Impact of continuous glucose monitoring on everyday life of young children with type 1 diabetes and their parents: An evaluation of 114 families.

INTRODUCTION: The prevalence of type 1 diabetes is increasing worldwide. The advent of new monitoring devices has enabled tighter glycemic control. AIM: To study the impact of glucose monitoring devices on the everyday life of young children with type 1 diabetes (T1D) and their parents. METHODS: A questionnaire was addressed to parents of children with T1D under the age of 6 years with an insulin pump treated in one of the hospitals of the ADIM network in France between January and July 2020. RESULTS: Among the 114 families included in the study, 53% of parents (26/49) woke up every night to monitor blood glucose levels when their child had flash glucose monitoring (FGM), compared with 23% (13/56) of those whose child had continuous glucose monitoring (CGM). Overall, 81% of parents (86/108) found that glucose monitoring improved their own sleep and parents whose child had CGM were significantly more likely to report improved sleep (86% vs 73%, p = 0.006). Forty-nine percent of parents (55/113) declared that they (in 87% of cases, the mother only) had reduced their working hours or stopped working following their child's T1D diagnosis. Maternal unemployment was significantly associated with the presence of siblings (p = 0.001) but not with glycemic control (p = 0,87). Ninety-eight percent of parents (105/107) think that glucose monitoring improves school integration. CONCLUSION: In these families of children with T1D, new diabetes technologies reduced the burden of care but sleep disruption remained common. Social needs evaluation, particularly of mothers, is important at initial diagnosis of T1D in children.

[Uncommon neonatal case of hypoglycemia: ACTH resistance syndrome]. / Hypoglycémie néonatale sévère et récidivante sans perte de sel révélatrice d'un syndrome de résistance à l'ACTH.

Monitoring of blood glucose is usually reported to reduce the risk of hypoglycemia in term newborns with high risk factors and for prematurity in neonatal intensive care unit patients. Differential diagnosis has rarely been discussed. In the eutrophic term newborn, hypoglycemia remains rare and an etiological diagnosis must be made. Intensive management of neonatal hypoglycemia is required to prevent neurodevelopmental defects. Without evident cause or if hypoglycemia persists, a systematic review of possible causes should be made. We report isolated glucocorticoid deficiency diagnosed in an infant at 10 months of age. This boy had neonatal hypoglycemia and mild jaundice that had not been investigated. During his first 9 months of life, he presented frequent infections. At 10 months of age, febrile seizures occurred associated with shock, hypoglycemia, hyponatremia, mild hyperpigmentation, and coma. He was diagnosed with hypocortisolemia and elevated ACTH levels. Brain injury was revealed by MRI after resuscitation, with hypoxic-ischemic and hypoglycemic encephalopathy. The molecular studies demonstrated the presence of p.Asp107Asn and previously unreported frameshift p.Pro281GlnfsX9 MC2R gene mutations. A substitutive hormone therapy was provided and during a follow-up of 12 months no adrenal crisis was noted. We report an unusual case of familial glucocorticoid deficiency with severe neurological injury. This case demonstrates the importance of an appropriate etiological diagnosis in neonatal hypoglycemia.

[Association of type 1 diabetes mellitus and epilepsy in children. A cohort of 10 cases]. / Association diabète de type 1et épilepsie chez l'enfant. À propos d'une série de 10 cas.

UNLABELLED: The association of type 1 diabetes mellitus (DM) and epilepsy has been previously reported. However, the physiopathology of this association remains misunderstood. OBJECTIVE: To describe epilepsy combined with type 1 DM in children. METHODS: Retrospective monocentric study of all the epileptic and type 1 diabetic children consulting at the Timone University Hospital, Marseille, France. For each patient, the type of epilepsy and its electroclinical and radiographic characteristics were studied as well as the type of diabetes (biological characteristics, glycemic control), and the onset of these 2 diseases. RESULTS: Ten patients are reported. Five suffered from generalized epilepsy (4 idiopathic, 1 nonidiopathic) and 5 from focal epilepsy (4 non-idiopathic, 1 idiopathic). For most of these cases, presence of GAD (glutamic acid decarboxylase) autoantibodies were confirmed and epilepsy followed diabetes. CONCLUSIONS: The 2 most common types of epilepsy in this association are idiopathic generalized epilepsy and non-idiopathic temporal epilepsy. Several mechanisms could be involved (immune, glycemia, and genetic disorders).

Pituitary stalk interruption syndrome in 83 patients: novel HESX1 mutation and severe hormonal prognosis in malformative forms.

BACKGROUND: Pituitary stalk interruption syndrome (PSIS) is a particular entity in the population of patients with hypopituitarism. Only rare cases have a known genetic cause. OBJECTIVES: i) To compare subgroups with or without extra-pituitary malformations (EPM) in a cohort of PSIS patients to identify predictive factors of evolution, ii) to determine the incidence of mutations of the known pituitary transcription factor genes in PSIS. Study design We analyzed features of 83 PSIS patients from 80 pedigrees and screened HESX1, LHX4, OTX2, and SOX3 genes. RESULTS: PSIS had a male predominance and was rarely familial (5%). Pituitary hypoplasia was observed only in the group with EPM. Multiple hormone deficits were observed significantly more often with versus without EPM (87.5 vs 69.5% respectively). Posterior pituitary location along the stalk was a significant protective factor regarding severity of hormonal phenotype. A novel HESX1 causative mutation was found in a consanguineous family, and two LHX4 mutations were present in familial PSIS. CONCLUSION: PSIS patients with EPM had a more severe hormonal disorder and pituitary imaging status, suggesting an antenatal origin. HESX1 or LHX4 mutations accounted for <5% of cases and were found in consanguineous or familial cases.

[Idiopathic hypothalamic syndrome: retrospective study and literature review]. / Aspects cliniques des syndromes hypothalamiques idiopathiques: étude rétrospective et revue de la littérature.

UNLABELLED: Hypothalamic obesity is usually induced by tumoral or genetic alterations such as craniopharyngioma or Prader-Willi syndrome, respectively. However, few cases have been reported without recognized etiology, this syndrome is also called idiopathic hypothalamic syndrome. OBJECTIVES: To improve definition and frequency of complications associated with this syndrome. POPULATION AND METHODS: A retrospective cohort study was performed in French endocrine paediatric departments and was associated with a literature review. RESULTS: We report five cases of idiopathic hypothalamic syndrome. This syndrome is correlated with a high mortality (one of our five cases, 25% in the literature) by neurovegetative dysfunction (breathing or thermal alteration). Obesity began before six years old because of compulsive eating and resulted in social behaviour disorders. Abnormal endocrine secretions were characterized by early hyperprolactinemia, permanent but later somatotrope deficiency and 80% of thyreotrope deficiency. Puberty abnormalities included hypogonadotropic hypogonadism as well as precocious (one of our cases, three cases including literature) or normal puberty. Neurogenic hypernatremia and water and electrolytic disorders were also responsible of acute neurological alterations. CONCLUSION: This largest study ever reported of idiopathic hypothalamic syndrome emphasizes the need of a multidisciplinary coordination to provide the best care of these patients.

Improved metabolic control in diabetic adolescents using the continuous glucose monitoring system (CGMS).

OBJECTIVE: To determine the utility of the continuous glucose monitoring system (CGMS) as an outpatient procedure to improve management of diabetes in adolescents. RESEARCH DESIGN AND METHODS: Twelve adolescents (mean age: 16.2 +/- 3 years) with poorly controlled type 1 diabetes (HbA(1c) > 8%) were included in this trial. Mean HbA(1c) during the previous year was 10.1 +/- 1.2%. Insulin treatment consisted of 2 or 3 daily injections in 10 cases and CSII in 2. At the beginning of the study, HbA(1c) was determined and low blood glucose index (LBGI) was calculated. Continuous glucose monitoring was performed for three days. After downloading and analyzing data, results were discussed with the patient and insulin treatment was adjusted. Two months later testing was repeated and all parameters were reassessed. RESULTS: Initial CGMS profiles demonstrated glycemic excursions unrecognized by capillary measurements in all twelve patients. Glycemia before and after meals varied from<60 mg/dL to > 200 mg/dL in 2 patients (2 episodes). Postprandial hyperglycemia exceeded 200 mg/dL in 10 patients (24 episodes). Prolonged overnight hyperglycemia was observed in 5 patients (7 episodes), dawn phenomenon in 4 patients (6 episodes) and nighttime hypoglycemia in 4 patients (4 episodes). A day-to-day reproducibility of glycemic profiles was observed in 8 patients. Then insulin treatment was adjusted according to CGMS data. Changes involved dose levels in 3 patients, insulin type in 7, number of injections, i.e. 3 instead of 2, in 5 or change from insulin injection to CSII in 1. Reassessment two months later demonstrated a significant reduction of glycemic excursions in 8 patients. HbA(1c) (m +/- SD) decreased from 10.3 +/- 2.1% to 8.75 +/- 1.06% (p<0.05). LBGI increased from 1.7 +/- 0.9 to 2.4 +/- 1.4 but the difference was not significant. CONCLUSIONS: Use of CGMS in diabetic adolescent outpatients achieved a significant improvement in metabolic control not only by providing accurate data for adjustment of insulin treatment but also by promoting patient communication and motivation.

JC-1: a very sensitive fluorescent probe to test Pgp activity in adult acute myeloid leukemia.

One of the best-characterized resistance mechanisms in acute myeloid leukemia (AML) is the drug extrusion mediated by P-glycoprotein (Pgp). Recently the results of workshops organized by several groups concluded that accurate measurement of low activity of Pgp is a difficult goal in clinical samples. Therefore, highly sensitive and specific assays were developed to assess the functionality of Pgp using JC-1, a fluorescent molecule with the different emission wavelength (green and red fluorescence) according to its concentration in 129 AML samples. It was shown that JC-1 (green and red bands) may define 3 groups of patients: resistant (R) (29% of patients), intermediate (I) (36%), and sensitive (S) (35%). In contrast, rhodamine 123 assay detected only the R group defined by JC-1. Nevertheless, the I group has an intermediate expression of Pgp (0.39, 0.29, and 0.19 for the R, I, and S groups, respectively, P =.002), an intermediate biologic profile (percentage of CD34, 95%, 67%, and 44%, respectively, P <.0001; in vitro resistance to daunorubicin, 94 microM, 20 microM, and 12 microM, respectively, P =. 02), and an intermediate prognosis (achievement of complete remission, 55%, 65%, and 87%, P =.006; 3-year disease-free survival, 11%, 16%, and 36%, respectively, P =.005; and 3-year overall survival, 0%, 20%, and 51%, respectively, P <.0001). Therefore, JC-1 appeared to be a more convenient and simple way to detect a functional Pgp in clinical AML samples than rhodamine 123. (Blood. 2001;97:502-508)

Simultaneous determination of ivabradine and its metabolites in human plasma by liquid chromatography--tandem mass spectrometry.

A rapid, selective, sensitive and reproducible liquid chromatographic method with tandem mass spectrometric detection has been developed and validated for the analysis of a new specific bradycardic agent, ivabradine (S 16257) and six potentially active metabolites in human plasma. Isolation of these compounds and of the internal standard was performed by an automated solid-phase extraction system using Oasis cartridges. Separation and detection of ivabradine and its metabolites were achieved using a C18 column and a MS-MS detector with a positive electrospray ionization source. Ivabradine and its metabolites gave a linear response ranging from 0.1 or 0.2 to 20 ng/ml and the limits of quantitation ranged from 0.1 to 0.2 ng/ml using a 0.5 ml plasma sample size. A complete validation demonstrated the method to be accurate, precise and specific for the simultaneous quantification of ivabradine and its metabolites in human plasma. The method was subsequently applied to the quantitative determination of ivabradine and its metabolites in human plasma samples from healthy volunteers participating in a clinical study to provide pharmacokinetic data.

The immunophenotype of 177 adults with acute myeloid leukemia: proposal of a prognostic score.

In acute myeloid leukemia (AML) patients, a variety of clinical and biologic parameters, including phenotype, have been examined for potential value in predicting treatment response and survival. The European Group for the Immunological Classification of Leukaemias (EGIL) has proposed that AML be defined immunologically by the expression of 2 or more of the following myeloid markers: myeloperoxidase, CD13, CD33, CDw65, and CD117. With regard to this classification, the prognostic significance of 21 antigens taken separately and with immunophenotypic subgroups were evaluated and compared with other clinical and biological variables in 177 adult AML patients. None of the antigens tested were associated with treatment outcome. In contrast, patients with blasts disclosing a full expression of panmyeloid phenotype (defined by the expression of all 5 myeloid markers) had a higher complete remission rate (P <. 0001) and differed significantly in disease-free survival (P =.02) and overall survival (P =.008) than patients whose cells expressed fewer than 5 of these markers. In multivariate analysis, only age, panmyeloid phenotype, performance status, and permeability glycoprotein activity influence treatment outcome. Cytogenetics was significant in univariate analysis but not in multivariate analysis, most likely because of the redundancy with panmyeloid phenotype and a higher sensitivity of immunophenotyping. Patients whose cells exhibit the panmyeloid phenotype appear to define a relatively homogeneous biological subset of AML. The 4 independent prognostic factors were used to create a prognostic score, defined by the number of factors present. This score permitted a stratification of patients with AML, thereby allowing for the consideration of innovative therapies to improve outcome in the poorer outcome groups.

Both Pgp and MRP1 activities using calcein-AM contribute to drug resistance in AML.

Thirteen cell lines with different levels of Pgp and MRP1 expression were used to assess the ability of calcein-AM uptake and calcein efflux to measure Pgp and MRP1 functions, respectively. There was a good correlation between MRP1 expression and the modulatory effect of probenecid (a specific modulator of MRP1) on the calcein efflux (r = 0.91, p = 0.0003) and between Pgp expression and the modulatory effect of CsA on calcein-AM uptake (r = 0.96, p < 0.0001). On light of the high correlations for both proteins, we tested calcein-AM uptake and efflux in fresh myeloid leukemic cells. In 53 AML patients, there was also a good correlation between MRP1 expression (measured by RT/PCR and by MRPm6 expression by flow cytometry) and the modulatory effect of probenecid on the calcein fluorescence (r = 0.92, p < 0.0001) and between Pgp expression as measured by UIC2 antibody binding on flow cytometry and the modulatory effect of CsA on calcein-AM uptake (r = 0.83, p < 0.0001). Pgp activity was higher in CD34+ leukemia than in CD34- leukemia (2.26 +/- 1.50 vs 1.46 +/- 1.21 respectively, p = 0.003) and MRP1 activity was higher in CD34- leukemia than in CD34+ leukemia (1.77 +/- 0.40 vs 1.4 +/- 0.29 respectively, p = 0.004). Pgp expression and activity (p = 0.004 and p = 0.01, respectively), MRP1 activity (p = 0.03) but not MRP1 expression were prognostic factors for achievement of CR. The effect of probenecid and CsA together were higher than the effect of either probenecid or CsA alone on calcein-AM uptake. These results suggest that functional testing (with calcein-AM +/- modulators) for the presence of both MRP1 and Pgp activities is of prognostic value and that MRP1 contributes to drug resistance in AML.

Simultaneous activity of MRP1 and Pgp is correlated with in vitro resistance to daunorubicin and with in vivo resistance in adult acute myeloid leukemia.

In adult acute myeloid leukemia (AML), the weight of the contribution of the combined activity of Pgp and MRP1 to drug resistance is not known. To address this question, we compared the activity of these proteins to the in vitro resistance to daunorubicin (DNR), etoposide, and cytosine arabinoside (Ara-C), using the calcein-AM uptake and the 3-[4, 5-di-methyl-thiazol-2, 5-diphenyl] tetrazolium bromide (MTT) assay in 80 adult AML patients. We found no correlation or only a weak correlation between the in vitro drug resistance to DNR and etoposide and MRP1 or Pgp expression or function when tested separately. However, a strong correlation was observed between the simultaneous activity of MRP1 and Pgp (quantified as the modulation of calcein-AM uptake by cyclosporin A and probenecid) and the LC50 of DNR (r =.77, P <.0001). This emphasized the role of these two proteins, not separately, but together in the resistance to DNR. In contrast, Mvp/LRP expression did not correlate with the LC50 of DNR. A high level of simultaneous activity of Pgp and MRP1 was predictive of a poor treatment outcome (for achievement of CR [P =.008], duration of relapse-free survival [RFS; P =.01], and duration of overall survival [OS; P =.02]). In addition, high LC50 of DNR and high LC50 of etoposide together were also predictive of a poor treatment outcome (for duration of RFS [P =.02] and duration of OS [P =.02]). The unfavorable cytogenetic category was more closely associated with the combined activity of both MRP1 and Pgp (P =.002) than with the activity of Pgp or MRP1 separately. This could explain the poor prognosis and the in vitro resistance to daunorubicin in this group of patients. These data suggest that treatment outcome may be improved when cellular DNR and etoposide resistance can be circumvented or modulated. Modulation of not only Pgp but also MRP1 could be essential to attain this aim in adult AML.

Relationship between HLA-DQ and -DR genotypes and clinical characteristics in a French population of Type 1 diabetic patients.

AIMS: The present study was designed to look for a heterogeneity in the association between Type 1 diabetes mellitus (DM) and class II alleles of major histocompatibility complex (MHC) according to clinical presentation and C-peptide secretion during the first year of the disease, in a population living in south of France. METHODS: HLA DRB1 and DQB1 genotypes were determined in 129 Caucasoid patients with Type 1 DM and compared to a control group (n = 88). In a subgroup of 46 young adult diabetic patients, basal and postglucagon C-peptide secretion was followed during the first year of the disease (at 0, 1, 3, 6, 9 and 12 months). RESULTS: The two main haplotypes associated with Type 1 DM were DRB1*04DQB1*0302 and DRB1*03DQB1*02. The genotypes DRB1* 04DQB1 *0302/DRB1*04DQB1*0302 and DRB1 *03DQB1*02/DRB1*04DQB1* 0302 were associated with an early onset of diabetes, while homozygosity for DRB1*03DQB1*02 was characterized by later onset. Levels of residual insulin secretion in patients genotyped DRB1*03DQA1*0501DQB1* 02/DRB1* 04DQA1*0301DQB1*0302 were higher than in patients genotyped DRB1* 3DQA1*0501DQB1*02/DRB1*XDQA1*XDQB1*X or DRB1* XDQA1* XDQB1*X/DRB1*XDQA1*XDQB1*X. CONCLUSIONS: This study confirms some clinical heterogeneity of Type 1 DM linked to HLA DR and DQ genotypes, and leads to a paradoxical finding: DQB1*02/ DQB1*0302 combination predisposes to an early onset in the whole population but residual secretion of insulin disappears more slowly in a subgroup of young adults with recently diagnosed diabetes. These data suggest that interrelations between MHC genotype and diabetogenic process could be different at various ages of life.

[Precocious puberty secondary to an intramedullary germinoma]. / Puberté précoce secondaire à un germinome intramédullaire.

BACKGROUND: hCG secreting tumors are responsible for 21% of precocious puberties in boys. Usual localizations are hepatic, cerebral, mediastinal and gonadic. CASE REPORT: A 4-year-old boy developed precocious puberty with rapid evolution. Serum beta hCG suggested germinal etiology, but radiological procedures failed to find any usual localization. Further occurrence of pain in the legs led to carry out a lumbar puncture. The high cerebrospinal fluid/blood gradient of beta hCG suggested the presence of an intramedullar tumor. Medullar magnetic resonance imaging found a large tumor facing L1 and L2. CONCLUSION: To our knowledge, this localization is described for only the second time.

Determination of melatonin in biological fluids in the presence of the melatonin agonist S 20098: comparison of immunological techniques and GC-MS methods.

Immunoassays were investigated for the determination of melatonin in biological samples in the presence of a naphthalenic structural analogue S 20098, which is currently under development as a melatonin agonist. The lack of specificity of commercially available antibodies in the presence of closely related molecules led us to develop an LC-RIA procedure with a quantification limit set at 15 pg/ml(-1). Because this technique was not sensitive enough and difficult to use on a routine basis, a more sensitive GC-MS technique was developed. This method involved automated solid-phase extraction (plasma) or liquid-liquid extraction (saliva), derivatization of the indolic moiety and GC separation with an automated switching device before MS detection. The method was validated over the range 1-100 pg/ml(-1), with a quantification limit set at 1 pg/ml(-1) in human plasma and saliva. Intra-assay and inter-assay precision and accuracy were within 16% for all concentrations investigated and each biological matrix. The stability of melatonin in plasma and saliva under various storage conditions was also determined. The specificity of the assay for the analysis of melatonin in the presence of S 20098 and its metabolises was demonstrated. The method was subsequently applied for the determination of endogenous melatonin concentrations in plasma and saliva samples from clinical studies performed with S 20098 to provide pharmacodynamic data.

Lung resistance protein (LRP) gene expression in adult acute myeloid leukemia: a critical evaluation by three techniques.

The role of LRP in clinical drug resistance in acute myeloid leukemia (AML) is controversial. We therefore compared multiple assays, including RT-PCR, immunocytochemistry (ICC) and flow cytometry (FC), in 10 cell lines and in 47 fresh and thawed AML cells in order to validate and to quantitate measures for LRP phenotype detection. We also compared different ways of expressing the results. Lastly, in cell lines, we analyzed the 50% lethal concentration (LC50), by MTT assay, of cisplatin which could estimate the functionality of LRP. The reproducibility of LRP detection measured by RT-PCR, ICC and FC was good. In the same way, within the same technique, there was good correlation between the different methods of expressing the results of LRP level. Therefore, the discrepancies noted with the three techniques used were neither a problem of reproducibility nor a problem of results expression. On the other hand, there was only a correlation between ICC and FC, and no correlation between RT-PCR and LRP protein detection techniques. Therefore, RT-PCR is probably not the optimal technique for LRP detection. We have shown in 10 cell lines a higher correlation between FC and LC50 of cisplatin than between ICC and LC50 of cisplatin and no correlation between RT-PCR and LC50 of cisplatin. For five patients, there was a dissociation between ICC and FC. Four patients were positive by FC and negative by ICC and only one patient was negative by FC and positive by ICC. Therefore, if in vitro resistance to cisplatin represents the functionality of LRP, we recommend the use of FC rather than ICC to detect LRP expression. Besides the measurement of LRP as a diagnostic tool in the evaluation of resistance to chemotherapy in patients with AML, we urgently need to establish a functional test in order to assess LRP activity.

Expression of genes implicated in multidrug resistance in acute lymphoblastic leukemia in India.

In order to investigate the phenomenon of multidrug resistance as a possible mechanism for poor response to treatment in patients with acute lymphoblastic leukemia (ALL) from India, a series of 32 cases of de novo untreated ALLs were analyzed by a cDNA-PCR approach to estimate the relative mRNA levels of the MDR-associated genes encoding MDR1, MRP, GSTpi, and GSTmu. The expression of beta2 microglobulin served as an internal standard. Quantifiable transcripts were observed in 20 patients for MRP, in 5 for MDR1, in 24 for GSTpi, and in 19 for GSTmu. The values ranged from undetectable to 132% of the control A549 cell line for MRP, undetectable to 49% of the HL60/DNR control cell line for MDR1, undetectable to 268% of A549 control cell line for GSTpi, and undetectable to 247% of A549 control cell line for GSTmu mRNA. Increased MRP levels were associated with increased GSTpi and GSTmu levels (p<0.01 for both), and increased levels of MDR1 were associated with increased GSTpi levels (p<0.05). The present observations showed no correlation between the MDR1 and MRP values with treatment outcome, in terms of either achieving a complete remission or predilection to early relapse. In view of some recent studies that envisage MRP as an energy-dependent pump involved in the efflux of GSH conjugates, the simultaneous up-regulation of transcription of all these genes might well be part of an integrated detoxification response that has been switched on after exposure to an environmental stress.

Pgp and MRP activities using calcein-AM are prognostic factors in adult acute myeloid leukemia patients.

Thirteen cell lines with different levels of Pgp and MRP expression were used to assess the ability of calcein acetoxymethyl ester (calcein-AM) uptake and calcein efflux to measure Pgp and MRP functions, respectively. There was a good correlation between MRP expression and the modulatory effect of probenecid (a specific modulator of MRP) on the calcein efflux (r = .91, P = .0003) and between Pgp expression and the modulatory effect of CsA on calcein-AM uptake (r = .96, P < .0001). In light of the high correlations for both proteins, we tested calcein-AM uptake and efflux in fresh myeloid leukemic cells. In 53 acute myeloid leukemia (AML) patients, there was also a good correlation between MRP expression (measured by reverse transcription-polymerase chain reaction and by MRPm6 expression by flow cytometry) and the modulatory effect of probenecid on the calcein fluorescence (r = .92, P < .0001) and between Pgp expression as measured by UIC2 antibody binding on flow cytometry and the modulatory effect of cyclosporin A on calcein-AM uptake (r = .83, P < .0001). Pgp activity was higher in CD34+ leukemia than in CD34- leukemia (2.26 +/- 1.50 v 1.46 +/- 1.21, respectively; P = .003), and MRP activity was higher in CD34- leukemia than in CD34+ leukemia (1.77 +/- 0.40 v 1.4 +/- 0. 29, respectively; P = .004). Pgp expression and activity (P = .004 and P = .01, respectively) and MRP activity (P = .03) but not MRP expression were prognostic factors for achievement of complete remission. These results suggest that functional testing (with calcein-AM +/- modulators) for the presence of both MRP and Pgp activities is of prognostic value and that MRP contributes to drug resistance in AML.

Adult biphenotypic acute leukaemia: an entity with poor prognosis which is related to unfavourable cytogenetics and P-glycoprotein over-expression.

Biphenotypic acute leukaemia (BAL) patients represented 8% of the 287 de novo consecutive adult acute leukaemias (23 BAL, 230 acute myeloid leukaemia (AML) and 34 acute lymphoblastic leukaemia (ALL)) referred to our department during the last 4-year period. Of these 23 BAL patients, 14 patients showed myeloid morphology and nine cases lymphoid morphology according to FAB criteria. There were no differences between lymphoid and myeloid BAL according to clinical and biological presentation and treatment outcome. We confirm the poor prognosis of BAL when compared to AML or ALL seen during the same period of time, in terms of complete remission (47%, 62% and 82% respectively, BAL v AML, NS and BAL v ALL, P = 0.006) and 4-year overall survival (8.1%, 25.8% and 23.8% respectively, BAL v AML, P = 0.05 and BAL v ALL, P = 0.003). Comparing adult BAL patients with AML patients, we found an increase in poor prognostic factors: CD34+ phenotype (82% v 60% respectively, P = 0.03), unfavourable karyotype (60% v 20%, P < 0.0001) and Pgp over-expression by RT-PCR (0.705 v 0.107, P < 0.0001) and flow cytometry (0.824 v 0.391, P = 0.0001). MRP and LRP were not found to be poor prognostic factors. Comparing BAL patients with ALL patients, we found also an increase in poor prognostic factors: age (51 v 39, P = 0.003) and CD34+ phenotype (82% v 50%, P = 0.02). We conclude that BAL patients need a more aggressive treatment procedure, including high-dose AraC or the use of Pgp modulators for first-line therapy.

Effect of the multidrug inhibitor GG918 on drug sensitivity of human leukemic cells.

The drug GG918 has been specifically developed for overcoming MDR phenotype and is now in use in clinical trials. In this study, the effects of GG918 on leukemic cell were investigated using a 3 day MTT assay. Results showed that, in a highly resistant P-gp(+) leukemic cell line, 0.1 microM of GG918 gives rise to a 40-fold sensitization to daunorubicin (DNR) (residual resistance: 2.1), a 57-fold sensitization to mitoxantrone (residual resistance: 1.5), and a 3.3-fold sensitization to idarubicin (residual resistance: 2.9). When human AB serum was added to the incubation medium, 1 microM of GG918 was needed to observe the full P-gp modulation potency described above. The effect of 1 microM of GG918 was tested on 27 samples of poor prognosis acute leukemia (25 AML, two ALL). DNR sensitization (using the MTT assay) and modulation of rhodamine 123 uptake were monitored and used as criteria for comparing the in vitro modulation potency of this new compound to the potency of 10 microM of verapamil, which was used as reference. A good correlation (r = 0.8, P = 0.001) was observed between the results of the two tests. Eleven out of the 26 cases tested were MDR1(+) (42%), and showed a higher IC50 for DNR than the negative cases (861 +/- 1284 nM vs 187 +/- 246 nM, P = 0.05). GG918 was able to modulate the in vitro resistance to DNR in eight cases (seven MDR1(+), no MDR1(-), one non-tested). Verapamil did not increase DNR toxicity in four of these eight cases, but was more efficient in one other MDR1(+) case. In conclusion, the DNR sensitivity of the majority of the fresh AML samples expressing P-gp could be modulated in vitro by 1 microM of GG918.