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.

Paroxysmal nocturnal hemoglobinuria in childhood and adolescence--a retrospective analysis of 18 cases.

OBJECTIVE: To assess the clinical and hematological profile of PNH in children. METHODS: Clinical and laboratory features of children with PNH diagnosed in the past six years at our centre were reviewed. Various investigations done included a complete blood count and peripheral smear examination, plasma hemoglobin, urine hemosiderin, acid ham test, sucrose lysis test, immunophenotyping of erythrocytes by sephadex column gel card and of granulocytes by flow cytometry. There were 18 children with a marked male predominance (M 14: F 4). RESULTS: Pallor, jaundice, dark urine and bleeding manifestations were the major presenting complaints. One girl suffered an arterial stroke. All children had cytopenia in at least one cell line. Children were treated with danazol, stanazolol, prednisolone and cyclosporin A variously. Overall response rate was 61%. Children with classical PNH performed slightly better with response rates of 66% (6/9) as compared to aplastic anemia-PNH group which has a response rate of 55% (5/9). Amongst various variables only danazol correlated with better response (p=0.029). CONCLUSION: PNH is an uncommon disease in children and should be included in the differential diagnosis of children presenting with cytopenia.

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.

HFE mutation H63D predicts risk of iron over load in thalassemia intermedia irrespective of blood transfusions.

Iron overload is a well-documented complication in thalassemia intermedia. Moreover, it is seen that the number of blood transfusions received does not correlate with the degree of overload. Since, HFE gene is associated with iron overload; the present study was conducted in an attempt to evaluate its role in thalassemia intermedia. The subjects were consecutive thalassemia intermedia cases attending the Hematology outpatient clinic. Controls were healthy hospital staff with negative family history of hemolytic anemia or liver disease. The molecular analysis for HFE mutations H63D and C282Y were done with primers described earlier. ELISA was used to measure serum ferritin. Sixty-three patients of thalassemia intermedia including 48 beta-homozygous/heterozygous thalassemia intermedia and 15 HbE-beta-thalassemia were studied. Six (12.5%) of the former and two (13.3%) of the latter were heterozygous for H63D; one of which, a 51-year old male also had clinical features of hemochromatosis. In healthy controls, prevalence of H63D heterozygosity was 7.5% (6/80). An interesting feature observed was that though the age and transfusions taken were similar in both groups, the serum ferritin greater than 500 ng/dl were observed in all patients (100%) with HFE mutation whereas it was seen in 12/42 (28.6 %) of patients without the mutation (p = 0.002). Thus, it is concluded that thalassemia intermedia patients with co-existent HFE mutation have a higher likelihood of developing iron overload and may require early iron chelation.

Gel card in the diagnosis of autoimmune haemolytic anemia.

The diagnosis of autoimmune haemolytic anaemia (AIHA) requires the establishment of haemolysis and demonstration of autoantibodies against red cells. Most laboratories use the conventional Coomb's test for the demonstration of the autoantibodies. However, in approximately 2-6% of the patients who present with the clinical and haematological features of AIHA, the direct agglutination test is negative on repeated testing. Attempts are therefore being made to identify a test which could be more sensitive than the conventional test, yet retaining the simplicity and cost effectiveness of the test. In the present study, the efficacy of the newly developed gel card test has been compared with the conventional Coomb's test for detection of autoantibodies in 50 cases clinically suspected to have haemolytic anemia. The gel card picked up the antibodies in all the cases detected to be positive by the conventional test. In addition, the gel card also picked up 5 tests which were negative by the conventional method. The sensitivity and specificity of the gel card Direct Coomb's test (DCT) as compared to the conventional tube test for DCT was found to be 100% and 95.1% respectively. The Indirect Coomb's test (ICT) was 100% sensitive and 92.5% specific. In view of the high sensitivity and specificity and the simplicity of the procedure, this test may be effectively used for diagnosis of AIHA.