09), no obstante, para ambos sexos esta relación no fue estadísticamente significativa (p < 0,05). Conclusión: Se concluye que el perímetro abdominal no está relacionado de forma significativa con la resistencia a esfuerzos intermitentes en universitarios físicamente activos(AU)

Introduction: The abdominal perimeter and endurance to intermittent efforts reflected in VO2max are two major indicators; the first for cardiovascular risk and the second for maximum aerobic capacity. This study will make it possible to determine whether abdominal perimeter measurements are related to the subject's ability to respond to intermittent efforts. Objective: Determine the association between the abdominal perimeter and the endurance to intermittent efforts reflected in the VO2max. Methods: The participants were 91 men and 22 female students of the Bachelor's Degree in Physical Education, Recreation and Sports of the University of Pamplona. For the assessment of intermittent endurance, the intermittent fitness test 30-15 (30-15 ITF) was used with which the VO2max was determined. The abdominal perimeter was taken taking into account the criteria of the International Diabetes Federation. The tabulation and analysis of data was carried out in the PSPP statistical package, applying the Kolmogorov-Smirnov normality test for men and Shapiro-Wilk for women, and, Spearman's correlational coefficient (p < 0,05) (p-value of 0,05). Results: A negative association was found between the variables abdominal girth and the indicator of endurance to intermittent efforts VO2max, in men (r = -0,17) and in women (r = 0,09), however, for both sexes, this relationship was not statistically significant (p < 0,05). Conclusion: It is concluded that, the abdominal perimeter is not significantly related to resistance to intermittent efforts in physically active university students(AU)

Structural dynamics of inosine triphosphate pyrophosphatase (ITPA) protein and two clinically relevant mutants: molecular dynamics simulations.

The inosine triphosphate pyrophosphatase (ITPA) protein is responsible for removing noncanonical purine nucleoside triphosphates from intracellular nucleotide pools. Absence of ITPA results in genomic instability and increased levels of inosine in DNA and RNA. The proline to threonine substitution at position 32 (P32T) affects roughly 15% of the global population and can modulate treatment outcomes for cancer, lupus, and hepatitis C patients. The substitution of arginine with cysteine at position 178 (R178C) is extremely uncommon and has only been reported in a small cohort of early infantile encephalopathy patients suggesting that a functional ITPA protein is required for life in humans. Here we present molecular dynamic simulations that describe the structure and dynamics of the wild-type ITPA homodimer and two of its clinically relevant mutants, P32T and R178C. The simulation results indicate that both the P32T and R178C mutations alter the structure and dynamic properties of the protein and provide a possible explanation of the experimentally observed effect of the mutations on ITPA activity. Specifically, the mutations increased the overall flexibility of the protein and changed the dominant collective motions of the top lobe as well as the helix 2 of the lower lobe. Moreover, we have identified key active-site residues that are classified as essential or intermediate for inosine triphosphate (ITP) hydrolyzing activity based on their hydrogen bond occupancy. Here we also present biochemical data indicating that the R178C mutant has very low ITP hydrolyzing activity.Communicated by Ramaswamy H. Sarma.

2-Substituted 2'-deoxyinosine 5'-triphosphates as substrates for polymerase synthesis of minor-groove-modified DNA and effects on restriction endonuclease cleavage.

Five 2-substituted 2'-deoxyinosine triphosphates (dRITP) were synthesized and tested as substrates in enzymatic synthesis of minor-groove base-modified DNA. Only 2-methyl and 2-vinyl derivatives proved to be good substrates for Therminator DNA polymerase, whilst all other dRITPs and other tested DNA polymerases did not give full length products in primer extension. The DNA containing 2-vinylhypoxanthine was then further modified through thiol-ene reactions with thiols. Cross-linking reaction between cysteine-containing minor-groove binding dodecapeptide and DNA proceeded thanks to the proximity effect between thiol and vinyl groups inside the minor groove. 2-Substituted dIRTPs and also previously prepared 2-substituted 2'-deoxyadenosine triphosphates (dRATP) were then used for enzymatic synthesis of minor-groove modified DNA to study the effect of minor-groove modifications on cleavage of DNA by type II restriction endonucleases (REs). Although the REs should recognize the sequence through H-bonds in the major groove, some minor-groove modifications also had an inhibiting effect on the cleavage.

[Curative Efficacy of Rituximab for ITP Patients with Different Sensitivity to Hormone].

OBJECTIVE: To investigatc the curative efficacy of low dose rituximab for glucocorticoid ineffective on dependent ITP patients and its relation with sensitivity to glucocorticoid so as to provide reference basis for rational use of drugs in clinical treatmant. METHODS: Seventy-ninth ITP patients enrolled in this study included the glucocorticoid-ineffective patients (19 cases) and glucocorticoid-dependent patients (60 cases). All ITP patients were treated with regimen consisted of high dose dexamethasone plus low dose rituximab (dexal-methasone 40 mg/d for 4 days per os, ritaximab 100 mg by intravenous infusion at D7, 14, 21 and 28 respectively). The patients after treatment were followed-up for 12 month, and the relation of patients sensitivity to glucocorticoid with therapentic response of rituximab was analyzed. The changes of Treg cell ratio and BAFF, IL-2 and sCD40L levels before and after treatment were detected by flow cytometry and ELISA respectively. RESULTS: The overall response rate (ORR) of patients treated with above- mentioned regemen at 1, 3, 6 and 12 months after treatment was 79.7% (63/79), 69.6% (55/79), 63.3% (50/79) and 60.8% (48/79) respectivcly, out of which the ORR of glucocorticoid ineffective and glucocorticoid-dependent ITP patients treated with above-mentioned regimen at 1, 3, 6 and 12 months after treatment was 47.4% (9/19) vs 90.0% (54/60), 36.8% (7/19) vs 80.0% (48/60), 21.1% (4/19) vs 76.7% (46/60), 21.1% (4/19) vs 73.3% (44/60), and the difference between 2 groups was statistically significant. The detection of T reg cell showed that the T reg cell ratio in glucocorticoid- ineffective and dependent patients at 1, 3, 6 and 12 months after treatment was (1.70±0.43)% vs (3.47±0.72)%, (1.66±0.33)% vs (4.29±0.91)%, (1.71±0.37)% vs (4.44±0.97)%, (3.36±0.54)% vs (4.29±1.04)%, respectively. The detection of cytokines showed that the levels of BAFF, IL-2 and sCD40L in plasma of glucocorticoid-dependent patients at 1 month after treatment significanlly decreased (P＜0.05), the levels of BAFF, IL-2 and sCD40L in plasma of glucocorticoid-ineffective patients although decreased at 1 mouth after treatment, but there was no statistical difference as compared with glucocosticoid-depenment patients. CONCLUSION: The treatment of glucocorticoid-dependent ITP patients with rituximab is more effective. The regulatory effect of rituximab on the T-reg cells, BAFF, IL-2 and sCD40L may be one of its mechanisms.

Metabolism and biochemical properties of nicotinamide adenine dinucleotide (NAD) analogs, nicotinamide guanine dinucleotide (NGD) and nicotinamide hypoxanthine dinucleotide (NHD).

Nicotinamide adenine dinucleotide (NAD) is an important coenzyme that regulates various metabolic pathways, including glycolysis, ß-oxidation, and oxidative phosphorylation. Additionally, NAD serves as a substrate for poly(ADP-ribose) polymerase (PARP), sirtuin, and NAD glycohydrolase, and it regulates DNA repair, gene expression, energy metabolism, and stress responses. Many studies have demonstrated that NAD metabolism is deeply involved in aging and aging-related diseases. Previously, we demonstrated that nicotinamide guanine dinucleotide (NGD) and nicotinamide hypoxanthine dinucleotide (NHD), which are analogs of NAD, are significantly increased in Nmnat3-overexpressing mice. However, there is insufficient knowledge about NGD and NHD in vivo. In the present study, we aimed to investigate the metabolism and biochemical properties of these NAD analogs. We demonstrated that endogenous NGD and NHD were found in various murine tissues, and their synthesis and degradation partially rely on Nmnat3 and CD38. We have also shown that NGD and NHD serve as coenzymes for alcohol dehydrogenase (ADH) in vitro, although their affinity is much lower than that of NAD. On the other hand, NGD and NHD cannot be used as substrates for SIRT1, SIRT3, and PARP1. These results reveal the basic metabolism of NGD and NHD and also highlight their biological function as coenzymes.

Inverse cationic ITP for separation of methadone enantiomers with sulfated ß-cyclodextrin as chiral selector.

Chiral ITP of the weak base methadone using inverse cationic configurations with H+ as leading component and multiple isomer sulfated ß-CD (S-ß-CD) as leading electrolyte (LE) additive, has been studied utilizing dynamic computer simulation, a calculation model based on steady-state values of the ITP zones, and capillary ITP. By varying the amount of acidic S-ß-CD in the LE composed of 3-morpholino-2-hydroxypropanesulfonic acid and the chiral selector, and employing glycylglycine as terminating electrolyte (TE), inverse cationic ITP provides systems in which either both enantiomers, only the enantiomer with weaker complexation, or none of the two enantiomers form cationic ITP zones. For the configuration studied, the data reveal that only S-methadone migrates isotachophoretically when the S-ß-CD concentration in the LE is between about 0.484 and 1.113 mM. Under these conditions, R-methadone migrates zone electrophoretically in the TE. An S-ß-CD concentration between about 0.070 and 0.484 mM results in both S- and R-methadone forming ITP zones. With >1.113 mM and < about 0.050 mM of S-ß-CD in the LE both enantiomers are migrating within the TE and LE, respectively. Chiral inverse cationic ITP with acidic S-ß-CD in the LE is demonstrated to permit selective ITP trapping and concentration of the less interacting enantiomer of a weak base.

[Changes of DC Subsets and CD80 and CD86 Expression in Peri-pheral Blood of Patients with ITP and Their Correlation with Efficacy of Dexamethasone Treatment].

OBJECTIVE: To analyze the changes of DC subsets and the expression of CD80 and CD86 in peripheral blood of ITP patients and their correlation with dexamethasone efficacy. METHODS: Peripheral blood sample of 80 cases of ITP and 20 normal controls from June 2015 to June 2017 in our hospital were retrospectively analyzed. The specific distribution of DC subsets in the peripheral blood of all the subjects was detected by flow cytometry, and the expressions of CD80 and CD86 were detected by ELISA. RESULTS: The proportion of DC2 in DC subsets of ITP patients before treatment was significantly higher than that in normal control group (P<0.05). The proportion of DC2 in DC subset of ITP patients was still significantly higher than that of the control group (P<0.05). The level of CD80 expression on DC1 and DC2 in ITP patients before treatment was significantly higher than that in the normal control group (P<0.05), and the expression level of CD86 on DC2 was significantly higher than that of the normal control group (P<0.05). Both IL-2 and IFN- γ levels in the patients before the treatment were significantly higher than those in the normal control group (P<0.05), and the expression levels after treatment with dexamethasone decreased significantly. Before treatment, both IL-4 and IL-10 levels in ITP patients were significantly lower than those in the normal control group (P<0.05), and their expression levels after treatment with dexamethasone significantly increased (P<0.05). CONCLUSION: The incidence of ITP patients closely relates with the level and dysfunction of DC subsets in peripheral blood and the expression levels of IL-2, IL-4, IL-10, IFN- γ, which significantly correlates with the efficacy of dexamethasone.