Abstract
Karyotype, bone marrow blast percentage and cytopenia influence the prognosis of myelodysplastic syndrome. We studied the abnormalities detected by fluorescence in situ hybridization (FISH) in myelodysplastic syndrome and associated haematological profile with abnormalities detected by FISH. Complete blood counts, peripheral blood and bone marrow of patients were evaluated for cytopenia, dysplasia and blasts. FISH probes were used to detect del(5q), gain of chromosome 8, de (7q/-7) and del(20 q). Multiple regression analysis was used to study the association of FISH abnormalities, age and sex with haematological profile. Mc Nemar's test studied the relationship between FISH abnormalities and dysplastic features in bone marrow. Cytogenetic abnormalities were detected by FISH in 25.7% of patients. Del(20 q) was seen in 14.2% of patients. FISH was able to predict changes in peripheral blood blast count by 80% (p ? 0.0001). Cytogenetic abnormalities were not seen in 74.2% of patients. Groups with FISH abnormalities have a different haematological profile, and these abnormalities have a significant effect on blast percentage.
Lay description Background: Fluorescence in situ hybridization (FISH) and light microscopy of bone marrow and peripheral blood play an important role in classification and prognostication of myelodysplastic syndrome. However statistical relationship between morphological findings as seen in light microscopy, cytogenetic abnormalities visualized by FISH microscopy and hematological parameters have not been discussed previously. Materials: In this study, we evaluated peripheral blood and bone marrow from 35 patients with myelodysplastic syndrome by light microscopy and FISH microscopy using FISH probes del(5q), gain of chromosome 8, del(7q/-7) and del(20 q). Based on cytogenetic abnormalities detected by FISH, we had two groups- one without (Group 1) and other with (Group 2) cytogenetic abnormalities. Association of hematological findings (hemoglobin level, total leucocyte count, platelet count, blast percentage in peripheral blood and bone marrow), age and sex with cytogenetic abnormalities was studied by multiple regression analysis. Furthermore, we analysed the significance of finding dysplastic changes in bone marrow with detection of cytogenetic abnormalities. Results: By morphologic evaluation, 57.1% had dysplastic findings in various lineages. Cytogenetic abnormalities were seen in 25.7% of patients with myelodysplastic syndrome and del(20q) was the commonest abnormality seen. Only blast percentage in peripheral blood showed a significant association (p ? 0.0001) with cytogenetic abnormalities, sex and age. None of the other hematological parameters showed significant association with cytogenetic abnormalities. Results of Mc Nemar's test indicate that there is a significant difference between patients exhibiting dysplasia by light microscopy and those with cytogenetic abnormalities detected by FISH. Conclusion: 74.2% of patients with myelodysplastic syndrome have no cytogenetic abnormalities. del(20q) followed by gain of chromosome 8 were the commonest cytogenetic abnormalities. None of the cytogenetic abnormalities along with sex and age are predictive of hemoglobin level, total leucocyte counts or platelet counts. Light microscopy and FISH microscopy though mutually exclusive at times are together indispensable in the diagnosis as well as prognostication of myelodysplastic syndrome.