Immuno-intervention and preservation of beta-cell function in type 1 diabetes

Vertical Distributions and Bioavailabilities of Heavy Metals in Soil in An-Tea Plantations in Qimen County, China

Heavy metals mainly enter tea from the soil. In this study, stratified soil samples were collected, at a depth of 0–60 cm, using a soil drill in An-tea plantations. Speciation of As, Cd, Cr, Cu, Ni, Pb, and Zn was determined using the European Community Bureau of Reference sequential extraction method, and the heavy metal concentrations in the extracts were determined by inductively coupled plasma−mass spectrometry. Compared with other soil layers, the mean Cd, Cu, Pb, and Zn concentrations were highest in the 0–20 cm layer, the Ni concentrations were highest in the 20–40 cm layer, and the As and Cr concentrations were highest in the 40–60 cm layer. The mean contributions of the non-residual fractions, including the acid-soluble, reducible, and oxidizable fractions, to the total concentrations were higher than those of the residual fraction for Cr, Cu, and Ni at all depths in soil from a flat area, as well as for Cd and Zn at all depths in soil from a sloping area. The contributions of non-residual fractions to the total As and Pb concentrations were higher than those of the residual fraction in soil from a depth of 0–20 cm from the flat area and soil from a depth of 20–60 cm from the sloping area. The total heavy metal concentrations correlated well with the acid-soluble fraction and reducible fraction concentrations in soil from 0–40 cm.

IFN-gamma and IL-10 islet-antigen-specific T cell responses in autoantibody-negative first-degree relatives of patients with type 1 diabetes

AIMS/HYPOTHESIS

Islet antibody-negative first-degree relatives of type 1 diabetes patients have a very low risk of developing diabetes. We studied the balance between IFN-gamma (proinflammatory) and IL-10 (regulatory) T cell responses in these participants.

METHODS

Peripheral blood T cells from adult (18-50 years old, n = 40) DRB1*0401-positive first-degree relatives negative for GAD and tyrosine phosphatase-like insulinoma antigen 2 (IA-2) antibodies were tested for IFN-gamma and IL-10 responses in a sensitive cytokine enzyme-linked immunospot assay against a panel of seven peptide epitopes derived from IA-2 and proinsulin. Comparison was made with HLA-matched newly diagnosed type 1 diabetic patients (n = 42) and healthy controls (n = 39).

RESULTS

First-degree relatives and newly diagnosed type 1 diabetic patients displayed a similar frequency of IFN-gamma responses to the peptide panel and both were significantly greater than in healthy controls (relatives 9.6%, patients 11.8%, controls 4.0%, p = 0.003). First-degree relatives and newly diagnosed type 1 diabetic patients also showed similar frequencies of IL-10 responses, which were significantly lower than in healthy controls (relatives 7.1%, patients 9.0%, controls 15.8%, p = 0.003). However, individual IL-10 responses of first-degree relatives were similar in size to those in healthy controls and larger than those in newly diagnosed type 1 diabetic patients (relatives median 29 spot-forming cells/1 x 10(6) peripheral blood mononuclear cells, controls 33, patients 11, p = 0.02).

CONCLUSIONS/INTERPRETATION

Taken together, these results suggest that antibody-negative first-degree relatives have a balance of proinflammatory and regulatory T cells, which is intermediate between that of newly diagnosed type 1 diabetic patients and healthy controls. This suggests that even a moderate regulatory response may be sufficient to prevent the development of clinical type 1 diabetes in genetically predisposed individuals.

Type 1 diabetes mellitus: primary, secondary, and tertiary prevention

We have entered the era of clinical trials to prevent type 1 diabetes mellitus (T1DM). Before 1922, when insulin was first given to a patient with diabetes, a diagnosis of T1DM was considered a death sentence. Advances in treatment for subjects with diabetes are not yet sufficient to prevent the deleterious impact of diabetes on both day-to-day activities and the early morbidity and mortality still associated with the disease. We now understand a great deal about blood glucose regulation and potential health complications associated with long-term T1DM, but the mystery of why, or the pathogenesis of this devastating disease, remains elusive. Great strides toward unraveling this mystery have been made over the past several decades. Even without definitive answers, we are moving from the period of discovery and animal research to the era of clinical trials. In this review, we wish to convey the palpable excitement in the field. It is time to determine if we can safely change the course of T1DM.