Significance And Expression Of CD4⁺CD25⁺CD127^low Regulatory T Cells,Notch1 Pathway And TGF-β In Patients With Idiopathic Thrombocytopenic Purpura

Objective To detect the expression levels of CD4⁺CD25⁺CD127^lowTreg cells, TGF-βand Notchl-mRNA in peripheral blood of the patients with ITP in pre-treatment and post-treatment period, and to investigate their significance and pathogenesis.Methods Peripheral blood was selected from thirty patients with ITP and twenty normal controls, then the number of CD4⁺CD25⁺CD127^lowTregs,CD4⁺CD25⁺Tregs was detected by the immunofluorescence and flow cytometry; plasma TGF-βlevel was determined by Enzyme-linked immunoad Sorbent assay; total RNA was extracted and the expression level of Notch1 mRNA was measured by real-time quantitativereverse transcription polymerase chain reaction.Results 1. The expression levels of CD4⁺CD25⁺CD127^lowTreg and CD4⁺CD25⁺Treg in initial ITP group were significantly lower than those of normal controls, which were (2.87%±0.91%)VS(3.81%±0.95%) and (6.33%±0.96%)VS(7.70%±0.86%); After therapy, proportion of Tregs increased to (5.17%±0.74%) and (4.16%±0.68%), but still lower compared with normal controls (p<0.01). The levels of Tregs in excellence group were higher than satis and progress group, and them in satis and progress group were higher than ineffective group(p<0.01). 2. Density of TGF-βin initial ITP group (460.10±30.55)(ng/l) was obviously lower than normal controls (1545.61±44.36)(ng/l); After therapy, the density of TGF-βincreased to (961.53±60.10) (ng/l), but still lower compared with normal controls (p<0.01). The level of TGF-βin excellence group was higher than satis and progress group, moreover them in satis and progress group was higher than ineffective group(p<0.05). 3. The expression of Notch1 mRNA in initial ITP group (0.45±0.04) was obviously lower than normal controls (2.71±0.44); After therapy, the expression of Notch1 mRNA increased to (1.35±0.10), but still lower compared with normal controls(p<0.01). The level of T Notch1 in excellence group was higher than satis and progress group, moreover them in satis and progress group was higher than ineffective group(p<0.01). 4. The expression levels of TGF-βand Notchl in ITP patients were correlated to CD4⁺CD25⁺CD127^lowTreg cell (p<0.01).Conclusion 1. The levels of CD4⁺CD25⁺CD127^low Tregs, Notchl-mRNA and TGF-βin peripheral blood of the patients with ITP were significantly lower than those of normal control; decrease of the three indexes indicated that ITP patients existed obvious cellular imunologic abnormality which might be closely related to the occurrence and development of ITP. 2. ITP patients existed intimate correlation between the levels of CD4⁺CD25⁺CD127^low Tregs and Notch1 gene, which indicated that Notch signal might be revalent to Treg's immunosuppression function.