Comparative Analysis of Fluorescence In Situ Hybridization and Real Time Polymerase Chain Reaction in Diagnosis of Chronic Myeloid Leukemia.

OBJECTIVE: To compare the sensitivity and specificity of fluorescence in situ hybridization (FISH) with real time polymerase chain reaction (RT-PCR) in the diagnosis of Chronic Myeloid Leukemia (CML). STUDY DESIGN: A cross-sectional, analytical study. PLACE AND DURATION OF STUDY: Haematology Department, Armed Forces Institute of Pathology, Rawalpindi, from January 2012 to February 2014. METHODOLOGY: A total number of 87 patients of CML were studied. The diagnosis was made on the basis of clinical history, peripheral blood and bone marrow aspiration. These patients were tested for the presence of BCR-ABL1 fusion gene by RT-PCR and FISH. About 5 ml of venous blood was collected, half was taken in heparin for FISH and half in ethylenediamine tetra-acetic acid (EDTA) for CBC and PCR. For FISH, cells were cultured for 24 hours in RPMI 1640 medium and evaluated using BX51 fluorescence microscope for dual fusion signal of yellow colour. Samples having 20 or more interphases positive for dual fusion signals were taken as positive. For PCR, RNA extraction was done by Tri-Reagent LS (MRC, USA) and cDNA was synthesized using reverse transcriptase and gene specific primer. RT-PCR was done on ABI-7500. The positive samples were identified when fluorescence exceeded threshold limit. Results of RT-PCR and FISH were compared. RESULTS: Out of the 87 patients, 85 (97.7%) were PCR positive and 2 (2.3%) were PCR negative, whereas in FISH 83 (95.4%) were positive and 4 (4.5%) were negative. Sensitivity and specificity of FISH was 97.6% and 100%, respectively. CONCLUSION: FISH is a reliable supplementary method to PCR for detection of BCR-ABL1 fusion gene in the diagnosis of CML.

Immature Reticulocyte Fraction and Absolute Neutrophil Count as Predictor of Hemopoietic Recovery in Patients with Acute Lymphoblastic Leukemia on Remission Induction Chemotherapy.

OBJECTIVE: Acute lymphoblastic leukemia (ALL) encompasses a group of lymphoid neoplasms that are more common in children and arise from B-and T-lineage lymphoid precursor cells. The immature reticulocyte fraction (IRF), a new routine parameter in hematology analyzers, can give an indication of hemopoietic recovery like absolute neutrophil count (ANC). The purpose of this study was to evaluate IRF in excess of 5% was considered as IRF recovery. MATERIALS AND METHODS: In this descriptive study, 2.5 to 3 mL of EDTA blood of 45 ALL patients undergoing the remission induction phase of their treatment was sampled and analyzed with a Sysmex XE-5000 on day 1 and every second day thereafter until the day of recovery. ANC of >0.5x109/L on the day corresponding to the first of the three consecutive counts was considered as the day of ANC recovery. IRF recovery was an IRF in excess of 5%. RESULTS: The mean age of the patients was 12.04±5.30 years; 25 patients (55.6%) were male and 20 patients (44.4%) were female. On day 1 of induction remission, the mean IRF value was 9.68±1.41, while the mean ANC value was 0.077±0.061. Mean recovery day for IRF was 11.84±7.44 and mean recovery day for ANC was 17.67±8.77 (two- tailed p-value <0.0001 with 95% confidence interval). By day 28, out of 45 patients 36 (80%) showed ANC recovery, while 41 (91%) showed IRF recovery. The remaining patients who had not shown recovery by day 28 were further followed up and all of them showed recovery of both parameters by day 39. CONCLUSION: This study concluded that postinduction bone marrow hemopoietic recovery was earlier by IRF than ANC in children with ALL on chemotherapy.