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 Table of Contents  
ORIGINAL ARTICLE
Year : 2018  |  Volume : 46  |  Issue : 1  |  Page : 67-76

CD4 and CD25 cells in children under the age of 5 diagnosed with type І diabetes mellitus


1 Clinical Pathology Department, Tanta University Hospital, Egypt
2 Clinical Pathology Department, Faculty of Medicine, Tanta University, Tanta, Egypt
3 Pediatrics Department, Faculty of Medicine, Tanta University, Tanta, Egypt

Date of Submission07-Jun-2017
Date of Acceptance13-Nov-2017
Date of Web Publication26-Jul-2018

Correspondence Address:
Muhammad I.M El-Masry
32 Eltelb Street, Kafr El Zayat, El Gharbia, 31511
Egypt
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DOI: 10.4103/tmj.tmj_31_17

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  Abstract 


Background and aim Type І diabetes mellitus (T1DM) is a T-cell-mediated, chronic disease characterized by a deficiency or absence of insulin, when the body’s own immune system attacks the β cells in the islets of Langerhans of the pancreas. The increased incidence of T1DM in children under the age of 5 years and the aggressive process of β-cell destruction in this age group indicate the need to assess the immune system. CD4+CD25+high regulatory T cells (Tregs) appear to be critical in regulating immune responses to self-antigens. The aim of this study is to evaluate CD4+CD25+ Tregs frequency in the peripheral blood of children diagnosed with T1DM under the age of 5 in comparison with those diagnosed at a later age and healthy controls.
Patients and methods The present study was carried out on 80 children who were classified into three groups: group I included 20 children with newly diagnosed T1DM under the age of 5; group II included 20 children with newly diagnosed T1DM older than 5 years of age; group III included 40 apparently healthy children as a reference group divided into age-dependent groups. The history of all children included in the study was recorded. Clinical examination and laboratory investigations included fasting and postprandial serum glucose, renal and liver function tests, complete blood count, glycated hemoglobin, and fasting C-peptide. Flow cytometric analysis was carried out for peripheral blood lymphocytes using monoclonal antibodies against CD4 [fluorescein isothiocyanate (FITC) labeled] and CD25 [phycoerythrin (PE) labeled].
Results We found that both patient groups had highly significantly lower mean percentage of CD4+CD25+high Tregs in comparison with the control groups. Also, a highly significantly lower mean% CD4+CD25+high Tregs in patients younger than 5 years of age in comparison with patients older than 5 years of age was found. Also, diabetic children younger than 5 years of age had a highly significantly lower fasting C-peptide than diabetic children older than 5 years of age.
Conclusion This study highlights the distinctiveness of diabetes in children under age of five who had a low secretion of C-peptide which reflect a more destructive lesion of β-cells with consequent lower absolute cell mass in this age group and very low CD4+CD25high T-regs that evince the pathogenesis of autoimmunity. Understanding the differences in the immune system activity in young diabetic children may pave the way toward identification of children at risk of T1DM and enable the use of novel forms of intervention.

Keywords: CD4+CD25+high cells, regulatory T cells, type І diabetic mellitus


How to cite this article:
El-Masry MI, El-Sheikh EH, Abo El Ezz AA, Hodeib HA. CD4 and CD25 cells in children under the age of 5 diagnosed with type І diabetes mellitus. Tanta Med J 2018;46:67-76

How to cite this URL:
El-Masry MI, El-Sheikh EH, Abo El Ezz AA, Hodeib HA. CD4 and CD25 cells in children under the age of 5 diagnosed with type І diabetes mellitus. Tanta Med J [serial online] 2018 [cited 2018 Nov 14];46:67-76. Available from: http://www.tdj.eg.net/text.asp?2018/46/1/67/237621




  Introduction Top


Type I diabetes mellitus (TIDM) is a T-cell-mediated, chronic disease characterized by a deficiency in or absence of insulin, when the body’s own immune system attacks the β cells in the  Islets of Langerhans More Details of the pancreas [1],[2].

The autoimmune process usually begins years before the first clinical symptoms become apparent. A growing interest has been focused on a population of Tregs that plays a crucial role in the maintenance of homeostasis and self-tolerance through their inhibitory impact on autoreactive effector T cells [3].

The highest annual increase in the incidence of T1DM in children under the age of 5 years as shown by the EURODIAB study and the aggressive process of the destruction of β cells in this age group than in patients diagnosed at a later age indicate the need to assess the immune system in this age group. It is not entirely clear as to why β-cell destruction is so aggressive in the youngest of children [4],[5].

CD4+CD25+ T cells were named Tregs and since then, have been characterized intensively by many groups. It has now been well documented in a variety of models that CD4+CD25+ play indispensable roles in the maintenance of natural self-tolerance, in preventing autoimmune responses, as well as in controlling inflammatory reactions [6],[7].


  Participants and methods Top


Participants

The present study was carried out at the Clinical Pathology Department of Tanta University on 80 cases that were classified into three groups:
  1. Group I included 20 children with newly recognized T1DM under the age of 5. There were 13 (65%) males and seven (35%) females, and their ages ranged from 6 to 55.2 months, with a mean of 27.96±15.47 months.
  2. Group II included 20 children with newly recognized T1DM older than 5 years of age. There were five (25%) males and 15 (75%) females, and their ages ranged from 9 to 15 years, with a mean of 12.4±2.06 years.
  3. Group III included 40 apparently healthy children as a reference group divided into age-dependent groups. Under the age of 5 years, there were 20 children, 14 (70%) males and six (30%) females, and their ages ranged from 12 to 60 months, with a mean of 34.86±13.93 months. Also, there were 20 children older than 5 years of age, eight (40%) males and 12 (60%) females, and their ages ranged from 5.5 to 16 years, with a mean of 10.6±4.05 years.


Inclusion criteria

  1. Patients with T1DM with or without complications.
  2. Consent was obtained from the parents of all minors as well as from participants older than 16 years of age.
  3. Random blood glucose above100 mg/dl with no personal or familial history of T1DM for the control group.


Exclusion criteria

The following patients were excluded from the study:
  1. Patients older than 18 years of age.
  2. Patients with other autoimmune, chronic, inflammatory, or neoplastic disease.


All children were subjected to the following:
  1. Detailed clinical evaluation including history and clinical examination, with a special focus on age, sex, presence of diabetes, and symptoms of hyperglycemia (polyuria, polydipsia, polyphagia, and weight loss).
  2. Blood collection and laboratory investigations:


Sample collection

Blood samples were obtained under completely aseptic conditions and divided into two tubes:
  1. An EDTA vacutainer tube for complete blood count, flow cytometry, and glycated hemoglobin (HbA1C).
  2. A plain tube that was allowed to clot and serum was separated for the measurement of serum glucose, liver and renal function tests, lipids profile, and fasting C-peptide level.


Routine laboratory investigations

  1. Serum glucose level, fasting and 2 h postprandial.
  2. Renal function tests (urea and creatinine).
  3. Liver function tests (total and direct bilirubin, total protein, albumin, alanine aminotransferase and aspartate aminotransferase).
  4. Lipid profile (cholesterol and triglycerides).
    • All previous tests were carried out using Indiko Plus (operating principle: fully automated, sample oriented, random access chemistry analyzer) (Thermo Scientific, Vantaa, Finland).
  5. Complete blood count was determined using the ERMA cell counter (model PCE-210N, fully automated blood cell counter; ERMA Inc., Tokyo, Japan).
  6. HbA1C level was determined using Tosoh HPLC G8 (automated glycohemoglobin analyzer; Tosoh Bioscience, Tokyo, Japan).
  7. Serum fasting C-peptide level was determined using DPC Immulite 1000 (fully automated, sample oriented, random access, chemiluminescent immunoassay system; Siemens, Munich, Germany).


Specific laboratory investigations

Flow cytometric analysis was carried out for peripheral blood lymphocytes using monoclonal antibodies against CD4 [fluorescein isothiocyanate (FITC) labeled] and CD25 (PE labeled) [8].

Methods

Flow cytometry

For the determination of CD4+CD25+high Tregs, we used anti-CD4 monoclonal antibody FITC labeled (L-200) (eBioscience, Catalogue no. ab 550628, Thermo Scientific, Vantaa, Finland), anti-CD25 monoclonal antibody PE labeled (M-A251) (eBioscience, Catalogue no. ab 555432, Thermo Scientific, Vantaa, Finland), and PE mouse IgG2κ and FITC (negative control).

For each sample, two tubes were labeled: one for all monoclonal antibodies used and the other tube for negative isotypic control. 100 μl of each sample was placed in each tube, followed by 10 μl of each monoclonal antibody that were added to the positive tubes. The tubes were vortexed and incubated in the dark at 4°C for 25 min. Subsequently, 1.5 ml of the lysing solution was added to each tube, and then the tubes were vortexed again and incubated for 20 min in the dark at 4°C. The tubes were centrifuged at 3000 rpm for 5 min and the supernatant was discarded, and then 3 ml of PBS as a washing solution was added to each tube and mixed thoroughly. Then, the tubes were centrifuged at 3000 rpm for 5 min and the supernatant was discarded; this step was repeated. Cell pellets were suspended in 300 μl 1% paraformaldehyde and were ready for acquiring data by the cytometer.

Flow cytometric analysis

After warming up the argon laser (488 nm) for 30 min, the full alignment procedure was performed using standard immunocheck alignment fluorospheres for adjusting forward scatter, side scatter, and photomultiplier tube. Control samples (PE IgG2b and FITC) were introduced in the machine and inserted into the sheath by the sample pressure button (run button), where the laser scatter was received on both forward scatter detectors and scale to show the cell population in a basic histogram and to adjust the regions. At least 10000 events (cells) were passed in front of the laser for each case from which the lymphocytes were selectively gated (surrounded by a line to separate them from other cells in the basic histogram) for immunophenotyping analysis. The sample tubes were then introduced and processed in the same way as the control, where the monoclonal cells tagged with PE and FITC were analyzed. The fraction of cells coated by CD4CD25 antibodies was determined in the gated population of lymphocytes and assessed in the histogram [9].

Interpretation of the results

After 10000 events were counted, the numbers of lymphocytes expressing the receptors emitting fluorescence signals were summated and multiplied in the photomultiplier tube (PMT) and the computer analyzed the data as a dot-plot assay.

Statistical analysis

Data analyses were carried out using statistical package for the social sciences (IBM SPSS Statistics, Version 22.0. Armonk, NY: IBM Corp.). Student’s t-test was used for comparison between groups for quantitative data and the χ2 for comparison between two groups for qualitative data. A two-tailed P-value less than 0.05 was considered statistically significant and a P-value less than 0.01 was considered highly significant.


  Results Top


Our study was carried at the Clinical Pathology Department of Tanta University on 80 cases that were classified into three groups. A comparison was performed between the patient and the control groups in terms of age and sex; the patients were categorized into those younger than 5 years of age and those older than 5 years of age. There were no statistically significant differences between age and sex between the groups studied.

[Table 1] shows the highly significantly lower mean age of onset of diabetes for the patient group younger than 5 years than in patients older than 5 years. Also, a highly significantly shorter mean duration of the disease was found for the patient group younger than 5 years than patients older than 5 years, with a P-value less than 0.001 for both. Fasting blood glucose and postprandial blood glucose were 264.35±55.06 and 411.0±91.64 for the patient group younger than 5 years, respectively, and 187.75±54.01 and 231.75±38.84 for patients older than 5 years, with significantly higher fasting blood glucose and postprandial blood glucose in patients younger than 5 years than in patients older than 5 years. The mean HbA1C for patients younger than 5 years was 11.52±2.272, whereas it was 8.38±1.644 for patients older than 5 years, with a significant increase in patients younger than 5 years than in patients older than 5 years.
Table 1 Clinical data of patient groups

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There was a highly significantly lower fasting C-peptide level in diabetic patients younger than 5 years in comparison with diabetic patients older than 5 years, with P-value of 0.001 as shown in [Table 2].
Table 2 Fasting C-peptide levels among patient groups

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A significantly lower mean percentage of CD4+ lymphocytes (30.45±10.22) was found in patients younger than 5 years in comparison with patients older than 5 years (36.22±4.339), with P-value of 0.026, whereas a highly significantly lower mean count of CD4+ lymphocytes was found in comparison between patient groups, with a P-value less than 0.001 as shown in [Table 1] and [Table 2]. However, the mean percentage and count of both CD4+ and CD4+CD25+ lymphocytes were not significantly different between the patient and control groups as the percentage of CD4+CD25+ T lymphocytes in diabetic patients younger than 5 years was found to be 10.98±8.538 compared with 8.910±2.522 in the control group of children of the same age and it was 7.765±4.984 in diabetic patients older than 5 years compared with 7.035±0.495 in the control group older than 5 years. Both patient groups had highly significantly lower mean percentage and count of CD4+CD25+high Tregs in comparison with the control groups, with a P-value less than 0.001, where the estimated percentage of CD4+CD25+high in T1DM patients younger than 5 years was 0.485±0.262 versus 1.700±0.710 in the control children younger than 5 years, whereas it was 0.850±0.497 in patients older than 5 years versus 3.920±0.254 in the control group of children of the same age ([Table 3] and [Table 4]).
Table 3 Comparison between patient and control groups younger than 5 years in different CD percentages

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Table 4 Comparison between patient and control groups older than 5 years in different CD percentages

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Also, a highly significantly lower mean percentage and count of CD4+CD25+high Tregs was found in patients younger than 5 years in comparison with patients older than 5 years, with P-values of 0.006 and 0.008, respectively, in [Figure 1],[Figure 2],[Figure 3].
Figure 1 Comparison between patient & control groups <5 years as regard different CD percentage.

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Figure 2 Comparison between patient & control groups >5 years as regard different CD percentage.

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Figure 3 Comparison between patient groups of different CD percentages.

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There was a significantly positive correlation between the mean percentage of CD4CD25high and age in both diabetic patients and healthy children, with r=0.133 and 0.801 and P-values of 0.021 and 0.001, respectively, as shown in [Figure 4].
Figure 4 Scatter diagram showing the correlation between the mean percentage of CD4CD25high and age in diabetic patients.

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Flow cytometry analysis

Flow cytometric results are shown in [Figure 5],[Figure 6],[Figure 7].
Figure 5 Dot blot by flow cytometry showing R1 that represent gated lymphocytes by forward (FS) and side scattering (SS).

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Figure 6 Dot blot of CD4 and CD25 lymphocytes by flow cytometry in patients and controls younger than 5 years showing a lower percentage in patients than controls (R2=CD4+CD25+high lymphocytes).

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Figure 7 Dot blot of CD4 and CD25 lymphocytes by flow cytometry in patients and controls older than 5 years showing lower percentage in patients than controls (R2=CD4+CD25+high lymphocytes).

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  Discussion Top


T1DM is caused by a progressive autoimmune destruction of the pancreatic β cells. The autoimmune process usually begins years before the first clinical symptoms become apparent. Growing interest has been focused on a population of Tregs that plays a crucial role in the maintenance of homeostasis and self-tolerance through their inhibitory impact on autoreactive effector T cells [3].

Natural Tregs are essential to maintain self-tolerance [10],[11]. The loss of these cells leads to a fatal autoimmune syndrome affecting multiple organs [12]. In addition, these cells interfere with the development of organ-specific autoimmune diseases, such as T1DM [13],[14].

Many individuals with the immunological markers of preclinical T1DM do not progress to clinical disease. An attractive hypothesis is that individuals who have islet autoantibodies and susceptibility genes, but who do not progress to T1DM, may benefit from a successful regulatory immune response. Considerable attention has therefore been focused on the analysis of immunoregulatory function associated with T1DM autoimmunity on the basis of the likelihood that a failure of immune regulation is required for complete immune-mediated β cell loss [15].

A high annual increase in the incidence of T1DM in children younger than the age of 5 as shown by the EURODIAB study and the aggressive process of β-cell destruction in this age group than in patients diagnosed at a later age indicate the need to assess the immune system in this age group [8].

The aim of this study is to evaluate CD4+CD25+ Tregs frequency in the peripheral blood of children with T1DM diagnosed younger than the age of 5 years in comparison with those diagnosed at a later age and healthy controls.

In this study, the age and sex of both the patient and control groups divided into children younger or older than 5 years showed a nonstatistically significant difference between the groups, with P-values of 0.147 and 0.098 for age and 0.736 and 0.723 for sex, for both the patient group and the corresponding control groups, respectively. This means that both groups were matched for age and sex. Therefore, the differences in results cannot be attributed to factors related to differences in age or sex.

This result is in agreement with that of Agnieszka et al. [8], who studied the frequency of Tregs in children with T1DM younger than the age of 5 and compared them with older patients and corresponding control groups; they found no difference in age between both study groups and the corresponding control groups.

In the present study, there was no statistically significant difference between patients and control groups in total leukocytic count (TLC) and lymphocytic count in diabetic patients versus the control group.

These data are in close agreement with those of Asmaa et al. [16], who found that lymphocytic count was not significantly different between patients and controls.

In contrast to the results of this study, Känel et al. [17] investigated immunological effects specific to standardized hyperglycemia in nondiabetic individuals to exclude immunological changes potentially related to diabetes stage and treatment. Patients showed a significant decrease in TLC and lymphocytes with the oral glucose tolerance test (OGTT) compared with the placebo solution. They found that in nondiabetic individuals, short-term hyperglycemia induces immunological changes that may be relevant to explain similar findings in patients with diabetes mellitus.

It is not clear why the incidence of diabetes is so high and the process of β-cell destruction is so rapid in the youngest of children. These observations indicate the need to assess the immune system of diabetic children to shed light on the pathogenesis of this phenomenon.

In this study, we found that diabetic children younger than 5 years of age had a highly significant lower fasting C-peptide than diabetic children older than 5 years of age, with P-value less than 0.001, a finding that reflects a more destructive lesion of β cells with consequent lower absolute cell mass in this age group.

Similarly, Agnieszka et al. [8] reported that their results of highly significantly lower fasting C-peptide in diabetic children younger than 5 years reflects a more aggressive autoimmune process and a lower absolute β-cell mass in this age group than the children with T1DM presenting at a later age.

In this study, there was no correlation between fasting C-peptide levels and the percentage of CD4+CD25+high T lymphocytes in both patient groups, with P-values 0.055 and 0.811, respectively.

In agreement with this result, Agnieszka et al. [8] found no association between fasting C-peptide levels and percentage of CD4+CD25+high T lymphocytes in two patient groups divided by age, younger than and older than 5 years of age, with a P-value of 0.932.

In contrast to the results of this study, Asmaa et al. [16] found a positive correlation between C-peptide levels and percentage of CD4+CD25+high T lymphocytes between patients and controls. They attributed their results to the fact that autoimmune destruction of the β cells of the pancreas results in deficiency of both insulin and insulin C-peptide.

In this study, there was a nonsignificant relation between CD4+CD25+high (%) and HbA1C in both patient groups, with P-values of 0.305 for diabetic patients younger than 5 years and 0.614 for patients older than 5 years.

In agreement with the results of the present study, Avanzini et al. [18] found no correlation between the percentage of various T cells and the HbA1C level. However, Ryba et al. [19] found that the level of HbA1C had a significant relation with the frequency of CD4+CD25high.

Ryba et al. [19] confirmed these results reporting that patients with a high percent of CD4+CD25+ Tregs have larger numbers of preserved well-functioning β cells (hence, more likely to have better glycemic control) compared with those with a lower% of CD4+CD25+ Tregs [20].

In this study, there was a significant positive correlation between the mean percentage of CD4CD25high and age in both diabetic patients and healthy children, with r=0.133 and 0.801 and P-values 0.021 and 0.001, respectively.

In agreement with the present study, Gregg et al. [21] reported that CD4+CD25high T-cell numbers in healthy volunteers increase with age.

In contrast to this, Ryba et al. [19] found no association between the peripheral blood level of CD4+CD25high Tregs and age.

Therefore, the aggressive autoimmune process that is observed in diabetic children younger than the age of 5 years might be explained by the significant decrease in CD4+CD25high Tregs with age.

In this study, the percentage of CD4+ T lymphocytes was 30.45±10.22 in the patient group younger than 5 years and 26.32±11.38 in the control group of the same age, and it was 36.22±4.339 in the patient group older than 5 years and 35.10±10.52 in the control group older than 5 years. There was no statistically significant difference between both patient and control groups in the percent of CD4+ T cells.

This work is in agreement with that of Milicevic et al. [22] and Luczyński et al. [23], who studied the percentages of different T lymphocytes in the early stage of T1DM. They also found no statistically significant difference between patients and controls in % CD4+ cells.

In the present study, the percentage of CD4+CD25+ T lymphocytes in diabetic patients younger than 5 years was found to be 10.98±8.538 versus 8.910±2.522 in the control group of the same age and it was 7.765±4.984 in diabetic patients older than 5 years versus 7.035±0.495 in the control group older than 5 years. The difference was statistically nonsignificant. The same result was found on comparison between the two patient groups, with a nonsignificant difference between them.

These data are in close agreement with those of Putnam et al. [24] in terms of % CD4+CD25+ T lymphocytes. They also found that there was no significant difference in the percentage of CD4+ lymphocytes that express CD25+ between the patients with T1DM and control participants.

Although a deficiency in CD4+CD25+ T cells was reported by Kukreja et al. [25], the age gap between the newly diagnosed T1DM patients (mean age 9.4±2.16 years) and control participants (mean age 37±5.66 years) might explain the difference between the groups in the latter work.

Discrepancies reported by different studies might be because of technical difficulties in Tregs phenotypic characterization. As the interleukin-2 (IL-2) receptor α chain (CD25) is transiently upregulated in T cells after activation, circulating CD4+CD25+ T cells are a heterogeneous population. Some studies suggest that almost half of the bulk CD4+CD25+ T cells detected in humans do not express Foxp3 (the gene responsible for differentiation of Tregs) when the gate is set to include the top 10–15% of the CD25+ cells. Even when the top 5% of the CD25+ cells are gated, significant contamination with Foxp3 cells is still present in some samples. The top 2% CD25 bright gate most reliably identifies a highly enriched Foxp3+ population [26].

Some studies have suggested that the regulatory cells among the CD4+CD25+ population predominantly express high levels of CD25 (CD25high) [27].

Therefore, on the basis of the previous facts, in our present study, we gated on CD4+ T cells that are high (bright) in CD25. The estimated percentage of CD4+CD25+high in T1DM patients younger than 5 years was 0.485±0.262 versus 1.700±0.710 in the control group children younger than 5 years, whereas it was 0.850±0.497 in patients older than 5 years versus 3.920±0.254 in the control group of the same age. There was a highly significant difference, with a P-value less than of 0.001. Also, there was a highly significant difference, P-value of 0.006, between the two patient groups.

Moreover, the same significant differences were found between the groups in terms of the mean absolute count of CD4+CD25+high, with a highly significantly lower mean count of CD4+CD25high+ Tregs in patients younger than 5 years in comparison with patients older than 5 years, with P-value of 0.008, and both patient groups had a highly significantly lower mean count of CD4+CD25+high Tregs in comparison with the control groups, with a P-value less than 0.001.

This work is in agreement with that of Ryba et al. [19], who found a lower number and percentage of CD4+CD25high T cells in patients.

Also, Luczyński et al. [23] found statistically significantly lower percentages of Tregs and CD4+CD25high in diabetic children compared with the children in the control group. They postulated that the recruitment or migration of Tregs from the blood to the inflammatory site may be responsible for the decreased number of Tregs in peripheral blood [28].

Other reasons for the low percentage of these cells in T1DM might be Tregs apoptosis. Glisic et al. [29] found high levels of CD4+CD25+high T-cell apoptosis in patients with newly diagnosed T1DM.

Functionally, the suppressive capacity of Tregs is not only contact dependent but also based on the production of immunosuppressive cytokines including IL-10 and TGF-β. Karges et al. [30] concluded that IL-10- dependent regulatory CD4+ T-cells are involved in β-cell mass recovery after the onset of hyperglycemia in autoimmune T1DM. Lindley et al. [31] noted that CD4+CD25+ T cells showed reduced ability to inhibit T-cell proliferation in patients with newly diagnosed T1DM compared with the control group. Therefore, the imbalance in the immune system in newly diagnosed children withT1DM can be attributed to both disturbed functionality as well as decreased number of these cells.

In contrast to the results of this study, a report found increased percentages of Tregs in children who tested positive for diabetes-associated autoantibodies. They used additional cell surface markers (CD69, HLA-DR, and CD62L) in the detection of Tregs. CD69 is considered to be a very early activation marker, whereas HLA-DR is a marker of more constant immunological activation. Autoantibody-positive individuals testing positive for three to four autoantibodies had a significantly higher frequency of CD4+CD25high HLA-DR and CD4+CD25highCD69 T cells than the healthy controls [32].

Much of this muddle is probably because of methodological differences in various laboratories, given that the precise definition of human Tregs has changed several times in recent years, and most of these studies have not distinguished between potentially distinct Tregs subsets [15].

Tregs clearly influence the development of T1DM. Their experimental depletion or a genetic deficiency in their numbers or activity leads to a more aggressive disease, whereas their transfer or therapeutic enhancement has protective effects [33], which may be very promising in the clinic [34]. Several reports suggest the role of Tregs in T1DM pathogenesis. It is quite possible that these results will be used in future immunotherapeutic trials. For example, in nonobese diabetic mice, continuous infusions of Tregs prevented diabetes onset, which was mediated by TNF-α [35].

At the end of our study, we recommend further studies with larger numbers of participants to obtain better results and to use more markers that could be useful in identifying Tregs in a more specific manner.

In conclusion, this study shed light on the differences in immune system activity in young diabetic children to open the way to identify children at risk for T1DM. They also represent an attractive therapeutic approach with many potential targets for intervention.


  Conclusion Top


This study highlights the distinctiveness of diabetes in children younger than the age of 5 years. The youngest children had a low secretion of C-peptide, reflecting a more destructive lesion of β cells with resultant lower absolute cell mass in this age group and very low CD4+CD25high Tregs that evince the pathogenesis of autoimmunity. Understanding the differences in the immune system activity in young diabetic children may pave the way to identify children at risk for T1DM and enable the use of novel forms of therapeutic intervention as; anti-T-cell strategies, induction of tolerance and T-cell regeneration.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
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