Sarina Levy-Mendelovich1,2,3, Shraga Aviner4,5, Nechama Sharon6,7, Hagit Miskin8, Joanne Yacobovich9, Gili Kenet10,11,12, Hagit Hauschner13, Nurit Rosenberg10,11,12. 1. Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. Levysarina@gmail.com. 2. The Israeli National Hemophilia Center and Thrombosis Unit, Sheba Medical Center, Tel Hashomer, Israel. Levysarina@gmail.com. 3. Amalia Biron Research Institute of Thrombosis and Hemostasis, Sheba Medical Center, Tel Hashomer, Israel. Levysarina@gmail.com. 4. Department of Pediatrics, Barzilai University Medical Center, Ashkelon, Israel. 5. The Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel. 6. Pediatric Hemato-oncology Department, Laniado Hospital, Netanya, Israel. 7. Ruth and Bruce Rappaport Faculty of Medicine, Technion, Haifa, Israel. 8. Pediatric Hematology Unit, Shaare Zedek Medical Center, affiliated with the Faculty of Medicine, Hebrew University, Jerusalem, Israel. 9. Schneider Pediatric Hospital, affiliated with the Sackler School of Medicine, Tel Aviv University, Petach Tikvah, Israel. 10. Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. 11. The Israeli National Hemophilia Center and Thrombosis Unit, Sheba Medical Center, Tel Hashomer, Israel. 12. Amalia Biron Research Institute of Thrombosis and Hemostasis, Sheba Medical Center, Tel Hashomer, Israel. 13. Scientific Equipment Center, The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel.
Abstract
BACKGROUND: In all, 15-30% of pediatric immune thrombocytopenia (ITP) patients will remain chronically thrombocytopenic at 1 year post diagnosis. All attempts to classify patients at diagnosis have proven unsuccessful. We hypothesized that a different pathophysiology is responsible for non-chronic versus chronic pediatric ITP. We aimed to examine differences in the apoptotic markers' presentation at diagnosis between non-chronic and chronic patients. METHODS: Blood samples were collected from 42 pediatric patients with newly diagnosed ITP prior to initiation of treatment. We incubated patients' sera with control platelets and compared the results among three research groups: healthy controls, chronic ITP, and non-chronic ITP patients. We measured apoptotic markers phosphatidylserine (PS) exposure and mitochondrial inner membrane potential (ΔΨm) by flow cytometry and the level of human apoptotic proteins by Human Apoptosis Array. RESULTS: We found increased platelet PS exposure and decreased ΔΨm in response to all ITP patients' sera compared to control subjects. Human Apoptotic Array revealed an increased expression of five apoptotic proteins: BIM, CD40, IGFBP2, P21, and SMAC, following sera incubation of non-chronic pediatric ITP patients, compared to chronic patients' sera, at diagnosis. CONCLUSIONS: Our data contribute to knowledge on apoptosis markers that may aid in predicting the prognosis of children with ITP. IMPACT: The key message of our article is that children with chronic ITP have a different apoptotic profile compared to non-chronic ITP. Addition to existing literature: This is the first study comparing apoptotic markers between children with chronic ITP to non-chronic ITP. IMPACT: Our findings indicate that, in the future, apoptotic markers may help to classify ITP patients into non-chronic versus chronic ones, at diagnosis.
BACKGROUND: In all, 15-30% of pediatric immune thrombocytopenia (ITP) patients will remain chronically thrombocytopenic at 1 year post diagnosis. All attempts to classify patients at diagnosis have proven unsuccessful. We hypothesized that a different pathophysiology is responsible for non-chronic versus chronic pediatric ITP. We aimed to examine differences in the apoptotic markers' presentation at diagnosis between non-chronic and chronic patients. METHODS: Blood samples were collected from 42 pediatric patients with newly diagnosed ITP prior to initiation of treatment. We incubated patients' sera with control platelets and compared the results among three research groups: healthy controls, chronic ITP, and non-chronic ITP patients. We measured apoptotic markers phosphatidylserine (PS) exposure and mitochondrial inner membrane potential (ΔΨm) by flow cytometry and the level of human apoptotic proteins by Human Apoptosis Array. RESULTS: We found increased platelet PS exposure and decreased ΔΨm in response to all ITP patients' sera compared to control subjects. Human Apoptotic Array revealed an increased expression of five apoptotic proteins: BIM, CD40, IGFBP2, P21, and SMAC, following sera incubation of non-chronic pediatric ITP patients, compared to chronic patients' sera, at diagnosis. CONCLUSIONS: Our data contribute to knowledge on apoptosis markers that may aid in predicting the prognosis of children with ITP. IMPACT: The key message of our article is that children with chronic ITP have a different apoptotic profile compared to non-chronic ITP. Addition to existing literature: This is the first study comparing apoptotic markers between children with chronic ITP to non-chronic ITP. IMPACT: Our findings indicate that, in the future, apoptotic markers may help to classify ITP patients into non-chronic versus chronic ones, at diagnosis.
Authors: Valery Leytin; Sergiy Mykhaylov; Alison F Starkey; David J Allen; Herbert Lau; Heyu Ni; John W Semple; Alan H Lazarus; John Freedman Journal: Br J Haematol Date: 2006-04 Impact factor: 6.998