ABSTRACT
Introduction: Gaps still exist regarding knowledge on regulatory cells in transplant recipients. We studied the phenotypic patterns of CD4+, CD8+CD28- Tregs, and CD19+IL-10+ Bregs in the blood of healthy controls (HC), end-stage kidney disease patients (ESKD), early and late stable renal transplant recipients (Tx), and transplant recipients with steroid-treated acute cellular rejection 1 week-3 months after successful treatment. We also investigated the relationship between immunosuppressive drugs and the aforementioned regulatory cells in transplant recipients. Methods: We recruited 32 HC, 83 ESKD, 51 early Tx, 95 late Tx, and 9 transplant patients with a recent steroid-treated acute cellular rejection. Besides CD19+IL-10+ Bregs, we analyzed absolute and relative frequencies of CD4+CD25+CD127-Foxp3+ Tregs and CD8+CD28- Tregs and their expression of IL-10, TGF-ß, IFN-g, and Helios. Results: We found a negative correlation between absolute CD4+CD25+CD127-Foxp3+ Treg and relative CD19+IL-10+ Breg frequencies in early Tx recipients (r=-0.433, p=0.015, n=31). In that group, absolute CD4+CD25+CD127-Foxp3+ Tregs were negatively associated with steroid dose and tacrolimus trough levels (r=-0.377, p = 0.021, n=37; r=-0.43, p=0.033, n=25, respectively), opposite to IL-10+ Bregs, whose frequency apparently was not negatively affected by potent immunosuppression early posttransplant. We found also lower CD4+CD25+CD127-Foxp3+ Tregs in patients treated with basiliximab or rATG as compared with ESKD patients (p=0.001 and p <0.001, respectively). No difference in absolute IL-10+ Bregs could be detected among these 3 patient groups. Early Tx recipients showed lower CD4+CD25+CD127-Foxp3+ Tregs within 3 months of antibody induction than after 3 months (p = 0.034), whereas IL-10+ Bregs showed higher relative counts during the first 3 months post antibody induction than after 3 months (p = 0.022). Our findings suggest that IL-10+ Bregs decrease with time posttransplantation independent of the effect of antibody induction and dose of other immunosuppressive drugs. Conclusion: These findings suggest that CD19+IL-10+ Bregs and CD4+CD25+CD127-Foxp3+ Tregs behave in opposite ways during the early posttransplant period, possibly due to a predominant negative impact of high doses of immunosuppressants on Tregs. CD19+IL-10+Bregs do not seem to be suppressed by antibody induction and early potent immunosuppression with chemical drugs.
Subject(s)
Kidney Transplantation , T-Lymphocyte Subsets/immunology , T-Lymphocyte Subsets/metabolism , T-Lymphocytes, Regulatory/immunology , T-Lymphocytes, Regulatory/metabolism , Transplant Recipients , Adult , Antigens, Surface/metabolism , B-Lymphocytes, Regulatory/drug effects , B-Lymphocytes, Regulatory/immunology , B-Lymphocytes, Regulatory/metabolism , CD8-Positive T-Lymphocytes/drug effects , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/metabolism , Case-Control Studies , Cell Communication/immunology , Cytokines/metabolism , Female , Humans , Immunophenotyping , Immunosuppressive Agents/pharmacology , Immunosuppressive Agents/therapeutic use , Kidney Transplantation/adverse effects , Kidney Transplantation/methods , Lymphocyte Count , Male , Middle Aged , T-Lymphocytes, Regulatory/drug effectsABSTRACT
Objective: The study was designed to evaluate the changes and significance of circulating CD4~+CD25~+ and CD8~+CD28~- regulatory T cells (Tregs) in patients with multiple myeloma (MM).Methods:CD4~+CD25~+ and CD8~+CD28~-Tregs in peripheral blood of 38 patients with MM and of 20 healthy doners were measured by flow cytometry.Serum albumin and β_2-MG in patients with MM were measured using bromocresol green method,transmission turbidimetry respectively.Results:Compared to those of the controls,the proportions of CD4~+CD25~(+/high),CD4~+CD25~(high) CD127~(low) and CD8~+CD28~-Treg cells in newly diagnosed MM patients were elevated.Furthermore,the proportions of CD4~+CD25~(high) and CD4~+CD25~(high)CD127~(low) Tregs in each clinical stage were elevated when compared to those of the controls.The number of the Tregs were increasing with clinical stages and were significantly higher in stage Ⅲ MM than in stageⅠ MM;In stageⅡand Ⅲ MM,there were also elevated proportions of CD8~+CD28~- Tregs,increasing with clinical stages.However,there were no differences when compared between stage Ⅰ MM and the controls;Both the proportions of CD4~+CD25~(+/high) and CD4~+CD25~(high)CD127~(low) Tregs in active MM were not different from stable MM,although all of them were higher than those of controls.The proportion of CD8~+CD28~- Tregs was higher in active MM than in stable MM and controls,but there were no differences when compared between active and stable MM.The proportions of both CD4~+CD25~(high) Tregs and CD4~+CD25~(high)CD127~(low)Tregs had negative correlation with the levels of serum albumin.Conclusion:MM patients have elevated levels of circulating CD4~+CD25~+ and CD8~+CD28~-Tregs,which may be an important mechanism of MM immune evasion,and may be associated with clinical stages,disease progression and prognosis of MM to some extent.