Telomere Of Lymphocytes And CD34~+Cells Of The Patients With Autoimmune Bone Marrow Failure Disease

Autoimmune disease is a group of large amount of autoantibodies and autoreactive T cells induced disease, the pathogenesis is not clear. But T cell activation of autoimmune mediated is central point. Telomere is a special structure at the ends of linear chromosomes, providing buffer of non transcribed DNA, preventing chromosome degradation, end-to-end fusion, fracture and recombination, protecting gene integrity, regulating cell growth, and closely relating to apoptosis, transformation, immortality. Telomere length determined the cell cycle, except cancerous cells, in the process of proliferation and differentitation, telomere shorteing slowly.In recent years, in autoimmune diseases, there is abnormal shortened telomere. And autoimmune bone marrow failure disease is a kind of acquired, mediated by immunity, bone marrow nucleated cells hypoplasia, pancytopenia disease, manifested as anemia, hemorrhage, infection, included immuno-related pancytopenia and aplastic anemia. So in our study mainly include the following two aspects:Part1Telomere of lymphocytes and CD34+bone marrow cells of the patients with immuno-related pancytopeniaObjective:To investigate the changes of relative telomere length(RTL) of peripheral blood CD3+T,CD3+CD4+T,CD3+CD8+T and CD19+B lymphocytes and CD34+bone marrow cells of the patients with untreated immuno-related pancytopenia (IRP) and explore the role of RTL in IRP.Methods:Forty untreated IRP patients and38healthy controls with the same race, living area, gender and age were enrolled in this study. The peripheral blood CD3+T, CD3+CD4+T, CD3+CD8+T, CD19+B lymphocytes and CD34+bone marrow cells were separated by magnetic activated cell sorting (MACS), and their relative telomere lengths(RTLs) were measured with flow-fluorescence in situ hybridization.Results:1. The RTL of CD3+T, CD3+CD4+T and CD3+CD8+T lymphocytes of untreated IRP patients were (27.7544±16.3229)%,(7.5257±3.7453)%and (25.8543±14.7887)%, which were significantly shorter than those of healthy controls (54.5549±19.7822)%, (12.0958±2.8048)%and (38.3670±4.6257)%(P<0.05). The RTL of CD19+lymphocytes of untreated IRP patients was (22.1360±16.1415)%, which was significantly shorter than that of healthy controls (42.8457±16.3533)%(P<0.01). There was no significant difference of RTL in CD34+bone marrow cells between the untreated IRP patients (22.5284±21.6009)%and the healthy controls (23.9364±19.8224)%(P>0.05).2. There were significant positive correlations between the RTL of B lymphocytes and the count of WBC (r=0.706,P=0.015); and there were negative correlations between RTL of B lymphoyces and the severity of illness Index (r=-0.613,P=0.045), otherwise,positive correlations with therapeutic effect (r=0.775,P=0.005).Conclusion:The shorter RTL of CD3+, CD3+CD4+, CD3+CD8+and CD19+lymphocytes, and is closely related to the white blood cell count, severity of illness and the therapeutic effect, while no obvious abnormal of RTL in bone marrow CD34+cells were found, which might imply that IRP is a kind of acquired autoimmune diseases, rather than a clone disease. The telomere length abnormality of lymphocytes further provides clues for prevention and therapeuti in the hands of IRP.Part2Telomer of lymphocytes and CD34+bone marrow cells of the patients with severe aplastic anemiaObjective:To investigate the change of relative telomere length(RTL) of peripheral blood CD3+T,CD3+CD4+T,CD3+CD8+T and CD19+B lymphocytes and CD34+bone marrow cells of the patients with untreated severe aplastic anemia (SAA) and explore the pathogenic mechanism of SAA.Methods:Twenty-nine untreated SAA patients and32healthy control with the same race, living area, gender and age were enrolled in this study. The peripheral blood CD3+T, CD3+CD4+T, CD3+CD8+T, CD19+B lymphocytes and CD34+bone marrow cells were separated by magnetic activated cell sorting (MACS), and their relative telomere lengths(RTLs) were measured with flow-fluorescence in situ hybridization.Results:1.The RTL of CD3+T, CD3+CD4+T, CD3+CD8+T lymphocytes of untreated SAA separately were (21.0376±15.3885)%,(8.2019±2.7142)%,(16.0670±11.7219) shorter than healthy donors [(54.5549±19.7822)%,(13.6251±1.5533),(38.7257±2.8303)%](P<0.01). The RTL of CD19+lymphocytes of untreated SAA were (40.6227±6.3068)%, compared with the healthy donors(42.8457±16.3533)%were no statistically difference(P>0.05). The RTL of CD34+bone marrrow cells of untreated SAA were (25.6248±19.8564)%, and the healthy donors were (23.9364±19.8224)%, both no statisticance difference (P>0.05).2.There were negative correlations between RTL of CD3+CD8+T lymphoyces and the quantity of clinical feature (r=-0.791,P=0.034), while there were no relationship between RTL of CD3+CD8T lymphocytes and white blood count, hemoglobin level, platelet count, reticulocyte proportion, viral infection, immune abnomalities and curative effect.Conclusion:The shorter RTL of CD3+T, CD3+CD4+T and CD3+CD8T lymphocytes in untreated SAA were found, while no obvious abnormal of RTL in CD19+B cells and bone marrow CD34+cells, which might imply that SAA is a kind of acquired diseases, rather than congenital or cloning, and further confirmed that cell immunity mechanism of pathogenesis of SAA.