The t(8;14)(q24.1;q32) and its variant translocations: A study of 34 cases.

BACKGROUND: The t(8;14)(q24.1;q32) and its variants - the t(2;8)(p12;q24.1) and t(8;22)(q24.1;q11.2) are associated with B-cell neoplasia and result in MYC/immunoglobulin (IG) gene rearrangement. PATIENTS AND METHODS: We correlated the cytogenetic, molecular and clinico-pathological findings of patients with 8q24 translocations seen in the Department of Haematology, Christian Medical College, Vellore, from January 2003 to December 2015. RESULTS: There were 34 patients with 8q24 translocations (31, ALL and three myeloma). The t(8;14) was seen in 25 patients, t(8;22) in seven and t(2;8) in two. The salient findings were as follows: 85% males; 79% adults, median age 37 years; L3 morphology in 61%; mature B immunophenotype in 77%; extra-medullary disease in 41%; additional abnormalities in 28 (85%), notably, structural abnormalities of chromosome 1q (41%) and 13q (9%) and monosomy 13 (15%); complex karyotypes in 68%. There were two double-hit lymphoma/leukemia, one with a t(14;18)(q32;q21) and the other with a t(3;14)(q27;q11.2), associated with nodal high grade B cell lymphoma and dermal leukemic infiltrates respectively. Only 13 samples were processed for DNA PCR and all these samples were positive for MYC-IgH (c-gamma type) rearrangement. Only in one patient, in addition to c-gamma, c-alpha rearrangement was also detected. CONCLUSION: The frequency (1.7%) and distribution of these translocations in our series and the association with 1q and 13q abnormalities is similar to the literature. Trisomies 7 and 12 were seen in less than 10% of our patients.

Association between CYP1A2 gene single nucleotide polymorphisms and clinical responses to clozapine in patients with treatment-resistant schizophrenia.

OBJECTIVES: Despite clozapine's superior clinical efficacy in treatment-resistant schizophrenia (TRS), its adverse effects, need for periodic leukocyte monitoring, cost and variable clinical outcomes mandate a clinical need to predict its treatment response. Although cytochrome P450 1A2 (CYP1A2) is the principal determinant of metabolism of clozapine, the role of CYP1A2 gene in the clinical response to clozapine is uncertain. Hence, we investigated its association with treatment responses and adverse events of clozapine in TRS. METHODS: We evaluated four single nucleotide polymorphisms (SNP) in the CYP1A2 gene, clinical responses and serum clozapine levels in 101 consecutive patients with TRS on stable doses of clozapine. We defined clozapine response a priori and investigated allelic and genotypic associations. We assessed the socio-demographic and clinical profiles, premorbid adjustment, traumatic life events, cognition and disability of the participants, using standard assessment schedules for appropriate multivariate analyses. RESULTS: Our results revealed that CYP1A2 gene SNP (*1C, *1D, *1E and *1F) were not associated with clozapine treatment response, adverse effects, serum clozapine levels or with disability (p values > 0.10). CONCLUSION: As CYP1A2 gene SNP do not help to predict the clinical response to clozapine, routine screening for them prior to start clozapine is currently unwarranted. We suggest future longitudinal genome-wide association studies investigating clinical and pharmacogenetic variables together.

Outcome definitions and clinical predictors influence pharmacogenetic associations between HTR3A gene polymorphisms and response to clozapine in patients with schizophrenia.

RATIONALE: Pharmacogenetics of schizophrenia has not yet delivered anticipated clinical dividends. Clinical heterogeneity of schizophrenia contributes to the poor replication of the findings of pharmacogenetic association studies. Functionally important HTR3A gene single-nucleotide polymorphisms (SNPs) were reported to be associated with response to clozapine. OBJECTIVE: The aim of this study was to investigate how the association between HTR3A gene SNP and response to clozapine is influenced by various clinical predictors and by differing outcome definitions in patients with treatment-resistant schizophrenia (TRS). METHODS: We recruited 101 consecutive patients with TRS, on stable doses of clozapine, and evaluated their HTR3A gene SNP (rs1062613 and rs2276302), psychopathology, and serum clozapine levels. We assessed their socio-demographic and clinical profiles, premorbid adjustment, traumatic events, cognition, and disability using standard assessment schedules. We evaluated their response to clozapine, by employing six differing outcome definitions. We employed appropriate multivariate statistics to calculate allelic and genotypic association, accounting for the effects of various clinical variables. RESULTS: T allele of rs1062613 and G allele of rs2276302 were significantly associated with good clinical response to clozapine (p = 0.02). However, varying outcome definitions make these associations inconsistent. rs1062613 and rs2276302 could explain only 13.8 % variability in the responses to clozapine, while combined clinical predictors and HTR3A pharmacogenetic association model could explain 38 % variability. CONCLUSIONS: We demonstrated that the results of pharmacogenetic studies in schizophrenia depend heavily on their outcome definitions and that combined clinical and pharmacogenetic models have better predictive values. Future pharmacogenetic studies should employ multiple outcome definitions and should evaluate associated clinical variables.

Cytochrome P4501A1 and glutathione S transferase gene polymorphisms in patients with aplastic anemia in India.

The etiology of acquired aplastic anemia (AA) in most patients remains unclear. It is believed that patients with a reduced ability to detoxify environmental toxins are at increased risk of developing AA. Cytochrome P450 (CYP450) and glutathione S transferase (GST) are the major phase I and phase II xenobiotic-metabolizing enzymes. We analyzed the impact of the polymorphisms in CYP4501A1 and GSTM1 and GSTT1 genes on the susceptibility and disease severity in 200 patients with AA and compared the frequency with the normal population. There was a significantly increased frequency of the CYP1A1m4 allele in AA patients compared with normal controls (odds ratio = 3.01; 95% confidence interval 1.76-5.17; p = 0.00001). None of the other CYP1A1 genotypes or the GST genotypes were significantly different between AA patients and controls. Altered metabolism of benzo(a)pyrene due to the polymorphism in the CYP1A1 gene might be an etiologic factor in the increased incidence of AA in these patients. The CYP1A1m4 allele may play a role in determining the risk of AA in India.

Hematological and molecular remission with combination chemotherapy in a patient with PLZF-RARalpha acute promyelocytic leukemia (APML).

Patients with acute promyelocytic leukemia (APML) with the t(11;17) translocation usually respond poorly to all-trans retinoic acid (ATRA) and chemotherapy. We describe a patient with promyelocytic leukemia zinc finger/retinoic acid receptor alpha (PLZF/RARalpha) APML who was treated with combination chemotherapy after poor response to arsenic trioxide. He achieved hematological remission in 4 weeks followed by achievement of molecular remission in 8 weeks. Four cycles of consolidation chemotherapy followed by four cycles of maintenance therapy were given over a period of 9 months. At a follow-up of 32 months after achieving hematological remission, he continues to remain in hematological and molecular remission with normal blood parameters and negative reverse transcriptase polymerase chain reaction (RT-PCR) results. Combination chemotherapy can achieve sustained remission in patients with PLZF/RARalpha APML.

Treatment of children with newly diagnosed acute promyelocytic leukemia with arsenic trioxide: a single center experience.

A total of 11 children (five males and six females) with hypergranular type of acute promyelocytic leukemia (APML) were treated with intravenous arsenic trioxide (As(2)O(3)) between December 1998 and October 2003. Eight cycles of As(2)O(3) (0.15 mg/kg/day) were administered (induction, consolidation and six cycles of maintenance) over a period of 12 months. The median WBC count at diagnosis was 3400/mm(3) (range: 800-9800). In all, 10 patients (91%) achieved hematological remission at a mean duration of 48 days (range: 41-60) with all 10 patients achieving molecular remission at a median duration of 81 days (range: 64-109). Toxicity was minimal with leukocytosis in six patients, ichthyosis and hyperpigmentation of skin in five and mild peripheral neuropathy in one patient. One patient who relapsed 6 months after completing therapy achieved a second hematological and molecular remission with As(2)O(3). With a median follow-up of 30 months (range: 4-62), the overall (OS) survival is 91% with a relapse-free survival (RFS) of 81%. As(2)O(3) achieves hematological and molecular remission in majority of newly diagnosed children with APML with minimal toxicity, but long-term follow-up is required to evaluate late effects of As(2)O(3) and study the minimum dose and duration required for a sustained remission.

Glutathione S-transferase activity influences busulfan pharmacokinetics in patients with beta thalassemia major undergoing bone marrow transplantation.

Busulfan, at a dose of 16 mg/kg, is widely used in combination with cyclophosphamide as a conditioning regimen for patients undergoing bone marrow transplantation. Wide interindividual variation in busulfan kinetics and rapid clearance of the drug have been reported, especially in children. Some of the factors contributing to interpatient variability have been identified. They include circadian rhythms, age, disease, drug interaction, changes in hepatic function, and busulfan bioavailability. In this study, we demonstrate that hepatic glutathione S-transferase (GST) activity correlates negatively with busulfan maximum and minimum concentrations (Pearson's correlation r = -0.74 and -0.77, respectively) and positively with busulfan clearance (Pearson's correlation r = 0.728) in children with thalassemia major in the age range of 2 to 15 years. We also found that plasma alpha GST levels were 5 to 10 times higher in patients with thalassemia than in normal controls and age-matched leukemic patients, either reflecting extensive liver damage, elevated expression of the enzyme, or both in thalassemic patients. Plasma alpha GST concentrations showed a similar correlation with busulfan kinetic parameters to that observed for hepatic GST. The status of hepatic GST activity accounts, at least in part, for the observed interindividual variation in busulfan kinetics, while the observed association with plasma alpha GST is difficult to explain at present.

Pharmacokinetics of oral busulphan in children with beta thalassaemia major undergoing allogeneic bone marrow transplantation.

The pharmacokinetics of busulphan were studied in 23 thalassaemic children undergoing BMT. Patients received busulphan at a dose of either 16 mg/kg with cyclophosphamide and ATG (Group A) or 600 mg/m2 (with cyclophosphamide alone) (Group B) in 16 divided doses every 6 h over 4 days. Busulphan levels were analyzed by a modified GC-MS method. The dose of busulphan/kg for patients in group B was 64% (range 56-71%) higher than that for patients in group A. The mean AUC, Css, Cmax and MRV were significantly higher in group B as compared with group A for both doses 1 and 13. There was no significant difference in Vd/F, T1/2 and Kel between the two groups. A significant decrease in AUC and Css was found between 1st and 13th doses in group B, but not in group A. The Cl/F values in group A were significantly higher than those in group B after dose 1, but not after dose 13. No increase in toxicity due to the higher dose of busulphan was noted. We conclude that busulphan at 600 mg/m2 results in much higher systemic exposure to the drug as compared to 16 mg/kg, without increase in toxicity in children with beta thalassaemia major.

High-performance liquid chromatographic method for quantification of busulfan in plasma after derivatization by tetrafluorothiophenol.

A high-performance liquid chromatographic (HPLC) method was developed and validated for the determination of busulfan in plasma. Busulfan was extracted in toluene, derivatized by 2,3,5,6-tetrafluorothiophenol to obtain di-TFTP-butane, the derivatization product was then re-extracted in toluene and injected into the HPLC system with ultraviolet detection (wavelength: 275 nm). Recovery from extraction was 80%, the limit of quantification was 50 ng/ml and linearity ranged from 50 to 2000 ng/ml. In addition, forty-two samples obtained from pediatric patients treated with busulfan were analyzed by the HPLC and GC-MS assays based on the same derivatization procedure. The correlation between the di-TFTP-butane concentrations was highly significant (p<0.0001), demonstrating that the two methods were in good agreement.

Quantification of busulfan in plasma by gas chromatography-mass spectrometry following derivatization with tetrafluorothiophenol.

A specific and highly sensitive method has been developed for the determination of busulfan in plasma by gas chromatography-mass spectrometry using a deuterium-labeled busulfan (busulfan-d8) as internal standard. Plasma containing busulfan and busulfan-d8 were extracted with ethyl acetate and derivatized with 2,3,5,6-tetrafluorothiophenol prior to the monitoring of specific ions. The limit of quantification of the assay was 20 ng/ml and the calibration curve was linear over the range of 10 to 2000 ng/ml of derivatized busulfan. This method was in good agreement with the GC-MS assay using derivatization with sodium iodide and measuring diiodobutane. In addition, a pharmacokinetic study of busulfan was conducted in six children. The apparent oral clearance was 5.7+/-1.9 ml/kg/min and the volume of distribution was 1.0+/-0.4 l/kg and were similar to those previously reported in pediatric patients.

Comparison of HPLC & EMIT methods of cyclosporine assay in blood after bone marrow transplantation.

Cyclosporine (CsA) analysis in blood from patients who had undergone bone marrow transplantation for various haematological disorders was done both by high performance liquid chromatography (HPLC) and enzyme multiplied immunoassay technique (EMIT) and the results were compared. HPLC kit from Biorad Laboratories, USA, and EMIT kit from SYVA, UK, were used. The procedure for EMIT was slightly modified in-house to suit the Hitachi 704 discrete selective analyser. The CsA values obtained by these two methods correlated well within the therapeutic range (r value 0.96), HPLC method being most suitable outside the therapeutic range. Although HPLC is the ideal method for CsA, EMIT is quite suitable and can be adopted by any laboratory with an autoanalyser incorporating our modified procedure.

Effect of uric acid on sodium oxalate-induced urolithiasis in rats--biochemical and histological evidences.

Effect of uric acid on sodium oxalate-induced biochemical and histological changes were studied in rats. Rats injected with sodium oxalate (0.7 mg/100 g body wt, ip) show calcium deposits in the lumen of kidney tubules. Uric acid administration was found to potentiate calcium oxalate calculi formation. Lipid peroxide formation was increased up to 100% in kidney and 28% in liver by sodium, oxalate treatment. Uric acid administration was found to reduce lipid peroxide level up to 12% in liver and 20% in kidney. From this study it is concluded that lipid peroxidation may not be the cause of sodium oxalate-induced urolithiasis and the results are discussed with reference to the epitaxic nature of uric acid on kidney stone formation.