Effect of the glycemic control on intracellular cytokine production from peripheral blood mononuclear cells of type 1 and type 2 diabetic patients

AIMS

To evaluate the intracellular production of tumor necrosis factor (TNF-alpha), interleukine-6 (IL-6), INF-gamma, IL-8 and IL-10 in peripheral blood lymphomononuclear cells from type 1 and type 2 diabetic patients, stratified according to the glycemic control.

METHODS

Thirty-five diabetic patients (17 type 1 and 18 type 2) and nine healthy individuals paired to patients in terms of sex and age were studied. Nine patients of each group were on inadequate glycemic controls. Intracellular cytokines were evaluated using flow cytometry. Cell cultures were stimulated with LPS to evaluate TNF-alpha and IL-6 or with PMA and Ionomycin to evaluate IFN-gamma, IL-8 and IL-10 intracellular staining.

RESULTS

The percentages of CD33(+) cells bearing TNF-alpha and CD3(+) cells bearing IL-10 were increased in type 1 diabetic patients with inadequate glycemic control in relation to those with adequate control. In contrast, the percentage of CD3(+) cells bearing IL-8 was decreased in type 2 patients under inadequate glycemic control.

CONCLUSIONS

The glycemic control is important for the detection of intracellular cytokines, and may contribute towards the susceptibility to infections in diabetic patients.

Impaired cytokine production by peripheral blood mononuclear cells in type 1 diabetic patients

AIMS

The objective of the present investigation was to study the production of IL-1, IL-6, IL-10, IFNgamma and TNFalpha in cultures of peripheral blood mononuclear cells (PBMC) taken from type 1 diabetic patients with inadequate metabolic control.

METHODS

Seventeen type 1 diabetic patients and a gender- and age-matched group of 17 healthy individuals were studied. PBMC cultures were stimulated with phytohemagglutinin (PHA; 20 microg/ml) and lipopolysaccharide (LPS; 10 microg/ml), and enzyme immunoassay (Elisa) was used to measure IL-1, IL-6, IL-10, IFNgamma and TNFalpha in the cell-culture supernatants.

RESULTS

IFNgamma levels in PHA-stimulated cultures were lower in the type 1 diabetics than in the non-diabetic controls (P<0.0001) while, in contrast, IL-10 levels were increased in the PHA-stimulated culture supernatants of the diabetics compared with the controls (P<0.0001). In addition, supernatant levels of the cytokines IL-1, IL-6 and TNFalpha released in the presence of LPS in the cell cultures from the diabetic patients were significantly lower than in the non-diabetic subjects (P<0.0001, P<0.0001 and P<0.03, respectively).

CONCLUSIONS

The impaired production of IL-1, IL-6, TNFalpha and IFNgamma, and the increased production of IL-10, in PBMC cultures from type 1 diabetics with inadequate metabolic control compared with healthy subjects may be an indication of a deficiency in mononuclear cell activation and, consequently, a deficient immune cellular adaptive response that, in turn, may be the cause of the increased incidence of infections in people with type 1 diabetes.

Effect of metabolic control on interferon-gamma and interleukin-10 production by peripheral blood mononuclear cells from type 1 and type 2 diabetic patients

The objective of the present study was to evaluate the production of cytokines, interferon-gamma (INF-gamma) and interleukin-10 (IL-10), in cultures of peripheral blood mononuclear cells (PBMC) from type 1 and type 2 diabetic patients and to correlate it with inadequate and adequate metabolic control. We studied 11 type 1 and 13 type 2 diabetic patients and 21 healthy individuals divided into two groups (N = 11 and 10) paired by sex and age with type 1 and type 2 diabetic patients. The PBMC cultures were stimulated with concanavalin-A to measure INF-gamma and IL-10 supernatant concentration by ELISA. For patients with inadequate metabolic control, the cultures were performed on the first day of hospitalization and again after intensive treatment to achieve adequate control. INF-gamma levels in the supernatants of type 1 diabetic patient cultures were higher compared to type 2 diabetic patients with adequate metabolic control (P < 0.001). Additionally, INF-gamma and IL-10 tended to increase the liberation of PBMC from type 1 and 2 diabetic patients with adequate metabolic control (P = 0.009 and 0.09, respectively). The increased levels of INF-gamma and IL-10 released from PBMC of type 1 and 2 diabetic patients with adequate metabolic control suggest that diabetic control improves the capacity of activation and maintenance of the immune response, reducing the susceptibility to infections.

Dermatoses em pacientes com diabetes mellitus

OBJETIVO: Ainda é desconhecida a relação do diabetes com fatores determinantes ou precipitantes de lesões dermatológicas em pacientes diabéticos. Assim, o objetivo do estudo foi investigar a presença de lesões cutâneas, não referidas pelo paciente diabético e sua relação com o controle metabólico da doença. MÉTODOS: Foram examinados 403 pacientes, dos quais 31% eram diabéticos do tipo 1 e 69% do tipo 2. Em ambulatório de um hospital universitário, os pacientes foram atendidos por endocrinologista para a avaliação endócrino-metabólica e por dermatologista para a avaliação dermatológica. O grau de controle metabólico foi documentado em 136 pacientes por meio da dosagem de hemoglobina glicada. RESULTADOS: Houve predomínio de dermatofitoses (82,6%), seguido de grupo de dermatoses como acne e degeneração actínica (66,7%), piodermites (5%), tumores cutâneos (3%) e necrobiose lipoídica (1%). Entre as dermatoses mais comuns em diabéticos, foram confirmados com exame histológico: dois diagnósticos de necrobiose (0,4%), cinco de dermopatia diabética (1,2%) e três casos de mal perfurante plantar (0,7%). Os valores da hemoglobina glicada foram: 7,2% em pacientes com controle metabólico adequado nos dois tipos de diabetes e de 11,9% e 12,7% nos tipos 1 e 2, respectivamente, com controle inadequado. Nos pacientes com controle metabólico inadequado foi observada freqüência maior de dermatofitoses, em ambos os tipos de diabetes. CONCLUSÕES: Os dados revelaram freqüência elevada de lesão dermatológica nos pacientes diabéticos, especialmente dermatofitoses. Dessa forma, o descontrole metabólico do diabético propicia maior suscetibilidade a infecções cutâneas.

Comparison of the homeostasis model assessment and quantitative insulin sensitivity check index with data from forearm metabolic studies for the in vivo assessment of insulin sensitivity

The present study was designed to compare the homeostasis model assessment (HOMA) and quantitative insulin sensitivity check index (QUICKI) with data from forearm metabolic studies of healthy individuals and of subjects in various pathological states. Fifty-five healthy individuals and 112 patients in various pathological states, including type 2 diabetes mellitus, essential hypertension and others, were studied after an overnight fast and for 3 h after ingestion of 75 g of glucose, by HOMA, QUICKI and the forearm technique to estimate muscle uptake of glucose combined with indirect calorimetry (oxidative and non-oxidative glucose metabolism). The patients showed increased HOMA (1.88 +/- 0.14 vs 1.13 +/- 0.10 pmol/l x mmol/l) and insulin/glucose (I/G) index (1.058.9 +/- 340.9 vs 518.6 +/- 70.7 pmol/l x (mg/100 ml forearm)-1), and decreased QUICKI (0.36 +/- 0.004 vs 0.39 +/- 0.006 ( microU/ml + mg/dl)-1) compared with the healthy individuals. Analysis of the data for the group as a whole (patients and healthy individuals) showed that the estimate of insulin resistance by HOMA was correlated with data obtained in the forearm metabolic studies (glucose uptake: r = -0.16, P = 0.04; non-oxidative glucose metabolism: r = -0.20. P = 0.01, and I/G index: r = 0.17, P = 0.03). The comparison of QUICKI with data of the forearm metabolic studies showed significant correlation between QUICKI and non-oxidative glucose metabolism (r = 0.17, P = 0.03) or I/G index (r = -0.37, P < 0.0001). The HOMA and QUICKI are good estimates of insulin sensitivity as data derived from forearm metabolic studies involving direct measurements of insulin action on muscle glucose metabolism.