Multiparameter flow cytometry in haematological malignancies
Date
2011-10-31
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Abstract
Läbivoolu tsütomeetria on moderne laseril põhinev meetod, mille abil on võimalik iseloomustada rakkude koostist, suurust ja granulaarsust. Hematoloogiliste patsientide punktaadid lümfisõlmedest ja luuüdist on ideaalsed substraadid, mida saab uurida läbivoolu tsütomeetrilisel meetodil. Läbivoolu tsütomeetria abil on võimalik suurte rakkude populatsioonide hulgast üles leida väike hulk rakke, mis eristuvad teatud kindla tunnuse, näiteks rakupinna markeri järgi. Uuemate monoklonaalsete antikehade abil on võimalik täpsemalt uurida erinevaid vereloomest pärinevaid rakke ja nende muutusi ravi käigus. Uurimistöös hindasime läbivoolu tsütomeetria rakendatavust pahaloomuliste hematoloogiliste haiguste korral. Uurisime läbivoolu tsütomeetria kasulikkust lümfoomide diagnostikas peennõelbiopsial saadud materjalist. Samuti uurisime noortel ägeda müeloidse leukeemiaga täiskasvanutel minimaalse residuaalse haiguse olemasolu keemiaravi käigus ja keemiaravi lõppedes ning selle prognostilist tähtsust. Hindasime veel dendriitiliste rakkude arvu ägeda lümfoblastse leukeemiaga lastel haiguse diagnoosimisel ja rakkude taastumist luuüdis keemiaravi ajal. Töö tulemused näitasid, et läbivoolu tsütomeetria abil on võimalik 97% täpsusega eristada healoomulist lümfoidset hüperplaasiat maliigsetest lümfoomidest ja maliigseid lümfoome täpsemalt klassifitseerida 90% juhtudest. Leidsime, et minimaalse residuaalse haiguse olemasolu ägeda müeloidse leukeemia ravi lõppedes on väga halva prognostilise tähendusega ja haigete prognoosi parandab vaid vereloome tüvirakkude siirdamine. Uurimistöö näitas samuti, et ägeda lümfoblastse leukeemiaga lastel on dendriitilisi rakke luuüdis haiguse diagnoosimisel väga vähe. Dendriitilised rakud taastuvad referentsväärtusteni induktsioonravi lõppedes seitsmendal ravinädalal, kuid pikaaegne keemiaravi kahjustab standardriskigrupi lastel müeloidseid dendriitilisi rakke. Nende arv langes keemiaravi lõppedes uuesti ja nende hulk jäi madalaks ka kuus kuud peale keemiaravi lõppu. Kokkuvõttes näitas uurimistöö, et läbivoolu tsütomeetria on oluline meetod pahaloomuliste verehaiguste diagnoosimisel, ravitulemuste ja ravimõjude hindamisel.
Multiparameter flow cytometry is a modern laser-based technology that is used to characterize a cell characteristics, size and granularity. Aspirates from lymph nodes and bone marrow form haematological patients are ideal sources of material for flow cytometry studies. Flow cytometry is a sensitive method to detect the defined small cell population within large cellular background according to specific, for example cell surface marker. With new monoclonal antibodies it is possible to explore various cell types of the haematopoietic system and follow their changes during treatment. In the present study we evaluated the usefulness of flow cytometry in haematological malignancies. We investigated the value of flow cytometry in lymphoma diagnosis in fine-needle aspiration material. We also investigated the presence of minimal residual disease in young adult acute myeloid leukemia patients during and at the end of chemotherapy and its prognostic relevance. In addition, we evaluated the dendritic cells levels at diagnosis and their pattern of regeneration in bone marrow of children treated for acute lymphoblastic leukemia. Results of our study showed that in 97% of samples flow cytometry was able to distinguish the reactive lymphoid hyperplasia from malignant lymphoma and allowed precise lymphoma classification in 90% of samples. We found that the presence of minimal residual disease at the end of acute myeloid leukemia chemotherapy shows dismal prognosis which could be improved only by haematopoietic stem cell transplantation. Our study also showed that children with acute lymphoblastic leukemia have a severe deficiency of dendritic cells in bone marrow at diagnosis. Dendritic cell levels regenerate to reference levels by the induction treatment at week seven, but long-term chemotherapy affects myeloid dendritic cells in standard-risk group children. Their number decreased again significantly and remained reduced even at six month after the end of treatment. In summary this study demonstrated that flow cytometry is a valuable tool in diagnostics of haematological malignancies and in evaluating treatment responses and effects.
Multiparameter flow cytometry is a modern laser-based technology that is used to characterize a cell characteristics, size and granularity. Aspirates from lymph nodes and bone marrow form haematological patients are ideal sources of material for flow cytometry studies. Flow cytometry is a sensitive method to detect the defined small cell population within large cellular background according to specific, for example cell surface marker. With new monoclonal antibodies it is possible to explore various cell types of the haematopoietic system and follow their changes during treatment. In the present study we evaluated the usefulness of flow cytometry in haematological malignancies. We investigated the value of flow cytometry in lymphoma diagnosis in fine-needle aspiration material. We also investigated the presence of minimal residual disease in young adult acute myeloid leukemia patients during and at the end of chemotherapy and its prognostic relevance. In addition, we evaluated the dendritic cells levels at diagnosis and their pattern of regeneration in bone marrow of children treated for acute lymphoblastic leukemia. Results of our study showed that in 97% of samples flow cytometry was able to distinguish the reactive lymphoid hyperplasia from malignant lymphoma and allowed precise lymphoma classification in 90% of samples. We found that the presence of minimal residual disease at the end of acute myeloid leukemia chemotherapy shows dismal prognosis which could be improved only by haematopoietic stem cell transplantation. Our study also showed that children with acute lymphoblastic leukemia have a severe deficiency of dendritic cells in bone marrow at diagnosis. Dendritic cell levels regenerate to reference levels by the induction treatment at week seven, but long-term chemotherapy affects myeloid dendritic cells in standard-risk group children. Their number decreased again significantly and remained reduced even at six month after the end of treatment. In summary this study demonstrated that flow cytometry is a valuable tool in diagnostics of haematological malignancies and in evaluating treatment responses and effects.
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Keywords
pahaloomulised kasvajad, vere- ja vereloomeelundite haigused, monoklonaalsed antikehad, läbivoolu tsütomeetria, malignant neoplasms, hematopoietic system, monoclonal antibodies, flow cytometry