Analysis On Safety And Efficacy Of Stem Cells From Human Exfoliated Deciduous Teeth In Treating Diabetics With Different Islet Function

BackgroundEpidemiological survey shows that the incidence rate of diabetes mellitus is increasing year by year.With the disease progression,the islet function of diabetic patients will decrease progressively,resulting in intractable hyperglycemia and increased glucose fluctuation,which will further aggravate islet dysfunction and finally form a vicious circle.At present,the common hypoglycemic treatment measures,such as lifestyle improvement,oral hypoglycemic drugs,subcutaneous injection of glucagon like peptide-1 receptor agonist or insulin can effectively control the blood glucose,but fail to effectively repair the progressive islet dysfunction.Promoting the regeneration of isletβcells and restoring the function of endogenous insulin secretion is an ideal method for diabetes treatment.Stem cells have the potential to restore the islet function,which are hope for diabetes treatment.Mesenchymal stem cells are kinds of stem cells which not only have the common characteristics of stem cells,such as self-renewal and multi-directional differentiation,but also have many other advantages such as immune regulation,low immunogenicity,multiple sources and so on,thus attracting extensive attention.Mesenchymal stem cells come from variable sources,including bone marrow,placenta,umbilical cord,dental pulp and so on,and the characteristics of different tissue-derived mesenchymal stem cells are not exactly same.For example,dental pulp stem cells from human natural deciduous teeth not only have stronger proliferation,differentiation and repair ability,but also have sufficient sources,simple access and no ethical controversy,which provide new choices for diabetes treatment.Our research team has confirmed and reported the effectiveness and mechanism of stem cells from human exfoliated deciduous teeth in the treatment of diabetic rats,but there is no relevant clinical research report.Stem cell therapy for diabetic patients is also in process of exploration,and no consensus has been reached.In order to confirm its clinical efficacy,we conducted allogeneic stem cells from human exfoliated deciduous teeth infusion through peripheral vein in diabetic patients for the first time,adjusted the treatment plan according to islet function,and observed the adverse reactions and therapeutic effects.ObjectiveTo evaluate the safety and efficacy of stem cells from human exfoliated deciduous teeth in diabetes treatment,and explore the stem cell treatment plan for patients with different islet function status,thus providing new choices for diabetes treatment,providing new ideas and methods for the development of relevant research and clinical work.Methods1.24 type 2 diabetic patients were selected from the endocrinology department of Shanghai Changhai hospital from May to August 2018.Screening period lasted for 1 week.During this period,various tests were carried out and the test values were the baseline values of this study.The treatment period lasted for 6 weeks.During this period,the patients were infused with stem cells from human exfoliated deciduous teeth through peripheral vein 3 times at the time of enrollment,1 week and 4 weeks after the first infusion separately.Each infusion dose was 0.1U/kg body weight,and each unit contained1.0×10~7 stem cells.There were 3 follow-up visits during the treatment period,which were1 week after the first treatment,2 weeks after the second and the third treatment separately.The follow-up period lasted for 1 year.There were 4 follow-up visits,which were 1 month,3 months,6 months and 12 months after the end of the treatment period separately.2.20 diabetic patients with significant islet dysfunction were selected from the endocrinology department of Shanghai Changhai hospital from February 2019 to June2020.Screening period lasted for 1 week.During this period,various tests were carried out.The adjustment period lasted for 3 weeks.During this period,only the lifestyle and insulin dose were adjusted without changing the type and dose of oral drugs.The treatment period lasted for 26 weeks.During this period,stem cell therapy was divided into two stages.The first 3 infusions time were the time of formal enrollment,2 weeks and 6 weeks after the first treatment separately.This was the first stage of treatment.6 weeks after the third infusion,patients who stopped insulin received another stem cell infusion,otherwise they received another 3 stem cell infusions with an interval of 6 weeks.This was the second stage of treatment.All 20 patients in this study received 6 stem cell treatments.Each infusion dose was 0.11U/kg body weight,and each unit contained 1×10~7 stem cells.There were 6 follow-up visits during the treatment period,which were 2 weeks after the first treatment,3 weeks after the second treatment,5 weeks after the third,fourth and fifth treatment and 2 weeks after the sixth treatment separately.3.The hypoglycemic therapy of patients remained consistent before and after enrollment.During the study,only the insulin dose was adjusted in time according to the blood glucose level of patients,while the type,dose and medication method of oral hypoglycemic drugs were not adjusted(except for relevant side effects or hypoglycemia after stopping insulin during the study).4.Blood routine,blood biochemistry,blood lipid profile,glycosylated hemoglobin(Hb A1c),glycosylated albumin(GA),continuous blood glucose monitoring,steamed bread meal test and insulin release test were performed at the follow-up visits.In addition,at follow-up visits of the second batch patients,the serum samples were taken at fasting,1hour and 2 hours after steamed bread meal and stored in the refrigerator at-80℃.The cytokine level was detected uniformly after all treatments.The inflammatory factors included interleukin-1β(IL-1β),interleukin-6(IL-6)and monocyte chemoattractant protein-1(MCP-1).The oxidative stress factors included paraoxonase-1(PON-1)and malondialdehyde(MDA).The daily dose of insulin was recorded in detail during the study.5.The daily dose of insulin was the main efficacy evaluation index.Insulin daily dose reduction≥50%or discontinuation of insulin is significantly effective;reduction≥20%but<50%is effective;reduction<20%is ineffective;total effective rate=significantly effective rate+effective rate.Hb A1c,c-peptide and time in range(TIR)were secondary efficacy evaluation indexes.6.SPSS 23.0 statistical software was used to analyze the trend of each index during the study.Patients who received the same treatment were grouped and compared.Results1.Type 2 diabetic patients(1)24 type 2 diabetic patients included 19 males and 5 females,with an average age of 55.96±4.81 years and an average insulin dose of 39.00±14.19U/d.2 patients withdrew after the second follow-up visit due to personal reasons in the follow-up period.(2)During the study,the daily dose of insulin decreased significantly(p<0.001).Compared with baseline,the insulin reduction at the end of treatment period,6 months and12 months after the end of treatment period were 28.89%,42.72%and 38.72%respectively,and the total effective rates were 86.36%,81.82%and 68.18%respectively.3 patients stopped using insulin,and did not use insulin by the end of follow-up period.(3)Compared with baseline,the GA level decreased significantly after each stem cell treatment and 1 month after the end of treatment period(all p<0.05);the Hb A1c level decreased significantly at the end of treatment period and 3 months after the end of treatment period(both p<0.001);the level of total cholesterol(TC)decreased significantly after each stem cell treatment and 1 month after the end of treatment period(all p<0.05);the level of low-density lipoprotein cholesterol(LDL-C)decreased significantly after the second,third stem cell treatment and 1 month after the end of treatment period(all p<0.05);the level of 2 hours postprandial c-peptide after steamed bread meal increased significantly at the end of treatment period(p<0.001);TIR increased significantly after each stem cell treatment(all p<0.05).(4)Patients were grouped according to islet function.There was no difference in insulin dose and TIR between groups at baseline.After stem cell treatments,the daily insulin dose reduction was more obvious in patients with baseline FCP>1.21ng/m L than patients with baseline FCP≤1.21ng/m L(p<0.05),and the TIR of patients with baseline P1h CP≥2.63ng/m L,baseline P2h CP≥3.44ng/m L was higher than that in patients with baseline P1h CP<2.63ng/m L,baseline P2h CP<3.44ng/m L respectively(both p<0.05).Patients were grouped according to blood lipid level.There was no difference in insulin dose between groups at baseline.After stem cell treatments,the insulin dose reduction was more obvious in patients with baseline TC≤5.34mmol/L,baseline LDL-C≤3.25mmol/L than that in patients with baseline TC>5.34mmol/L,baseline LDL-C>3.25mmol/L respectively(both p<0.05).It was speculated that islet function and blood lipid level affected the clinical efficacy of stem cell.(5)Hypoglycemia was the most common adverse reaction during the study period.Other adverse reactions included fever,fatigue and rash,which improved after symptomatic treatment and no serious adverse reactions occurred.2.Diabetic patients with significant islet dysfunction(1)20 diabetic patients with significant islet dysfunction included 15 males and 5females,with an average age of 51.05±11.26 years and an average insulin dose of34.70±12.82U/d.(2)After stem cell treatments,the daily dose of insulin decreased significantly(p<0.001).The total effective rates after 6 stem cell infusions were 20%(4/20),65%(13/20),70%(14/20),80%(16/20),80%(16/20)and 75%(15/20)respectively.2 patients stopped using insulin after the fourth and fifth stem cell infusion respectively.(3)Compared with baseline,the Hb A1c and GA level after stem cell infusion decreased significantly(both p<0.05).The high-density lipoprotein cholesterol,fasting c-peptide and TIR increased significantly(all p<0.05).The fasting IL-6,IL-1β,MDA and 1hour postprandial MDA level decreased significantly(all p<0.05).(4)Patients were grouped according to islet function.There was no difference in TIR between groups at baseline.But after stem cell treatments,the TIR of patients with baseline FCP≥0.44ng/m L,baseline P2h CP>1.20ng/m L was higher than that in patients with baseline FCP<0.44ng/m L,baseline P2h CP≤1.20ng/m L respectively(both p<0.05).There was no efficacy difference between groups after dividing and comparing patients according to TC,LDL-C and other indicators.It was speculated that islet function affected the clinical efficacy of stem cell.(5)Hypoglycemia was still the most common adverse reaction,while other adverse reactions did not occur.Conclusions1.This study is the first clinical study of peripheral venous infusion of stem cells from human exfoliated deciduous teeth in the treatment of diabetic patients.The treatment is simple and safe,which will not cause serious adverse reactions.2.Stem cells from human exfoliated deciduous teeth can effectively improve the diabetic patients’glucose metabolism,lipid metabolism and islet function.It can reduce the patients’insulin dose,and even some patients can stop using insulin after a short period of treatment.3.The inflammation and oxidative stress cytokine level in diabetic patients decrease significantly after treatment of stem cells from human exfoliated deciduous teeth.4.Islet function status is one of the important factors affecting the efficacy of stem cells from human exfoliated deciduous teeth in treatment of diabetes mellitus.