C1236T polymorphism in MDR1 gene correlates with therapeutic response to imatinib mesylate in Indian patients with chronic myeloid leukaemia.

Patients with chronic myeloid leukaemia show an excellent response to treatment with imatinib. However, in some patients, the disease is resistant to imatinib. This resistance may be related to the presence of genetic variations on the drug’s pharmacokinetics and metabolism. We therefore studied three polymorphisms (C1236T, G2677T and C3435T) in the human multidrug-resistance gene (MDR1) in 86 patients with chronic myeloid leukaemia treated with imatinib. Imatinib resistance was more frequent in patients with TT genotype at locus 1236 than in those with CT/CC genotypes (p=0.003). For the other two loci (G2677T and C3435T), resistance was seen to be higher for TT genotype when compared to GG/GT and CT/CC but it was not statistically significant (p=0.13 and p=0.099). In conclusion, determination of C1236T MDR1 genotype may help to predict response to imatinib therapy in patients with chronic myeloid leukaemia. Natl Med J India 2015;28:272–5

Correlation of JAK2V617F mutational status in primary myelofibrosis with clinico-hematologic characteristics and international prognostic scoring system scoring: A single center experience.

Introduction: Somatic mutation in the exon 14 of Janus Kinase 2 gene is an established diagnostic marker in bcr-abl negative myeloproliferative neoplasms, especially primary idiopathic myelofi brosis (PIMF). Aim: Our primary aim was to fi nd out the correlation between the JAK2V617F mutational status and the clinico-hematologic characteristics, as well as the international prognostic scoring system (IPSS) scoring of patients with PIMF. Materials and Methods: Clinical and hematologic features were reviewed for 68 patients with primary idiopathic myelofi brosis (PIMF). JAK2V617F mutation status was analyzed by amplifi cation refractory mutation screening-polymerase chain reaction. The patients were further stratifi ed into low, intermediate-1, intermediate-2 and high-risk groups on the basis of IPSS scoring. Results: The JAK2V617F mutation was detected in 58.8% patients. Univariate analysis of variables at presentation identifi ed that JAK2V617F negative patients were signifi cantly associated with more severe anemia (P = 0.045), younger age (P = 0.008), higher transfusion requirement (P = 0.017), and thrombocytopenia (P = 0.015). Patients who were homozygous for JAK2V617F mutation were associated with thrombocytosis (P = 0.014) and also had higher median total leucocyte count (P = 0.20) than the other groups. No signifi cant correlation was detected between JAK2V617F mutational status and the presence of constitutional symptoms, spleen size, grade of bone marrow fi brosis or prognostic risk stratifi cation of the PIMF patients. Conclusion: The variations in the prognostic implication of PIMF patients with mutation status as stated by various publications worldwide, reinstates the need for larger prospective studies using standardized JAK2V617F quantifi cation methods as well as estimation of other newer molecular markers to develop deeper insight into various molecular alterations involving PIMF patients in India as well as worldwide.

Cytogenetic profile of Indian patients with de novo myelodysplastic syndromes.

Background & objectives: Myelodysplastic syndrome (MDS) is a clonal haematopoietic stem cell disorder characterized by ineffective haematopoiesis and leukaemia progression. Cytogenetic analysis has proven to be a mandatory part of the diagnosis of MDS as well as a major indicator for predicting clinical course and outcome. Studies on cytogenetics of MDS are reported mostly from the West and only a few are available from Asian countries. We report herein cytogenetic studies on 40 Indian patients with primary MDS to find out the occurrence and type of chromosome abnormalities and recurring defects. Methods: Cytogenetic analysis was done using GTG banding and karyotyped according to the International System for Human Cytogenetic Nomenclature (ISCN). Results: Of the 40 patients, 19 patients (47.5%) showed clonal karyotypic abnormalities with distribution as follows: 3 of 15 (20%) of refractory anaemia (RA), 4 of 7 (57%) of refractory anaemia with excess blasts-1 (RAEB-1), 4 of 6 (67%) of refractory anaemia with excess blasts 2 (RAEB-2), 2 of 3 (67%) of refractory anaemia with ring sideroblasts (RARS), 2 of 4 (50%) of refractory cytopenia with multilineage dysplasia (RCMD), none (0%) RCMD-ringed sideroblasts (RCMD-RS) and 4 patients with 5q syndrome. The frequent abnormalities observed in our study were -7, 5q-and trisomy 8. Interpretation & conclusions: Two rare chromosomal abnormalities (6q-, 3q-) were found with unknown prognostic significance. Hence, cytogenetic analysis may be incorporated in the routine diagnosis of MDS since there are racial differences in clinical pictures and the molecular events.

Prevalence of JAK2 V617F mutation in Indian patients with chronic myeloproliferative disorders.

Background & objectives: The Janus-associated Kinase-2 mutation JAK2 V617F in chronic myeloproliferative disorders (CMPDs) has been described as a frequent genetic event in majority of patients with polycythemia vera (PV), essential thrombocythemia (ET) and idiopathic myelofibrosis (IMF). Its frequency varies in different populations but there are no data from India. We therefore, looked for JAK2 V617F mutation in Indian patients with chronic myeloproliferative disorders. Methods: Mutation screening for JAK2 V617F in patients with polycythemia vera, essential thrombocythemia and idiopathic myelofibrosis was performed in 75 patients attending Haematology clinic in a tertiary care hospital in north India, by polymerase chain reaction and restriction enzyme-based assay. Results: JAK2 V617F mutation was found in 51 of 75 cases (68%) of CMPD, 82 per cent in PV, 70 per cent in ET and 52 per cent of IMF. The presence of JAK2 V617F mutation was associated with a higher haemoglobin level (P<0.05), a higher white blood cell count (P<0.01) and higher age (P<0.05). Interpretation & conclusion: The JAK2 V617F mutation was detected in 86 per cent of patients with CMPD disorders. Peripheral blood mutation screening for JAK2 V617F can be incorporated into the initial evaluation of patients suspected to have CMPD.

Haematological & molecular profile of acute myelogenous leukaemia in India.

Background & objectives: Recurrent balanced translocations are generally recognized to be a major parameter for prognostication in acute myeloid leukaemia (AML). The chromosomal translocation t(15;17) results in PML/RARα fusion gene, t(8;21) results in AML1/ETO fusion gene and Inv 16 generates CBFβ/MYH11 fusion gene. Patients with these mutations have a good prognosis unlike abnormalities in chromosome 5 or 7 or FLT3 genes. Therefore, we screened the AmL patients for known specific genetic abnormalities that could lead to more definitive prognoses. Methods: A total of 113 AML patients were evaluated at diagnosis based on routine morphology and cytochemistry and classified according to the WHO criteria. The distribution of AML subtypes was M1(1), M2(32), M3(57), M4(14), M5(1), M6(1) and seven cases where morphological subtype could not be classified. RT-PCR was performed to identify PML/RARα, AML1/ETO, CBFβ/MYH11 and FLT3 internal tandem duplication (ITD). Results: Of the 57 patients with M3 subtype, 55 had the PML-RARα fusion transcript. The prevalence of bcr3 (short isoform) was higher (62%) than that of bcr1 (long isoform) (38%) and no correlation was found with age, sex or white blood cell count. FLT3 internal tandem duplication (ITD) mutations were more frequent in patients with APL than in other AML subtypes (17.5 vs. 8.9%), the frequency greater in patients with bcr3 isoform (70%) than in those with in bcr1 isoform (30%). Patients with FLT3/ITD mutations had a significantly higher median white cell count than those without these mutations (55 x 109/l vs. 6.3 x 109/l; P<0.001). More patients with FLT3/ITD mutations died early (53%) than those without these mutations (16%) (P<0.01). AML1-ETO fusion transcript was detected in 16 of 56 patients with no correlation with clinical or haematological parameters. Interpretation & conclusion: The results of the present study showed presence of bcr3 (short isoform) higher than bcr1 (long isoform). FLT3 internal tandem duplication (ITD) mutation was predominant in acute promyelocytic leukaemia patients with bcr3 isoform. Thus, patients with APL who have FLT3 mutation appear to have a poorer prognosis. Therefore, rapid identification of specific translocations at diagnosis is important for prognostic purposes and their detection should be incorporated into routine assessment.

Does acute promyelocytic leukemia in Indian patients have biology different from the West?

Acute promyelocytic leukemia (APML) is a well-characterized malignancy with typical clinico-hematological and molecular features. However, Indian data on this malignancy are limited. This study was conducted to determine the clinico-hematological profile of APML in India. Thirty-five patients with APML presenting to Hematology Department, AIIMS, New Delhi, between July 2003 and June 2005 were evaluated for presenting clinical features, hemogram, peripheral smear, bone marrow morphology and cytochemistry. Reverse transcriptase PCR (RT-PCR) for PML-RARalpha was done in all cases. Male-to-female ratio was 0.9:1 (males--17 and females--18) with median age 25 years (range 11-57 years). Presenting features included anemia, bleeding, fever, gum hypertrophy and scrotal ulceration. All cases showed hypergranular abnormal promyelocytes. Median hemoglobin was 6.3 g/dL (range - 3.0-9.0 g/dL), total leukocyte count (TLC) was 33.88 x 10(9) /L (range - 1-170 x 10(9) /L). Platelet count was 28 x 10(9) /L (range - 4-170 x 10(9) /L). All cases were positive for myeloperoxidase and sudan black (SB), whereas 60% cases also showed non specific esterase (NSE) positivity with 40% cases being fluoride sensitive. RT-PCR showed PML-RARalpha in 33/35 cases with the bcr3 isoform being present in 24/33 positive cases (72.7%). The two cases negative for PML-RARalpha showed typical morphology and responded to ATRA. On statistical analysis, no correlation was found between bcr isoform and TLC, platelet count, age sex and early death. Unusual features included gum hypertrophy and scrotal ulceration at presentation and high median presenting TLC (33.8 x 10(9) /L). There was, however, no microgranular variant. Another interesting feature was a high incidence of NSE positivity (60%), which was fluoride sensitive in 40%. Moreover, the bcr3 isoform was significantly overexpressed (72.7%) in comparison to other studies. APML in India has certain unusual features, which may reflect a different biology.

AML1-ETO positive AML: first report from India.

Translocation (8;21) is associated with few typical morphological features and favorable prognosis. All patients of AML and MDS with increased blasts (N = 35) according to FAB criteria, presenting (between Jan 2004 to June 2005) to the Department of Hematology, AIIMS were studied. RT-PCR was done for the AML1-ETO fusion transcript in all cases. Overall incidence of AML1-ETO was 28.57% and no correlation was found between AML1-ETO positivity and clinical or hematological parameters except for a direct correlation with absolute blast count (ABC) (a lower ABC in the AML1-ETO positive cases). Interestingly, 1/3 MDS cases were positive for the same fusion transcript and thus, it appears worthwhile to look for AML1-ETO in all cases of MDS with increased blasts. Objective morphological evaluation using a scoring system based on morphological features was not helpful in predicting positivity for AML1-ETO. The effect of this translocation on long-term survival could not be determined by the present study.